flood re is a levy and pool system in the united kingdom , which replaced the statement of principles agreed between the government and insurance companies to provide flood insurance coverage to domestic properties deemed at significant risk of flooding ( this is generally defined as no worse than a 1.3 % or 1 in 75 annual probability of flooding ) .

it is estimated that it will ultimately cover the most at risk 2 % , or 250,000 homes , though the centre for climate change economics and policy suggest 370,000 homes are eligible .

flood re

there is more detail on how flood re was designed and operates on our background page , flood re explained .
copyright © flood re . flood re limited is registered in england and wales ( 08670444 ) . flood re is authorised by the prudential regulation authority and regulated by the prudential regulation authority and financial conduct authority ( frn 706046 )
flood re has been set up to help those households who live in a flood risk area find affordable home insurance .
insurance companies are able to pass on the flood risk element of eligible home insurance policies to flood re . flood re charges the insurers a premium for each policy , based on the property’s council tax band .
to see in full which properties are eligible for the flood re scheme please click here .
flood re is , essentially , insurance for insurance companies . this means that when a homeowner makes a flood claim , the insurer can pay out to the customer , and flood re will then reimburse the insurer .
brendan mccafferty , chief executive of flood re , said its introduction should make flood cover more affordable and accessible over time .
flood re will continue to add the names of brands to the list as soon as they become able to provide insurance to householders which are likely to include the benefits of flood re .
a list of the insurers using flood re is regularly updated on the flood re website and there is an online broker finding service provided by the british insurance brokers association ( biba ) .
no . flood re will only reinsure properties where the build was completed prior to january 2009 .
flood re charges insurers a fixed premium for flood risks passed to it , based on a property’s council tax band . in addition , flood re charges an insurer an excess of only £250 per policy . to cover the shortfall between the estimated cost of flood damage and the new , lower premiums and excesses , insurers pay flood re a combined total levy of £180m per year .
in 2039 the flood re scheme will end and there will be a free market for flood risk insurance . there will be a review at least every 5 years to assess flood re’s progress in managing a transition to this free market , which may consider the premium charged for each policy and the levy charged by flood re to uk home insurers .
flood re welcomes the news that the secondary legislation that defines how flood re will operate has today been laid before parliament by the secretary of state for the environment , food and rural affairs , elizabeth truss .
here is some further information about flood re and its background , what’s covered and why and funding issues .
flood re is a new way to help people who live in flood risk areas get affordable home insurance . it launched on april 4th 2016 .
flood re also offers insurers an excess per policy of £250 . although flood re has no control over the way insurers set the excesses for individual customers , this mechanism should benefit people living in areas at risk of flooding .
flood re is planned to be in place until 2039 . as well as helping to enable home insurance to remain affordable in areas at risk of flooding , flood re also has a role to help manage a transition to home insurance prices that fully reflect flood risk . this means that people benefiting from flood re need to become more aware of their flood risk and , if possible , take action to reduce it .
launched on april 4 , 2016 , flood re aims to give homeowners in high flood - risk areas more options when it comes to protecting their properties .
please note that flood re is not responsible for setting prices or the terms of a home insurance policy as this is at the discretion of each insurer . in publishing the list , flood re is not acting as an introducer , administrator or intermediary for household insurance policies . flood re does not sell home insurance , recommend particular brands or provide advice .
flood re is a scheme that gives households at high risk of flooding access to affordable insurance . all insurers who offer home and contents cover pay into an annual pot of £180 million and any claims against flood damage from policies eligible for flood re will be drawn from there .
76 . ministers concede that flood re constitutes a
novel approach ,
with many details still to be worked through with the industry , including the relationship between flood re and parliament . flood re , rather than ministers , would be directly accountable to parliament for its operations , with ministers remaining accountable for overall flood insurance policy . the government proposes introducing a
bespoke scrutiny , administrative and regulatory arrangement
for flood re since this would avoid the scheme ' s funding being considered tax and therefore public expenditure . [
70 . the committee received evidence from richfords fire and flood proposing a variation on the flood re model ; ' flood re mutual ' under which a levy on all insurers offering household insurance would be pooled to fund reinsurance and pay out for areas with a greater than 1 - in - 75 year flood risk . [
the launch of the flood re scheme is the result of the government working closely with the insurance industry to make affordable flood insurance available to households across the uk .
it is great news that flood re is now open for business . it is fantastic step forward - making flood insurance affordable for people regardless of where they live .
“we , the government and the abi recognised this lack of competition in the market and that’s where the idea of flood re - a not - for - profit re - insurer - first came from . ”
in the event of a huge flood event , which led to a national emergency , the government would step in if the money in the flood re scheme was insufficient .
these agreements did not address the affordability of the home insurance provided , however , and so the insurance companies and the government worked together to develop a different way of dealing with flood insurance . they decided on a ‘flood re - insurance’ scheme – known as flood re – to help support households at highest flood risk . an important part of the flood re scheme is to provide information to consumers about how to increase their understanding of their level of flood risk and how they can take action to reduce that risk .
the introduction of flood re means you have peace of mind that , even after a flood claim , you should still be able to find insurance with affordable premiums and excesses .
six months after launching on 4 april 2016 53 , 000 home insurance policies are now backed by flood re , benefiting customers in high flood risk areas all over the uk .
the cost per household premium per year is cited in the government ' s consultation on flood re as being £10 . 50 per year
the list below shows brands that are currently able to provide insurance to householders which are likely to include the benefits of flood re .
“the customer never gets involved directly with flood re , their relationship is always directly with insurers , ” bostock adds . “we , as insurers , will always pass on any savings to the customer from their eligibility for flood re cover , and that is all determined by the level of flood risk for that property .
only people who live in flood risk areas will benefit from flood re , and even then it will depend on how much you pay for the flooding part of your home insurance .
through the scheme , flood insurance for those at the highest risk of flooding starts at £210 ( council tax band a ) with the excess charged by flood re set at £250 .
there are many specialist catastrophe reinsurers around the world such as swiss re and munich re . these companies have specialists who calculate the probabilities of time scale over which these catastrophes occur .
the abi has comes up with the idea of flood re , which is an emergency fund that would pay out claims related to flooding .
here is flood re’s first transition plan , published on schedule , in february 2016 , three months after the secondary legislation passed through parliament .
homeowners will not have to deal with flood re directly and should not have to do anything differently when it comes to making a claim .
flood re is a success story of how government can work with industry to bring real changes that will benefit hundreds of thousands of households .
the flood re scheme was not designed to cover small and medium enterprises ( smes ) . the focus of the scheme has always been purely residential , enabling homeowners to protect their own homes . flood re is aware of a new commercial insurance scheme launched by the british insurance brokers’ association ( “biba” ) which may be able to assist smes which are not eligible for the flood re scheme . details can be obtained from biba .
worse , cccep note that far from alleviating the problem , the flood re scheme may actually make things worse . for example , mortgage providers and developers profit from building properties on flood plains , and while an uninsurable property cannot be mortgaged , flood re provides low cost insurance to the otherwise uninsurable . cccep’s response emphasises that mortgage providers and developers should also contribute to reducing flood risks .
“laying the secondary legislation is a highly significant milestone on the path to the establishment of flood re . it marks the completion of negotiations with government , allowing the legislative process to be completed after the election , and is the result of many months of very detailed work between flood re , the industry and government . the regulations provide the certainty necessary to allow us to move into the build and test phases of flood re’s development .
insurers are still in control of pricing for overall home insurance . flood re charges a fixed premium per policy to insurers , relating to the flood element of the policies transferred to flood re . these premiums are lower than would be the case if the flood risks were fully taken into account , as contributions to the costs come from a statutory levy on all home insurers in the uk .
flood re does not set prices for home insurance , but gives insurers the opportunity of passing to it the flood risk element of a home insurance policy ( buildings and contents ) at a premium that is capped , depending on the council tax band of the property . it is up to an insurer to decide whether they wish to pass the flood risk element of the cover to flood re .
“the reason for the 2009 cut - off is to encourage responsible construction - the introduction of flood re shouldn’t be seen as a way of opening up areas to build upon in flood plains . ”
flood re accepts the ceding of policies covering tenants’ possessions and contents of rented properties subject to the usual eligibility criteria , which can be found here .
in simple terms , a wider choice of insurers and lower premiums for those at risk of flood damage or who’ve made a similar claim before . these are the people who , bostock says , will benefit the most from flood re because “they’re the ones who , at the moment , will almost always be on the ‘declined’ list” . the determination of ‘high risk’ does differ from insurer to insurer though , and isn’t a decision made by flood re .
flood re replaces a previous agreement between the government and members of the association of british insurers ( abi ) , which guaranteed flood insurance for high - risk properties . it also had a few drawbacks .
] however , the government states that these arrangements
offer parliament less control and less insight into flood re ' s operations
than if the scheme were treated as part of the public sector . flood re would also be likely to be classed as state aid and would need european commission approval . [
flood re is partly subsidised by a tax levied on all insurers that offer home insurance in the uk . flood re does not regulate if or how insurers choose to pass on this tax to their customers . it is therefore possible that an insurer will choose to spread the costs across even those policies within their portfolio that do not include high flood risk .
] the association told us that under flood re policies for these properties would be charged at a set price , according to council tax band . it estimated that in a free market premiums for a home in a high risk area would be around £1 , 400 as opposed to around £750 under flood re . [
74 . the government acknowledges that flood re does not achieve
the level of value for money normally required of government policies
since the costs of flood re , including the necessary reinsurance contract , are expected to be greater than its economic benefits . a ministerial direction would be required before implementation can proceed . [
the flood re scheme is simple . customers will buy home insurance as normal but the extra insurance costs associated with a high risk of flooding will be passed on to flood re - to be funded by a levy on the insurance industry . other home insurance customers will not see their bills rise as a result .
“flood re will make a difference in people being able to afford the right cover . there are areas of the country that very few insurers will touch because it’s too big a risk but we , as an industry , have an obligation to ensure those people are protected . flood re will help with that . ”
the proposed model creates a reinsurance pool called flood re to which insurers may cede the worst flood insurance risks . this way an insurer can retain only the risks it considers of commercial value in its own portfolio . flood re acts as a reinsurer that takes on only the very worst risks , removing them from the market and saving those in high - risk households the high premiums they would otherwise have to pay for flood insurance .
we reported back in january that this winter’s floods had hit businesses particularly badly , and many weren’t covered by insurance because it was too expensive . while flood re , which came into force in april , offers affordable flood insurance for homeowners , businesses aren’t covered . but sustained pressure from interest groups led to a u turn on this and so we now await ‘flood re 2’ .
of the eligible households in the uk , we expect around 350 , 000 to benefit from the effects of flood re over time . that’s 2 % of eligible households . people won’t be dealing with flood re directly , they’ll still be buying their insurance as usual . insurers will be well prepared to deal with customer enquiries .
for the avoidance of doubt , flood re will only cover contents and fixtures and fittings that relate to the residential part of any mixed use premises . we would not expect appliances and trade tools used solely for business purposes ( such as dog grooming appliances or hairdressing tools ) to be covered by flood re’s definition of “contents” .
four broad ways to address the availability and affordability of flood insurance have been considered . there are no easy options to deliver affordable flood insurance and all involve a degree of cost . however , following extensive discussions the government has reached a headline agreement with the association of british insurers on a proposed way forward . this will focus on delivering the abi’s proposed “flood re” reinsurance pool for high risk households . a memorandum of understanding on flood re is being published alongside this consultation , with further details provided in this document . i would welcome your views on flood re as the leading proposal at this stage .
we then take responsibility for that part of your policy and if you make a valid claim on your insurance we’ll reimburse the insurer from the central flood re fund .
there has been a temporary ‘memorandum of understanding’ in place in the interim , but this has to be replaced by a definitive solution that will be titled ‘flood re’ .
one of the biggest criticisms of the new flood re scheme , which came into force earlier in the year , is that it doesn’t cover small businesses . we’ve written lots over the last few years about this : flood re has been introduced to provide affordable flood insurance for properties in high - risk areas , but it excludes businesses , buy - to - let properties and new builds .
james dalton , director of general insurance policy , association of british insurers said : “flood re shows the insurance industry’s commitment to making sure affordable home insurance is accessible , even to those at high flood risk . insurers have invested substantial time and money on the development of flood re so it’s encouraging to see that only six months in there are already 50 , 000 households benefitting . flood re’s benefits will continue to expand over time and we would encourage those who haven’t done so already to shop around to see how the new competitive market can help them . ”
flood re makes no difference to how you purchase your home insurance , whether that’s through a price comparison site , directly from an insurer or through a broker . once you have purchased your policy you will always deal with your own insurer even if you need to make a claim . you do not need to contact flood re directly .
up to half a million households in high flood risk areas now have access to affordable flood insurance as flood re has officially opened for business . following the final green light from the prudential regulatory authority ( pra ) , the world - first scheme is now accepting policies from insurers .
yes , flood re has purchased its own reinsurance and holds reserves and capital so that it can fully cover all claims in at least 99 . 5 % of years .
flood re requires insurers to meet all of the eligibility requirements , in good faith . the scheme is designed to assist homeowners most at risk of flooding , not businesses or properties being rented out for commercial gain . flood re’s own reinsurance is based on the same eligibility criteria so it is important that only eligible risks are ceded to us .
the government and the association of british insurers agreed on a way to allow for affordable insurance in areas affected by flooding . this is known as ' flood re ' .
information about the role of the flood risk strategy team , policies and strategies the council has , the flood risk asset register , and plans to invest in flood risk infrastructure .
flood re is not a home insurer itself – instead it works behind the scenes with existing insurance companies . flood re helps insurers offer more affordable flood insurance to those in areas at risk of flooding . it will mean people can shop around more easily to find policies with more affordable premiums and excesses . the scheme will develop over time so people should find they have even more choice in the future .
james dalton , general director of the association of british insurers , said there was no rush to take action today , as the “benefits of flood re will develop over time” .
flood re makes no difference to the way customers themselves buy their home insurance . all claims continue to be handled by the insurance companies themselves , and insurers continue to set the premiums they charge to their customers , taking into account the flood re premium and other important factors ( such as the risks of fire , theft , subsidence and other costs ) . as a result of the flood re scheme , there is now greater choice of home insurance policies for customers at risk of flooding and those policies should be more affordable .
you’ll probably notice little to no difference in the way you take out an insurance policy . flood re will just work in the background to enable insurers to offer more competitive deals , and give homeowners more choices on both contents and buildings insurance . part of the overall premium you pay will go towards the flood re pot – but that’s about it .
it seems that things are on track for what could be called flood re 2 . according to recent reports , a new scheme to extend flood re to cover businesses is likely to be launched in the autumn . it’s not good news for all businesses : it seems that only smaller businesses will be covered , but precise details have not yet been announced .
six months on from launch , consumers in high flood risk areas are taking the opportunity to access more affordable flood cover .
part of the flood re scheme includes providing information to people about how to increase their understanding of their level of flood risk and where they can find information about taking action to reduce their risk , where possible . flood re will only operate for 25 years , allowing time for the government , local authorities , insurers and communities to become better prepared for flooding . this could mean , for example , making use of effective land planning , sustainable drainage , sustainable development and effective flood risk management .
insurers remain responsible for pricing and deciding how best to pass on the benefits of lower premiums and excesses charged by flood re to customers . for further information on the funding structure click here
floods minister thérèse coffey said : “thousands of families will have peace of mind this winter and in the future as they benefit from affordable flood insurance to protect their homes thanks to flood re . if the worst happens , this support will be invaluable .
flooding is devastating . nothing can take away the distress it causes . but affordable flood insurance will help people get back on their feet more quickly and secure their futures . so the government and the insurance industry have worked together to establish flood re to provide affordable excesses and premiums for people in flood effected homes .
according to the annual report , just over 1 . 25 million policies have been backed by flood re in this first year . it’s really good to hear that four out of five householders with previous flood claims have seen a reduction of over 50 per cent in the price of available quotes for their flood insurance .
where information has been provided , you can find out more about how they are each using the flood re scheme and where you can get a quote by using the contact details noted below .
from monday , house insurers will be able to pass on the flood risk of the policy to flood re . the householder would have the price of the flood element of their policy fixed according to the home’s council tax band . a homeowner in band awould pay £210 a year for buildings and contents flood cover , rising to £1 , 200 a year for a large band h residence .
we’re helping the insurance industry to offer affordable insurance to everyone owning or living in eligible properties that may be prone to flooding .
flood re was developed following government intervention after insurers said they were no longer prepared to offer universal flood cover . billions of pounds have been paid out by the industry in recent years following a series of devastating flooding events , particularly in the north of england .
ministers concede that they must publish further details on these issues . these must be provided urgently so that parliament can scrutinise fully both the flood re scheme proposals and the measures in the water bill .
flood re , which claims to be a world first , received the final go ahead from financial regulators last week , and on monday will start accepting the first premiums and offering cover to householders .
my home was previously used for residential purposes and then used as an office . i am now returning it to be a domestic property and live in it . will i qualify for flood re ?
] this appears to produce a higher average cost per household than flood re . the abi questioned whether a method similar to that used by noah , such as the richfords model , which cedes flood risk into a mutual pool could guarantee to maintain affordable premiums . [
there remain a number of aspects of flood re that need to be agreed with parliament , the industry and the european commission . for this reason , the government also intends to use the water bill to seek powers to allow us to regulate the industry to deliver affordable flood insurance should flood re prove unworkable or fail to achieve our goals . your views on this alternative option are also invited , including in relation to how it might work if it were to be needed .
one of the key gripes about flood re , which was launched earlier in the year , was that it only offered affordable flood insurance for residential properties . this was put into particular focus by the winter floods of 2015 and 2016 , when so many businesses were hit .
flood re would be a major undertaking for uk insurers and the work insurers have undertaken to get here reflects the industry ' s desire to cover flood risk at an affordable price in the face of the increasing flood threat in the uk . the hard work now begins for both sides if we are to make this vision a reality .
there is also a strategic flood risk assessment for land use planning purposes that contains detailed flood risk maps and advice about what types of land uses may not be suitable in certain locations due to flood risk and where flood risk mitigation measures may be needed to make a development safe .
the flood re pooled fund will be in place for a minimum of 25 years although the total of the levy due , which has been set by an independent actuary , will be reviewed every five years .
64 . the focus of evidence to us was on two main approaches ' flood re ' and ' noah ' ( modified to ' flood mu ' ) . much media focus has been on the former ; a model proposed by the abi . however , representatives of the insurance and reinsurance industry presented arguments to us on the merits of alternative models , including the noah / flood mu model , and flood re mutual proposed by richfords fire and flood , discussed below . media reports indicate a high level of disagreement within the sector over the best way forward . and no model garnered universal support from witnesses to this inquiry . [
customers should continue to buy their home insurance in the same way as before and all the contact will be directly with their chosen insurer . if a customer needs to make a claim , they should contact their insurance company directly . flood re works ‘behind the scenes’ with the insurance company , to reimburse them for any payments they make to their customers and so there is no need for homeowners to contact flood re directly .
through flood re , those living in high risk areas will see their insurance premiums set at affordable levels - according to their council tax band - while the same customers currently face insurance bills totalling thousands of pounds .
only properties that were built , as evidenced by the council tax register , prior to january 2009 are eligible for the scheme . however , flood re is aware of certain instances where a build had been completed in 2008 and the dwelling was used as residential premises , but a council tax band was not issued until 2009 due to a delay in administrative proceedings . in such cases , flood re will accept these premises provided that the owner can show to flood re’s satisfaction that they lived in the premises , using them as their home , prior to january 2009 . this can be evidenced , for example , through furnishing a utility bill .
this week we joined a group of mps and stakeholders , including the leasehold knowledge partnership , british insurance brokers association ( biba ) , and residential landlords association , for a meeting with the flood minister , dr thérèse coffey mp , to discuss how the introduction of flood re is impacting excluded groups ( leasehold property , smes , private landlords , etc ) . there has always been significant dissatisfaction on our part that , whilst flood re is a positive development overall , it has left some groups outside the scheme , and possibly finding it even more difficult to get flood cover .
excesses for policies that fall into the flood re category will be capped at £250 for flood damage ( currently they can run into thousands ) , and total premiums are calculated on a property’s council tax band . all costs to customers remain at the discretion of the individual insurers , though .
75 . provisions are included in the water bill to enable direct regulation of the insurance market if flood re
does not deliver what we need and insurers are otherwise unable to keep prices at affordable levels
. [
to help improve this situation and make home insurance accessible to as many people as possible , the insurance sector set up flood re along with the government . it is the first scheme of its kind in the world .
the team ' s primary responsibilities are to prepare and monitor the local flood risk management strategy , build and maintain the flood risk asset register and manage the council ' s programme of flood and coastal erosion risk management work .
flood re is intended to make affordable insurance available to owners of property identified as flood - prone by the environment agency . it involves an industry - backed levy to support insurers in covering those most at risk from flooding . all uk insurers will pay into this pool to create a fund which will then be used to pay flood - related claims in high - risk areas .
yes . dwellings which form part of a single mixed - use property can be eligible for buildings / combined cover if the dwelling has its own council tax band and does not attract business rates . examples include b & bs and homes where incidental business activity takes place . however , flood re can only accept policies that fulfil the definition of a “home insurance policy” , where such policies are not being treated differently to non - flood re ceded policies .
“rsa has been involved from the point flood re was first proposed , which was about three years ago , shortly before the statement of principles was due to expire in july 2013 , ” he says . “there’s been lots of complexity involved , at all points in the process - insurers , consumers and flood re itself . insurers’ information systems needed to be fully updated and there were changes needed throughout the industry , the pra ( prudential regulation authority ) .
one problem with extending flood re’s reach , according to its chief executive , is that the government and insurers still use language which is difficult to understand , leaving consumers confused about risks and what is available . he’s advised them to check the flood re website to see which insurance providers are now participating and to find out more . and the association of british insurers has advised people to shop around to see how this more competitive market can help them .
the flood re scheme also helps people to better understand their level of flood risk and explains how they can take action to reduce their risk , where possible . the scheme is intended to operate for 25 years , allowing time for the government , local authorities , insurers and communities to work together to improve flood preparedness . this could mean , for example , making use of effective land planning , sustainable drainage , sustainable development and effective flood - risk management .
however , the government ' s announcement raises many questions about the operation of flood re , in particular how the scheme will be accountable to ministers and parliament , and how taxpayers ' interests will be protected in the event of an extreme flood event requiring funding beyond the capacity of the scheme . it is unclear who will bear the costs from such a 1 in 200 year flood event .
the reason for maintaining 2009 as the cut - off point is to ensure continuity with the statement of principles which did not apply to properties built after 1st january of that year . flood re should incentivise rigorous and responsible planning decisions .
no . flood re will only reimburse insurers for damage done to contents located in the dwelling affected by the flood in question . this is because the definition of “contents” relates to the “dwelling” in which they are located and the purpose of the scheme is to help protect homes at risk of flooding and their contents .
as well as finding out what your existing insurer can offer it’s a good idea to shop around , as the existence of flood re should , over time , mean you have more choice of affordable flood cover , even if you are at high flood risk . comparison websites may not be the best way to do this if your home is at flood risk . these sites generally suit people with standard needs and insuring a property at flood risk may be best done by dealing directly with an insurer or insurance broker so they can consider your individual circumstances .
flood re would be funded by premiums paid on policies that cover high risk homes and the extra cost that goes on to normal policies to cross - subsidise the riskier policies – which works out at £8 per policy according to abi calculations .
flood re will cover policies on those properties where it can be proven that the property had been built and used as a private , residential property ( i . e not a business or an office ) prior to 1 st january 2009 .
despite that , plenty of insurers have been keen to quickly move customers on to the scheme . axa said last week that it was contacting all customers in flood risk areas who had bought a policy since january to encourage them to cancel it and move to a new , flood re - backed policy - penalty - free .
the cost of paying claims for widespread flood damage will be significantly reduced for insurers because the risk will now be spread across the entire industry . insurers will pay a levy to flood re , based on their total market share , and that will go into a £180m annual pot to effectively act as an insurance scheme for insurers .
craig monks , rsa’s home claims functional leader and national events coordinator , has been dealing with flood claims for the past 22 years and says the introduction of flood re will have a very real impact for people who live in high - risk areas because it will take away some of the worry that comes with sorting out adequate cover .
it’s hard to believe that flood re has been in operation for over a year , and it has just issued its first annual report . this government - backed scheme , which we’ve written about many times , was launched in 2016 after years of wrangling and is designed to provide affordable flood insurance for properties in high - risk areas .
flood re is the first scheme of its kind in the world and is a highly complex undertaking . the laying of the regulations is an important step towards enabling affordable insurance to be available for those households and families most at risk of flooding . ”
this added to the momentum for something to be introduced which would extend the reach of flood re ( we wrote about this a couple of months ago ) . so now biba should be congratulated for sticking to its promises and finding a solution . and this doesn’t just apply to businesses : it will also offer flood cover for rented properties .
unless a new agreement is reached , insurers will no longer guarantee to offer flood cover . this could mean that upward of 200 , 000 properties will be uninsurable for flood .
73 . flood re would only operate for a limited time ; it would be withdrawn within 20 - 25 years . whilst stating that an immediate move to a free market would cause
significant hardship for many households
, the government wished to see a
transition to a free market for flood insurance so that flood risk is accurately reflected in prices and the right incentives are in place to manage the risk of flooding
. [
] on the same day , defra launched a public consultation on how the government intended to move forward . insurers agreed to continue to meet their commitments under the statement of principles until such time as a new model , flood re , could begin operating . [
brendan mccafferty chief executive of flood re , said : “six months after launch we are pleased with the progress that has been made . those customers with the 53 , 000 policies backed by flood re are now able to access more affordable cover , having previously been , in many cases , locked out of the market . the environment agency says that millions of people across the country are at risk of flooding and these people now have peace of mind that if the worst happens they will be able to benefit in future .
but however effective flood re 2 turns out to be , it won’t help if businesses haven’t got the correct insurance in the first place . a business insurance expert has recently written about what to consider when buying commercial insurance , which can be summarised as follows :
those people who pay higher premiums as a result of their home having flooded can expect their home insurance to become more affordable . this is due to a combination of insurers being able to pass the flood risk to flood re , and the policyholder now being able to shop around in a more competitive market that may have been closed to them previously .
this represents a 1 . 3 % chance of a flood event occurring in any one year
firstly , the new scheme for affordable flood insurance , flood re , has now been in operation for six months and apparently 53 , 000 properties have been protected through it , which is great . and having started with 16 insurers , there are now 41 providing cover to high - risk properties under the scheme . but there’s still a long way to go , with an estimated 350 , 000 homes which could benefit from more affordable flood insurance .
“consumers should check the flood re website to see which insurers are signed up , speak to their current insurer and be prepared to shop around . when buying a policy , they should make sure it is the best one for them , not just the cheapest . ”
getting to this stage has required compromise by both sides , and there remain issues that need to be overcome ,
he said .
insurers and the government are now working towards a shared vision , with flood re as the government ' s preferred choice .
the government’s aim is that flood re should be introduced to provide protection for the most at risk properties . over 20 - 25 years , premiums will be allowed to gradually rise to market level while flood prevention measures continue to be taken , to bring insurance costs down to a reasonable level . but as the cccep report notes , flood risk is rising , losses are increasing , and there is no detailed explanation of how the scheme will be phased out .
when flood re ends , it is anticipated that there will be a system for home insurance prices that will be based more accurately on the kind of flood risks each household actually faces ( known as ‘risk reflective pricing’ ) . there is , therefore , an incentive for homeowners , local authorities and the government to take action to try and mitigate the effects of flooding .
] the company considered that reinsurance had a key role to play in managing flood re ' s ' survivability ' ( the ability to meet its obligations ) and ' sustainability ' ( the ability to survive and trade after an event ) . reinsurance achieved this through substantially reducing both the probability of failure and the volatility of results . the company ' s early estimates were that flood re ' s ability to pay out for a single catastrophic event would be some £2 billion ,
far in excess
of the scheme ' s estimated premium income . [
now the two sides have struck a deal that means a not - for - profit fund - called flood re - will be built up from a levy charged on insurers to cover the cost of insuring these homes . in the meantime the current arrangements will remain in place .
another problem that cccep highlights is that a scheme like flood re sends the wrong message to the insurance market , homeowners and local authorities . the statement of principles , the agreement between the insurance industry and the government following the particularly severe floods in 2007 entails that the government continue to invest in flood defences . it is vital this continues , but by providing guaranteed reinsurance for the porperties most at risk , the sense of urgency to build flood protection measures is reduced .
i rent a property in a flood risk area . can i get still get contents insurance ?
more information on both of these documents is available on the local flood risk management strategy page .
67 . however , flood re has been criticised by some in the insurance and reinsurance industry . insurance company marsh ltd suggested that the model would create perverse incentives for homes in high - risk areas not to manage their flood risk and for developers to build in such areas , prices would rise excessively as tariffs would not be contested , and reinsurance costs would be substantial . [
the flood re scheme is designed to help people who buy the buildings or contents insurance for properties which are at risk of flooding , providing they own and live in them . there is also a rule meaning you won’t be eligible if your property was built after january 1st 2009 .
but according to some recent press reports , there may be some good news for small businesses around the corner . as we wrote in may , the industry has been looking at introducing a ‘flood re 2’ to cover small businesses , and this is likely to be launched later this month .
72 . after we finished taking evidence , on 27 june , the government launched a six week public consultation on its proposal to adopt the flood re model under which up to 500 , 000 high risk households could benefit by paying
significantly less for their insurance than they might otherwise
. the model would also constrain the excesses that could be imposed on households at high flood risk . [
the establishment of flood re has enabled insurers to offer competitive premiums and lower excesses to high flood risk homes across the uk . six months after launch , the number of insurance providers signed up to support the scheme is now at 41 , a 156 % rise from the 16 which were on board on 4 april . those 41 insurance providers represent 90 % of the overall home insurance market .
the government and others agreed with us that the flood insurance statement of principles established in 2000 had become unsustainable and that a new approach was needed to help households at risk of flood obtain affordable flood insurance . the statement was only ever intended to be a temporary measure and restricted customer choice as insurers only had commitments to their existing customers , and new insurers could decide to whom they offered flood insurance .
map of small to medium sized flood alleviation works ( pdf 7 . 79mb opens in new window )
any changes that may be needed at each five year review will reflect the need for the transition to risk reflective premiums over flood re’s 25 year existence . any changes that are considered necessary will be discussed with and approved by the secretary of state and effected through a change in the current legislation .
66 . flood reinsurance is a key aspect of the model . reinsurance company , aon benfield , which has been working with the abi on the details of flood re , noted that all insurance companies in the uk buy some form of reinsurance protection for their property exposures ( risks ) which provides
a robust , proven , and well regulated mechanism for transferring risk and protecting insurers ' financial positions
. [
“there was some discussion about whether to include small and medium enterprises but , on balance , it was decided affordable cover already exists for businesses . flood re is to protect homeowners , ” he explains . “that’s also the reason blocks of flats and leasehold properties are excluded , unless they are owner - occupied .
no . in line with its transition plan , flood re is currently carrying out research into the relative value and effectiveness of resilience measures and will report separately on its findings in due course . in the meanwhile , in accordance with the terms of the treaty , flood re will not indemnify insurers for resilient repair . the definitions of “loss” and “flood risk element” currently preclude claims payments covering betterment for the purpose of potential resilient repair . therefore , flood re will only indemnify insurers for the cost of like for like repairs and will not follow the fortunes of underlying policies even if they allow for betterment as a standard term . any payments made to an insured above the cost of like for like repairs will be borne by the insurer . for the avoidance of doubt , where building work has to be completed to a higher standard due to a change in laws or regulations , then such build difference will not be considered “betterment” , provided it is the insurer’s normal practice to indemnify such cost within a new - for - old cover .


user-mode driver framework ( umdf ) is a device-driver development platform first introduced with microsoft 's windows vista operating system , and is also available for windows xp .

it facilitates the creation of drivers for certain classes of devices .

user - mode driver framework

for ways to use these extensions , see user - mode driver framework debugging .
user mode driver framework architecture ( windows embedded ce 6 . 0 ) | microsoft docs
this topic describes the advantages of writing a user - mode driver framework ( umdf ) driver instead of a kernel - mode driver .
when a driver is flagged as a user mode driver in the registry , the device manager will access the user mode driver reflector . the user mode driver reflector launches the appropriate user mode driver host process and forwards i / o requests to it . the user mode driver host process in turn forwards i / o requests to the user mode driver .
the user mode driver framework is divided into two physical components . the first component is the user mode driver reflector , which resides inside the device manager . the second component is the user mode driver host , which is a user mode application that is launched and managed by the user mode driver reflector .
in an implementation , non - hardware kernel stub interfaces may be provided by a user - mode framework reflector 108 . the user - mode framework reflector 108 may be a kernel - mode windows device mode ( wdm ) filter driver that is installed at the top of a kernel - mode device stack for each device that a user - mode framework driver 101 manages . the user - mode framework reflector 108 manages communication between the kernel - mode components and the user - mode driver host process .
microsoft user - mode driver framework feature pack 1 . 0 - add or remove programs entry information
user - mode driver framework version 1 . 11 update for windows 7 , and windows server 2008 r2
user - mode driver framework : technical synopsis peter wieland development lead windows device experience group microsoft corporation .
extension commands that are useful for debugging user - mode driver framework drivers are implemented in wudfext . dll .
windows 10 , version 1803 ( redstone 4 ) includes kernel - mode driver framework ( kmdf ) version 1 . 25 and user - mode driver framework ( umdf ) version 2 . 25 .
kernel - mode driver framework ( kmdf ) version 1 . 11 update for windows 7
the process of using a user mode driver begins with a user application or with a parent bus driver . user applications and parent bus drivers can load user mode drivers by calling activatedevice or activatedeviceex . user applications and parent bus drivers can unload user mode drivers by calling deactivatedevice . once loaded , any user application or driver can access the user mode driver by using the device handle .
in this topic , you ' ll learn about the naming conventions for the file names of the kernel - mode driver framework ( kmdf ) library and the user - mode driver framework ( umdf ) library .
add or remove programs entry for microsoft user - mode driver framework feature pack 1 . 0 . microsoft ' s user - mode driver framework feature pack is a component of windows media player 11 required to interact with zunes and other peripherals .
18 . the device driver framework of claim 17 , wherein the user - mode module is stopped and a driver call stack is unwound .
urltoken ; note : the asterisks and different addresses allow your urltoken to update the kernel - mode driver framework to that do not have the 1 . 11 version of kmdf , windows 7 sp1 , windows7 . the kernel - mode driver framework ( kmdf ) version 1 . 11 update contains the following changes : kernel - mode driver framework version 1 . 11 update for windows . error code 8004402f for important update for kernel - mode driver framework version 1 . 11 for windows 7 update for kernel - mode driver framework version . update for kernel - mode driver framework version 1 . 11 for windows 7 ( kb2685811 ) keeps failing error 8007007e ? upload failed . resolve imaging issues with your drivers and dell hardware by updating your kernel mode driver framework to 1 . 11 . client portal log in newsletter sign up kk remote . update for kernel - mode driver framework update for kernel - mode driver framework version 1 . 11 for windows 7 failed error details : code 80041002 update . windows 8 . 1 includes user - mode driver framework ( umdf ) version 2 . 0 and kernel - mode driver framework iot core updates ; windows 8 . 1 includes user - mode driver . unable to install windows update : update : update kernel - mode driver framework . i am unable to update the kernel - mode driver framework ver 1 . 11 for windows . windows update - kernel - mode driver framework version kernel - mode driver framework version 1 . 11 failed update ; i have been getting a
windows framework driver . kernel - mode driver framework version 1 . 11 update for windows that have failed . and install version 1 . 11 of the files . during driver .
this section contains information that applies only to user - mode driver framework ( umdf ) versions 1 . 11 and earlier .
this topic lists available user - mode driver framework ( umdf ) sample drivers that you can download from the windows driver samples repository on github .
18 . windows user mode driver framework virtual printer driver clr host . net data converter . net data converter . net data converter native native native
the following diagram shows how driver host processes , driver manager , and reflector communicate across the user mode / kernel mode boundary .
at 206 , the umdf user - mode code prepares a dma transfer . the user - mode framework driver 101 may invoke the kernel stub 106 to perform device programming for this dma operation .
download user - mode driver framework version 1 . 11 update for windows 7 , and windows server 2008 r2 from official microsoft download center
kernel and user mode driver framework 1 . 11 update - what it is and why you need it ! - updated ! ! !
figure 1 : microdrivers split device driver functionality between a kernel - mode component and a user - mode component .
this topic describes how the driver manager builds a user - mode device stack , and how the host process , reflector , and driver manager process an i / o request that an application sends to a user - mode driver framework ( umdf ) driver .
for a complete description of the extension commands in wudfext . dll , see user - mode driver framework extensions ( wudfext . dll ) .
providing the user - mode driver and the kernel stub at a same interrupt level .
the user mode driver has restricted access rights to the hardware , which prevents it from being able to accommodate requests such as mapping physical memory or calling interrupt functions . to accomplish these types of requests , the user mode driver calls the user mode driver reflector , and enables the user mode driver reflector to handle the request . the user mode driver reflector then checks the user request against the registry settings to determine whether it should perform the requested action . unlike with interrupts and the mapping of physical addresses , the user mode driver can , via the device handle and without the aid of the user mode driver reflector , access the parent bus driver regardless of where the parent bus driver is located .
stopping user - mode driver execution if a device exception is encountered using the reset stub .
at 308 , the user - mode framework reflector 108 sends a software interrupt to the user - mode framework driver 101 to take control of the processing . at 310 , the user - mode framework driver 101 may synchronize access with registers and other resources . the isr or kernel stub 106 may queue a deferred procedure call to finish i / o operations at a lower priority ( irql ) than that at which the isr executes .
i am sure you ' ve heard a lot about the kernel mode driver framework ( kmdf ) , the new paradigm for writing kernel mode drivers for windows . but have you heard about the user mode driver framework ( umdf ) ? this article introduces umdf and gives a brief overview of its architecture .
the driver host process loads vendor - supplied umdf drivers and framework dlls , provides an execution environment for user - mode drivers , and routes messages between drivers in a user - mode stack . for more information , see umdf driver host process .
the umdf driver is an in - process com component that controls the hardware from user mode .
the user mode driver reflector , which is aware of the original process and the destination process , uses cefsiocontrol to forward the device manager ' s request to the user mode driver host . the user mode driver host then parses the request to either load , unload , or call the parent bus driver ' s entry .
the reflector is a kernel mode wdm filter driver that is installed at the top of the kernel mode device stack for each device that is managed by a umdf driver . the reflector manages communication between the kernel mode components and the user mode driver host process .
synchronizing the kernel stub and the user - mode driver using a deferred procedure call ( dpc ) .
a combination of the kernel stubs , the software based fault isolation mechanism 107 , or the user - mode framework reflector 108 may monitor for an interrupt storm and reset the device if one occurs . in some implementations , upon detection of an interrupt storm , the isr may be routed through the user - mode framework reflector 108 , or there may be some communication between a kernel interrupt dispatcher and the user - mode framework reflector 108 such that the user - mode framework reflector 108 can detect or be notified when a device is causing an interrupt storm . the user - mode framework reflector 108 may then call stub _ reset ( i . e . , the reset stub 105 ) , and then either notify or terminate the host driver .
if the driver is a user mode driver , the call to activatedevice or to activatedeviceex will result in the device manager calling the user mode driver reflector function as well . a driver is recognized as a user mode driver when the flags value is set to the setting devflags _ load _ as _ userproc ( 0x10 ) in the registry key of the device .
user - mode driver framework ( umdf ) debugging extensions are implemented in the extension module wudfext . dll . you can use these extensions to debug drivers that use umdf .
in an implementation , a dma device for a user - mode framework driver is one that implements no device specific kernel code . the device may have the following attributes :
you can debug a umdf driver by using user - mode debuggers or kernel - mode debuggers . for more info , see debugging wdf drivers .
all wdf driver samples and visual studio driver templates are universal windows driver compliant .
windows driver frameworks ( wdf ) is a set of libraries that you can use to write device drivers that run on the windows operating system . wdf defines a single driver model that is supported by two frameworks : kernel - mode driver framework ( kmdf ) and user - mode driver framework ( umdf ) . this topic provides answers to frequently asked questions about umdf .
in some implementations , drivers are written completely in a user - mode framework . no code in the kernel results in a very stable implementation , where generic driver functions from a split driver model are sufficient .
similar to a kernel - mode stack , the construction and tear down of a user - mode stack is driven by plug and play ( pnp ) events . after the kernel - mode stack has been built , the reflector notifies the driver manager to start construction of the user - mode stack . the driver manager launches the driver host process and provides sufficient information to the launched process to build the user - mode stack . in this way , the user - mode stack can be considered an extension of the kernel - mode stack .
the user - mode framework reflector 108 may invoke the kernel stubs to handle requests for “stub operations” in response to xksoperation calls in the xks _ uapi . the user - mode framework reflector 108 may call a kernel stub interface at dirql holding the proper locks in a manner that allows for safe execution of the kernel stubs using xfi . in an implementation , the downcall interface for the user - mode framework reflector 108 to call an kernel stub operation could be :
the run - time environment dispatches i / o requests , loads the driver , constructs and destroys the user mode device stack , manages a user mode thread pool , and handles messages from the reflector and the driver managers .
the run - time environment dispatches i / o requests , loads the driver , constructs and destroys the user mode device stack , manages a user mode thread pool , and handles message from the reflector and the driver manager .
how does a user i / o sent to a umdf driver get processed ? as figure 1 shows , a user mode application sends its requests to kernel mode as for any device . once in kernel mode , the reflector sends the requests to the proper wudfhost process running in user mode for processing . the action of the requests is totally transparent to the application - - only the umdf driver knows it is running in user mode .
this topic provides a high - level overview of user - mode driver framework ( umdf ) components and describes how your driver interacts with system - supplied components . it applies to both umdf versions 1 and 2 .
windows driver frameworks ( wdf ) contains umdf , a framework for the creation of user - mode drivers . like kernel - mode driver framework ( kmdf ) , umdf provides an abstraction layer from wdm , handling much of the plug and play ( pnp ) and power management functionality , and allowing the driver to opt in for specific functionality and event handling .
a reflector to manage communication between the user - mode module and the kernel stub .
when a driver is in user mode , the pbuscontext passed into activatedeviceex must be a dword instead of a pointer .
a umdf driver can receive i / o requests from a kernel - mode driver . for more info about kernel - mode clients , see supporting kernel - mode clients in umdf 2 drivers .
if you built your driver using a version of the kmdf library that is more recent than the version of the framework that is on the system , then the latter must be updated . for information about updating the framework library , see redistributable framework components .
. second , it must move the remaining ( non - critical ) functions to a user - mode component , and generate code for communication between the kernel - mode and user - mode components . this is achieved by the
a microdriver consists of a kernel - mode component that implements critical functionality and a user - mode process that implements non - critical functionality . device driver functionality is split between the kernel - mode and user - mode components at function boundaries . the two components communicate using an lrpc - like mechanism [
the driver host process provides the execution environment for user - mode drivers and routes messages between drivers in the user - mode stack . the reflector uses a message - based interprocess communication mechanism to communicate with the driver manager and host process .
into microdrivers . this provides a path to execute device drivers written for commodity operating systems in user - mode without sacrificing performance . prior efforts at user - mode device drivers have either required rewriting the driver completely [
the umdf driver is an in - process component object model ( com ) component that controls the hardware from user mode .
user - mode drivers operate in a much simpler environment than kernel - mode drivers . for example , kernel - mode drivers must take into account irql , page faults , and thread context . in user mode , however , these issues do not exist . user - mode drivers always run in a different thread from the requesting process and can always take page faults .
19 . the device driver framework of claim 18 , wherein the kernel stub calls a deferred procedure call ( dpc ) to synchronize with one of an interrupt service routine and the user - mode module .
for an overview of how to debug user - mode driver framework ( umdf ) drivers , including information on how to start this kind of debugging session , see the debugging umdf drivers section of the windows driver kit ( wdk ) documentation .
providing the kernel stub access to a shared memory space that is shared between the kernel stub and the user - mode driver .
sharing information between the user - mode driver and the kernel stub regarding the hardware device and the interrupt in a shared memory .
you can debug umdf drivers by using either a user - mode debugger or , starting with umdf version 2 , a kernel - mode debugger .
when protecting systems against kernel mode drivers using the software fault isolation mechanism 107 , the software isolation augments the kernel mode driver such that driver exceptions may be detected . when the software isolation code detects a driver exception , it stops the driver code and unwinds the driver call stacks to return a proper error code back to the user - mode framework reflector 108 . the user - mode framework reflector 108 in turn calls a driver provided reset stub 105 that functions like a “kill switch” to stop the hardware from any further operations which may corrupt the system states . the reset stub 105 is provided by the driver at the driver initialization . the “kill switch” stops the hardware immediately , including any outstanding dma transfers .
in some implementations , a method includes loading a user - mode driver associated with a device ; loading kernel stubs having a reset stub associated with the user - mode driver in a kernel of an operating system ; receiving an interrupt ; invoking the kernel stub to perform an interrupt service routine ; monitoring for an exception ; and obtaining information about the interrupt using the user - mode driver .
the user - mode framework reflector 108 may forward i / o , power , and plug and play messages from the operating system to the driver host process , so that user - mode drivers can respond to i / o requests and participate in plug and play device installation , enumeration , and management . the user - mode framework reflector 108 or the software based fault isolation mechanism 107 may also monitor the driver host process to ensure that it responds properly to messages and completes critical operations in a timely manner , thus helping to prevent driver and application hangs .
when debugging a umdf driver , you can merge framework logs with driver logs by issuing : ! wdfkd . wdflogdump < drivername . dll > - m
figure 1 shows the overall architecture of a umdf driver . a umdf driver runs in a driver host process that also hosts umdf and a run - time environment . each such driver operates as part of a stack of drivers that manage a device . the user mode drivers are loaded above the kernel mode drivers at the top of the stack . because user mode components do not have access to the system address space where the system and kernel mode drivers maintain i / o requests and other shared data , the umdf architecture includes components that communicate between kernel mode and user mode .
the user mode driver framework ( umdf ) is one of two major sub - frameworks in the windows driver foundation ( wdf ) framework . it in essence sits on top of the windows 7 operating system , and uses the windows win32 api’s primarily to communicate with the operating system , which ultimately communicates with the computer system hardware device .
user - mode and kernel - mode drivers have different structures , different entry points , and different system interfaces . whether a device requires a user - mode or kernel - mode driver depends on the type of device and the support already provided for it in the operating system . most device drivers run in kernel - mode . kernel - mode drivers can perform certain protected operations and can access system structures that user - mode drivers cannot access . moreover , kernel - mode drivers often offer lower - latency services . however , kernel - mode drivers can cause instability and system crashes if not implemented properly , as well as introduce security vulnerabilities .
] offer apis to program user - mode device drivers that communicate with a kernel module . chubb [
as figure 2 shows , the user mode driver runs under the host process , which combines with kernel mode drivers ( including the reflector ) to form the device stack for the device .
this solution demonstrates how a user - mode driver framework ( umdf ) version 2 driver can implement f - state - based power management . the singlecomp project demonstrates how a umdf version 2 driver can implement f - state - based power management for a device that has only a single component .
my copy of windows 7 is pirated and i want to use my xbox one controller with it but that requires a few updates , user - mode driver framework version 1 . 11 and kernel - mode driver framework version 1 . 11 to be exact . i ' m wondering if instaling these will make windows realise my copy isn ' t genuine , so is it safe to install these updates ?
the request is either completed by one of the drivers in the user - mode stack or forwarded by one of the drivers back to the reflector . when the reflector receives a request from the user - mode driver stack , it sends the request down the kernel - mode stack for completion .
] . in the kernel - mode component , direct calls to functions implemented in the user - mode component are replaced with upcalls through stubs . stubs marshal data structures accessed by the called function and unmarshal them when the call returns . a symmetric downcall mechanism enables the user - mode component to invoke kernel functions . to handle multiple requests from the kernel - mode component , the user - mode process is multithreaded .
20 . the device driver framework of claim 19 , wherein the user - mode module and the kernel stub are provided at a same interrupt level , and wherein the dpc processes i / o requests at a lower interrupt level .
as figure 4 . 1 shows , windows supports a layered i / o architecture . user mode applications and services issue i / o requests through the win32 api and communicate with the user mode pnp manager to perform plug and play and power activities . the win32 api and user mode pnp manager , in turn , communicate with the kernel mode i / o system , which includes the kernel mode i / o manager , pnp manager , and power manager . the kernel mode i / o system communicates with the kernel mode drivers .
the reflector is a kernel mode wdm filter driver that is installed at the top of the kernel mode device stack for each device that a umdf driver manages . the reflector manages communication between the kernel mode components and the user mode driver host process . the reflector forwards i / o , power , and plug and play messages from the operating system to the driver host process , so that user mode drivers can respond to i / o requests and participate in plug and play device installations , enumeration , and management .
if you have a debugger connected , you can access both the driver and framework ifr logs by issuing ! wdfkd . wdflogdump .
the windows kernel creates i / o request packets ( irps ) to represent the user mode i / o requests and forwards them to the top of the kernel mode driver stack for the target device .
a user - mode driver can impersonate its client process only for i / o requests , and not for plug and play or other system messages .
at 216 , it is determined if an exception occurred . the exception may be an interrupt storm . the sfi 107 detects exceptions in kernel mode . the reflector 108 receives the indications of exception in kernel mode and takes actions to stop driver at 216 . at 218 , the driver call stack is unwound , and at 220 the hardware is stopped in kernel mode without signaling the user mode driver .
when you build your driver , the msbuild utility links the driver with a stub file that contains the version number of the library that the msbuild utility used . when the operating system loads your driver , the framework ' s loader checks the version information in your driver ' s stub to determine if the driver will run with the version of the framework library that is on the system .
the framework exposes the user mode ddi , which is a dynamic - link library ( dll ) of com - style objects that support the presentation , flow , and management of i / o , power , and plug and play requests to the driver .
drivers in operating systems run in either user - mode or kernel - mode . user - mode drivers run in the non - privileged processor mode in which other application code , including protected subsystem code , executes . user - mode drivers cannot gain access to system data or hardware except by calling an application programming interface ( api ) which , in turn , calls system services . kernel - mode drivers run as part of the operating system ' s executive , the underlying operating system component that supports one or more protected subsystems .
run device drivers as user - mode processes . a bug exercised in a device driver only results in the failure of the user - mode process running that driver . this approach , however , has two key problems . first , this architecture is not compatible with commodity operating systems , which are designed as monolithic kernels . providing support for user - mode device drivers in commodity operating systems thus requires kernel modifications and rewriting device drivers [
yes . even if your driver requires access to some kernel - mode resources or features , you might be able to split your driver into two parts . this approach enables you to benefit from some of the advantages of developing and running drivers in user mode .
the kernel stubs may also provide sequencing of operations for hardware devices where certain sequences of operations are timing sensitive and cannot tolerate pauses incurred by context - switching out a user - mode driver . where a pure user - mode driver would have to be scheduled onto a cpu to acknowledge each of the interrupts , the kernel stub _ isr 106 reduces this latency because it is invoked by the kernel - mode interrupt handler and may run in an arbitrary context at a raised irql . the user - mode framework driver 101 may support multiple devices , and therefore may multiplex requests from multiple devices through a single instance of the kernel stub _ isr 106 .
17 . the device driver framework of claim 16 , wherein if the software based fault isolation mechanism detects an exception , the device is stopped .
a user - mode driver is started by the driver manager and runs in a driver host process . a single instance of the driver can service simultaneous requests from multiple applications . to communicate with the driver , applications issue i / o requests to the driver ' s device through the win32 api . the primary entry point in a user - mode driver is the idriverentry interface ( umdf 1 . 11 and earlier ) or the driverentry routine ( starting in umdf 2 . 0 ) , rather than a main ( ) function .
startup / shutdown and error - handling ) . the user - mode component is implemented as a standalone process that is called from the kernel - mode component . together , they provide the functionality of a traditional device driver .
although this chapter focuses on kernel - mode drivers , windows includes a growing number of drivers that actually run in user mode , as previously described , using the user - mode driver framework ( umdf ) that is part of the wdf . before finishing our discussion on drivers , we’ll take a quick look at the architecture of umdf and what it offers . once again , for a much more complete overview on the subject , please refer to urltoken .
the process of moving the driver package to the target computer and installing the driver is called deploying the driver . you can deploy a driver sample automatically or manually .
down in kernel mode , the umdf kernel mode reflector driver ( or simply reflector ) provides the necessary connections between user mode and a kernel device stack . there is one reflector device instance installed in each kernel umdf device stack . the reflector is responsible for forwarding i / o , power , and pnp messages from kernel mode to the host process .
this section describes user - mode driver framework ( umdf ) and details the differences between umdf versions 1 and 2 . it also provides high - level architectural information about umdf . use this section to determine if a umdf driver is the right choice for your needs , and to decide which umdf version to use .
16 . the device driver framework of claim 15 , wherein the kernel stub invokes an interrupt service routine in response to an interrupt received from a device ; and wherein the software based fault isolation mechanism monitors for exceptions thrown by a device associated with the user - mode module .
at 210 , a hardware device raises an interrupt . executable code within kernel stub 106 for the isr is invoked that copies volatile device state into the sdd memory 104 . at 212 , the user - mode framework driver is signaled . this may be performed through the isr execution .
] . we show that program analysis techniques can automatically identify critical functions in a device driver , following which a semantics - preserving transformation can split the driver into a user - mode and a kernel - mode component . we discuss the design and implementation of such a refactoring tool in
the driver includes code to handle only those events for which its device requires device - specific support . all other events can be handled by framework defaults .
optimizing device drivers for terminal servers plug and play device redirection framework gaurav daga program manager windows terminal server microsoft .
microsoft believes that by moving these types of drivers to user mode , it will simplify driver writing and improve the overall stability of the windows operating system . i certainly agree with this statement since user mode is a much more forgiving environment . let ' s face it , if you can develop a driver for a device without having to worry about the complexities of kernel mode programming or risking crashing a user ' s machine when it misbehaves , your customers and microsoft will be much happier .
for more information about using msbuild to build a driver package , see building a driver .
as the name implies , a umdf driver runs in user mode , specifically in a process running the executable image wudfhost . exe . the general layout of umdf modules is shown in
umdf is based on the same conceptual driver programming model as the kernel mode driver framework ( kmdf ) that is also part of wdf . however , the two frameworks implement the model with different components , device - driver interfaces ( ddis ) , and data structures . kmdf includes some objects that are available . . .
to make porting code easier from kernel mode to user mode , and to keep a consistent architecture , umdf uses the same conceptual driver programming model as kmdf , but it uses different components , interfaces , and data structures . for example , kmdf includes objects unique to kernel mode , while umdf includes some objects unique to user mode . objects and functionality that can’t be accessed through umdf include direct handling of interrupts , dma , nonpaged pool , and strict timing requirements . furthermore , a umdf driver can’t be on any kernel driver stack or be a client of another driver or the kernel itself .
in an implementation , the xks _ isr interface 114 may be implemented by a small shim in the user - mode framework reflector 108 . the xks _ isr interface 114 may be responsible for watching for interrupt storms . an exemplary isr interface may be :
the splitter analyzes the device driver and determines how functions implemented in the driver must be split between kernel - mode and user - mode . it builds a static call - graph of the driver ( including edges for indirect calls ) , identifies critical root functions , and classifies functions transitively called by them as critical , as described in the study in
umdf exposes the user mode device - driver interface ( ddi ) . umdf is a dll of com - style objects that support the presentation , flow , and management of i / o and plug and play requests to the driver .
thus , an implementation to solve the contention may be to use a stop - and - go strategy where a device is initialized in non - interrupting state . when the user - mode driver receives transfer requests , it sets up one dma transfer including enabling interrupt for the dma transaction . the user - mode driver then waits on the interrupt event . at some point , interrupt occurs either due to error or completion of the transfer . the kernel mode isr dismisses and disables the interrupt , by reading and writing registers , and it signals the user mode isr which processes the result . the user - mode driver then can continue the next dma transfer if there is one . this serialization of isr and dma request eliminates the contention of accessing hardware registers and any shared resources .
a device driver includes a kernel mode and a user - mode module . the device driver may access device registers while operating in user - mode to promote system stability while providing a low - latency software response from the system upon interrupts . the device driver may include kernel stubs that are loaded into the operating system , and may be device specific code written . the stubs may be called by a reflector to handle exceptions caught by the stubs . a reset stub may be invoked by the reflector when the user - mode module or host terminates abruptly or detects an interrupt storm . the reset stub may also be invoked if errant dma operations are being performed by a hardware device . the reset stub may ensure that hardware immediately stops unfinished dma from further transfer , and may be called by the user - mode driver module .
all kmdf and umdf 2 drivers can use an always on , always available inflight trace recorder ( ifr ) . when a driver provides a custom trace , the driver ifr log contains the trace messages . note that the new driver ifr log is separate from the framework ifr log that wdf creates for each driver .
i ' m sure i noticed that when i installed wmp11 one of the install steps was registering the user - mode driver framework . or words to that affect . does this mean that the umdf can be taken downstream , or is the installer talking rubbish ? ( or me , it could be me talking rubbish )
the user - mode framework driver 101 may transfer data from a system to a device using dma , which is a capability provided by some computer bus architectures , including pci , pcmcia and cardbus , which allows data to be sent directly from an attached device to the memory on the host , freeing the cpu from involvement with the data transfer and thus improving the host ' s performance . dma buffers 102 provide a memory where data is buffered as it is communicated to / from the user - mode framework driver 101 . the dma buffers 102 may be allocated as a contiguous buffer or may be fragmented in the physical memory and mapped to a contiguous buffer in the calling process ' s virtual address space . in some implementations , the dma buffers 102 may come from requests presented to the user - mode framework driver 101 , in which case they may not need to be mapped into the address space of the host or even accessible directly to the stub .
i realise you probably cant tell me this which i can perfectly understand i mean its not optimised yet etc but . . . do you have any rough benchmarks at the moment comparing a user mode driver to kernel mode and if so what were the results and the device being testing ? on a seperate note , sorry if this is mentioned elsewhere but will the user mode process run at a higher priority to normal apps ?
a device driver framework in a computing system may include a user - mode module , one or more kernel stubs including a reset stub , a shared memory to share information between the user - mode module and the kernel stubs , and a reflector to manage communication between the user - mode module , the kernel stubs , and an application . the kernel stubs may include code that is invoked as an interrupt service routine in response to an interrupt received from a device and write information from the device to the shared memory . the user - mode module may then read information from the shared memory . after executing the interrupt service routine , the kernel stub may hand off handling of the interrupt to the user - mode module . the kernel stub may be protected using a software - based fault isolation mechanism that monitors for exceptions such as an interrupt storm . upon detecting an interrupt storm , the reset stub may stop a hardware device from generating the interrupts to maintain system stability . the kernel stubs may synchronize with the interrupt service routine and / or user - mode module using a deferred procedure call .
safe device driver model based on kernel - mode jvm
, chen et al . , 2007 , pages 1 - 8
3 . checking and dismissing interrupts may take a read and a write to the registers for most hardware . therefore , it is non - atomic . if drivers set up dma in user - mode , which has to manipulate hardware registers , there may be contention between isr and the user - mode code .
three factors lead us to believe that implementing non - critical functionality as a user - mode process will also improve system reliability and availability as a whole .
the driver manager is a windows service that manages all instances of the wudfhost driver host process . the driver manager launches and tracks information about each driver host process . each host is a child process of the driver manager . only one driver manager exists per system . the driver manager starts during installation of the first umdf device and runs on the system thereafter .
the code generator uses the critical functions identified and emits code for the kernel - mode and user - mode components . it also generates all the code to handle upcalls and downcalls , including stubs and code to marshal / unmarshal data structures . the object tracker and threadpool implementation ( for the multithreaded user - mode component ) are common to all microdrivers and need to be written just once .
] report user - mode driver performance comparable to in - kernel device drivers . however , unlike microdrivers , they require both kernel support , and rewriting device drivers , making them incompatible with existing operating systems .
of course , microdrivers are not a panacea for device driver reliability problems . a bug in the kernel - mode component of a microdriver could still crash the operating system . it is also possible that by splitting functionality between a user - mode and kernel - mode component , microdrivers can expose otherwise latent bugs . for example , a latent race condition in a device driver could potentially be exposed in its microdriver implementation .
commodity operating systems achieve good performance by running device drivers in - kernel . unfortunately , this architecture offers poor fault isolation . this paper introduces microdrivers , which reduce the amount of driver code running in the kernel by splitting driver functionality between a small kernel - mode component and a larger user - mode component . this paper presents the microdriver architecture and techniques to refactor existing device drivers into microdrivers , achieving most of the benefits of user - mode drivers with the performance of kernel - mode drivers . experiments on a network driver show that 75 % of its code can be removed from the kernel without affecting common - case performance .
the kernel stubs may be untrusted , while executing safely in the kernel because of a software based fault isolation mechanism 107 , such as xfi , that allows user - mode framework drivers to add kernel stub to the kernel without possibly corrupting the integrity of the kernel itself , or its subsystems .
in addition to the wudfhost process hosting your driver , there is another user mode process that ' s part of the umdf
system .
the second process is the umdf driver manager service that communicates with the wudfhost process running your driver and any other wudfhost processes running on the system . this service , which is started as part of starting the device , is responsible for host process lifetimes and responding to messages from the umdf kernel mode reflector driver .
umdf drivers run in a driver host process , which runs in the security credentials of a localservice account , although the host process itself is not a windows service . thus , user - mode drivers are as secure as any other user - mode service . when a umdf driver issues i / o requests , it can optionally impersonate its client process . impersonation enables the driver thread to run in the security context of the client so that the system performs access checks against the client ' s identity rather than that of the driver host process .
before writing a driver—even a user mode driver—you must understand the basics of the windows i / o architecture , as shown in figure 1 . in this overview , we will discuss some of the major principles behind the i / o system and define the most important terms .
before writing a user mode driver you must understand the basics of the umdf architecture . ron reeves , author of windows 7 device driver , looks at the overall block diagram of the umdf , and at the major activity : the i / o flow for the umdf .
unlike kmdf drivers , which run as driver objects representing a . sys image file , umdf drivers run in a driver host process , similar to a service - hosting process . the host process contains the driver itself ( which is implemented as an in - process com component ) , the user - mode driver framework ( implemented as a dll containing com - like components for each umdf object ) , and a run - time environment ( responsible for i / o dispatching , driver loading , device - stack management , communication with the kernel , and a thread pool ) .
] , synchronizes copies of a data structure in the kernel ' s address space and the user - mode process ' address space . it has three main functions .
several enhancements are possible to the basic architecture of a microdriver . functions that are repeatedly called from both the kernel - mode component and user - mode component can potentially be replicated in both components , thus avoiding the overhead of an address - space change each time the function is accessed . similarly , a frequently - accessed data structure can be allocated in a shared memory region that is accessible both to the kernel and the user - mode process . finally , to ensure fast operation of the user - mode process , the operating system can pin the process ' pages to memory .
the host process is the process in which the user mode driver runs . the host process is a child process of the driver manager and runs in the security credentials of a localservice account , although it is not a windows service . the host process includes the following components :
by default , if the objectsforleakdetection key is not specified , the framework monitors wdfrequest , wdfworkitem , wdfkey , wdfstring , wdfobject , and wdfdevice .
] , and is an important motivation for microkernels . this has resulted in several services , that were previously implemented in the kernel , being implemented in user - mode (
kernel - mode drivers if specific kernel support for a device that is managed by a umdf driver is needed , it is also possible to write a companion kernel - mode driver that fills that role . in this way , it is possible for a device to be managed both by a umdf and a kmdf ( or wdm ) driver .
3 . handling of level triggered interrupts that are not shared . this mechanism may be implemented with a minimal amount of kernel - mode code . if the interrupt is not shared , then the interrupt handler may mask the interrupt at the interrupt controller ( effectively blocking it ) and notify the user - mode driver to handle the device . the user - mode driver code may make a request to the system ( reflector , etc . ) at the end of processing that unmasks the interrupt line , at which point a new interrupt may come in .
first , fault isolation improves . any bugs that crash the user - mode process of a microdriver will potentially render the corresponding device unusable but will not affect the rest of the operating system . the device driver can then be restarted in isolation to restore operation of the device . note that because the kernel - mode component of a microdriver implements critical device functionality , such as interrupt processing , it is possible to keep the device operational even if the user - mode process crashes . for example , the kernel - mode component can implement error - checking code that detects that the user - mode process has crashed , and wait until the process restarts . however , as it does so , it can still serve other requests to / from the device .
to determine the version of the library that your driver is running with , the driver can call wdfdriverisversionavailable or wdfdriverretrieveversionstring .
] . second , switching between the kernel and a user - mode device driver involves the costly overhead of changing protection domains . for devices such as high - throughput network cards , this can result in significant latencies and performance penalties [
2 . interrupt information is reflected in completed buffers or in a hardware register set which is manipulated by user mode code which may synchronize among multiple threads that access hardware registers .
the reflector is a kernel - mode driver that permits an application and a driver host process ( and user - mode device stacks ) to communicate . the reflector creates a separate device object for each device instance and handles plug and play ( pnp ) and power i / o requests associated with each device instance . all communication between the application and the driver host process happens through the reflector . for more information , see architecture of umdf .
the host process is the process in which the user mode driver runs . it is separate from the application process and the driver manager . it runs in the security credentials of a localservice account , although it is not a windows service . the host process contains the user mode device stack for the device . the device stack is visible to all applications across the system . each instance of a device has its own device stack . currently each instance has a separate driver host process , too . the host process includes the following components :
umdf is a new way of allowing drivers that support protocol bus based devices ( initially just usb ) to be written in user mode . the types of devices currently supported are :
second , because the kernel - mode component of the microdriver implements critical and heavily - used functionality , this code is likely more heavily tested than the user - mode component . further , because the kernel - mode component is a relatively small entity , it can either be verified , subject to thorough code audits , or be protected with mechanisms such as sfi [
to achieve this goal , the framework is designed to work with drivers on an
opt - in
basis . when you write a umdf driver , you provide callback routines for only the events that affect your device . for example , some devices require intervention immediately after they are turned on and just before they are turned off . the driver for such a device can implement callback functions that the framework calls at those times .
the user - mode framework driver 101 may operate as part of a stack of drivers that manage a hardware device . in an implementation , to provide for hardware that requires a low - latency response , the user - mode framework driver 101 may include kernel stubs loaded into the operating system , and may be device specific code written by , e . g . , hardware vendors . the kernel stubs may be provided to handle outstanding dma transfers and to provide better performance . the stubs are called by a reflector 108 via xkd _ ddi 112 . the reflector 108 contains code to handle exceptions in stubs caught by sfi 107 . the following kernel - mode stubs may be implemented : stub _ reset 105 ( reset ) , stub _ isr 106 ( isr ) and stub _ syncexe 109 ( syncexe ) . these three stubs execute at dirql with the interrupt spinlock , hence synchronization is provided for .