x86: eliminate has_arch_mmios()

... as being generally insufficient: Either has_arch_pdevs() or
cache_flush_permitted() should be used (in particular, it is
insufficient to consider MMIO ranges alone - I/O port ranges have the
same requirements if available to a guest).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
libxl: save/restore errno in SIGCHLD handler

Without this, code interrupted by SIGCHLD may experience strange
values of errno.  (As far as I know this is not the cause of any
reported bugs.)

This fix should be backported in due course.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
QEMU_TAG update
common/vsprintf: fix signed->unsigned error, causing glacial performance

The original patch for

  c/s 67a3542c5bc356e6452d8305991617c875f87de4
  "common/vsprintf: Refactor string() out of vsnprintf()"

specifically used signed integers, identical to the code copied out of vsprintf.

When committed, these had changed to unsigned integers, which causes a
functional change.  This causes glacial boot performance and an excessive
quantity of spaces printed to the serial console, as we loop to the upper
bound of a 32bit integer.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
libxl: Introduce nested async operations (nested ao)

This allows a long-running ao to avoid accumulating memory.  Each
nested ao has its own gc.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Tested-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
libxl: Do not generate short block in libxl__datacopier_prefixdata

libxl__datacopier_prefixdata would prepend a deliberately short block
(not just a half-full one, but one with a short buffer) to the
dc->bufs queue.  However, this is wrong because datacopier_readable
will find it and try to continue to fill it up.

Instead, allocate a full-sized buffer.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Tested-by: Chunyan Liu <cyliu@suse.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
libxl: Deprecate synchronous waiting for the device model

libxl__wait_for_device_model blocks, with the ctx lock held, waiting
for a response from the device model.  If the dm doesn't respond
quickly (for example, because it has crashed), this may block the
whole process.  Explain this in a comment, rename the function to
libxl__wait_for_device_model_deprecated, and explain what to use
instead.

libxl__wait_for_offspring is the core implementation for the above.
Its name leads people to think it might be generally useful for
waiting for children, which is far from the case.  It only waits for
xenstore.  Also it has the problems described above.  Explain this,
rename it to libxl__xenstore_child_wait_deprecated, and explain what
to use instead.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
libxl: Avoid realloc(,0) when libxl__xs_directory returns empty list

If the named path is a leaf node, libxl__xs_directory can succeed,
returning non-null, but set *nb to 0.

In three places in libxl this may result in a zero size argument being
passed to malloc() or realloc(), which is not adviseable.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
VMX: allow vmx_update_debug_state to be called when v!=current

Removing the assert allows the PVH code to call this during vmcs
construction in a later patch, making the code more robust by removing
duplicate code.

Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Acked-by: Tim Deegan <tim@xen.org>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
Acked-by: Eddie Dong <eddie.dong@intel.com>
libxc: move temporary grant table mapping to end of memory

In order to set up the grant table for HVM guests, libxc needs to map
the grant table temporarily.  At the moment, it does this by adding the
grant page to the HVM guest's p2m table in the MMIO hole (at gfn 0xFFFFE),
then mapping that gfn, setting up the table, then unmapping the gfn and
removing it from the p2m table.

This breaks with PVH guests with 4G or more of ram, because there is
no MMIO hole; so it ends up clobbering a valid RAM p2m entry, then
leaving a "hole" when it removes the grant map from the p2m table.
Since the guest thinks this is normal ram, when it maps it and tries
to access the page, it crashes.

This patch maps the page at max_gfn+1 instead.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Tim Deegan <tim@xen.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Keir Fraser <keir@xen.org>
Acked-by: Eddie Dong <eddie.dong@intel.com>
pvh prep: code motion

There are many functions where PVH requires some code in common with
HVM.  Rearrange some of these functions so that the code is together.

In general, the HVM code that PVH also uses includes:
 - cacheattr functionality
 - paging
 - hvm_funcs
 - hvm_assert_evtchn_irq tasklet
 - tm_list
 - hvm_params

And code that PVH shares with PV but not with PVH:
 - updating the domain wallclock
 - setting v->is_initialized

There should be no end-to-end changes in behavior.

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Acked-by: Tim Deegan <tim@xen.org>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
Acked-by: Eddie Dong <eddie.dong@intel.com>
pvh: tolerate HVM guests having no ioreq page

PVH guests don't have a backing device model emulator (qemu); just
tolerate this situation explicitly, rather than special-casing PVH.

For unhandled IO, hvmemul_do_io() will now return X86EMUL_OKAY, which
is I believe what would be the effect if qemu didn't have a handler
for the IO.

This also fixes a potetial DoS in the host from the reworked series:
If the guest makes a hypercall which sends an invalidate request, it
would have crashed the host.

Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
Acked-by: Eddie Dong <eddie.dong@intel.com>
pvh prep: introduce pv guest type and has_hvm_container macros

The goal of this patch is to classify conditionals more clearly, as to
whether they relate to pv guests, hvm-only guests, or guests with an
"hvm container" (which will eventually include PVH).

This patch introduces an enum for guest type, as well as two new macros
for switching behavior on and off: is_pv_* and has_hvm_container_*.  At the
moment is_pv_* <=> !has_hvm_container_*.  The purpose of having two is that
it seems to me different to take a path because something does *not* have PV
structures as to take a path because it *does* have HVM structures, even if the
two happen to coincide 100% at the moment.  The exact usage is occasionally a bit
fuzzy though, and a judgement call just needs to be made on which is clearer.

In general, a switch should use is_pv_* (or !is_pv_*) if the code in question
relates directly to a PV guest.  Examples include use of pv_vcpu structs or
other behavior directly related to PV domains.

hvm_container is more of a fuzzy concept, but in general:

* Most core HVM behavior will be included in this.  Behavior not
appropriate for PVH mode will be disabled in later patches

* Hypercalls related to HVM guests will *not* be included by default;
functionality needed by PVH guests will be enabled in future patches

* The following functionality are not considered part of the HVM
container, and PVH will end up behaving like PV by default: Event
channel, vtsc offset, code related to emulated timers, nested HVM,
emuirq, PoD

* Some features are left to implement for PVH later: vpmu, shadow mode

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Acked-by: Tim Deegan <tim@xen.org>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
Acked-by: Eddie Dong <eddie.dong@intel.com>
pvh: introduce PVH guest type

Introduce new PVH guest type, flags to create it, and ways to identify it.

To begin with, it will inherit functionality marked hvm_container.

Code to actually check for hardware support, in the VMX case, will be added
in future patches.

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
Acked-by: Eddie Dong <eddie.dong@intel.com>
pvh: disable unneeded features of HVM containers

Things kept:
* cacheattr_region lists
* irq-related structures
* paging
* tm_list
* hvm params
* hvm_domaim.io_handler (for handling PV io)

Things disabled for now:
* compat xlation

Things disabled:
* Emulated timers and clock sources
* IO/MMIO ioreq pages, event channels
* msix tables
* hvm_funcs
* nested HVM
* Fast-path for emulated lapic accesses

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
Acked-by: Eddie Dong <eddie.dong@intel.com>
pvh: vmx-specific changes

Changes:
* Enforce HAP mode for now
* Disable exits related to virtual interrupts or emulated APICs
* Disable changing paging mode
 - "unrestricted guest" (i.e., real mode for EPT) disabled
 - write guest EFER disabled
* Start in 64-bit mode
* Paging mode update to happen in arch_set_info_guest

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
Acked-by: Eddie Dong <eddie.dong@intel.com>
pvh: do not allow PVH guests to change paging modes

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>
Acked-by: Eddie Dong <eddie.dong@intel.com>
pvh: access to hypercalls

Hypercalls where we now have unrestricted access:
* memory_op
* console_io
* vcpu_op
* mmuext_op

We also restrict PVH domain access to HVMOP_*_param to reading and
writing HVM_PARAM_CALLBACK_IRQ.

Most hvm_op functions require "is_hvm_domain()" and will default to
-EINVAL; exceptions are HVMOP_get_time and HVMOP_xentrace.

Finally, we restrict setting IOPL permissions for a PVH domain.

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Acked-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>
Acked-by: Eddie Dong <eddie.dong@intel.com>
pvh: use PV e820

Allow PV e820 map to be set and read from a PVH domain.  This requires
moving the pv e820 struct out from the pv-specific domain struct and
into the arch domain struct.

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Keir Fraser <keir@xen.org>
Acked-by: Eddie Dong <eddie.dong@intel.com>
pvh: set up more PV stuff in set_info_guest

Allow the guest to set up a few more things when bringing up a vcpu.

This includes cr3 and gs_base.

Also set up wallclock, and only initialize a vcpu once.

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
Acked-by: Eddie Dong <eddie.dong@intel.com>