kvm tools: pci: register virtio pba structure as mmio region with kvm

Despite allocating and providing code to handle accesses to the pba
structure, virtio msix blocks in fact only register the msix table with
kvm.

This patch fixes the MMIO region so that it includes the pba structure
for msix io blocks of virtio pci devices. The corresponding BAR is also
updated to advertise the full size of the io block.

Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
kvm tools: pci: remove BAR 3 hangover from virtio pci msix code

Despite not being used anymore, there are still traces of BAR 3 in both
the code and comments for the virtio pci msix implementation.

This patch removes the redundant code and fixes up the comments to match
what we're actually doing.

Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
kvm tools: net: don't propagate error codes from tx/rx operations

Currently, if a ->tx or ->rx callback into the net_dev_operations
encounters an error, it returns -1 to the virtio-net code, which in turn
treats this as an unsigned (size_t) size describing the data available.
The resulting memcpy operation then quickly explodes with a SEGV.

This patch detects the error code from the low-level callbacks and
exits the thread dealing with the erroneous queue.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
kvm tools: net: allow a mixture of pci and mmio virtio devices

When attempting to initialise a mixture of pci and mmio virtio devices,
we cannot share an ops structure, otherwise the transport-specific
fields (init/exit and signal handling) will be globally set to the
transport of the last registered device.

This patch dynamically allocates a new ops structure for each instance
of a virtio net device.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
kvm tools: pci: register 24-bit configuration space below MMIO region

Rather than performing all config accesses via ioports, map in a 24-bit
memory-mapped configuration space directly below the PCI MMIO region.

This will allow architectures to support PCI without having to support
legacy ioports in the guest kernel. Instead, kvm tool can forward the
config accesses directly to the relevant ioport config callbacks.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
kvm tools: pci: ensure BARs are naturally aligned

BARs must be naturally aligned, so enforce this in the PCI IO space
allocator.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
kvm tools: pci: add MMIO interface to virtio-pci devices

This patch adds an MMIO interface for each virtio-pci device, so that
they can be accessed without having to use an ioport. For each device, a
new memory BAR is added which corresponds to an area of MMIO space with
a shim trap handler. This handler simply translates the access into an
ioport access via kvm__emulate_io. Since guests can generate accesses
via either the ioport or MMIO regions, an ioeventfd is registered for
both.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
kvm tools: irq: remove pin parameter from irq__register_device

In preparation for moving the irq allocation into generic code, remove
the pin parameter from irq__register_device and temporarily place the
onus on the emulation driver to allocate the pin (which is always 1 and
only used on PCI anyway).

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
kvm tools: irq: replace the x86 irq rbtree with the PCI device tree

The x86 code keeps its own rbtree of PCI devices in order to allocate
interrupts. However, this functionality can be moved into the generic
PCI device tree and be reused by other architectures.

This patch removes the x86 tree and reworks the ACPI mptable generation
to use the PCI device tree for enumerating the bus.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
kvm tools: irq: remove remaining parameters to irq__register_device

With the removal of the x86 irq rbtree, the only parameter used by
irq__register_device is actually used to return the new line.

This patch removes all of the parameters from irq__register_device and
returns the allocated line directly.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
kvm tools: irq: rename irq__register_device to irq__alloc_line

Since irq__register_device no longer registers a device with anything,
rename it to irq__alloc_line, which better describes what is actually
going on.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
kvm tools: irq: make irq__alloc_line generic

All architectures are now doing the same thing for irq__alloc_line:

  1. Initialise a global counter to some fixed offset
  2. Return the current value of the counter and increment it

This is better off in core code, with each architecture specifying the
initial offset, which is specific to the interrupt controller being used
by the guest.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
kvm tools: irq: move irq line allocation into device registration

For the MMIO and PCI buses, drivers typically allocate an IRQ line for
their device before registering the device with the device tree for the
relevant bus.

This patch moves the IRQ allocation into the bus code, which is then
called directly by the device tree when a new device is registered.
IOPORT devices, however, tend to use hardcoded IRQs for legacy reasons,
so they are still required to deal with their interrupts (which also
require remapping for non-x86 architectures).

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
kvm tools: ARM: route guest PCI accesses to the emulation layer

This patch routes guest PCI accesses to kvm__emulate_mmio, rather than
exiting lkvm via a die invocation. The guest command-line is also
updated to prevent the guest from attempting to program the BARs with
new addresses (i.e. probe-only).

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
kvm tools: ARM: generate an fdt node for our PCI emulation

This patch factors out some of the openfirmware PCI binding definitions
from the powerpc spapr PCI code and uses them to generate appropriate
FDT properties for the PCI node on ARM.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
kvm tools: powerpc: make use of common of_pci.h header definitions

Now that we have some common OF PCI definitions in of_pci.h, make use
of them when generating the devicetree for spapr_pci on ppc.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
kvm tools: ARM: allow default virtio transport to be passed on cmdline

This patch changes VIRTIO_DEFAULT_TRANS to take a struct kvm parameter,
allowing architectures to choose the default transport dynamically.

For ARM, this is driven by an arch-specific cmdline option.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>