The read and write functions are nearly identical, combine them
and convert to a switch statement.  This also makes it easy to
narrow the scope of when we use the io/mem accessors in case new
regions are added.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Even PCIe 1.x had extended config space.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

A read from a range hidden from the user (ex. MSI-X vector table)
attempts to fill the user buffer up to the end of the excluded range
instead of up to the requested count.  Fix it.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Cc: stable@vger.kernel.org

Devices making use of PM reset are getting incorrectly identified as
not supporting reset because pci_pm_reset() fails unless the device is
in D0 power state.  When first attached to vfio_pci devices are
typically in an unknown power state.  We can fix this by explicitly
setting the power state or simply calling pci_enable_device() before
attempting a pci_reset_function().  We need to enable the device
anyway, so move this up in our vfio_pci_enable() function, which also
simplifies the error path a bit.

Note that pci_disable_device() does not explicitly set the power
state, so there's no need to re-order vfio_pci_disable().
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

The two labels for error recovery in function vfio_pci_init() is out of
order, so fix it.
Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Move the device reset to the end of our disable path, the device
should already be stopped from pci_disable_device().  This also allows
us to manipulate the save/restore to avoid the save/reset/restore +
save/restore that we had before.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Generated by: coccinelle/api/memdup_user.cocci
Acked-by: NJulia Lawall <julia.lawall@lip6.fr>
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

The virq_disabled flag tracks the userspace view of INTx masking
across interrupt mode changes, but we're not consistently applying
this to the interrupt and masking handler notion of the device.
Currently if the user sets DisINTx while in MSI or MSIX mode, then
returns to INTx mode (ex. rebooting a qemu guest), the hardware has
DisINTx+, but the management of INTx thinks it's enabled, making it
impossible to actually clear DisINTx.  Fix this by updating the
handler state when INTx is re-enabled.

Cc: stable@vger.kernel.org
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

We need to be ready to recieve an interrupt as soon as we call
request_irq, so our eventfd context setting needs to be moved
earlier.  Without this, an interrupt from our device or one
sharing the interrupt line can pass a NULL into eventfd_signal
and oops.

Cc: stable@vger.kernel.org
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Our mmap path mistakely relied on vma->vm_pgoff to get set in
remap_pfn_range.  After b3b9c293, that path only applies to
copy-on-write mappings.  Set it in our own code.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

The VM_RESERVED flag was killed off in commit 314e51b9 ("mm: kill
vma flag VM_RESERVED and mm->reserved_vm counter"), and replaced by the
proper semantic flags (eg "don't core-dump" etc).  But there was a new
use of VM_RESERVED that got missed by the merge.

Fix the remaining use of VM_RESERVED in the vfio_pci driver, replacing
the VM_RESERVED flag with VM_DONTEXPAND | VM_DONTDUMP.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation,org>

vfoi-pci supports a mechanism like KVM's irqfd for unmasking an
interrupt through an eventfd.  There are two ways to shutdown this
interface: 1) close the eventfd, 2) ioctl (such as disabling the
interrupt).  Both of these do the release through a workqueue,
which can result in a segfault if two jobs get queued for the same
virqfd.

Fix this by protecting the pointer to these virqfds by a spinlock.
The vfio pci device will therefore no longer have a reference to it
once the release job is queued under lock.  On the ioctl side, we
still flush the workqueue to ensure that any outstanding releases
are completed.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Add PCI device support for VFIO.  PCI devices expose regions
for accessing config space, I/O port space, and MMIO areas
of the device.  PCI config access is virtualized in the kernel,
allowing us to ensure the integrity of the system, by preventing
various accesses while reducing duplicate support across various
userspace drivers.  I/O port supports read/write access while
MMIO also supports mmap of sufficiently sized regions.  Support
for INTx, MSI, and MSI-X interrupts are provided using eventfds to
userspace.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>