Commit Graph

12 Commits

Author SHA1 Message Date
Gavin Shan b8f02af096 vfio/pci: Restore MSIx message prior to enabling
The MSIx vector table lives in device memory, which may be cleared as
part of a backdoor device reset. This is the case on the IBM IPR HBA
when the BIST is run on the device. When assigned to a QEMU guest,
the guest driver does a pci_save_state(), issues a BIST, then does a
pci_restore_state(). The BIST clears the MSIx vector table, but due
to the way interrupts are configured the pci_restore_state() does not
restore the vector table as expected. Eventually this results in an
EEH error on Power platforms when the device attempts to signal an
interrupt with the zero'd table entry.

Fix the problem by restoring the host cached MSI message prior to
enabling each vector.

Reported-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2014-09-29 10:16:24 -06:00
Alexander Gordeev 94cccde648 vfio: Use pci_enable_msi_range() and pci_enable_msix_range()
pci_enable_msix() and pci_enable_msi_block() have been deprecated; use
pci_enable_msix_range() and pci_enable_msi_range() instead.

[bhelgaas: changelog]
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
2014-02-14 14:23:40 -07:00
Alex Williamson 3be3a074cf vfio-pci: Don't use device_lock around AER interrupt setup
device_lock is much too prone to lockups.  For instance if we have a
pending .remove then device_lock is already held.  If userspace
attempts to modify AER signaling after that point, a deadlock occurs.
eventfd setup/teardown is already protected in vfio with the igate
mutex.  AER is not a high performance interrupt, so we can also use
the same mutex to protect signaling versus setup races.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2014-01-14 16:12:55 -07:00
Alex Williamson 20e7745784 vfio-pci: Use fdget() rather than eventfd_fget()
eventfd_fget() tests to see whether the file is an eventfd file, which
we then immediately pass to eventfd_ctx_fileget(), which again tests
whether the file is an eventfd file.  Simplify slightly by using
fdget() so that we only test that we're looking at an eventfd once.
fget() could also be used, but fdget() makes use of fget_light() for
another slight optimization.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-08-28 09:49:55 -06:00
Linus Torvalds 0b2e3b6bb4 vfio updates for v3.10
Changes include extension to support PCI AER notification to userspace, byte granularity of PCI config space and access to unarchitected PCI config space, better protection around IOMMU driver accesses, default file mode fix, and a few misc cleanups.
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Merge tag 'vfio-for-v3.10' of git://github.com/awilliam/linux-vfio

Pull vfio updates from Alex Williamson:
 "Changes include extension to support PCI AER notification to
  userspace, byte granularity of PCI config space and access to
  unarchitected PCI config space, better protection around IOMMU driver
  accesses, default file mode fix, and a few misc cleanups."

* tag 'vfio-for-v3.10' of git://github.com/awilliam/linux-vfio:
  vfio: Set container device mode
  vfio: Use down_reads to protect iommu disconnects
  vfio: Convert container->group_lock to rwsem
  PCI/VFIO: use pcie_flags_reg instead of access PCI-E Capabilities Register
  vfio-pci: Enable raw access to unassigned config space
  vfio-pci: Use byte granularity in config map
  vfio: make local function vfio_pci_intx_unmask_handler() static
  VFIO-AER: Vfio-pci driver changes for supporting AER
  VFIO: Wrapper for getting reference to vfio_device
2013-05-02 14:02:32 -07:00
Wei Yongjun 0bced2f728 vfio: make local function vfio_pci_intx_unmask_handler() static
vfio_pci_intx_unmask_handler() was not declared. It should be static.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-03-25 11:15:44 -06:00
Arnd Bergmann 25e9789ddd vfio: include <linux/slab.h> for kmalloc
The vfio drivers call kmalloc or kzalloc, but do not
include <linux/slab.h>, which causes build errors on
ARM.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Cc: kvm@vger.kernel.org
2013-03-15 12:58:20 -06:00
Vijay Mohan Pandarathil dad9f8972e VFIO-AER: Vfio-pci driver changes for supporting AER
- New VFIO_SET_IRQ ioctl option to pass the eventfd that is signaled when
  an error occurs in the vfio_pci_device

- Register pci_error_handler for the vfio_pci driver

- When the device encounters an error, the error handler registered by
  the vfio_pci driver gets invoked by the AER infrastructure

- In the error handler, signal the eventfd registered for the device.

- This results in the qemu eventfd handler getting invoked and
  appropriate action taken for the guest.

Signed-off-by: Vijay Mohan Pandarathil <vijaymohan.pandarathil@hp.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-03-11 09:31:22 -06:00
Alex Williamson 899649b7d4 vfio: Fix PCI INTx disable consistency
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: Alex Williamson <alex.williamson@redhat.com>
2012-10-10 09:10:32 -06:00
Alex Williamson 9dbdfd23b7 vfio: Move PCI INTx eventfd setting earlier
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: Alex Williamson <alex.williamson@redhat.com>
2012-10-10 09:10:32 -06:00
Alex Williamson b68e7fa879 vfio: Fix virqfd release race
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: Alex Williamson <alex.williamson@redhat.com>
2012-09-21 10:48:28 -06:00
Alex Williamson 89e1f7d4c6 vfio: Add PCI device driver
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: Alex Williamson <alex.williamson@redhat.com>
2012-07-31 08:16:24 -06:00