diff options
| author | Alex Williamson <alex.williamson@redhat.com> | 2019-02-09 13:43:30 -0700 |
|---|---|---|
| committer | Alex Williamson <alex.williamson@redhat.com> | 2019-02-18 14:55:53 -0700 |
| commit | 51ef3a004b1eb6241e56b3aa8495769a092a4dc2 (patch) | |
| tree | efbec861a722c7ab01af18d246e286e45f4bb0a8 /drivers/vfio/pci/vfio_pci_private.h | |
| parent | a3906855890d94736d240f0f637585c1470d8d02 (diff) | |
| download | linux-51ef3a004b1eb6241e56b3aa8495769a092a4dc2.tar.bz2 | |
vfio/pci: Restore device state on PM transition
PCI core handles save and restore of device state around reset, but
when using pci_set_power_state() we can unintentionally trigger a soft
reset of the device, where PCI core only restores the BAR state. If
we're using vfio-pci's idle D3 support to try to put devices into low
power when unused, this might trigger a reset when the device is woken
for use. Also power state management by the user, or within a guest,
can put the device into D3 power state with potentially limited
ability to restore the device if it should undergo a reset. The PCI
spec does not define the extent of a soft reset and many devices
reporting soft reset on D3->D0 transition do not undergo a PCI config
space reset. It's therefore assumed safe to unconditionally restore
the remainder of the state if the device indicates soft reset
support, even on a user initiated wakeup.
Implement a wrapper in vfio-pci to tag devices reporting PM reset
support, save their state on transitions into D3 and restore on
transitions back to D0.
Reported-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/vfio/pci/vfio_pci_private.h')
| -rw-r--r-- | drivers/vfio/pci/vfio_pci_private.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h index 8c0009f00818..1812cf22fc4f 100644 --- a/drivers/vfio/pci/vfio_pci_private.h +++ b/drivers/vfio/pci/vfio_pci_private.h @@ -114,7 +114,9 @@ struct vfio_pci_device { bool has_vga; bool needs_reset; bool nointx; + bool needs_pm_restore; struct pci_saved_state *pci_saved_state; + struct pci_saved_state *pm_save; struct vfio_pci_reflck *reflck; int refcnt; int ioeventfds_nr; @@ -161,6 +163,10 @@ extern int vfio_pci_register_dev_region(struct vfio_pci_device *vdev, unsigned int type, unsigned int subtype, const struct vfio_pci_regops *ops, size_t size, u32 flags, void *data); + +extern int vfio_pci_set_power_state(struct vfio_pci_device *vdev, + pci_power_t state); + #ifdef CONFIG_VFIO_PCI_IGD extern int vfio_pci_igd_init(struct vfio_pci_device *vdev); #else |