On Tue, 28 Jul 2026 23:24:30 +0000 Josh Hilke <[email protected]> wrote:
> Add retry logic to vfio_pci_device_reset() to handle the case where PCI > resets fail due to lock contention, in which case > pci_try_reset_function() returns -EAGAIN. > > Suggested-by: David Matlack <[email protected]> > Signed-off-by: Josh Hilke <[email protected]> > --- > .../vfio/lib/include/libvfio/vfio_pci_device.h | 1 + > tools/testing/selftests/vfio/lib/vfio_pci_device.c | 17 > ++++++++++++++++- > 2 files changed, 17 insertions(+), 1 deletion(-) > > diff --git > a/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h > b/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h > index 2e67afc0d580..27bdf561925f 100644 > --- a/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h > +++ b/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h > @@ -41,6 +41,7 @@ struct vfio_pci_device { > struct vfio_pci_device *vfio_pci_device_init(const char *bdf, struct iommu > *iommu); > void vfio_pci_device_cleanup(struct vfio_pci_device *device); > > +int __vfio_pci_device_reset(struct vfio_pci_device *device); > void vfio_pci_device_reset(struct vfio_pci_device *device); > > void vfio_pci_config_access(struct vfio_pci_device *device, bool write, > diff --git a/tools/testing/selftests/vfio/lib/vfio_pci_device.c > b/tools/testing/selftests/vfio/lib/vfio_pci_device.c > index 7b8394d0ac50..1b29cef96b04 100644 > --- a/tools/testing/selftests/vfio/lib/vfio_pci_device.c > +++ b/tools/testing/selftests/vfio/lib/vfio_pci_device.c > @@ -1,5 +1,6 @@ > // SPDX-License-Identifier: GPL-2.0-only > #include <dirent.h> > +#include <errno.h> > #include <fcntl.h> > #include <libgen.h> > #include <stdint.h> > @@ -221,9 +222,23 @@ void vfio_pci_config_access(struct vfio_pci_device > *device, bool write, > write ? "write to" : "read from", config); > } > > +int __vfio_pci_device_reset(struct vfio_pci_device *device) > +{ > + if (ioctl(device->fd, VFIO_DEVICE_RESET, NULL)) > + return -errno; > + > + return 0; > +} > + > void vfio_pci_device_reset(struct vfio_pci_device *device) > { > - ioctl_assert(device->fd, VFIO_DEVICE_RESET, NULL); > + int r; > + > + do { > + r = __vfio_pci_device_reset(device); > + } while (r == -EAGAIN); > + > + VFIO_ASSERT_EQ(r, 0, "ioctl(device->fd, VFIO_DEVICE_RESET) failed\n"); > } This has roughly the same unbounded loop issue that Sashiko flagged waiting for the register level reset to complete, shouldn't we also introduce a retry cap here? A delay would also help bound that retry cap versus the instant retry here. Also, please rebase to linux-next to keep the driver inclusion consistent with the already merged nv_falcon driver (trivial) and unblock Sashiko from applying the series for review (more important). David's R-bs from v6 can also carry forward on the unmodified patches. Thanks, Alex
