Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH AUTOSEL 5.4 2/9] virtio_mmio: Restore guest page size on resume | Date | Wed, 6 Jul 2022 11:33:08 -0400 |
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From: Stephan Gerhold <stephan.gerhold@kernkonzept.com>
[ Upstream commit e0c2ce8217955537dd5434baeba061f209797119 ]
Virtio devices might lose their state when the VMM is restarted after a suspend to disk (hibernation) cycle. This means that the guest page size register must be restored for the virtio_mmio legacy interface, since otherwise the virtio queues are not functional.
This is particularly problematic for QEMU that currently still defaults to using the legacy interface for virtio_mmio. Write the guest page size register again in virtio_mmio_restore() to make legacy virtio_mmio devices work correctly after hibernation.
Signed-off-by: Stephan Gerhold <stephan.gerhold@kernkonzept.com> Message-Id: <20220621110621.3638025-3-stephan.gerhold@kernkonzept.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/virtio/virtio_mmio.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c index 2a2d817caeff..e781e5e9215f 100644 --- a/drivers/virtio/virtio_mmio.c +++ b/drivers/virtio/virtio_mmio.c @@ -527,6 +527,9 @@ static int virtio_mmio_restore(struct device *dev) { struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev); + if (vm_dev->version == 1) + writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE); + return virtio_device_restore(&vm_dev->vdev); } -- 2.35.1
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