mirror of
https://github.com/qemu/qemu.git
synced 2026-07-08 17:46:10 +00:00
6d4d9b69de
Add a qtest for AMD IOMMU command buffer head pointer wraparound.
The test programs a command buffer, fills it with COMPLETION_WAIT commands,
advances the tail to consume all but the final entry, then wraps the tail
to zero to force the final command to advance CmdHeadPtr past the end of
the buffer. The guest-visible CmdHeadPtr register must then wrap back to zero.
This covers the case fixed by an earlier CmdHeadPtr wraparound patch.
The Linux kernel AMD IOMMU driver is not affected by this bug because it
uses COMPLETION_WAIT with a memory store doorbell to detect command progress.
Signed-off-by: Costas Argyris <costas.argyris@amd.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20260530183458.7778-1-costas.argyris@amd.com>
(cherry picked from commit 8a1c09cbd3)
(Mjt: context fixup in MAINTAINERS)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>