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[Qemu-devel] [PATCH 03/11] vfio-pci: Unmap and retry DMA mapping
From: |
Alex Williamson |
Subject: |
[Qemu-devel] [PATCH 03/11] vfio-pci: Unmap and retry DMA mapping |
Date: |
Thu, 04 Oct 2012 16:17:52 -0600 |
User-agent: |
StGIT/0.14.3 |
Occasionally we get regions added that overlap with existing mappings.
These always seems to be in the VGA ROM range. VFIO returns EBUSY
for these mapping attempts. We can try a little harder and assume
that the latest mapping is correct by removing any overlapping ranges
and retrying the original request.
Signed-off-by: Alex Williamson <address@hidden>
---
hw/vfio_pci.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/hw/vfio_pci.c b/hw/vfio_pci.c
index 2d89d17..7413f2d 100644
--- a/hw/vfio_pci.c
+++ b/hw/vfio_pci.c
@@ -819,12 +819,19 @@ static int vfio_dma_map(VFIOContainer *container,
target_phys_addr_t iova,
map.flags |= VFIO_DMA_MAP_FLAG_WRITE;
}
- if (ioctl(container->fd, VFIO_IOMMU_MAP_DMA, &map)) {
- DPRINTF("VFIO_MAP_DMA: %d\n", -errno);
- return -errno;
+ /*
+ * Try the mapping, if it fails with EBUSY, unmap the region and try
+ * again. This shouldn't be necessary, but we sometimes see it in
+ * the the VGA ROM space.
+ */
+ if (ioctl(container->fd, VFIO_IOMMU_MAP_DMA, &map) == 0 ||
+ (errno == EBUSY && vfio_dma_unmap(container, iova, size) == 0 &&
+ ioctl(container->fd, VFIO_IOMMU_MAP_DMA, &map) == 0)) {
+ return 0;
}
- return 0;
+ DPRINTF("VFIO_MAP_DMA: %d\n", -errno);
+ return -errno;
}
static void vfio_listener_dummy1(MemoryListener *listener)
- [Qemu-devel] [PATCH 00/11] vfio-pci cleanup and fixes, Alex Williamson, 2012/10/04
- [Qemu-devel] [PATCH 01/11] vfio-pci: Update slow path INTx algorithm, Alex Williamson, 2012/10/04
- [Qemu-devel] [PATCH 02/11] vfio-pci: Re-order map/unmap, Alex Williamson, 2012/10/04
- [Qemu-devel] [PATCH 03/11] vfio-pci: Unmap and retry DMA mapping,
Alex Williamson <=
- [Qemu-devel] [PATCH 05/11] vfio-pci: No spurious MSIs, Alex Williamson, 2012/10/04
- [Qemu-devel] [PATCH 06/11] vfio-pci: Roll the header into the .c file, Alex Williamson, 2012/10/04
- [Qemu-devel] [PATCH 07/11] vfio-pci: Don't peak at msi_supported, Alex Williamson, 2012/10/04
- [Qemu-devel] [PATCH 11/11] vfio-pci: Cleanup on INTx setup failure, Alex Williamson, 2012/10/04
- [Qemu-devel] [PATCH 08/11] vfio-pci: Use uintptr_t for void* cast, Alex Williamson, 2012/10/04
- [Qemu-devel] [PATCH 10/11] vfio-pci: Extend reset, Alex Williamson, 2012/10/04
- [Qemu-devel] [PATCH 04/11] vfio-pci: Rework MSIX setup/teardown, Alex Williamson, 2012/10/04
- [Qemu-devel] [PATCH 09/11] vfio-pci: Remove setting of MSI qsize, Alex Williamson, 2012/10/04