On 9/24/25 09:02, Zhenzhong Duan wrote:
VFIO type1 kernel uAPI supports unmapping whole address space in one call
since commit c19650995374 ("vfio/type1: implement unmap all"). use the
unmap_all variant whenever it's supported in kernel.
Signed-off-by: Zhenzhong Duan <[email protected]>
---
hw/vfio/container.c | 33 ++++++++++++++++++++-------------
1 file changed, 20 insertions(+), 13 deletions(-)
diff --git a/hw/vfio/container.c b/hw/vfio/container.c
index 030c6d3f89..2e13f04803 100644
--- a/hw/vfio/container.c
+++ b/hw/vfio/container.c
@@ -122,12 +122,12 @@ unmap_exit:
static int vfio_legacy_dma_unmap_one(const VFIOContainerBase *bcontainer,
Side note for rebase :
I would prefer internal routines of file hw/vfio/container.c,
which was renamed recently to hw/vfio/container-legacy.c, to
take a 'VFIOLegacyContainer *container' parameter.
The 'VFIOContainer *bcontainer' parameter should be kept for
high-level routines that wrap the IOMMU backend implementation.
hwaddr iova, ram_addr_t size,
- IOMMUTLBEntry *iotlb)
+ uint32_t flags, IOMMUTLBEntry *iotlb)
{
const VFIOContainer *container = VFIO_IOMMU_LEGACY(bcontainer);
struct vfio_iommu_type1_dma_unmap unmap = {
.argsz = sizeof(unmap),
- .flags = 0,
+ .flags = flags,
.iova = iova,> .size = size,
};
@@ -187,25 +187,32 @@ static int vfio_legacy_dma_unmap(const VFIOContainerBase
*bcontainer,
hwaddr iova, ram_addr_t size,
IOMMUTLBEntry *iotlb, bool unmap_all)
{
+ uint32_t flags = 0;
int ret;
if (unmap_all) {
- /* The unmap ioctl doesn't accept a full 64-bit span. */
- Int128 llsize = int128_rshift(int128_2_64(), 1);
+ const VFIOContainer *container = VFIO_IOMMU_LEGACY(bcontainer);
- ret = vfio_legacy_dma_unmap_one(bcontainer, 0, int128_get64(llsize),
- iotlb);
+ assert(!iova && !size);
The assert deserves an explanation and so probably a new patch.
- if (ret == 0) {
- ret = vfio_legacy_dma_unmap_one(bcontainer, int128_get64(llsize),
- int128_get64(llsize), iotlb);
- }
+ ret = ioctl(container->fd, VFIO_CHECK_EXTENSION, VFIO_UNMAP_ALL);
+ if (ret) {
+ flags = VFIO_DMA_UNMAP_FLAG_ALL;
+ } else {
+ /* The unmap ioctl doesn't accept a full 64-bit span. */
+ Int128 llsize = int128_rshift(int128_2_64(), 1);
+ size = int128_get64(llsize);
+
+ ret = vfio_legacy_dma_unmap_one(bcontainer, 0, size, flags, iotlb);
+ if (ret) {
+ return ret;
+ }
Could we introduce an helper to test 'unmap_all' support in the host
kernel ? The result would be something like :
if (unmap_all) {
if (vfio_legacy_has_unmap_all(VFIO_IOMMU_LEGACY(bcontainer))) {
flags = VFIO_DMA_UNMAP_FLAG_ALL;
} else {
/* The unmap ioctl doesn't accept a full 64-bit span. */
Int128 llsize = int128_rshift(int128_2_64(), 1);
...
}
}
Thanks,
C.
- } else {
- ret = vfio_legacy_dma_unmap_one(bcontainer, iova, size, iotlb);
+ iova = size;
+ }
}
- return ret;
+ return vfio_legacy_dma_unmap_one(bcontainer, iova, size, flags, iotlb);
}
static int vfio_legacy_dma_map(const VFIOContainerBase *bcontainer, hwaddr iova,
