With vIOMMU, IO virtual address range can get unmapped while in pre-copy phase
of migration. In that case, unmap ioctl should return pages pinned in that range
and QEMU should find its correcponding guest physical addresses and report
those dirty.
Note: This patch is not yet tested. I'm trying to see how I can test this code
path.
Suggested-by: Alex Williamson <alex.william...@redhat.com>
Signed-off-by: Kirti Wankhede <kwankh...@nvidia.com>
Reviewed-by: Neo Jia <c...@nvidia.com>
---
hw/vfio/common.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 61 insertions(+), 4 deletions(-)
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 66f1c64bf074..dc5768219d44 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -311,11 +311,30 @@ static bool vfio_devices_are_stopped_and_saving(void)
return true;
}
+static bool vfio_devices_are_running_and_saving(void)
+{
+ VFIOGroup *group;
+ VFIODevice *vbasedev;
+
+ QLIST_FOREACH(group, &vfio_group_list, next) {
+ QLIST_FOREACH(vbasedev, &group->device_list, next) {
+ if ((vbasedev->device_state & VFIO_DEVICE_STATE_SAVING) &&
+ (vbasedev->device_state & VFIO_DEVICE_STATE_RUNNING)) {
+ continue;
+ } else {
+ return false;
+ }
+ }
+ }
+ return true;
+}
+
/*
* DMA - Mapping and unmapping for the "type1" IOMMU interface used on x86
*/
static int vfio_dma_unmap(VFIOContainer *container,
- hwaddr iova, ram_addr_t size)
+ hwaddr iova, ram_addr_t size,
+ VFIOGuestIOMMU *giommu)
{
struct vfio_iommu_type1_dma_unmap unmap = {
.argsz = sizeof(unmap),
@@ -324,6 +343,44 @@ static int vfio_dma_unmap(VFIOContainer *container,
.size = size,
};
+ if (giommu && vfio_devices_are_running_and_saving()) {
+ int ret;
+ uint64_t bitmap_size;
+ struct vfio_iommu_type1_dma_unmap_bitmap unmap_bitmap = {
+ .argsz = sizeof(unmap_bitmap),
+ .flags = VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP,
+ .iova = iova,
+ .size = size,
+ };
+
+ bitmap_size = BITS_TO_LONGS(size >> TARGET_PAGE_BITS) *
+ sizeof(uint64_t);
+
+ unmap_bitmap.bitmap = g_try_malloc0(bitmap_size);
+ if (!unmap_bitmap.bitmap) {
+ error_report("%s: Error allocating bitmap buffer of size 0x%lx",
+ __func__, bitmap_size);
+ return -ENOMEM;
+ }
+
+ unmap_bitmap.bitmap_size = bitmap_size;
+
+ ret = ioctl(container->fd, VFIO_IOMMU_UNMAP_DMA_GET_BITMAP,
+ &unmap_bitmap);
+
+ if (!ret) {
+ cpu_physical_memory_set_dirty_lebitmap(
+ (uint64_t *)unmap_bitmap.bitmap,
+ giommu->iommu_offset + giommu->n.start,
+ bitmap_size >> TARGET_PAGE_BITS);
+ } else {
+ error_report("VFIO_IOMMU_GET_DIRTY_BITMAP: %d %d", ret, errno);
+ }
+
+ g_free(unmap_bitmap.bitmap);
+ return ret;
+ }
+
while (ioctl(container->fd, VFIO_IOMMU_UNMAP_DMA, &unmap)) {
/*
* The type1 backend has an off-by-one bug in the kernel (71a7d3d78e3c
@@ -371,7 +428,7 @@ static int vfio_dma_map(VFIOContainer *container, hwaddr
iova,
* the VGA ROM space.
*/
if (ioctl(container->fd, VFIO_IOMMU_MAP_DMA, &map) == 0 ||
- (errno == EBUSY && vfio_dma_unmap(container, iova, size) == 0 &&
+ (errno == EBUSY && vfio_dma_unmap(container, iova, size, NULL) == 0 &&
ioctl(container->fd, VFIO_IOMMU_MAP_DMA, &map) == 0)) {
return 0;
}
@@ -511,7 +568,7 @@ static void vfio_iommu_map_notify(IOMMUNotifier *n,
IOMMUTLBEntry *iotlb)
iotlb->addr_mask + 1, vaddr, ret);
}
} else {
- ret = vfio_dma_unmap(container, iova, iotlb->addr_mask + 1);
+ ret = vfio_dma_unmap(container, iova, iotlb->addr_mask + 1, giommu);
if (ret) {
error_report("vfio_dma_unmap(%p, 0x%"HWADDR_PRIx", "
"0x%"HWADDR_PRIx") = %d (%m)",
@@ -814,7 +871,7 @@ static void vfio_listener_region_del(MemoryListener
*listener,
}
if (try_unmap) {
- ret = vfio_dma_unmap(container, iova, int128_get64(llsize));
+ ret = vfio_dma_unmap(container, iova, int128_get64(llsize), NULL);
if (ret) {
error_report("vfio_dma_unmap(%p, 0x%"HWADDR_PRIx", "
"0x%"HWADDR_PRIx") = %d (%m)",
--
2.7.0
