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vfio: Add ioctl to get dirty pages bitmap during dma unmap

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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.

Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Neo Jia <cjia@nvidia.com>
[aw: fix error_report types, fix cpu_physical_memory_set_dirty_lebitmap() cast]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This commit is contained in:
Kirti Wankhede 2020-10-26 15:06:25 +05:30 committed by Alex Williamson
parent 9a04fe0957
commit 9e7b0442f2
1 changed files with 93 additions and 4 deletions
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97
hw/vfio/common.c
View File

@ -321,11 +321,95 @@ static bool vfio_devices_all_stopped_and_saving(VFIOContainer *container)
return true;
}
static bool vfio_devices_all_running_and_saving(VFIOContainer *container)
{
VFIOGroup *group;
VFIODevice *vbasedev;
MigrationState *ms = migrate_get_current();
if (!migration_is_setup_or_active(ms->state)) {
return false;
}
QLIST_FOREACH(group, &container->group_list, container_next) {
QLIST_FOREACH(vbasedev, &group->device_list, next) {
VFIOMigration *migration = vbasedev->migration;
if (!migration) {
return false;
}
if ((migration->device_state & VFIO_DEVICE_STATE_SAVING) &&
(migration->device_state & VFIO_DEVICE_STATE_RUNNING)) {
continue;
} else {
return false;
}
}
}
return true;
}
static int vfio_dma_unmap_bitmap(VFIOContainer *container,
hwaddr iova, ram_addr_t size,
IOMMUTLBEntry *iotlb)
{
struct vfio_iommu_type1_dma_unmap *unmap;
struct vfio_bitmap *bitmap;
uint64_t pages = TARGET_PAGE_ALIGN(size) >> TARGET_PAGE_BITS;
int ret;
unmap = g_malloc0(sizeof(*unmap) + sizeof(*bitmap));
unmap->argsz = sizeof(*unmap) + sizeof(*bitmap);
unmap->iova = iova;
unmap->size = size;
unmap->flags |= VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP;
bitmap = (struct vfio_bitmap *)&unmap->data;
/*
* cpu_physical_memory_set_dirty_lebitmap() expects pages in bitmap of
* TARGET_PAGE_SIZE to mark those dirty. Hence set bitmap_pgsize to
* TARGET_PAGE_SIZE.
*/
bitmap->pgsize = TARGET_PAGE_SIZE;
bitmap->size = ROUND_UP(pages, sizeof(__u64) * BITS_PER_BYTE) /
BITS_PER_BYTE;
if (bitmap->size > container->max_dirty_bitmap_size) {
error_report("UNMAP: Size of bitmap too big 0x%"PRIx64,
(uint64_t)bitmap->size);
ret = -E2BIG;
goto unmap_exit;
}
bitmap->data = g_try_malloc0(bitmap->size);
if (!bitmap->data) {
ret = -ENOMEM;
goto unmap_exit;
}
ret = ioctl(container->fd, VFIO_IOMMU_UNMAP_DMA, unmap);
if (!ret) {
cpu_physical_memory_set_dirty_lebitmap((unsigned long *)bitmap->data,
iotlb->translated_addr, pages);
} else {
error_report("VFIO_UNMAP_DMA with DIRTY_BITMAP : %m");
}
g_free(bitmap->data);
unmap_exit:
g_free(unmap);
return ret;
}
/*
* 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,
IOMMUTLBEntry *iotlb)
{
struct vfio_iommu_type1_dma_unmap unmap = {
.argsz = sizeof(unmap),
@ -334,6 +418,11 @@ static int vfio_dma_unmap(VFIOContainer *container,
.size = size,
};
if (iotlb && container->dirty_pages_supported &&
vfio_devices_all_running_and_saving(container)) {
return vfio_dma_unmap_bitmap(container, iova, size, iotlb);
}
while (ioctl(container->fd, VFIO_IOMMU_UNMAP_DMA, &unmap)) {
/*
* The type1 backend has an off-by-one bug in the kernel (71a7d3d78e3c
@ -381,7 +470,7 @@ 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;
}
@ -531,7 +620,7 @@ 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, iotlb);
if (ret) {
error_report("vfio_dma_unmap(%p, 0x%"HWADDR_PRIx", "
"0x%"HWADDR_PRIx") = %d (%m)",
@ -834,7 +923,7 @@ 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)",