On Tue, 5 May 2020 04:14:51 +0530
Kirti Wankhede <kwankh...@nvidia.com> wrote:
> 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.
This remark should go beneath the '---' line, so that it does not end
up in the final commit.
>
> 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 | 79
> +++++++++++++++++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 75 insertions(+), 4 deletions(-)
>
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index 4277b275ca21..b94e2bcb1178 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -311,11 +311,77 @@ static bool vfio_devices_are_stopped_and_saving(void)
> return true;
> }
>
> +static bool vfio_devices_are_running_and_saving(void)
Maybe s/are/all/ to make it sure that the scope is *all* vfio devices
here?
Is there any global state for this which we could use to check this in
a simpler way?
> +{
> + 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;
> +}
> +
> +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));
g_malloc0 cannot fail (it will abort). If you want to be able to
tolerate memory allocation failure, you should use g_try_malloc0().
> + if (!unmap) {
> + return -ENOMEM;
> + }
> +
> + unmap->argsz = sizeof(*unmap) + sizeof(*bitmap);
> + 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 / 8, sizeof(uint64_t));
> + bitmap->data = g_malloc0(bitmap->size);
> + if (!bitmap->data) {
> + error_report("UNMAP: Error allocating bitmap of size 0x%llx",
> + bitmap->size);
> + g_free(unmap);
> + return -ENOMEM;
> + }
> +
> + ret = ioctl(container->fd, VFIO_IOMMU_UNMAP_DMA, unmap);
> + if (!ret) {
> + cpu_physical_memory_set_dirty_lebitmap((uint64_t *)bitmap->data,
> + iotlb->translated_addr, pages);
> + } else {
> + error_report("VFIO_UNMAP_DMA with DIRTY_BITMAP : %d", -errno);
> + }
> +
> + g_free(bitmap->data);
> + g_free(unmap);
> + return ret;
> +}
> +
