On Thu, 22 Oct 2020 16:42:04 +0530
Kirti Wankhede <kwankh...@nvidia.com> wrote:
> When vIOMMU is enabled, register MAP notifier from log_sync when all
> devices in container are in stop and copy phase of migration. Call replay
> and get dirty pages from notifier callback.
>
> Suggested-by: Alex Williamson <alex.william...@redhat.com>
> Signed-off-by: Kirti Wankhede <kwankh...@nvidia.com>
> ---
> hw/vfio/common.c | 95
> ++++++++++++++++++++++++++++++++++++++++---
> hw/vfio/trace-events | 1 +
> include/hw/vfio/vfio-common.h | 1 +
> 3 files changed, 91 insertions(+), 6 deletions(-)
>
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index 2634387df948..98c2b1f9b190 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -442,8 +442,8 @@ static bool
> vfio_listener_skipped_section(MemoryRegionSection *section)
> }
>
> /* Called with rcu_read_lock held. */
> -static bool vfio_get_vaddr(IOMMUTLBEntry *iotlb, void **vaddr,
> - bool *read_only)
> +static bool vfio_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr,
> + ram_addr_t *ram_addr, bool *read_only)
> {
> MemoryRegion *mr;
> hwaddr xlat;
> @@ -474,8 +474,17 @@ static bool vfio_get_vaddr(IOMMUTLBEntry *iotlb, void
> **vaddr,
> return false;
> }
>
> - *vaddr = memory_region_get_ram_ptr(mr) + xlat;
> - *read_only = !writable || mr->readonly;
> + if (vaddr) {
> + *vaddr = memory_region_get_ram_ptr(mr) + xlat;
> + }
> +
> + if (ram_addr) {
> + *ram_addr = memory_region_get_ram_addr(mr) + xlat;
> + }
> +
> + if (read_only) {
> + *read_only = !writable || mr->readonly;
> + }
>
> return true;
> }
> @@ -485,7 +494,6 @@ static void vfio_iommu_map_notify(IOMMUNotifier *n,
> IOMMUTLBEntry *iotlb)
> VFIOGuestIOMMU *giommu = container_of(n, VFIOGuestIOMMU, n);
> VFIOContainer *container = giommu->container;
> hwaddr iova = iotlb->iova + giommu->iommu_offset;
> - bool read_only;
> void *vaddr;
> int ret;
>
> @@ -501,7 +509,9 @@ static void vfio_iommu_map_notify(IOMMUNotifier *n,
> IOMMUTLBEntry *iotlb)
> rcu_read_lock();
>
> if ((iotlb->perm & IOMMU_RW) != IOMMU_NONE) {
> - if (!vfio_get_vaddr(iotlb, &vaddr, &read_only)) {
> + bool read_only;
> +
> + if (!vfio_get_xlat_addr(iotlb, &vaddr, NULL, &read_only)) {
> goto out;
> }
> /*
> @@ -899,11 +909,84 @@ err_out:
> return ret;
> }
>
> +static void vfio_iommu_map_dirty_notify(IOMMUNotifier *n, IOMMUTLBEntry
> *iotlb)
> +{
> + VFIOGuestIOMMU *giommu = container_of(n, VFIOGuestIOMMU, dirty_notify);
> + VFIOContainer *container = giommu->container;
> + hwaddr iova = iotlb->iova + giommu->iommu_offset;
> + ram_addr_t translated_addr;
> +
> + trace_vfio_iommu_map_dirty_notify(iova, iova + iotlb->addr_mask);
> +
> + if (iotlb->target_as != &address_space_memory) {
> + error_report("Wrong target AS \"%s\", only system memory is allowed",
> + iotlb->target_as->name ? iotlb->target_as->name :
> "none");
> + return;
> + }
> +
> + rcu_read_lock();
> +
> + if (vfio_get_xlat_addr(iotlb, NULL, &translated_addr, NULL)) {
> + int ret;
> +
> + ret = vfio_get_dirty_bitmap(container, iova, iotlb->addr_mask + 1,
> + translated_addr);
> + if (ret) {
> + error_report("vfio_iommu_map_dirty_notify(%p, 0x%"HWADDR_PRIx", "
> + "0x%"HWADDR_PRIx") = %d (%m)",
> + container, iova,
> + iotlb->addr_mask + 1, ret);
> + }
> + }
> +
> + rcu_read_unlock();
> +}
> +
> static int vfio_sync_dirty_bitmap(VFIOContainer *container,
> MemoryRegionSection *section)
> {
> ram_addr_t ram_addr;
>
> + if (memory_region_is_iommu(section->mr)) {
> + VFIOGuestIOMMU *giommu;
> + int ret = 0;
> +
> + QLIST_FOREACH(giommu, &container->giommu_list, giommu_next) {
> + if (MEMORY_REGION(giommu->iommu) == section->mr &&
> + giommu->n.start == section->offset_within_region) {
> + Int128 llend;
> + Error *err = NULL;
> + int idx = memory_region_iommu_attrs_to_index(giommu->iommu,
> +
> MEMTXATTRS_UNSPECIFIED);
> +
> + llend =
> int128_add(int128_make64(section->offset_within_region),
> + section->size);
> + llend = int128_sub(llend, int128_one());
> +
> + iommu_notifier_init(&giommu->dirty_notify,
> + vfio_iommu_map_dirty_notify,
> + IOMMU_NOTIFIER_MAP,
> + section->offset_within_region,
> + int128_get64(llend),
> + idx);
> + ret = memory_region_register_iommu_notifier(section->mr,
> + &giommu->dirty_notify,
> &err);
> + if (ret) {
> + error_report_err(err);
> + break;
> + }
> +
> + memory_region_iommu_replay(giommu->iommu,
> + &giommu->dirty_notify);
> +
> + memory_region_unregister_iommu_notifier(section->mr,
> +
> &giommu->dirty_notify);
Is it necessary to do the register/unregister? It seemed to me that
perhaps we could do a replay independent of those.
I'd also be tempted to move dirty_notify to a temporary object rather
than store it on the giommu for such a brief usage, ie. define:
struct giommu_dirty_notfier {
IOMMUNotifier n;
VFIOGuestIOMMU *giommu;
}
struct giommu_dirty_notfier n = { .giommu = giommu };
iommu_notifier_init(&n,...);
memory_region_iommu_replay(giommu->iommu, &n);
...
struct giommu_dirty_notfier *ndnotifier = container_of(n, struct
giommu_dirty_notfier, n);
VFIOGuestIOMMU *giommu = n->giommu;
It's nice that we remove the extra bloat of the list/tree entirely with
this approach. Thanks,
Alex
> + break;
> + }
> + }
> + return ret;
> + }
> +
> ram_addr = memory_region_get_ram_addr(section->mr) +
> section->offset_within_region;
>
> diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
> index c3b35aa2cce8..d9cb8998a228 100644
> --- a/hw/vfio/trace-events
> +++ b/hw/vfio/trace-events
> @@ -163,3 +163,4 @@ vfio_load_device_config_state(const char *name) " (%s)"
> vfio_load_state(const char *name, uint64_t data) " (%s) data 0x%"PRIx64
> vfio_load_state_device_data(const char *name, uint64_t data_offset, uint64_t
> data_size) " (%s) Offset 0x%"PRIx64" size 0x%"PRIx64
> vfio_get_dirty_bitmap(int fd, uint64_t iova, uint64_t size, uint64_t
> bitmap_size, uint64_t start) "container fd=%d, iova=0x%"PRIx64" size=
> 0x%"PRIx64" bitmap_size=0x%"PRIx64" start=0x%"PRIx64
> +vfio_iommu_map_dirty_notify(uint64_t iova_start, uint64_t iova_end) "iommu
> dirty @ 0x%"PRIx64" - 0x%"PRIx64
> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> index b1c1b18fd228..92872fae59ee 100644
> --- a/include/hw/vfio/vfio-common.h
> +++ b/include/hw/vfio/vfio-common.h
> @@ -99,6 +99,7 @@ typedef struct VFIOGuestIOMMU {
> IOMMUMemoryRegion *iommu;
> hwaddr iommu_offset;
> IOMMUNotifier n;
> + IOMMUNotifier dirty_notify;
> QLIST_ENTRY(VFIOGuestIOMMU) giommu_next;
> } VFIOGuestIOMMU;
>
