On Wed, Mar 25, 2020 at 05:09:12AM +0800, Kirti Wankhede wrote:
> vfio_listener_log_sync gets list of dirty pages from container using
> VFIO_IOMMU_GET_DIRTY_BITMAP ioctl and mark those pages dirty when all
> devices are stopped and saving state.
> Return early for the RAM block section of mapped MMIO region.
>
> Signed-off-by: Kirti Wankhede <kwankh...@nvidia.com>
> Reviewed-by: Neo Jia <c...@nvidia.com>
> ---
> hw/vfio/common.c | 200
> +++++++++++++++++++++++++++++++++++++++++++++++++--
> hw/vfio/trace-events | 1 +
> 2 files changed, 196 insertions(+), 5 deletions(-)
>
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index 4a2f0d6a2233..6d41e1ac5c2f 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -29,6 +29,7 @@
> #include "hw/vfio/vfio.h"
> #include "exec/address-spaces.h"
> #include "exec/memory.h"
> +#include "exec/ram_addr.h"
> #include "hw/hw.h"
> #include "qemu/error-report.h"
> #include "qemu/main-loop.h"
> @@ -38,6 +39,7 @@
> #include "sysemu/reset.h"
> #include "trace.h"
> #include "qapi/error.h"
> +#include "migration/migration.h"
>
> VFIOGroupList vfio_group_list =
> QLIST_HEAD_INITIALIZER(vfio_group_list);
> @@ -288,6 +290,28 @@ const MemoryRegionOps vfio_region_ops = {
> };
>
> /*
> + * Device state interfaces
> + */
> +
> +static bool vfio_devices_are_stopped_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,
> @@ -408,8 +432,8 @@ 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;
> @@ -440,9 +464,17 @@ 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;
> }
>
> @@ -467,7 +499,7 @@ 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)) {
> + if (!vfio_get_xlat_addr(iotlb, &vaddr, NULL, &read_only)) {
> goto out;
> }
> /*
> @@ -813,9 +845,167 @@ static void vfio_listener_region_del(MemoryListener
> *listener,
> }
> }
>
> +static int vfio_get_dirty_bitmap(MemoryListener *listener,
> + MemoryRegionSection *section)
> +{
> + VFIOContainer *container = container_of(listener, VFIOContainer,
> listener);
> + VFIOGuestIOMMU *giommu;
> + IOMMUTLBEntry iotlb;
> + hwaddr granularity, address_limit, iova;
> + int ret;
> +
> + if (memory_region_is_iommu(section->mr)) {
> + QLIST_FOREACH(giommu, &container->giommu_list, giommu_next) {
> + if (MEMORY_REGION(giommu->iommu) == section->mr &&
> + giommu->n.start == section->offset_within_region) {
> + break;
> + }
> + }
> +
> + if (!giommu) {
> + return -EINVAL;
> + }
> + }
> +
> + if (memory_region_is_iommu(section->mr)) {
> + granularity = memory_region_iommu_get_min_page_size(giommu->iommu);
> +
> + address_limit = MIN(int128_get64(section->size),
> +
> memory_region_iommu_get_address_limit(giommu->iommu,
> +
> int128_get64(section->size)));
> + } else {
> + granularity = memory_region_size(section->mr);
> + address_limit = int128_get64(section->size);
> + }
> +
> + iova = TARGET_PAGE_ALIGN(section->offset_within_address_space);
> +
> + RCU_READ_LOCK_GUARD();
> +
> + while (iova < address_limit) {
> + struct vfio_iommu_type1_dirty_bitmap *dbitmap;
> + struct vfio_iommu_type1_dirty_bitmap_get *range;
> + ram_addr_t start, pages;
> + uint64_t iova_xlat, size;
> +
> + if (memory_region_is_iommu(section->mr)) {
> + iotlb = address_space_get_iotlb_entry(container->space->as, iova,
> + true,
> MEMTXATTRS_UNSPECIFIED);
> + if ((iotlb.target_as == NULL) || (iotlb.addr_mask == 0)) {
> + if ((iova + granularity) < iova) {
> + break;
> + }
> + iova += granularity;
> + continue;
> + }
> + iova_xlat = iotlb.iova + giommu->iommu_offset;
> + size = iotlb.addr_mask + 1;
> + } else {
> + iova_xlat = iova;
> + size = address_limit;
> + }
> +
> + dbitmap = g_malloc0(sizeof(*dbitmap) + sizeof(*range));
> + if (!dbitmap) {
> + return -ENOMEM;
> + }
> +
> + dbitmap->argsz = sizeof(*dbitmap) + sizeof(*range);
> + dbitmap->flags = VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP;
> + range = (struct vfio_iommu_type1_dirty_bitmap_get *)&dbitmap->data;
> + range->iova = iova_xlat;
> + range->size = size;
> +
> + /*
> + * cpu_physical_memory_set_dirty_lebitmap() expects pages in bitmap
> of
> + * TARGET_PAGE_SIZE to mark those dirty. Hence set bitmap's pgsize to
> + * TARGET_PAGE_SIZE.
> + */
> + range->bitmap.pgsize = TARGET_PAGE_SIZE;
> +
> + /*
> + * Comment from kvm_physical_sync_dirty_bitmap() since same applies
> here
> + * XXX bad kernel interface alert
> + * For dirty bitmap, kernel allocates array of size aligned to
> + * bits-per-long. But for case when the kernel is 64bits and
> + * the userspace is 32bits, userspace can't align to the same
> + * bits-per-long, since sizeof(long) is different between kernel
> + * and user space. This way, userspace will provide buffer which
> + * may be 4 bytes less than the kernel will use, resulting in
> + * userspace memory corruption (which is not detectable by valgrind
> + * too, in most cases).
> + * So for now, let's align to 64 instead of HOST_LONG_BITS here, in
> + * a hope that sizeof(long) won't become >8 any time soon.
> + */
> +
> + pages = TARGET_PAGE_ALIGN(range->size) >> TARGET_PAGE_BITS;
> + range->bitmap.size = ROUND_UP(pages, 64) / 8;
> + range->bitmap.data = g_malloc0(range->bitmap.size);
> + if (range->bitmap.data == NULL) {
> + error_report("Error allocating bitmap of size 0x%llx",
> + range->bitmap.size);
> + ret = -ENOMEM;
> + goto err_out;
> + }
> +
> + ret = ioctl(container->fd, VFIO_IOMMU_DIRTY_PAGES, dbitmap);
> + if (ret) {
> + error_report("Failed to get dirty bitmap for iova: 0x%llx "
> + "size: 0x%llx err: %d",
> + range->iova, range->size, errno);
> + goto err_out;
> + }
> +
> + if (memory_region_is_iommu(section->mr)) {
> + if (!vfio_get_xlat_addr(&iotlb, NULL, &start, NULL)) {
> + ret = -EINVAL;
> + goto err_out;
> + }
> + } else {
> + start = memory_region_get_ram_addr(section->mr) +
> + section->offset_within_region + iova -
> + TARGET_PAGE_ALIGN(section->offset_within_address_space);
> + }
> +
> + cpu_physical_memory_set_dirty_lebitmap((uint64_t
> *)range->bitmap.data,
> + start, pages);
> +
> + trace_vfio_get_dirty_bitmap(container->fd, range->iova, range->size,
> + range->bitmap.size, start);
> +err_out:
> + g_free(range->bitmap.data);
> + g_free(dbitmap);
> +
> + if (ret) {
> + return ret;
> + }
> +
> + if ((iova + size) < iova) {
> + break;
> + }
> +
> + iova += size;
> + }
> +
> + return 0;
> +}
> +
> +static void vfio_listerner_log_sync(MemoryListener *listener,
> + MemoryRegionSection *section)
> +{
> + if (vfio_listener_skipped_section(section)) {
> + return;
> + }
> +
> + if (vfio_devices_are_stopped_and_saving()) {
only get dirty in stopped and saving is not right.
> + vfio_get_dirty_bitmap(listener, section);
> + }
> +}
> +
> static const MemoryListener vfio_memory_listener = {
> .region_add = vfio_listener_region_add,
> .region_del = vfio_listener_region_del,
> + .log_sync = vfio_listerner_log_sync,
> };
>
> static void vfio_listener_release(VFIOContainer *container)
> diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
> index ac065b559f4e..bc8f35ee9356 100644
> --- a/hw/vfio/trace-events
> +++ b/hw/vfio/trace-events
> @@ -160,3 +160,4 @@ vfio_save_complete_precopy(char *name) " (%s)"
> vfio_load_device_config_state(char *name) " (%s)"
> vfio_load_state(char *name, uint64_t data) " (%s) data 0x%"PRIx64
> vfio_load_state_device_data(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
> --
> 2.7.0
>
