On 14.01.21 16:54, David Hildenbrand wrote: > On 14.01.21 00:27, Alex Williamson wrote: >> On Thu, 7 Jan 2021 14:34:16 +0100 >> David Hildenbrand <da...@redhat.com> wrote: >> >>> Implement support for RamDiscardMgr, to prepare for virtio-mem >>> support. Instead of mapping the whole memory section, we only map >>> "populated" parts and update the mapping when notified about >>> discarding/population of memory via the RamDiscardListener. Similarly, when >>> syncing the dirty bitmaps, sync only the actually mapped (populated) parts >>> by replaying via the notifier. >>> >>> Using virtio-mem with vfio is still blocked via >>> ram_block_discard_disable()/ram_block_discard_require() after this patch. >>> >>> Cc: Paolo Bonzini <pbonz...@redhat.com> >>> Cc: "Michael S. Tsirkin" <m...@redhat.com> >>> Cc: Alex Williamson <alex.william...@redhat.com> >>> Cc: Dr. David Alan Gilbert <dgilb...@redhat.com> >>> Cc: Igor Mammedov <imamm...@redhat.com> >>> Cc: Pankaj Gupta <pankaj.gupta.li...@gmail.com> >>> Cc: Peter Xu <pet...@redhat.com> >>> Cc: Auger Eric <eric.au...@redhat.com> >>> Cc: Wei Yang <richard.weiy...@linux.alibaba.com> >>> Cc: teawater <teawat...@linux.alibaba.com> >>> Cc: Marek Kedzierski <mkedz...@redhat.com> >>> Signed-off-by: David Hildenbrand <da...@redhat.com> >>> --- >>> hw/vfio/common.c | 200 ++++++++++++++++++++++++++++++++++ >>> include/hw/vfio/vfio-common.h | 12 ++ >>> 2 files changed, 212 insertions(+) >>> >>> diff --git a/hw/vfio/common.c b/hw/vfio/common.c >>> index 6ff1daa763..2bd219cf1d 100644 >>> --- a/hw/vfio/common.c >>> +++ b/hw/vfio/common.c >>> @@ -654,6 +654,136 @@ out: >>> rcu_read_unlock(); >>> } >>> >>> +static void vfio_ram_discard_notify_discard(RamDiscardListener *rdl, >>> + const MemoryRegion *mr, >>> + ram_addr_t offset, ram_addr_t >>> size) >>> +{ >>> + VFIORamDiscardListener *vrdl = container_of(rdl, >>> VFIORamDiscardListener, >>> + listener); >>> + const hwaddr mr_start = MAX(offset, vrdl->offset_within_region); >>> + const hwaddr mr_end = MIN(offset + size, >>> + vrdl->offset_within_region + vrdl->size); >>> + const hwaddr iova = mr_start - vrdl->offset_within_region + >>> + vrdl->offset_within_address_space; >>> + int ret; >>> + >>> + if (mr_start >= mr_end) { >>> + return; >>> + } >>> + >>> + /* Unmap with a single call. */ >>> + ret = vfio_dma_unmap(vrdl->container, iova, mr_end - mr_start, NULL); >>> + if (ret) { >>> + error_report("%s: vfio_dma_unmap() failed: %s", __func__, >>> + strerror(-ret)); >>> + } >>> +} >>> + >>> +static int vfio_ram_discard_notify_populate(RamDiscardListener *rdl, >>> + const MemoryRegion *mr, >>> + ram_addr_t offset, ram_addr_t >>> size) >>> +{ >>> + VFIORamDiscardListener *vrdl = container_of(rdl, >>> VFIORamDiscardListener, >>> + listener); >>> + const hwaddr mr_end = MIN(offset + size, >>> + vrdl->offset_within_region + vrdl->size); >>> + hwaddr mr_start = MAX(offset, vrdl->offset_within_region); >>> + hwaddr mr_next, iova; >>> + void *vaddr; >>> + int ret; >>> + >>> + /* >>> + * Map in (aligned within memory region) minimum granularity, so we can >>> + * unmap in minimum granularity later. >>> + */ >>> + for (; mr_start < mr_end; mr_start = mr_next) { >>> + mr_next = ROUND_UP(mr_start + 1, vrdl->granularity); >>> + mr_next = MIN(mr_next, mr_end); >>> + >>> + iova = mr_start - vrdl->offset_within_region + >>> + vrdl->offset_within_address_space; >>> + vaddr = memory_region_get_ram_ptr(vrdl->mr) + mr_start; >>> + >>> + ret = vfio_dma_map(vrdl->container, iova, mr_next - mr_start, >>> + vaddr, mr->readonly); >>> + if (ret) { >>> + /* Rollback */ >>> + vfio_ram_discard_notify_discard(rdl, mr, offset, size); >>> + return ret; >>> + } >>> + } >>> + return 0; >>> +} >>> + >>> +static void vfio_ram_discard_notify_discard_all(RamDiscardListener *rdl, >>> + const MemoryRegion *mr) >>> +{ >>> + VFIORamDiscardListener *vrdl = container_of(rdl, >>> VFIORamDiscardListener, >>> + listener); >>> + int ret; >>> + >>> + /* Unmap with a single call. */ >>> + ret = vfio_dma_unmap(vrdl->container, >>> vrdl->offset_within_address_space, >>> + vrdl->size, NULL); >>> + if (ret) { >>> + error_report("%s: vfio_dma_unmap() failed: %s", __func__, >>> + strerror(-ret)); >>> + } >>> +} >>> + >>> +static void vfio_register_ram_discard_notifier(VFIOContainer *container, >>> + MemoryRegionSection >>> *section) >>> +{ >>> + RamDiscardMgr *rdm = memory_region_get_ram_discard_mgr(section->mr); >>> + RamDiscardMgrClass *rdmc = RAM_DISCARD_MGR_GET_CLASS(rdm); >>> + VFIORamDiscardListener *vrdl; >>> + >>> + vrdl = g_new0(VFIORamDiscardListener, 1); >>> + vrdl->container = container; >>> + vrdl->mr = section->mr; >>> + vrdl->offset_within_region = section->offset_within_region; >>> + vrdl->offset_within_address_space = >>> section->offset_within_address_space; >>> + vrdl->size = int128_get64(section->size); >>> + vrdl->granularity = rdmc->get_min_granularity(rdm, section->mr); >>> + >>> + /* Ignore some corner cases not relevant in practice. */ >>> + g_assert(QEMU_IS_ALIGNED(vrdl->offset_within_region, >>> TARGET_PAGE_SIZE)); >>> + g_assert(QEMU_IS_ALIGNED(vrdl->offset_within_address_space, >>> + TARGET_PAGE_SIZE)); >>> + g_assert(QEMU_IS_ALIGNED(vrdl->size, TARGET_PAGE_SIZE)); >> >> Should probably toss in a test of vrdl->granularity vs >> container->pgsizes too, right? Looks good otherwise: > > Makes sense as a sanity check. What about > > g_assert(vrdl->granularity && !is_power_of_2(vrdl->granularity));
^ g_assert(vrdl->granularity >= 1 << ctz64(container->pgsizes)); -- Thanks, David / dhildenb