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[PATCH v6 05/12] vfio: Support for RamDiscardMgr in the !vIOMMU case
From: |
David Hildenbrand |
Subject: |
[PATCH v6 05/12] vfio: Support for RamDiscardMgr in the !vIOMMU case |
Date: |
Mon, 22 Feb 2021 12:57:01 +0100 |
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.
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Auger Eric <eric.auger@redhat.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: teawater <teawaterz@linux.alibaba.com>
Cc: Marek Kedzierski <mkedzier@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
hw/vfio/common.c | 203 ++++++++++++++++++++++++++++++++++
include/hw/vfio/vfio-common.h | 12 ++
2 files changed, 215 insertions(+)
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 6ff1daa763..f68370de6c 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -654,6 +654,139 @@ 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);
+
+ g_assert(vrdl->granularity && is_power_of_2(vrdl->granularity));
+ g_assert(vrdl->granularity >= 1 << ctz64(container->pgsizes));
+
+ /* 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));
+
+ ram_discard_listener_init(&vrdl->listener,
+ vfio_ram_discard_notify_populate,
+ vfio_ram_discard_notify_discard,
+ vfio_ram_discard_notify_discard_all);
+ rdmc->register_listener(rdm, section->mr, &vrdl->listener);
+ QLIST_INSERT_HEAD(&container->vrdl_list, vrdl, next);
+}
+
+static void vfio_unregister_ram_discard_listener(VFIOContainer *container,
+ MemoryRegionSection *section)
+{
+ RamDiscardMgr *rdm = memory_region_get_ram_discard_mgr(section->mr);
+ RamDiscardMgrClass *rdmc = RAM_DISCARD_MGR_GET_CLASS(rdm);
+ VFIORamDiscardListener *vrdl = NULL;
+
+ QLIST_FOREACH(vrdl, &container->vrdl_list, next) {
+ if (vrdl->mr == section->mr &&
+ vrdl->offset_within_region == section->offset_within_region) {
+ break;
+ }
+ }
+
+ if (!vrdl) {
+ hw_error("vfio: Trying to unregister missing RAM discard listener");
+ }
+
+ rdmc->unregister_listener(rdm, section->mr, &vrdl->listener);
+ QLIST_REMOVE(vrdl, next);
+
+ g_free(vrdl);
+}
+
static void vfio_listener_region_add(MemoryListener *listener,
MemoryRegionSection *section)
{
@@ -814,6 +947,16 @@ static void vfio_listener_region_add(MemoryListener
*listener,
/* Here we assume that memory_region_is_ram(section->mr)==true */
+ /*
+ * For RAM memory regions with a RamDiscardMgr, we only want to map the
+ * actually populated parts - and update the mapping whenever we're
notified
+ * about changes.
+ */
+ if (memory_region_has_ram_discard_mgr(section->mr)) {
+ vfio_register_ram_discard_notifier(container, section);
+ return;
+ }
+
vaddr = memory_region_get_ram_ptr(section->mr) +
section->offset_within_region +
(iova - section->offset_within_address_space);
@@ -950,6 +1093,10 @@ static void vfio_listener_region_del(MemoryListener
*listener,
pgmask = (1ULL << ctz64(hostwin->iova_pgsizes)) - 1;
try_unmap = !((iova & pgmask) || (int128_get64(llsize) & pgmask));
+ } else if (memory_region_has_ram_discard_mgr(section->mr)) {
+ vfio_unregister_ram_discard_listener(container, section);
+ /* Unregistering will trigger an unmap. */
+ try_unmap = false;
}
if (try_unmap) {
@@ -1077,6 +1224,59 @@ static void vfio_iommu_map_dirty_notify(IOMMUNotifier
*n, IOMMUTLBEntry *iotlb)
rcu_read_unlock();
}
+static int vfio_ram_discard_notify_dirty_bitmap(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;
+ ram_addr_t ram_addr;
+ int ret;
+
+ if (mr_start >= mr_end) {
+ return 0;
+ }
+
+ /*
+ * Sync the whole mapped region (spanning multiple individual mappings)
+ * in one go.
+ */
+ ram_addr = memory_region_get_ram_addr(vrdl->mr) + mr_start;
+ ret = vfio_get_dirty_bitmap(vrdl->container, iova, mr_end - mr_start,
+ ram_addr);
+ return ret;
+}
+
+static int vfio_sync_ram_discard_listener_dirty_bitmap(VFIOContainer
*container,
+ MemoryRegionSection
*section)
+{
+ RamDiscardMgr *rdm = memory_region_get_ram_discard_mgr(section->mr);
+ RamDiscardMgrClass *rdmc = RAM_DISCARD_MGR_GET_CLASS(rdm);
+ VFIORamDiscardListener tmp_vrdl, *vrdl = NULL;
+
+ QLIST_FOREACH(vrdl, &container->vrdl_list, next) {
+ if (vrdl->mr == section->mr &&
+ vrdl->offset_within_region == section->offset_within_region) {
+ break;
+ }
+ }
+
+ if (!vrdl) {
+ hw_error("vfio: Trying to sync missing RAM discard listener");
+ }
+
+ tmp_vrdl = *vrdl;
+ ram_discard_listener_init(&tmp_vrdl.listener,
+ vfio_ram_discard_notify_dirty_bitmap, NULL,
NULL);
+ return rdmc->replay_populated(rdm, section->mr, &tmp_vrdl.listener);
+}
+
static int vfio_sync_dirty_bitmap(VFIOContainer *container,
MemoryRegionSection *section)
{
@@ -1108,6 +1308,8 @@ static int vfio_sync_dirty_bitmap(VFIOContainer
*container,
}
}
return 0;
+ } else if (memory_region_has_ram_discard_mgr(section->mr)) {
+ return vfio_sync_ram_discard_listener_dirty_bitmap(container, section);
}
ram_addr = memory_region_get_ram_addr(section->mr) +
@@ -1737,6 +1939,7 @@ static int vfio_connect_container(VFIOGroup *group,
AddressSpace *as,
container->dirty_pages_supported = false;
QLIST_INIT(&container->giommu_list);
QLIST_INIT(&container->hostwin_list);
+ QLIST_INIT(&container->vrdl_list);
ret = vfio_init_container(container, group->fd, errp);
if (ret) {
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index 6141162d7a..af6f8d1b22 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -91,6 +91,7 @@ typedef struct VFIOContainer {
QLIST_HEAD(, VFIOGuestIOMMU) giommu_list;
QLIST_HEAD(, VFIOHostDMAWindow) hostwin_list;
QLIST_HEAD(, VFIOGroup) group_list;
+ QLIST_HEAD(, VFIORamDiscardListener) vrdl_list;
QLIST_ENTRY(VFIOContainer) next;
} VFIOContainer;
@@ -102,6 +103,17 @@ typedef struct VFIOGuestIOMMU {
QLIST_ENTRY(VFIOGuestIOMMU) giommu_next;
} VFIOGuestIOMMU;
+typedef struct VFIORamDiscardListener {
+ VFIOContainer *container;
+ MemoryRegion *mr;
+ hwaddr offset_within_region;
+ hwaddr offset_within_address_space;
+ hwaddr size;
+ uint64_t granularity;
+ RamDiscardListener listener;
+ QLIST_ENTRY(VFIORamDiscardListener) next;
+} VFIORamDiscardListener;
+
typedef struct VFIOHostDMAWindow {
hwaddr min_iova;
hwaddr max_iova;
--
2.29.2
[PATCH v6 02/12] virtio-mem: Factor out traversing unplugged ranges, David Hildenbrand, 2021/02/22
[PATCH v6 03/12] virtio-mem: Don't report errors when ram_block_discard_range() fails, David Hildenbrand, 2021/02/22
[PATCH v6 04/12] virtio-mem: Implement RamDiscardMgr interface, David Hildenbrand, 2021/02/22
[PATCH v6 05/12] vfio: Support for RamDiscardMgr in the !vIOMMU case,
David Hildenbrand <=
[PATCH v6 06/12] vfio: Query and store the maximum number of possible DMA mappings, David Hildenbrand, 2021/02/22
[PATCH v6 07/12] vfio: Sanity check maximum number of DMA mappings with RamDiscardMgr, David Hildenbrand, 2021/02/22
[PATCH v6 08/12] vfio: Support for RamDiscardMgr in the vIOMMU case, David Hildenbrand, 2021/02/22
[PATCH v6 09/12] softmmu/physmem: Don't use atomic operations in ram_block_discard_(disable|require), David Hildenbrand, 2021/02/22