If there are multiple containers and unmap-all fails for some container, we
need to remap vaddr for the other containers for which unmap-all succeeded.
Recover by walking all address ranges of all containers to restore the vaddr
for each. Do so by invoking the vfio listener callback, and passing a new
"remap" flag that tells it to restore a mapping without re-allocating new
userland data structures.
Signed-off-by: Steve Sistare <steven.sist...@oracle.com>
---
hw/vfio/common.c | 19 ++++++++-
hw/vfio/cpr-legacy.c | 91 +++++++++++++++++++++++++++++++++++++++++++
include/hw/vfio/vfio-common.h | 3 ++
include/hw/vfio/vfio-cpr.h | 11 ++++++
4 files changed, 123 insertions(+), 1 deletion(-)
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index e3e1da0..48663ad 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -592,6 +592,13 @@ static void vfio_listener_region_add(MemoryListener
*listener,
{
VFIOContainerBase *bcontainer = container_of(listener, VFIOContainerBase,
listener);
+ vfio_container_region_add(bcontainer, section, false);
+}
+
+void vfio_container_region_add(VFIOContainerBase *bcontainer,
+ MemoryRegionSection *section,
+ bool cpr_remap)
+{
hwaddr iova, end;
Int128 llend, llsize;
void *vaddr;
@@ -627,6 +634,11 @@ static void vfio_listener_region_add(MemoryListener
*listener,
int iommu_idx;
trace_vfio_listener_region_add_iommu(section->mr->name, iova, end);
+
+ if (cpr_remap) {
+ vfio_cpr_giommu_remap(bcontainer, section);
+ }
+
/*
* FIXME: For VFIO iommu types which have KVM acceleration to
* avoid bouncing all map/unmaps through qemu this way, this
@@ -669,7 +681,12 @@ static void vfio_listener_region_add(MemoryListener
*listener,
* about changes.
*/
if (memory_region_has_ram_discard_manager(section->mr)) {
- vfio_register_ram_discard_listener(bcontainer, section);
+ if (!cpr_remap) {
+ vfio_register_ram_discard_listener(bcontainer, section);
+ } else if (!vfio_cpr_register_ram_discard_listener(bcontainer,
+ section)) {
+ goto fail;
+ }
return;
}
diff --git a/hw/vfio/cpr-legacy.c b/hw/vfio/cpr-legacy.c
index bb5f802..90f9f14 100644
--- a/hw/vfio/cpr-legacy.c
+++ b/hw/vfio/cpr-legacy.c
@@ -28,6 +28,7 @@ static bool vfio_dma_unmap_vaddr_all(VFIOContainer
*container, Error **errp)
error_setg_errno(errp, errno, "vfio_dma_unmap_vaddr_all");
return false;
}
+ container->cpr.vaddr_unmapped = true;
return true;
}
@@ -60,6 +61,14 @@ static int vfio_legacy_cpr_dma_map(const VFIOContainerBase
*bcontainer,
return 0;
}
+static void vfio_region_remap(MemoryListener *listener,
+ MemoryRegionSection *section)
+{
+ VFIOContainer *container = container_of(listener, VFIOContainer,
+ cpr.remap_listener);
+ vfio_container_region_add(&container->bcontainer, section, true);
+}
+
static bool vfio_cpr_supported(VFIOContainer *container, Error **errp)
{
if (!ioctl(container->fd, VFIO_CHECK_EXTENSION, VFIO_UPDATE_VADDR)) {
@@ -124,6 +133,40 @@ static const VMStateDescription vfio_container_vmstate = {
}
};
+static int vfio_cpr_fail_notifier(NotifierWithReturn *notifier,
+ MigrationEvent *e, Error **errp)
+{
+ VFIOContainer *container =
+ container_of(notifier, VFIOContainer, cpr.transfer_notifier);
+ VFIOContainerBase *bcontainer = &container->bcontainer;
+
+ if (e->type != MIG_EVENT_PRECOPY_FAILED) {
+ return 0;
+ }
+
+ if (container->cpr.vaddr_unmapped) {
+ /*
+ * Force a call to vfio_region_remap for each mapped section by
+ * temporarily registering a listener, and temporarily diverting
+ * dma_map to vfio_legacy_cpr_dma_map. The latter restores vaddr.
+ */
+
+ VFIOIOMMUClass *vioc = VFIO_IOMMU_GET_CLASS(bcontainer);
+ vioc->dma_map = vfio_legacy_cpr_dma_map;
+
+ container->cpr.remap_listener = (MemoryListener) {
+ .name = "vfio cpr recover",
+ .region_add = vfio_region_remap
+ };
+ memory_listener_register(&container->cpr.remap_listener,
+ bcontainer->space->as);
+ memory_listener_unregister(&container->cpr.remap_listener);
+ container->cpr.vaddr_unmapped = false;
+ vioc->dma_map = vfio_legacy_dma_map;
+ }
+ return 0;
+}
+
bool vfio_legacy_cpr_register_container(VFIOContainer *container, Error **errp)
{
VFIOContainerBase *bcontainer = &container->bcontainer;
@@ -145,6 +188,10 @@ bool vfio_legacy_cpr_register_container(VFIOContainer
*container, Error **errp)
VFIOIOMMUClass *vioc = VFIO_IOMMU_GET_CLASS(bcontainer);
vioc->dma_map = vfio_legacy_cpr_dma_map;
}
+
+ migration_add_notifier_mode(&container->cpr.transfer_notifier,
+ vfio_cpr_fail_notifier,
+ MIG_MODE_CPR_TRANSFER);
return true;
}
@@ -155,6 +202,50 @@ void vfio_legacy_cpr_unregister_container(VFIOContainer
*container)
migration_remove_notifier(&bcontainer->cpr_reboot_notifier);
migrate_del_blocker(&container->cpr.blocker);
vmstate_unregister(NULL, &vfio_container_vmstate, container);
+ migration_remove_notifier(&container->cpr.transfer_notifier);
+}
+
+/*
+ * In old QEMU, VFIO_DMA_UNMAP_FLAG_VADDR may fail on some mapping after
+ * succeeding for others, so the latter have lost their vaddr. Call this
+ * to restore vaddr for a section with a giommu.
+ *
+ * The giommu already exists. Find it and replay it, which calls
+ * vfio_legacy_cpr_dma_map further down the stack.
+ */
+void vfio_cpr_giommu_remap(VFIOContainerBase *bcontainer,
+ MemoryRegionSection *section)
+{
+ VFIOGuestIOMMU *giommu = NULL;
+ hwaddr as_offset = section->offset_within_address_space;
+ hwaddr iommu_offset = as_offset - section->offset_within_region;
+
+ QLIST_FOREACH(giommu, &bcontainer->giommu_list, giommu_next) {
+ if (giommu->iommu_mr == IOMMU_MEMORY_REGION(section->mr) &&
+ giommu->iommu_offset == iommu_offset) {
+ break;
+ }
+ }
+ g_assert(giommu);
+ memory_region_iommu_replay(giommu->iommu_mr, &giommu->n);
+}
+
+/*
+ * In old QEMU, VFIO_DMA_UNMAP_FLAG_VADDR may fail on some mapping after
+ * succeeding for others, so the latter have lost their vaddr. Call this
+ * to restore vaddr for a section with a RamDiscardManager.
+ *
+ * The ram discard listener already exists. Call its populate function
+ * directly, which calls vfio_legacy_cpr_dma_map.
+ */
+bool vfio_cpr_register_ram_discard_listener(VFIOContainerBase *bcontainer,
+ MemoryRegionSection *section)
+{
+ VFIORamDiscardListener *vrdl =
+ vfio_find_ram_discard_listener(bcontainer, section);
+
+ g_assert(vrdl);
+ return vrdl->listener.notify_populate(&vrdl->listener, section) == 0;
}
static bool same_device(int fd1, int fd2)
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index 7f33476..1563f3a 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -315,6 +315,9 @@ int vfio_get_dirty_bitmap(const VFIOContainerBase
*bcontainer, uint64_t iova,
VFIORamDiscardListener *vfio_find_ram_discard_listener(
VFIOContainerBase *bcontainer, MemoryRegionSection *section);
+void vfio_container_region_add(VFIOContainerBase *bcontainer,
+ MemoryRegionSection *section, bool cpr_remap);
+
/* Returns 0 on success, or a negative errno. */
bool vfio_device_get_name(VFIODevice *vbasedev, Error **errp);
void vfio_device_set_fd(VFIODevice *vbasedev, const char *str, Error **errp);
diff --git a/include/hw/vfio/vfio-cpr.h b/include/hw/vfio/vfio-cpr.h
index 25ac944..40d4f06 100644
--- a/include/hw/vfio/vfio-cpr.h
+++ b/include/hw/vfio/vfio-cpr.h
@@ -8,11 +8,15 @@
#ifndef HW_VFIO_VFIO_CPR_H
#define HW_VFIO_VFIO_CPR_H
+#include "exec/memory.h"
#include "migration/misc.h"
typedef struct VFIOContainerCPR {
Error *blocker;
bool reused;
+ bool vaddr_unmapped;
+ NotifierWithReturn transfer_notifier;
+ MemoryListener remap_listener;
} VFIOContainerCPR;
typedef struct VFIODeviceCPR {
@@ -22,6 +26,7 @@ typedef struct VFIODeviceCPR {
struct VFIOContainer;
struct VFIOGroup;
+struct VFIOContainerBase;
int vfio_cpr_reboot_notifier(NotifierWithReturn *notifier, MigrationEvent *e,
Error **errp);
@@ -32,4 +37,10 @@ void vfio_legacy_cpr_unregister_container(struct
VFIOContainer *container);
bool vfio_cpr_container_match(struct VFIOContainer *container,
struct VFIOGroup *group, int *fd);
+
+void vfio_cpr_giommu_remap(struct VFIOContainerBase *bcontainer,
+ MemoryRegionSection *section);
+
+bool vfio_cpr_register_ram_discard_listener(
+ struct VFIOContainerBase *bcontainer, MemoryRegionSection *section);
#endif
--
1.8.3.1
