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[PATCH V9 34/46] vfio-pci: recover from unmap-all-vaddr failure
From: |
Steve Sistare |
Subject: |
[PATCH V9 34/46] vfio-pci: recover from unmap-all-vaddr failure |
Date: |
Tue, 26 Jul 2022 09:10:31 -0700 |
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 flat sections 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.sistare@oracle.com>
---
hw/vfio/common.c | 79 ++++++++++++++++++++++++++++++++++---------
hw/vfio/cpr.c | 36 ++++++++++++++++++++
include/hw/vfio/vfio-common.h | 2 +-
3 files changed, 100 insertions(+), 17 deletions(-)
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index b7b35d4..de821e1 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -895,15 +895,35 @@ static bool
vfio_known_safe_misalignment(MemoryRegionSection *section)
return true;
}
+static VFIORamDiscardListener *vfio_find_ram_discard_listener(
+ VFIOContainer *container, MemoryRegionSection *section)
+{
+ VFIORamDiscardListener *vrdl;
+
+ QLIST_FOREACH(vrdl, &container->vrdl_list, next) {
+ if (vrdl->mr == section->mr &&
+ vrdl->offset_within_address_space ==
+ section->offset_within_address_space) {
+ break;
+ }
+ }
+
+ if (!vrdl) {
+ hw_error("vfio: Trying to sync missing RAM discard listener");
+ /* does not return */
+ }
+ return vrdl;
+}
+
static void vfio_listener_region_add(MemoryListener *listener,
MemoryRegionSection *section)
{
VFIOContainer *container = container_of(listener, VFIOContainer, listener);
- vfio_container_region_add(container, section);
+ vfio_container_region_add(container, section, false);
}
void vfio_container_region_add(VFIOContainer *container,
- MemoryRegionSection *section)
+ MemoryRegionSection *section, bool remap)
{
hwaddr iova, end;
Int128 llend, llsize;
@@ -1033,6 +1053,30 @@ void vfio_container_region_add(VFIOContainer *container,
int iommu_idx;
trace_vfio_listener_region_add_iommu(iova, end);
+
+ /*
+ * If remap, then VFIO_DMA_UNMAP_FLAG_VADDR has been called, and we
+ * want to remap the vaddr. vfio_container_region_add was already
+ * called in the past, so the giommu already exists. Find it and
+ * replay it, which calls vfio_dma_map further down the stack.
+ */
+
+ if (remap) {
+ hwaddr as_offset = section->offset_within_address_space;
+ hwaddr iommu_offset = as_offset - section->offset_within_region;
+
+ QLIST_FOREACH(giommu, &container->giommu_list, giommu_next) {
+ if (giommu->iommu_mr == iommu_mr &&
+ giommu->iommu_offset == iommu_offset) {
+ memory_region_iommu_replay(giommu->iommu_mr, &giommu->n);
+ return;
+ }
+ }
+ error_report("Container cannot find iommu region %s offset %lx",
+ memory_region_name(section->mr), iommu_offset);
+ goto fail;
+ }
+
/*
* FIXME: For VFIO iommu types which have KVM acceleration to
* avoid bouncing all map/unmaps through qemu this way, this
@@ -1083,7 +1127,21 @@ void vfio_container_region_add(VFIOContainer *container,
* about changes.
*/
if (memory_region_has_ram_discard_manager(section->mr)) {
- vfio_register_ram_discard_listener(container, section);
+ /*
+ * If remap, then VFIO_DMA_UNMAP_FLAG_VADDR has been called, and we
+ * want to remap the vaddr. vfio_container_region_add was already
+ * called in the past, so the ram discard listener already exists.
+ * Call its populate function directly, which calls vfio_dma_map.
+ */
+ if (remap) {
+ VFIORamDiscardListener *vrdl =
+ vfio_find_ram_discard_listener(container, section);
+ if (vrdl->listener.notify_populate(&vrdl->listener, section)) {
+ error_report("listener.notify_populate failed");
+ }
+ } else {
+ vfio_register_ram_discard_listener(container, section);
+ }
return;
}
@@ -1417,19 +1475,8 @@ static int
vfio_sync_ram_discard_listener_dirty_bitmap(VFIOContainer *container,
MemoryRegionSection
*section)
{
RamDiscardManager *rdm =
memory_region_get_ram_discard_manager(section->mr);
- VFIORamDiscardListener *vrdl = NULL;
-
- QLIST_FOREACH(vrdl, &container->vrdl_list, next) {
- if (vrdl->mr == section->mr &&
- vrdl->offset_within_address_space ==
- section->offset_within_address_space) {
- break;
- }
- }
-
- if (!vrdl) {
- hw_error("vfio: Trying to sync missing RAM discard listener");
- }
+ VFIORamDiscardListener *vrdl =
+ vfio_find_ram_discard_listener(container, section);
/*
* We only want/can synchronize the bitmap for actually mapped parts -
diff --git a/hw/vfio/cpr.c b/hw/vfio/cpr.c
index 83f7872..1f682cb 100644
--- a/hw/vfio/cpr.c
+++ b/hw/vfio/cpr.c
@@ -34,6 +34,15 @@ vfio_dma_unmap_vaddr_all(VFIOContainer *container, Error
**errp)
return 0;
}
+static int
+vfio_region_remap(MemoryRegionSection *section, void *handle, Error **errp)
+{
+ VFIOContainer *container = handle;
+ vfio_container_region_add(container, section, true);
+ container->vaddr_unmapped = false;
+ return 0;
+}
+
static bool vfio_is_cpr_capable(VFIOContainer *container, Error **errp)
{
if (!ioctl(container->fd, VFIO_CHECK_EXTENSION, VFIO_UPDATE_VADDR) ||
@@ -99,6 +108,30 @@ static const VMStateDescription vfio_container_vmstate = {
}
};
+static void vfio_cpr_fail_notifier(Notifier *notifier, void *data)
+{
+ MigrationState *s = data;
+ VFIOContainer *container;
+ Error *err = NULL;
+
+ if (!migration_has_failed(s) || migrate_mode_of(s) != MIG_MODE_CPR_EXEC) {
+ return;
+ }
+
+ container = container_of(notifier, VFIOContainer, cpr_notifier);
+ if (container->vaddr_unmapped) {
+
+ /* Set reused so vfio_dma_map restores vaddr */
+ container->reused = true;
+ if (address_space_flat_for_each_section(container->space->as,
+ vfio_region_remap,
+ container, &err)) {
+ error_report_err(err);
+ }
+ container->reused = false;
+ }
+}
+
int vfio_cpr_register_container(VFIOContainer *container, Error **errp)
{
container->cpr_blocker = NULL;
@@ -109,6 +142,7 @@ int vfio_cpr_register_container(VFIOContainer *container,
Error **errp)
vmstate_register(NULL, -1, &vfio_container_vmstate, container);
+ migration_add_notifier(&container->cpr_notifier, vfio_cpr_fail_notifier);
return 0;
}
@@ -117,4 +151,6 @@ void vfio_cpr_unregister_container(VFIOContainer *container)
migrate_del_blocker(&container->cpr_blocker);
vmstate_unregister(NULL, &vfio_container_vmstate, container);
+
+ migration_remove_notifier(&container->cpr_notifier);
}
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index 17ad9ba..b682645 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -244,7 +244,7 @@ vfio_get_device_info_cap(struct vfio_device_info *info,
uint16_t id);
extern const MemoryListener vfio_prereg_listener;
void vfio_listener_register(VFIOContainer *container);
void vfio_container_region_add(VFIOContainer *container,
- MemoryRegionSection *section);
+ MemoryRegionSection *section, bool remap);
int vfio_spapr_create_window(VFIOContainer *container,
MemoryRegionSection *section,
--
1.8.3.1
- [PATCH V9 29/46] pci: export msix_is_pending, (continued)
- [PATCH V9 29/46] pci: export msix_is_pending, Steve Sistare, 2022/07/26
- [PATCH V9 11/46] qapi: strList_from_string, Steve Sistare, 2022/07/26
- [PATCH V9 07/46] migration: per-mode blockers, Steve Sistare, 2022/07/26
- [PATCH V9 35/46] vhost: reset vhost devices for cpr, Steve Sistare, 2022/07/26
- [PATCH V9 22/46] cpr: exec mode, Steve Sistare, 2022/07/26
- [PATCH V9 16/46] migration: simplify notifiers, Steve Sistare, 2022/07/26
- [PATCH V9 26/46] cpr: Mismatched GPAs fix, Steve Sistare, 2022/07/26
- [PATCH V9 37/46] chardev: cpr for simple devices, Steve Sistare, 2022/07/26
- [PATCH V9 38/46] chardev: cpr for pty, Steve Sistare, 2022/07/26
- [PATCH V9 32/46] vfio-pci: cpr part 2 (msi), Steve Sistare, 2022/07/26
- [PATCH V9 34/46] vfio-pci: recover from unmap-all-vaddr failure,
Steve Sistare <=
- [PATCH V9 40/46] python/machine: QEMUMachine full_args, Steve Sistare, 2022/07/26
- [PATCH V9 17/46] migration: check mode in notifiers, Steve Sistare, 2022/07/26
- [PATCH V9 45/46] migration: notifier error reporting, Steve Sistare, 2022/07/26
- [PATCH V9 36/46] chardev: cpr framework, Steve Sistare, 2022/07/26
- [PATCH V9 41/46] python/machine: QEMUMachine reopen_qmp_connection, Steve Sistare, 2022/07/26
- [PATCH V9 43/46] vl: start on wakeup request, Steve Sistare, 2022/07/26
- [PATCH V9 44/46] migration: fix suspended runstate, Steve Sistare, 2022/07/26