From: Steve Sistare <steven.sistare@oracle.com>
In the container pre_save handler, discard the virtual addresses in DMA
mappings with VFIO_DMA_UNMAP_FLAG_VADDR, because guest RAM will be
remapped at a different VA after in new QEMU. DMA to already-mapped
pages continues.
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/1749569991-25171-6-git-send-email-steven.sistare@oracle.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
---
hw/vfio/cpr-legacy.c | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)
diff --git a/hw/vfio/cpr-legacy.c b/hw/vfio/cpr-legacy.c
index ac4a9ab315eab515607fb2405032ddc1ab980cf0..ef106d0ea865e86e3fdce86928e987e812724a0e 100644
--- a/hw/vfio/cpr-legacy.c
+++ b/hw/vfio/cpr-legacy.c
@@ -15,6 +15,22 @@
#include "migration/vmstate.h"
#include "qapi/error.h"
+static bool vfio_dma_unmap_vaddr_all(VFIOContainer *container, Error **errp)
+{
+ struct vfio_iommu_type1_dma_unmap unmap = {
+ .argsz = sizeof(unmap),
+ .flags = VFIO_DMA_UNMAP_FLAG_VADDR | VFIO_DMA_UNMAP_FLAG_ALL,
+ .iova = 0,
+ .size = 0,
+ };
+ if (ioctl(container->fd, VFIO_IOMMU_UNMAP_DMA, &unmap)) {
+ error_setg_errno(errp, errno, "vfio_dma_unmap_vaddr_all");
+ return false;
+ }
+ return true;
+}
+
+
static bool vfio_cpr_supported(VFIOContainer *container, Error **errp)
{
if (!ioctl(container->fd, VFIO_CHECK_EXTENSION, VFIO_UPDATE_VADDR)) {
@@ -30,10 +46,23 @@ static bool vfio_cpr_supported(VFIOContainer *container, Error **errp)
}
}
+static int vfio_container_pre_save(void *opaque)
+{
+ VFIOContainer *container = opaque;
+ Error *local_err = NULL;
+
+ if (!vfio_dma_unmap_vaddr_all(container, &local_err)) {
+ error_report_err(local_err);
+ return -1;
+ }
+ return 0;
+}
+
static const VMStateDescription vfio_container_vmstate = {
.name = "vfio-container",
.version_id = 0,
.minimum_version_id = 0,
+ .pre_save = vfio_container_pre_save,
.needed = cpr_incoming_needed,
.fields = (VMStateField[]) {
VMSTATE_END_OF_LIST()
--
2.49.0