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[PULL 27/41] vhost: fix vq dirty bitmap syncing when vIOMMU is enabled
From: |
Michael S. Tsirkin |
Subject: |
[PULL 27/41] vhost: fix vq dirty bitmap syncing when vIOMMU is enabled |
Date: |
Wed, 21 Dec 2022 08:05:57 -0500 |
From: Jason Wang <jasowang@redhat.com>
When vIOMMU is enabled, the vq->used_phys is actually the IOVA not
GPA. So we need to translate it to GPA before the syncing otherwise we
may hit the following crash since IOVA could be out of the scope of
the GPA log size. This could be noted when using virtio-IOMMU with
vhost using 1G memory.
Fixes: c471ad0e9bd46 ("vhost_net: device IOTLB support")
Cc: qemu-stable@nongnu.org
Tested-by: Lei Yang <leiyang@redhat.com>
Reported-by: Yalan Zhang <yalzhang@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20221216033552.77087-1-jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
hw/virtio/vhost.c | 84 ++++++++++++++++++++++++++++++++++++-----------
1 file changed, 64 insertions(+), 20 deletions(-)
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 7fb008bc9e..fdcd1a8fdf 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -20,6 +20,7 @@
#include "qemu/range.h"
#include "qemu/error-report.h"
#include "qemu/memfd.h"
+#include "qemu/log.h"
#include "standard-headers/linux/vhost_types.h"
#include "hw/virtio/virtio-bus.h"
#include "hw/virtio/virtio-access.h"
@@ -106,6 +107,24 @@ static void vhost_dev_sync_region(struct vhost_dev *dev,
}
}
+static bool vhost_dev_has_iommu(struct vhost_dev *dev)
+{
+ VirtIODevice *vdev = dev->vdev;
+
+ /*
+ * For vhost, VIRTIO_F_IOMMU_PLATFORM means the backend support
+ * incremental memory mapping API via IOTLB API. For platform that
+ * does not have IOMMU, there's no need to enable this feature
+ * which may cause unnecessary IOTLB miss/update transactions.
+ */
+ if (vdev) {
+ return virtio_bus_device_iommu_enabled(vdev) &&
+ virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM);
+ } else {
+ return false;
+ }
+}
+
static int vhost_sync_dirty_bitmap(struct vhost_dev *dev,
MemoryRegionSection *section,
hwaddr first,
@@ -137,8 +156,51 @@ static int vhost_sync_dirty_bitmap(struct vhost_dev *dev,
continue;
}
- vhost_dev_sync_region(dev, section, start_addr, end_addr,
vq->used_phys,
- range_get_last(vq->used_phys, vq->used_size));
+ if (vhost_dev_has_iommu(dev)) {
+ IOMMUTLBEntry iotlb;
+ hwaddr used_phys = vq->used_phys, used_size = vq->used_size;
+ hwaddr phys, s, offset;
+
+ while (used_size) {
+ rcu_read_lock();
+ iotlb = address_space_get_iotlb_entry(dev->vdev->dma_as,
+ used_phys,
+ true,
+ MEMTXATTRS_UNSPECIFIED);
+ rcu_read_unlock();
+
+ if (!iotlb.target_as) {
+ qemu_log_mask(LOG_GUEST_ERROR, "translation "
+ "failure for used_iova %"PRIx64"\n",
+ used_phys);
+ return -EINVAL;
+ }
+
+ offset = used_phys & iotlb.addr_mask;
+ phys = iotlb.translated_addr + offset;
+
+ /*
+ * Distance from start of used ring until last byte of
+ * IOMMU page.
+ */
+ s = iotlb.addr_mask - offset;
+ /*
+ * Size of used ring, or of the part of it until end
+ * of IOMMU page. To avoid zero result, do the adding
+ * outside of MIN().
+ */
+ s = MIN(s, used_size - 1) + 1;
+
+ vhost_dev_sync_region(dev, section, start_addr, end_addr, phys,
+ range_get_last(phys, s));
+ used_size -= s;
+ used_phys += s;
+ }
+ } else {
+ vhost_dev_sync_region(dev, section, start_addr,
+ end_addr, vq->used_phys,
+ range_get_last(vq->used_phys,
vq->used_size));
+ }
}
return 0;
}
@@ -306,24 +368,6 @@ static inline void vhost_dev_log_resize(struct vhost_dev
*dev, uint64_t size)
dev->log_size = size;
}
-static bool vhost_dev_has_iommu(struct vhost_dev *dev)
-{
- VirtIODevice *vdev = dev->vdev;
-
- /*
- * For vhost, VIRTIO_F_IOMMU_PLATFORM means the backend support
- * incremental memory mapping API via IOTLB API. For platform that
- * does not have IOMMU, there's no need to enable this feature
- * which may cause unnecessary IOTLB miss/update transactions.
- */
- if (vdev) {
- return virtio_bus_device_iommu_enabled(vdev) &&
- virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM);
- } else {
- return false;
- }
-}
-
static void *vhost_memory_map(struct vhost_dev *dev, hwaddr addr,
hwaddr *plen, bool is_write)
{
--
MST
- [PULL 17/41] vdpa: request iova_range only once, (continued)
- [PULL 17/41] vdpa: request iova_range only once, Michael S. Tsirkin, 2022/12/21
- [PULL 18/41] vdpa: move SVQ vring features check to net/, Michael S. Tsirkin, 2022/12/21
- [PULL 20/41] vdpa: add asid parameter to vhost_vdpa_dma_map/unmap, Michael S. Tsirkin, 2022/12/21
- [PULL 24/41] vhost-user: send set log base message only once, Michael S. Tsirkin, 2022/12/21
- [PULL 26/41] acpi/tests/avocado/bits: add SPDX license identifiers for bios bits tests, Michael S. Tsirkin, 2022/12/21
- [PULL 21/41] vdpa: store x-svq parameter in VhostVDPAState, Michael S. Tsirkin, 2022/12/21
- [PULL 22/41] vdpa: add shadow_data to vhost_vdpa, Michael S. Tsirkin, 2022/12/21
- [PULL 25/41] include/hw: attempt to document VirtIO feature variables, Michael S. Tsirkin, 2022/12/21
- [PULL 23/41] vdpa: always start CVQ in SVQ mode if possible, Michael S. Tsirkin, 2022/12/21
- [PULL 19/41] vdpa: allocate SVQ array unconditionally, Michael S. Tsirkin, 2022/12/21
- [PULL 27/41] vhost: fix vq dirty bitmap syncing when vIOMMU is enabled,
Michael S. Tsirkin <=
- [PULL 29/41] pci: drop redundant PCIDeviceClass::is_bridge field, Michael S. Tsirkin, 2022/12/21
- [PULL 30/41] docs/acpi/bits: document BITS_DEBUG environment variable, Michael S. Tsirkin, 2022/12/21
- [PULL 34/41] hw/virtio: Add missing "hw/core/cpu.h" include, Michael S. Tsirkin, 2022/12/21
- [PULL 28/41] remove DEC 21154 PCI bridge, Michael S. Tsirkin, 2022/12/21
- [PULL 33/41] hw/cxl/device: Add Flex Bus Port DVSEC, Michael S. Tsirkin, 2022/12/21
- [PULL 31/41] acpi/tests/avocado/bits: add mformat as one of the dependencies, Michael S. Tsirkin, 2022/12/21
- [PULL 32/41] hw/acpi: Rename tco.c -> ich9_tco.c, Michael S. Tsirkin, 2022/12/21
- [PULL 35/41] hw/virtio: Rename virtio_ss[] -> specific_virtio_ss[], Michael S. Tsirkin, 2022/12/21
- [PULL 38/41] hw/virtio: Extract config read/write accessors to virtio-config-io.c, Michael S. Tsirkin, 2022/12/21
- [PULL 40/41] libvhost-user: Switch to unsigned int for inuse field in struct VuVirtq, Michael S. Tsirkin, 2022/12/21