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[PATCH 02/47] vhost: fix vq dirty bitmap syncing when vIOMMU is enabled
From: |
Michael Tokarev |
Subject: |
[PATCH 02/47] vhost: fix vq dirty bitmap syncing when vIOMMU is enabled |
Date: |
Wed, 8 Mar 2023 19:57:05 +0300 |
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>
(cherry picked from commit 345cc1cbcbce2bab00abc2b88338d7d89c702d6b)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
---
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 d1c4c20b8c..34d356e903 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)
{
--
2.30.2
- [RFC PATCH 00/47] Patch Round-up for stable 7.2.1, Michael Tokarev, 2023/03/08
- [PATCH 02/47] vhost: fix vq dirty bitmap syncing when vIOMMU is enabled,
Michael Tokarev <=
- [PATCH 05/47] target/arm: fix handling of HLT semihosting in system mode, Michael Tokarev, 2023/03/08
- [PATCH 13/47] target/arm: allow writes to SCR_EL3.HXEn bit when FEAT_HCX is enabled, Michael Tokarev, 2023/03/08
- [PATCH 12/47] target/arm: Fix sve_probe_page, Michael Tokarev, 2023/03/08
- [PATCH 11/47] configure: fix GLIB_VERSION for cross-compilation, Michael Tokarev, 2023/03/08
- [PATCH 14/47] target/arm: Fix in_debug path in S1_ptw_translate, Michael Tokarev, 2023/03/08
- [PATCH 18/47] qcow2: Fix theoretical corruption in store_bitmap() error path, Michael Tokarev, 2023/03/08
- [PATCH 17/47] migration/ram: Fix populate_read_range(), Michael Tokarev, 2023/03/08
- [PATCH 15/47] target/arm: Fix physical address resolution for Stage2, Michael Tokarev, 2023/03/08
- [PATCH 24/47] target/i386: Fix BZHI instruction, Michael Tokarev, 2023/03/08
- [PATCH 19/47] block: fix detect-zeroes= with BDRV_REQ_REGISTERED_BUF, Michael Tokarev, 2023/03/08