diff options
| author | Michael S. Tsirkin <mst@redhat.com> | 2015-10-28 17:48:02 +0200 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2015-11-09 09:59:32 +0000 |
| commit | 572ec519ed6fe68f10ec65963527536c2322eab0 (patch) | |
| tree | 8c197f6a2ed5f29dac13451492bee4cc4a919425 /hw/virtio | |
| parent | c4a7bf54e588ff2de9fba0898b686156251b2063 (diff) | |
| download | qemu-572ec519ed6fe68f10ec65963527536c2322eab0.tar.gz qemu-572ec519ed6fe68f10ec65963527536c2322eab0.tar.bz2 qemu-572ec519ed6fe68f10ec65963527536c2322eab0.zip | |
dataplane: simplify indirect descriptor read
Use address_space_read to make sure we handle the case of an indirect
descriptor crossing DIMM boundary correctly.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Tested-by: Igor Mammedov <imammedo@redhat.com>
Message-id: 1446047243-3221-1-git-send-email-mst@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'hw/virtio')
| -rw-r--r-- | hw/virtio/dataplane/vring.c | 28 |
1 files changed, 18 insertions, 10 deletions
diff --git a/hw/virtio/dataplane/vring.c b/hw/virtio/dataplane/vring.c index 68f1994434..0b92fcf859 100644 --- a/hw/virtio/dataplane/vring.c +++ b/hw/virtio/dataplane/vring.c @@ -257,6 +257,21 @@ static void copy_in_vring_desc(VirtIODevice *vdev, host->next = virtio_lduw_p(vdev, &guest->next); } +static bool read_vring_desc(VirtIODevice *vdev, + hwaddr guest, + struct vring_desc *host) +{ + if (address_space_read(&address_space_memory, guest, MEMTXATTRS_UNSPECIFIED, + (uint8_t *)host, sizeof *host)) { + return false; + } + host->addr = virtio_tswap64(vdev, host->addr); + host->len = virtio_tswap32(vdev, host->len); + host->flags = virtio_tswap16(vdev, host->flags); + host->next = virtio_tswap16(vdev, host->next); + return true; +} + /* This is stolen from linux/drivers/vhost/vhost.c. */ static int get_indirect(VirtIODevice *vdev, Vring *vring, VirtQueueElement *elem, struct vring_desc *indirect) @@ -284,23 +299,16 @@ static int get_indirect(VirtIODevice *vdev, Vring *vring, } do { - struct vring_desc *desc_ptr; - MemoryRegion *mr; - /* Translate indirect descriptor */ - desc_ptr = vring_map(&mr, - indirect->addr + found * sizeof(desc), - sizeof(desc), false); - if (!desc_ptr) { - error_report("Failed to map indirect descriptor " + if (!read_vring_desc(vdev, indirect->addr + found * sizeof(desc), + &desc)) { + error_report("Failed to read indirect descriptor " "addr %#" PRIx64 " len %zu", (uint64_t)indirect->addr + found * sizeof(desc), sizeof(desc)); vring->broken = true; return -EFAULT; } - copy_in_vring_desc(vdev, desc_ptr, &desc); - memory_region_unref(mr); /* Ensure descriptor has been loaded before accessing fields */ barrier(); /* read_barrier_depends(); */ |