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authorMichael S. Tsirkin <mst@redhat.com>2017-01-24 19:03:40 +0200
committerMichael S. Tsirkin <mst@redhat.com>2017-02-01 03:37:18 +0200
commitd56ec1e98c0005933fe677d633484297f422691a (patch)
tree3d7ad387f92654b107f6618016b48dd0bbae0713 /hw/virtio/vhost.c
parentc25d97c4ff37d48aeda395cb5bfb8182b786f0e1 (diff)
downloadfocaccia-qemu-d56ec1e98c0005933fe677d633484297f422691a.tar.gz
focaccia-qemu-d56ec1e98c0005933fe677d633484297f422691a.zip
vhost: skip ROM sections
vhost does not support RO protections on memory at the moment - adding
ROMs would mean that e.g. a buggy guest might change them in-memory - a
condition from which guest reset does not recover. Not nice.

We also definitely don't want to try logging writes into ROMs -
in particular guests set very high addresses for ROM BARs
so logging these writes would waste a lot of memory.

Maybe ROMs could be supported with the iotlb variant -
not sure, but there seems to be no good reason for virtio
to try to do DMA from ROM. So let's just skip ROM memory.

Suggested-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Tested-by: Laurent Vivier <lvivier@redhat.com>
Diffstat (limited to 'hw/virtio/vhost.c')
-rw-r--r--hw/virtio/vhost.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index b124d97d7c..febe519bbd 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -612,7 +612,8 @@ static void vhost_set_memory(MemoryListener *listener,
 
 static bool vhost_section(MemoryRegionSection *section)
 {
-    return memory_region_is_ram(section->mr);
+    return memory_region_is_ram(section->mr) &&
+        !memory_region_is_rom(section->mr);
 }
 
 static void vhost_begin(MemoryListener *listener)