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| author | Michael S. Tsirkin <mst@redhat.com> | 2015-03-12 12:56:43 +1030 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2015-03-13 15:55:43 +1030 |
| commit | 87e7bf1450c9f6bd0927f63ebc0fe2d12e8bc83d (patch) | |
| tree | a4292d97cd9671365d410c6c840d162c5a0da99b | |
| parent | 71e4b8bf0482fc7d70e9d4c10b13c207a285d58a (diff) | |
| download | lwn-87e7bf1450c9f6bd0927f63ebc0fe2d12e8bc83d.tar.gz lwn-87e7bf1450c9f6bd0927f63ebc0fe2d12e8bc83d.zip | |
virtio_mmio: generation support
virtio_mmio currently lacks generation support which
makes multi-byte field access racy.
Fix by getting the value at offset 0xfc for version 2
devices. Nothing we can do for version 1, so return
generation id 0.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| -rw-r--r-- | drivers/virtio/virtio_mmio.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c index cad569890908..9c877d2375a5 100644 --- a/drivers/virtio/virtio_mmio.c +++ b/drivers/virtio/virtio_mmio.c @@ -174,6 +174,16 @@ static void vm_set(struct virtio_device *vdev, unsigned offset, writeb(ptr[i], vm_dev->base + VIRTIO_MMIO_CONFIG + offset + i); } +static u32 vm_generation(struct virtio_device *vdev) +{ + struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); + + if (vm_dev->version == 1) + return 0; + else + return readl(vm_dev->base + VIRTIO_MMIO_CONFIG_GENERATION); +} + static u8 vm_get_status(struct virtio_device *vdev) { struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); @@ -440,6 +450,7 @@ static const char *vm_bus_name(struct virtio_device *vdev) static const struct virtio_config_ops virtio_mmio_config_ops = { .get = vm_get, .set = vm_set, + .generation = vm_generation, .get_status = vm_get_status, .set_status = vm_set_status, .reset = vm_reset, |