Message ID | 20230815122007.928049-1-thuth@redhat.com |
---|---|
State | New |
Headers | show |
Series | include/hw/virtio/virtio-gpu: Fix virtio-gpu with blob on big endian hosts | expand |
On Tue, Aug 15, 2023 at 4:20 PM Thomas Huth <thuth@redhat.com> wrote: > > Using "-device virtio-gpu,blob=true" currently does not work on big > endian hosts (like s390x). The guest kernel prints an error message > like: > > [drm:virtio_gpu_dequeue_ctrl_func [virtio_gpu]] *ERROR* response 0x1200 (command 0x10c) > > and the display stays black. When running QEMU with "-d guest_errors", > it shows an error message like this: > > virtio_gpu_create_mapping_iov: nr_entries is too big (83886080 > 16384) > > which indicates that this value has not been properly byte-swapped. > And indeed, the virtio_gpu_create_blob_bswap() function (that should > swap the fields in the related structure) fails to swap some of the > entries. After correctly swapping all missing values here, too, the > virtio-gpu device is now also working with blob=true on s390x hosts. > > Fixes: e0933d91b1 ("virtio-gpu: Add virtio_gpu_resource_create_blob") > Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2230469 > Signed-off-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> > --- > include/hw/virtio/virtio-gpu-bswap.h | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/include/hw/virtio/virtio-gpu-bswap.h b/include/hw/virtio/virtio-gpu-bswap.h > index 9124108485..637a0585d0 100644 > --- a/include/hw/virtio/virtio-gpu-bswap.h > +++ b/include/hw/virtio/virtio-gpu-bswap.h > @@ -63,7 +63,10 @@ virtio_gpu_create_blob_bswap(struct virtio_gpu_resource_create_blob *cblob) > { > virtio_gpu_ctrl_hdr_bswap(&cblob->hdr); > le32_to_cpus(&cblob->resource_id); > + le32_to_cpus(&cblob->blob_mem); > le32_to_cpus(&cblob->blob_flags); > + le32_to_cpus(&cblob->nr_entries); > + le64_to_cpus(&cblob->blob_id); > le64_to_cpus(&cblob->size); > } > > -- > 2.39.3 >
diff --git a/include/hw/virtio/virtio-gpu-bswap.h b/include/hw/virtio/virtio-gpu-bswap.h index 9124108485..637a0585d0 100644 --- a/include/hw/virtio/virtio-gpu-bswap.h +++ b/include/hw/virtio/virtio-gpu-bswap.h @@ -63,7 +63,10 @@ virtio_gpu_create_blob_bswap(struct virtio_gpu_resource_create_blob *cblob) { virtio_gpu_ctrl_hdr_bswap(&cblob->hdr); le32_to_cpus(&cblob->resource_id); + le32_to_cpus(&cblob->blob_mem); le32_to_cpus(&cblob->blob_flags); + le32_to_cpus(&cblob->nr_entries); + le64_to_cpus(&cblob->blob_id); le64_to_cpus(&cblob->size); }
Using "-device virtio-gpu,blob=true" currently does not work on big endian hosts (like s390x). The guest kernel prints an error message like: [drm:virtio_gpu_dequeue_ctrl_func [virtio_gpu]] *ERROR* response 0x1200 (command 0x10c) and the display stays black. When running QEMU with "-d guest_errors", it shows an error message like this: virtio_gpu_create_mapping_iov: nr_entries is too big (83886080 > 16384) which indicates that this value has not been properly byte-swapped. And indeed, the virtio_gpu_create_blob_bswap() function (that should swap the fields in the related structure) fails to swap some of the entries. After correctly swapping all missing values here, too, the virtio-gpu device is now also working with blob=true on s390x hosts. Fixes: e0933d91b1 ("virtio-gpu: Add virtio_gpu_resource_create_blob") Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2230469 Signed-off-by: Thomas Huth <thuth@redhat.com> --- include/hw/virtio/virtio-gpu-bswap.h | 3 +++ 1 file changed, 3 insertions(+)