| Message ID | 20250220-virtio-shm-page-size-v3-4-874fff6f3979@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | virtio: obtain SHM page size from device | expand |
On 2/20/25 17:28, Sergio Lopez wrote: > Add VIRTGPU_PARAM_HOST_SHM_PAGE_SIZE as a param that can be read with > VIRTGPU_GETPARAM by userspace applications running in the guest to > obtain the host's page size and find out the right alignment to be used > in shared memory allocations. > > Signed-off-by: Sergio Lopez <slp@redhat.com> > --- > drivers/gpu/drm/virtio/virtgpu_ioctl.c | 5 +++++ > include/uapi/drm/virtgpu_drm.h | 1 + > 2 files changed, 6 insertions(+) > > diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c > index c33c057365f85a2ace536f91655c903036827312..f112b862c2de4d021fb6a54a080f42ad75034227 100644 > --- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c > +++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c > @@ -117,6 +117,11 @@ static int virtio_gpu_getparam_ioctl(struct drm_device *dev, void *data, > case VIRTGPU_PARAM_EXPLICIT_DEBUG_NAME: > value = vgdev->has_context_init ? 1 : 0; > break; > + case VIRTGPU_PARAM_HOST_SHM_PAGE_SIZE: > + if (!vgdev->has_host_visible) > + return -ENOENT; > + value = vgdev->host_visible_region.page_size; > + break; > default: > return -EINVAL; > } > diff --git a/include/uapi/drm/virtgpu_drm.h b/include/uapi/drm/virtgpu_drm.h > index c2ce71987e9bb816d13a300679336cb756f1cbcf..72db6b3339e0dcaf550acbf5ac4381a6e5c2216d 100644 > --- a/include/uapi/drm/virtgpu_drm.h > +++ b/include/uapi/drm/virtgpu_drm.h > @@ -98,6 +98,7 @@ struct drm_virtgpu_execbuffer { > #define VIRTGPU_PARAM_CONTEXT_INIT 6 /* DRM_VIRTGPU_CONTEXT_INIT */ > #define VIRTGPU_PARAM_SUPPORTED_CAPSET_IDs 7 /* Bitmask of supported capability set ids */ > #define VIRTGPU_PARAM_EXPLICIT_DEBUG_NAME 8 /* Ability to set debug name from userspace */ > +#define VIRTGPU_PARAM_HOST_SHM_PAGE_SIZE 9 /* Host SHM page size, with format PAGE_SIZE >> 12 */ > > struct drm_virtgpu_getparam { > __u64 param; > Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c index c33c057365f85a2ace536f91655c903036827312..f112b862c2de4d021fb6a54a080f42ad75034227 100644 --- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c +++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c @@ -117,6 +117,11 @@ static int virtio_gpu_getparam_ioctl(struct drm_device *dev, void *data, case VIRTGPU_PARAM_EXPLICIT_DEBUG_NAME: value = vgdev->has_context_init ? 1 : 0; break; + case VIRTGPU_PARAM_HOST_SHM_PAGE_SIZE: + if (!vgdev->has_host_visible) + return -ENOENT; + value = vgdev->host_visible_region.page_size; + break; default: return -EINVAL; } diff --git a/include/uapi/drm/virtgpu_drm.h b/include/uapi/drm/virtgpu_drm.h index c2ce71987e9bb816d13a300679336cb756f1cbcf..72db6b3339e0dcaf550acbf5ac4381a6e5c2216d 100644 --- a/include/uapi/drm/virtgpu_drm.h +++ b/include/uapi/drm/virtgpu_drm.h @@ -98,6 +98,7 @@ struct drm_virtgpu_execbuffer { #define VIRTGPU_PARAM_CONTEXT_INIT 6 /* DRM_VIRTGPU_CONTEXT_INIT */ #define VIRTGPU_PARAM_SUPPORTED_CAPSET_IDs 7 /* Bitmask of supported capability set ids */ #define VIRTGPU_PARAM_EXPLICIT_DEBUG_NAME 8 /* Ability to set debug name from userspace */ +#define VIRTGPU_PARAM_HOST_SHM_PAGE_SIZE 9 /* Host SHM page size, with format PAGE_SIZE >> 12 */ struct drm_virtgpu_getparam { __u64 param;
Add VIRTGPU_PARAM_HOST_SHM_PAGE_SIZE as a param that can be read with VIRTGPU_GETPARAM by userspace applications running in the guest to obtain the host's page size and find out the right alignment to be used in shared memory allocations. Signed-off-by: Sergio Lopez <slp@redhat.com> --- drivers/gpu/drm/virtio/virtgpu_ioctl.c | 5 +++++ include/uapi/drm/virtgpu_drm.h | 1 + 2 files changed, 6 insertions(+)