From 35967bdcff325f4572b21b0d0005318da7e03f53 Mon Sep 17 00:00:00 2001 From: Changyuan Lyu Date: Wed, 20 Dec 2023 12:49:06 -0800 Subject: virtio_pmem: support feature SHMEM_REGION This patch adds the support for feature VIRTIO_PMEM_F_SHMEM_REGION (virtio spec v1.2 section 5.19.5.2 [1]). During feature negotiation, if VIRTIO_PMEM_F_SHMEM_REGION is offered by the device, the driver looks for a shared memory region of id 0. If it is found, this feature is understood. Otherwise, this feature bit is cleared. During probe, if VIRTIO_PMEM_F_SHMEM_REGION has been negotiated, virtio pmem ignores the `start` and `size` fields in device config and uses the physical address range of shared memory region 0. [1] https://docs.oasis-open.org/virtio/virtio/v1.2/csd01/virtio-v1.2-csd01.html#x1-6480002 Signed-off-by: Changyuan Lyu Message-Id: <20231220204906.566922-1-changyuanl@google.com> Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang --- include/uapi/linux/virtio_pmem.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/uapi') diff --git a/include/uapi/linux/virtio_pmem.h b/include/uapi/linux/virtio_pmem.h index d676b3620383..ede4f3564977 100644 --- a/include/uapi/linux/virtio_pmem.h +++ b/include/uapi/linux/virtio_pmem.h @@ -14,6 +14,13 @@ #include #include +/* Feature bits */ +/* guest physical address range will be indicated as shared memory region 0 */ +#define VIRTIO_PMEM_F_SHMEM_REGION 0 + +/* shmid of the shared memory region corresponding to the pmem */ +#define VIRTIO_PMEM_SHMEM_REGION_ID 0 + struct virtio_pmem_config { __le64 start; __le64 size; -- cgit