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 --- drivers/nvdimm/virtio_pmem.c | 36 ++++++++++++++++++++++++++++++++---- 1 file changed, 32 insertions(+), 4 deletions(-) (limited to 'drivers/nvdimm') diff --git a/drivers/nvdimm/virtio_pmem.c b/drivers/nvdimm/virtio_pmem.c index a92eb172f0e7..4ceced5cefcf 100644 --- a/drivers/nvdimm/virtio_pmem.c +++ b/drivers/nvdimm/virtio_pmem.c @@ -29,12 +29,27 @@ static int init_vq(struct virtio_pmem *vpmem) return 0; }; +static int virtio_pmem_validate(struct virtio_device *vdev) +{ + struct virtio_shm_region shm_reg; + + if (virtio_has_feature(vdev, VIRTIO_PMEM_F_SHMEM_REGION) && + !virtio_get_shm_region(vdev, &shm_reg, (u8)VIRTIO_PMEM_SHMEM_REGION_ID) + ) { + dev_notice(&vdev->dev, "failed to get shared memory region %d\n", + VIRTIO_PMEM_SHMEM_REGION_ID); + __virtio_clear_bit(vdev, VIRTIO_PMEM_F_SHMEM_REGION); + } + return 0; +} + static int virtio_pmem_probe(struct virtio_device *vdev) { struct nd_region_desc ndr_desc = {}; struct nd_region *nd_region; struct virtio_pmem *vpmem; struct resource res; + struct virtio_shm_region shm_reg; int err = 0; if (!vdev->config->get) { @@ -57,10 +72,16 @@ static int virtio_pmem_probe(struct virtio_device *vdev) goto out_err; } - virtio_cread_le(vpmem->vdev, struct virtio_pmem_config, - start, &vpmem->start); - virtio_cread_le(vpmem->vdev, struct virtio_pmem_config, - size, &vpmem->size); + if (virtio_has_feature(vdev, VIRTIO_PMEM_F_SHMEM_REGION)) { + virtio_get_shm_region(vdev, &shm_reg, (u8)VIRTIO_PMEM_SHMEM_REGION_ID); + vpmem->start = shm_reg.addr; + vpmem->size = shm_reg.len; + } else { + virtio_cread_le(vpmem->vdev, struct virtio_pmem_config, + start, &vpmem->start); + virtio_cread_le(vpmem->vdev, struct virtio_pmem_config, + size, &vpmem->size); + } res.start = vpmem->start; res.end = vpmem->start + vpmem->size - 1; @@ -122,10 +143,17 @@ static void virtio_pmem_remove(struct virtio_device *vdev) virtio_reset_device(vdev); } +static unsigned int features[] = { + VIRTIO_PMEM_F_SHMEM_REGION, +}; + static struct virtio_driver virtio_pmem_driver = { + .feature_table = features, + .feature_table_size = ARRAY_SIZE(features), .driver.name = KBUILD_MODNAME, .driver.owner = THIS_MODULE, .id_table = id_table, + .validate = virtio_pmem_validate, .probe = virtio_pmem_probe, .remove = virtio_pmem_remove, }; -- cgit