| Message ID | 20231220061301.228671-1-changyuanl@google.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] virtio_pmem: support feature SHMEM_REGION | expand |
On Tue, Dec 19, 2023 at 10:13:00PM -0800, Changyuan Lyu wrote: > On Tue, Dec 19, 2023 at 7:57 PM Jason Wang <jasowang@redhat.com> wrote: > > > > On Tue, Dec 19, 2023 at 3:19 PM Changyuan Lyu <changyuanl@google.com> wrote: > > > > > > +/* shmid of the shared memory region corresponding to the pmem */ > > > +#define VIRTIO_PMEM_SHMCAP_ID 0 > > > > NIT: not a native speaker, but any reason for "CAP" here? Would it be > > better to use SHMMEM_REGION_ID? > > I was following the name VIRTIO_FS_SHMCAP_ID_CACHE in > include/uapi/linux/virtio_fs.h, where I guess "CAP" was referring to > the shared memory capability when the device is on PCI bus. I agree > SHMMEM_REGION_ID is a better name. > > On Tue, Dec 19, 2023 at 3:19 PM Changyuan Lyu <changyuanl@google.com> wrote: > > > > + if (!have_shm) { > > + dev_err(&vdev->dev, "failed to get shared memory region %d\n", > > + VIRTIO_PMEM_SHMCAP_ID); > > + return -EINVAL; > > + } > > I realized that it needs to jump to tag out_vq to clean up vqs > instead of simply returnning an error. > > Thanks for reviewing the patch! > > ---8<--- > > As per virtio spec 1.2 section 5.19.5.2, if the feature > VIRTIO_PMEM_F_SHMEM_REGION has been negotiated, the driver MUST query > shared memory ID 0 for the physical address ranges. This is not a great description. Please describe what the patch does. > Signed-off-by: Changyuan Lyu <changyuanl@google.com> > > --- > V2: > * renamed VIRTIO_PMEM_SHMCAP_ID to VIRTIO_PMEM_SHMEM_REGION_ID > * fixed the error handling when region 0 does not exist > --- > drivers/nvdimm/virtio_pmem.c | 30 ++++++++++++++++++++++++++---- > include/uapi/linux/virtio_pmem.h | 8 ++++++++ > 2 files changed, 34 insertions(+), 4 deletions(-) > > diff --git a/drivers/nvdimm/virtio_pmem.c b/drivers/nvdimm/virtio_pmem.c > index a92eb172f0e7..8e447c7558cb 100644 > --- a/drivers/nvdimm/virtio_pmem.c > +++ b/drivers/nvdimm/virtio_pmem.c > @@ -35,6 +35,8 @@ static int virtio_pmem_probe(struct virtio_device *vdev) > struct nd_region *nd_region; > struct virtio_pmem *vpmem; > struct resource res; > + struct virtio_shm_region shm_reg; > + bool have_shm; > int err = 0; > > if (!vdev->config->get) { > @@ -57,10 +59,24 @@ 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)) { > + have_shm = virtio_get_shm_region(vdev, &shm_reg, > + (u8)VIRTIO_PMEM_SHMEM_REGION_ID); > + if (!have_shm) { > + dev_err(&vdev->dev, "failed to get shared memory region %d\n", > + VIRTIO_PMEM_SHMEM_REGION_ID); > + err = -ENXIO; > + goto out_vq; > + } > + 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; > @@ -122,7 +138,13 @@ 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, > diff --git a/include/uapi/linux/virtio_pmem.h b/include/uapi/linux/virtio_pmem.h > index d676b3620383..c5e49b6e58b1 100644 > --- a/include/uapi/linux/virtio_pmem.h > +++ b/include/uapi/linux/virtio_pmem.h > @@ -14,6 +14,14 @@ > #include <linux/virtio_ids.h> > #include <linux/virtio_config.h> > > +/* Feature bits */ > +#define VIRTIO_PMEM_F_SHMEM_REGION 0 /* guest physical address range will be > + * indicated as shared memory 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; > -- > 2.43.0.472.g3155946c3a-goog
diff --git a/drivers/nvdimm/virtio_pmem.c b/drivers/nvdimm/virtio_pmem.c index a92eb172f0e7..8e447c7558cb 100644 --- a/drivers/nvdimm/virtio_pmem.c +++ b/drivers/nvdimm/virtio_pmem.c @@ -35,6 +35,8 @@ static int virtio_pmem_probe(struct virtio_device *vdev) struct nd_region *nd_region; struct virtio_pmem *vpmem; struct resource res; + struct virtio_shm_region shm_reg; + bool have_shm; int err = 0; if (!vdev->config->get) { @@ -57,10 +59,24 @@ 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)) { + have_shm = virtio_get_shm_region(vdev, &shm_reg, + (u8)VIRTIO_PMEM_SHMEM_REGION_ID); + if (!have_shm) { + dev_err(&vdev->dev, "failed to get shared memory region %d\n", + VIRTIO_PMEM_SHMEM_REGION_ID); + err = -ENXIO; + goto out_vq; + } + 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; @@ -122,7 +138,13 @@ 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, diff --git a/include/uapi/linux/virtio_pmem.h b/include/uapi/linux/virtio_pmem.h index d676b3620383..c5e49b6e58b1 100644 --- a/include/uapi/linux/virtio_pmem.h +++ b/include/uapi/linux/virtio_pmem.h @@ -14,6 +14,14 @@ #include <linux/virtio_ids.h> #include <linux/virtio_config.h> +/* Feature bits */ +#define VIRTIO_PMEM_F_SHMEM_REGION 0 /* guest physical address range will be + * indicated as shared memory 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;