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.
Signed-off-by: Changyuan Lyu <[email protected]>
---
drivers/nvdimm/virtio_pmem.c | 29 +++++++++++++++++++++++++----
include/uapi/linux/virtio_pmem.h | 8 ++++++++
2 files changed, 33 insertions(+), 4 deletions(-)
diff --git a/drivers/nvdimm/virtio_pmem.c b/drivers/nvdimm/virtio_pmem.c
index a92eb172f0e7..5b28d543728b 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 +59,23 @@ 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_SHMCAP_ID);
+ if (!have_shm) {
+ dev_err(&vdev->dev, "failed to get shared memory region %d\n",
+ VIRTIO_PMEM_SHMCAP_ID);
+ return -EINVAL;
+ }
+ 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 +137,13 @@ 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..025174f6eacf 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_SHMCAP_ID 0
+
struct virtio_pmem_config {
__le64 start;
__le64 size;
--
2.43.0.472.g3155946c3a-goog
On Tue, Dec 19, 2023 at 3:19 PM Changyuan Lyu <[email protected]> wrote:
>
> 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.
>
> Signed-off-by: Changyuan Lyu <[email protected]>
> ---
> drivers/nvdimm/virtio_pmem.c | 29 +++++++++++++++++++++++++----
> include/uapi/linux/virtio_pmem.h | 8 ++++++++
> 2 files changed, 33 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/nvdimm/virtio_pmem.c b/drivers/nvdimm/virtio_pmem.c
> index a92eb172f0e7..5b28d543728b 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 +59,23 @@ 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_SHMCAP_ID);
> + if (!have_shm) {
> + dev_err(&vdev->dev, "failed to get shared memory region %d\n",
> + VIRTIO_PMEM_SHMCAP_ID);
> + return -EINVAL;
> + }
> + 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 +137,13 @@ 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..025174f6eacf 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_SHMCAP_ID 0
NIT: not a native speaker, but any reason for "CAP" here? Would it be
better to use SHMMEM_REGION_ID?
Thanks
> +
> struct virtio_pmem_config {
> __le64 start;
> __le64 size;
> --
> 2.43.0.472.g3155946c3a-goog
>
On Tue, Dec 19, 2023 at 7:57 PM Jason Wang <[email protected]> wrote:
>
> On Tue, Dec 19, 2023 at 3:19 PM Changyuan Lyu <[email protected]> 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 <[email protected]> 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.
Signed-off-by: Changyuan Lyu <[email protected]>
---
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
On Tue, Dec 19, 2023 at 10:13:00PM -0800, Changyuan Lyu wrote:
> On Tue, Dec 19, 2023 at 7:57 PM Jason Wang <[email protected]> wrote:
> >
> > On Tue, Dec 19, 2023 at 3:19 PM Changyuan Lyu <[email protected]> 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 <[email protected]> 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 <[email protected]>
>
> ---
> 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
On Tue, Dec 19, 2023 at 11:01 PM Michael S. Tsirkin <[email protected]> wrote:
>
> This is not a great description. Please describe what the patch does.
Thanks for the feedback! Please see the v3 patch below.
---8<---
This patch adds the support for feature VIRTIO_PMEM_F_SHMEM_REGION
(virtio spec v1.2 section 5.19.5.2 [1]). Feature bit
VIRTIO_PMEM_F_SHMEM_REGION is added to the driver feature
table.
If the driver feature bit VIRTIO_PMEM_F_SHMEM_REGION is found,
during probe, virtio pmem ignores the `start` and `size` fields in
device config and looks for a shared memory region of id 0. The
physical address range of the pmem is then determined by 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 <[email protected]>
---
v3:
* updated the patch description.
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
On Tue, Dec 19, 2023 at 11:32:27PM -0800, Changyuan Lyu wrote:
> On Tue, Dec 19, 2023 at 11:01 PM Michael S. Tsirkin <[email protected]> wrote:
> >
> > This is not a great description. Please describe what the patch does.
>
> Thanks for the feedback! Please see the v3 patch below.
>
> ---8<---
>
> This patch adds the support for feature VIRTIO_PMEM_F_SHMEM_REGION
> (virtio spec v1.2 section 5.19.5.2 [1]). Feature bit
> VIRTIO_PMEM_F_SHMEM_REGION is added to the driver feature
> table.
>
> If the driver feature bit VIRTIO_PMEM_F_SHMEM_REGION is found,
> during probe, virtio pmem ignores the `start` and `size` fields in
> device config and looks for a shared memory region of id 0. The
> physical address range of the pmem is then determined by 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 <[email protected]>
>
> ---
> v3:
> * updated the patch description.
> 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;
Maybe additionally, add a validate callback and clear
VIRTIO_PMEM_F_SHMEM_REGION if VIRTIO_PMEM_SHMEM_REGION_ID is not there.
> + }
> + 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
> + */
Either make this comment shorter to fit in one line, or put the
multi-line comment before the define.
> +
> +/* 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
Thanks Michael for the feedback!
On Tue, Dec 19, 2023 at 11:44 PM Michael S. Tsirkin <[email protected]> wrote:
>
> > On Tue, Dec 19, 2023 at 11:32:27PM -0800, Changyuan Lyu wrote:
> >
> > + 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;
> > + }
>
> Maybe additionally, add a validate callback and clear
> VIRTIO_PMEM_F_SHMEM_REGION if VIRTIO_PMEM_SHMEM_REGION_ID is not there.
Done.
> > +/* Feature bits */
> > +#define VIRTIO_PMEM_F_SHMEM_REGION 0 /* guest physical address range will be
> > + * indicated as shared memory region 0
> > + */
>
> Either make this comment shorter to fit in one line, or put the
> multi-line comment before the define.
Done.
---8<---
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 <[email protected]>
---
v4:
* added virtio_pmem_validate callback.
v3:
* updated the patch description.
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 | 36 ++++++++++++++++++++++++++++----
include/uapi/linux/virtio_pmem.h | 7 +++++++
2 files changed, 39 insertions(+), 4 deletions(-)
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,
};
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 <linux/virtio_ids.h>
#include <linux/virtio_config.h>
+/* 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;
--
2.43.0.472.g3155946c3a-goog
On Thu, Dec 21, 2023 at 4:49 AM Changyuan Lyu <[email protected]> wrote:
>
> Thanks Michael for the feedback!
>
> On Tue, Dec 19, 2023 at 11:44 PM Michael S. Tsirkin <[email protected]> wrote:
> >
> > > On Tue, Dec 19, 2023 at 11:32:27PM -0800, Changyuan Lyu wrote:
> > >
> > > + 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;
> > > + }
> >
> > Maybe additionally, add a validate callback and clear
> > VIRTIO_PMEM_F_SHMEM_REGION if VIRTIO_PMEM_SHMEM_REGION_ID is not there.
>
> Done.
>
> > > +/* Feature bits */
> > > +#define VIRTIO_PMEM_F_SHMEM_REGION 0 /* guest physical address range will be
> > > + * indicated as shared memory region 0
> > > + */
> >
> > Either make this comment shorter to fit in one line, or put the
> > multi-line comment before the define.
>
> Done.
>
> ---8<---
>
> 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 <[email protected]>
Acked-by: Jason Wang <[email protected]>
Thanks
> ---
> v4:
> * added virtio_pmem_validate callback.
> v3:
> * updated the patch description.
> 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 | 36 ++++++++++++++++++++++++++++----
> include/uapi/linux/virtio_pmem.h | 7 +++++++
> 2 files changed, 39 insertions(+), 4 deletions(-)
>
> 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,
> };
> 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 <linux/virtio_ids.h>
> #include <linux/virtio_config.h>
>
> +/* 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;
> --
> 2.43.0.472.g3155946c3a-goog
>