[PATCH] vfio: add get device info API

[PATCH] vfio: add get device info API

[Mingjin Ye]

This patch adds an API to support getting device information.

The driver can use the "rte_vfio_get_device_info" helper to get
device information from EAL.

Cc: stable@dpdk.org

Signed-off-by: Mingjin Ye <mingjinx.ye@intel.com>
---
 lib/eal/include/rte_vfio.h | 26 ++++++++++++++++++++++++++
 lib/eal/linux/eal_vfio.c   | 19 +++++++++++++++++++
 lib/eal/version.map        |  3 +++
 3 files changed, 48 insertions(+)

diff --git a/lib/eal/include/rte_vfio.h b/lib/eal/include/rte_vfio.h
index 3487c4f2a2..b3f55963e3 100644
--- a/lib/eal/include/rte_vfio.h
+++ b/lib/eal/include/rte_vfio.h
@@ -212,6 +212,32 @@ int
 rte_vfio_get_group_num(const char *sysfs_base,
 		      const char *dev_addr, int *iommu_group_num);
 
+/**
+ * Get device information
+ *
+ * This function is only relevant to linux and will return
+ * an error on BSD.
+ *
+ * @param sysfs_base
+ *   sysfs path prefix.
+ *
+ * @param dev_addr
+ *   device location.
+ *
+ * @param vfio_dev_fd
+ *   VFIO fd.
+ *
+ * @param device_info
+ *   Device information.
+ *
+ * @return
+ *   0 on success.
+ *   <0 on failure.
+ */
+int
+rte_vfio_get_device_info(const char *sysfs_base, const char *dev_addr,
+			int *vfio_dev_fd, struct vfio_device_info *device_info);
+
 /**
  * Open a new VFIO container fd
  *
diff --git a/lib/eal/linux/eal_vfio.c b/lib/eal/linux/eal_vfio.c
index ad3c1654b2..5810d9fcd7 100644
--- a/lib/eal/linux/eal_vfio.c
+++ b/lib/eal/linux/eal_vfio.c
@@ -1222,6 +1222,25 @@ vfio_set_iommu_type(int vfio_container_fd)
 	return NULL;
 }
 
+int
+rte_vfio_get_device_info(const char *sysfs_base, const char *dev_addr,
+			int *vfio_dev_fd, struct vfio_device_info *device_info)
+{
+	if (!device_info || *vfio_dev_fd < 0)
+		return -1;
+
+	if (*vfio_dev_fd == 0) {
+		if (rte_vfio_setup_device(sysfs_base, dev_addr,
+				vfio_dev_fd, device_info))
+			return -1;
+	} else {
+		if (ioctl(*vfio_dev_fd, VFIO_DEVICE_GET_INFO, &device_info))
+			return -1;
+	}
+
+	return 0;
+}
+
 int
 vfio_has_supported_extensions(int vfio_container_fd)
 {
diff --git a/lib/eal/version.map b/lib/eal/version.map
index e00a844805..8a211aaefd 100644
--- a/lib/eal/version.map
+++ b/lib/eal/version.map
@@ -413,6 +413,9 @@ EXPERIMENTAL {
 	# added in 23.07
 	rte_memzone_max_get;
 	rte_memzone_max_set;
+
+	# added in 23.11
+	rte_vfio_get_device_info; # WINDOWS_NO_EXPORT
 };
 
 INTERNAL {
-- 
2.25.1

Re: [PATCH] vfio: add get device info API

[Chenbo Xia]

> On Nov 14, 2023, at 18:23, Mingjin Ye <mingjinx.ye@intel.com> wrote:
> 
> External email: Use caution opening links or attachments
> 
> 
> This patch adds an API to support getting device information.
> 
> The driver can use the "rte_vfio_get_device_info" helper to get
> device information from EAL.
> 
> Cc: stable@dpdk.org

No stable

Please explain why this api is needed in your use case. Taking this with
the use-case patch could be more clear.

Thanks,
Chenbo

> 
> Signed-off-by: Mingjin Ye <mingjinx.ye@intel.com>
> ---
> lib/eal/include/rte_vfio.h | 26 ++++++++++++++++++++++++++
> lib/eal/linux/eal_vfio.c   | 19 +++++++++++++++++++
> lib/eal/version.map        |  3 +++
> 3 files changed, 48 insertions(+)

[PATCH] vfio: add get device info API

[Mingjin Ye]

This patch adds an API to support getting device information.

The driver can use the "rte_vfio_get_device_info" helper to get
device information from EAL.

Cc: stable@dpdk.org

Signed-off-by: Mingjin Ye <mingjinx.ye@intel.com>
---
 lib/eal/include/rte_vfio.h | 26 ++++++++++++++++++++++++++
 lib/eal/linux/eal_vfio.c   | 19 +++++++++++++++++++
 lib/eal/version.map        |  1 +
 3 files changed, 46 insertions(+)

diff --git a/lib/eal/include/rte_vfio.h b/lib/eal/include/rte_vfio.h
index 3487c4f2a2..b3f55963e3 100644
--- a/lib/eal/include/rte_vfio.h
+++ b/lib/eal/include/rte_vfio.h
@@ -212,6 +212,32 @@ int
 rte_vfio_get_group_num(const char *sysfs_base,
 		      const char *dev_addr, int *iommu_group_num);
 
+/**
+ * Get device information
+ *
+ * This function is only relevant to linux and will return
+ * an error on BSD.
+ *
+ * @param sysfs_base
+ *   sysfs path prefix.
+ *
+ * @param dev_addr
+ *   device location.
+ *
+ * @param vfio_dev_fd
+ *   VFIO fd.
+ *
+ * @param device_info
+ *   Device information.
+ *
+ * @return
+ *   0 on success.
+ *   <0 on failure.
+ */
+int
+rte_vfio_get_device_info(const char *sysfs_base, const char *dev_addr,
+			int *vfio_dev_fd, struct vfio_device_info *device_info);
+
 /**
  * Open a new VFIO container fd
  *
diff --git a/lib/eal/linux/eal_vfio.c b/lib/eal/linux/eal_vfio.c
index ad3c1654b2..5810d9fcd7 100644
--- a/lib/eal/linux/eal_vfio.c
+++ b/lib/eal/linux/eal_vfio.c
@@ -1222,6 +1222,25 @@ vfio_set_iommu_type(int vfio_container_fd)
 	return NULL;
 }
 
+int
+rte_vfio_get_device_info(const char *sysfs_base, const char *dev_addr,
+			int *vfio_dev_fd, struct vfio_device_info *device_info)
+{
+	if (!device_info || *vfio_dev_fd < 0)
+		return -1;
+
+	if (*vfio_dev_fd == 0) {
+		if (rte_vfio_setup_device(sysfs_base, dev_addr,
+				vfio_dev_fd, device_info))
+			return -1;
+	} else {
+		if (ioctl(*vfio_dev_fd, VFIO_DEVICE_GET_INFO, &device_info))
+			return -1;
+	}
+
+	return 0;
+}
+
 int
 vfio_has_supported_extensions(int vfio_container_fd)
 {
diff --git a/lib/eal/version.map b/lib/eal/version.map
index e00a844805..8b4a9c237e 100644
--- a/lib/eal/version.map
+++ b/lib/eal/version.map
@@ -300,6 +300,7 @@ DPDK_24 {
 	rte_vfio_noiommu_is_enabled; # WINDOWS_NO_EXPORT
 	rte_vfio_release_device; # WINDOWS_NO_EXPORT
 	rte_vfio_setup_device; # WINDOWS_NO_EXPORT
+	rte_vfio_get_device_info; # WINDOWS_NO_EXPORT
 	rte_zmalloc;
 	rte_zmalloc_socket;
 
-- 
2.25.1

Re: [PATCH] vfio: add get device info API

[Stephen Hemminger]

On Tue, 14 Nov 2023 10:48:16 +0000
Mingjin Ye <mingjinx.ye@intel.com> wrote:

> +/**
> + * Get device information
> + *
> + * This function is only relevant to linux and will return
> + * an error on BSD.
> + *
> + * @param sysfs_base
> + *   sysfs path prefix.
> + *
> + * @param dev_addr
> + *   device location.
> + *
> + * @param vfio_dev_fd
> + *   VFIO fd.
> + *
> + * @param device_info
> + *   Device information.
> + *
> + * @return
> + *   0 on success.
> + *   <0 on failure.
> + */
> +int
> +rte_vfio_get_device_info(const char *sysfs_base, const char *dev_addr,
> +			int *vfio_dev_fd, struct vfio_device_info *device_info);

New api's must be experimental.
Or is this just internal?

RE: [PATCH] vfio: add get device info API

[Ye, MingjinX]

Hi Nipun and all,

Introducing new rte_vfio_get_device_info api in EAL to support getting information about devices. 
Could you provide some suggestions?

Thanks,
Mingjin

> -----Original Message-----
> From: Stephen Hemminger <stephen@networkplumber.org>
> Sent: Wednesday, November 15, 2023 8:12 AM
> To: Ye, MingjinX <mingjinx.ye@intel.com>
> Cc: dev@dpdk.org; Yang, Qiming <qiming.yang@intel.com>;
> stable@dpdk.org; Burakov, Anatoly <anatoly.burakov@intel.com>
> Subject: Re: [PATCH] vfio: add get device info API
> 
> On Tue, 14 Nov 2023 10:48:16 +0000
> Mingjin Ye <mingjinx.ye@intel.com> wrote:
> 
> > +/**
> > + * Get device information
> > + *
> > + * This function is only relevant to linux and will return
> > + * an error on BSD.
> > + *
> > + * @param sysfs_base
> > + *   sysfs path prefix.
> > + *
> > + * @param dev_addr
> > + *   device location.
> > + *
> > + * @param vfio_dev_fd
> > + *   VFIO fd.
> > + *
> > + * @param device_info
> > + *   Device information.
> > + *
> > + * @return
> > + *   0 on success.
> > + *   <0 on failure.
> > + */
> > +int
> > +rte_vfio_get_device_info(const char *sysfs_base, const char *dev_addr,
> > +			int *vfio_dev_fd, struct vfio_device_info
> *device_info);
> 
> New api's must be experimental.
> Or is this just internal?
New api is experimental.

Re: [PATCH] vfio: add get device info API

[Stephen Hemminger]

On Wed, 15 Nov 2023 07:54:20 +0000
"Ye, MingjinX" <mingjinx.ye@intel.com> wrote:

> > > +int
> > > +rte_vfio_get_device_info(const char *sysfs_base, const char *dev_addr,
> > > +			int *vfio_dev_fd, struct vfio_device_info  
> > *device_info);
> > 
> > New api's must be experimental.
> > Or is this just internal?  
> New api is experimental.


Then please use __rte_experimental tag.

Re: [PATCH] vfio: add get device info API

[Burakov, Anatoly]

On 11/14/2023 11:48 AM, Mingjin Ye wrote:
> This patch adds an API to support getting device information.
> 
> The driver can use the "rte_vfio_get_device_info" helper to get
> device information from EAL.
> 
> Cc: stable@dpdk.org
> 
> Signed-off-by: Mingjin Ye <mingjinx.ye@intel.com>
> ---
>   lib/eal/include/rte_vfio.h | 26 ++++++++++++++++++++++++++
>   lib/eal/linux/eal_vfio.c   | 19 +++++++++++++++++++
>   lib/eal/version.map        |  1 +
>   3 files changed, 46 insertions(+)
> 
> diff --git a/lib/eal/include/rte_vfio.h b/lib/eal/include/rte_vfio.h
> index 3487c4f2a2..b3f55963e3 100644
> --- a/lib/eal/include/rte_vfio.h
> +++ b/lib/eal/include/rte_vfio.h
> @@ -212,6 +212,32 @@ int
>   rte_vfio_get_group_num(const char *sysfs_base,
>   		      const char *dev_addr, int *iommu_group_num);
>   
> +/**
> + * Get device information
> + *
> + * This function is only relevant to linux and will return
> + * an error on BSD.
> + *
> + * @param sysfs_base
> + *   sysfs path prefix.
> + *
> + * @param dev_addr
> + *   device location.
> + *
> + * @param vfio_dev_fd
> + *   VFIO fd.
> + *
> + * @param device_info
> + *   Device information.
> + *
> + * @return
> + *   0 on success.
> + *   <0 on failure.
> + */
> +int
> +rte_vfio_get_device_info(const char *sysfs_base, const char *dev_addr,
> +			int *vfio_dev_fd, struct vfio_device_info *device_info);
> +
>   /**
>    * Open a new VFIO container fd
>    *
> diff --git a/lib/eal/linux/eal_vfio.c b/lib/eal/linux/eal_vfio.c
> index ad3c1654b2..5810d9fcd7 100644
> --- a/lib/eal/linux/eal_vfio.c
> +++ b/lib/eal/linux/eal_vfio.c
> @@ -1222,6 +1222,25 @@ vfio_set_iommu_type(int vfio_container_fd)
>   	return NULL;
>   }
>   
> +int
> +rte_vfio_get_device_info(const char *sysfs_base, const char *dev_addr,
> +			int *vfio_dev_fd, struct vfio_device_info *device_info)
> +{
> +	if (!device_info || *vfio_dev_fd < 0)
> +		return -1;

Do we not need to check other parameters? E.g. sysfs_base, dev_addr, 
vfio_dev_fd itself (could be NULL dereference).

> +
> +	if (*vfio_dev_fd == 0) {
> +		if (rte_vfio_setup_device(sysfs_base, dev_addr,
> +				vfio_dev_fd, device_info))
> +			return -1;
> +	} else {
> +		if (ioctl(*vfio_dev_fd, VFIO_DEVICE_GET_INFO, &device_info))
> +			return -1;
> +	}

Couldn't this just be an `else if`?

Would also be nice to have some DEBUG output here.

With all of the above addressed,

Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>

> +
> +	return 0;
> +}
> +
>   int
>   vfio_has_supported_extensions(int vfio_container_fd)
>   {
> diff --git a/lib/eal/version.map b/lib/eal/version.map
> index e00a844805..8b4a9c237e 100644
> --- a/lib/eal/version.map
> +++ b/lib/eal/version.map
> @@ -300,6 +300,7 @@ DPDK_24 {
>   	rte_vfio_noiommu_is_enabled; # WINDOWS_NO_EXPORT
>   	rte_vfio_release_device; # WINDOWS_NO_EXPORT
>   	rte_vfio_setup_device; # WINDOWS_NO_EXPORT
> +	rte_vfio_get_device_info; # WINDOWS_NO_EXPORT
>   	rte_zmalloc;
>   	rte_zmalloc_socket;
>   

-- 
Thanks,
Anatoly