misc mdev tidyups

misc mdev tidyups

[Christoph Hellwig]

Hi all,

this series tidies up the mdev Kconfig interaction and documentation a bit.

Diffstat:
 Documentation/driver-api/vfio-mediated-device.rst |  108 ----------------------
 Documentation/s390/vfio-ap.rst                    |    1 
 arch/s390/Kconfig                                 |    6 -
 arch/s390/configs/debug_defconfig                 |    1 
 arch/s390/configs/defconfig                       |    1 
 drivers/gpu/drm/i915/Kconfig                      |    2 
 drivers/vfio/mdev/Kconfig                         |    8 -
 samples/Kconfig                                   |   16 +--
 samples/vfio-mdev/README.rst                      |  100 ++++++++++++++++++++
 9 files changed, 115 insertions(+), 128 deletions(-)

[PATCH 1/4] vfio-mdev: allow building the samples into the kernel

[Christoph Hellwig]

There is nothing in the vfio-mdev sample drivers that requires building
them as modules, so remove that restriction.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 samples/Kconfig | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/samples/Kconfig b/samples/Kconfig
index 0d81c00289ee36..f1b8d4ff123036 100644
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -184,23 +184,23 @@ config SAMPLE_UHID
 	  Build UHID sample program.
 
 config SAMPLE_VFIO_MDEV_MTTY
-	tristate "Build VFIO mtty example mediated device sample code -- loadable modules only"
-	depends on VFIO_MDEV && m
+	tristate "Build VFIO mtty example mediated device sample code"
+	depends on VFIO_MDEV
 	help
 	  Build a virtual tty sample driver for use as a VFIO
 	  mediated device
 
 config SAMPLE_VFIO_MDEV_MDPY
-	tristate "Build VFIO mdpy example mediated device sample code -- loadable modules only"
-	depends on VFIO_MDEV && m
+	tristate "Build VFIO mdpy example mediated device sample code"
+	depends on VFIO_MDEV
 	help
 	  Build a virtual display sample driver for use as a VFIO
 	  mediated device.  It is a simple framebuffer and supports
 	  the region display interface (VFIO_GFX_PLANE_TYPE_REGION).
 
 config SAMPLE_VFIO_MDEV_MDPY_FB
-	tristate "Build VFIO mdpy example guest fbdev driver -- loadable module only"
-	depends on FB && m
+	tristate "Build VFIO mdpy example guest fbdev driver"
+	depends on FB
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
@@ -208,8 +208,8 @@ config SAMPLE_VFIO_MDEV_MDPY_FB
 	  Guest fbdev driver for the virtual display sample driver.
 
 config SAMPLE_VFIO_MDEV_MBOCHS
-	tristate "Build VFIO mdpy example mediated device sample code -- loadable modules only"
-	depends on VFIO_MDEV && m
+	tristate "Build VFIO mdpy example mediated device sample code"
+	depends on VFIO_MDEV
 	select DMA_SHARED_BUFFER
 	help
 	  Build a virtual display sample driver for use as a VFIO
-- 
2.35.1

Re: [PATCH 1/4] vfio-mdev: allow building the samples into the kernel

[Anthony Krowiak]

On 1/10/23 4:10 AM, Christoph Hellwig wrote:
> There is nothing in the vfio-mdev sample drivers that requires building
> them as modules, so remove that restriction.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   samples/Kconfig | 16 ++++++++--------
>   1 file changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/samples/Kconfig b/samples/Kconfig
> index 0d81c00289ee36..f1b8d4ff123036 100644
> --- a/samples/Kconfig
> +++ b/samples/Kconfig
> @@ -184,23 +184,23 @@ config SAMPLE_UHID
>   	  Build UHID sample program.
>   
>   config SAMPLE_VFIO_MDEV_MTTY
> -	tristate "Build VFIO mtty example mediated device sample code -- loadable modules only"
> -	depends on VFIO_MDEV && m
> +	tristate "Build VFIO mtty example mediated device sample code"
> +	depends on VFIO_MDEV


Admittedly, I'm not very fluent with Kconfig, but in patch 2 you stated, 
"VFIO_MDEV is just a library with helpers for the drivers. Stop making 
it a user choice and just select it by the drivers that use the 
helpers". Why are you not selecting it here?


>   	help
>   	  Build a virtual tty sample driver for use as a VFIO
>   	  mediated device
>   
>   config SAMPLE_VFIO_MDEV_MDPY
> -	tristate "Build VFIO mdpy example mediated device sample code -- loadable modules only"
> -	depends on VFIO_MDEV && m
> +	tristate "Build VFIO mdpy example mediated device sample code"
> +	depends on VFIO_MDEV
>   	help
>   	  Build a virtual display sample driver for use as a VFIO
>   	  mediated device.  It is a simple framebuffer and supports
>   	  the region display interface (VFIO_GFX_PLANE_TYPE_REGION).
>   
>   config SAMPLE_VFIO_MDEV_MDPY_FB
> -	tristate "Build VFIO mdpy example guest fbdev driver -- loadable module only"
> -	depends on FB && m
> +	tristate "Build VFIO mdpy example guest fbdev driver"
> +	depends on FB
>   	select FB_CFB_FILLRECT
>   	select FB_CFB_COPYAREA
>   	select FB_CFB_IMAGEBLIT
> @@ -208,8 +208,8 @@ config SAMPLE_VFIO_MDEV_MDPY_FB
>   	  Guest fbdev driver for the virtual display sample driver.
>   
>   config SAMPLE_VFIO_MDEV_MBOCHS
> -	tristate "Build VFIO mdpy example mediated device sample code -- loadable modules only"
> -	depends on VFIO_MDEV && m
> +	tristate "Build VFIO mdpy example mediated device sample code"
> +	depends on VFIO_MDEV
>   	select DMA_SHARED_BUFFER
>   	help
>   	  Build a virtual display sample driver for use as a VFIO

Re: [PATCH 1/4] vfio-mdev: allow building the samples into the kernel

[Christoph Hellwig]

On Tue, Jan 10, 2023 at 09:54:51AM -0500, Anthony Krowiak wrote:
>> +	tristate "Build VFIO mtty example mediated device sample code"
>> +	depends on VFIO_MDEV
>
>
> Admittedly, I'm not very fluent with Kconfig, but in patch 2 you stated, 
> "VFIO_MDEV is just a library with helpers for the drivers. Stop making it a 
> user choice and just select it by the drivers that use the helpers". Why 
> are you not selecting it here?

Because this changes one thing at a time.  Patch 2 then switches this
depends to a select.

Re: [PATCH 1/4] vfio-mdev: allow building the samples into the kernel

[Anthony Krowiak]

On 1/10/23 10:27 AM, Christoph Hellwig wrote:
> On Tue, Jan 10, 2023 at 09:54:51AM -0500, Anthony Krowiak wrote:
>>> +	tristate "Build VFIO mtty example mediated device sample code"
>>> +	depends on VFIO_MDEV
>>
>> Admittedly, I'm not very fluent with Kconfig, but in patch 2 you stated,
>> "VFIO_MDEV is just a library with helpers for the drivers. Stop making it a
>> user choice and just select it by the drivers that use the helpers". Why
>> are you not selecting it here?
> Because this changes one thing at a time.  Patch 2 then switches this
> depends to a select.


My bad, I missed it.

Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>

Re: [PATCH 1/4] vfio-mdev: allow building the samples into the kernel

[Jason Gunthorpe]

On Tue, Jan 10, 2023 at 10:10:06AM +0100, Christoph Hellwig wrote:
> There is nothing in the vfio-mdev sample drivers that requires building
> them as modules, so remove that restriction.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  samples/Kconfig | 16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason

[PATCH 2/4] vfio-mdev: turn VFIO_MDEV into a selectable symbol

[Christoph Hellwig]

VFIO_MDEV is just a library with helpers for the drivers.  Stop making
it a user choice and just select it by the drivers that use the helpers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 Documentation/s390/vfio-ap.rst    | 1 -
 arch/s390/Kconfig                 | 6 ++++--
 arch/s390/configs/debug_defconfig | 1 -
 arch/s390/configs/defconfig       | 1 -
 drivers/gpu/drm/i915/Kconfig      | 2 +-
 drivers/vfio/mdev/Kconfig         | 8 +-------
 samples/Kconfig                   | 6 +++---
 7 files changed, 9 insertions(+), 16 deletions(-)

diff --git a/Documentation/s390/vfio-ap.rst b/Documentation/s390/vfio-ap.rst
index 00f4a04f6d4c6a..d46e98c7c1ec6c 100644
--- a/Documentation/s390/vfio-ap.rst
+++ b/Documentation/s390/vfio-ap.rst
@@ -553,7 +553,6 @@ These are the steps:
    * ZCRYPT
    * S390_AP_IOMMU
    * VFIO
-   * VFIO_MDEV
    * KVM
 
    If using make menuconfig select the following to build the vfio_ap module::
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 318fce77601d35..60fddcdad495e6 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -705,7 +705,8 @@ config EADM_SCH
 config VFIO_CCW
 	def_tristate n
 	prompt "Support for VFIO-CCW subchannels"
-	depends on S390_CCW_IOMMU && VFIO_MDEV
+	depends on S390_CCW_IOMMU
+	select VFIO_MDEV
 	help
 	  This driver allows usage of I/O subchannels via VFIO-CCW.
 
@@ -715,7 +716,8 @@ config VFIO_CCW
 config VFIO_AP
 	def_tristate n
 	prompt "VFIO support for AP devices"
-	depends on S390_AP_IOMMU && VFIO_MDEV && KVM
+	depends on S390_AP_IOMMU && KVM
+	select VFIO_MDEV
 	depends on ZCRYPT
 	help
 	  This driver grants access to Adjunct Processor (AP) devices
diff --git a/arch/s390/configs/debug_defconfig b/arch/s390/configs/debug_defconfig
index 2a827002934bc6..e78fc3ba7d442a 100644
--- a/arch/s390/configs/debug_defconfig
+++ b/arch/s390/configs/debug_defconfig
@@ -596,7 +596,6 @@ CONFIG_SYNC_FILE=y
 CONFIG_VFIO=m
 CONFIG_VFIO_PCI=m
 CONFIG_MLX5_VFIO_PCI=m
-CONFIG_VFIO_MDEV=m
 CONFIG_VIRTIO_PCI=m
 CONFIG_VIRTIO_BALLOON=m
 CONFIG_VIRTIO_INPUT=y
diff --git a/arch/s390/configs/defconfig b/arch/s390/configs/defconfig
index fb780e80e4c8f7..f7eb2e527b6e65 100644
--- a/arch/s390/configs/defconfig
+++ b/arch/s390/configs/defconfig
@@ -585,7 +585,6 @@ CONFIG_SYNC_FILE=y
 CONFIG_VFIO=m
 CONFIG_VFIO_PCI=m
 CONFIG_MLX5_VFIO_PCI=m
-CONFIG_VFIO_MDEV=m
 CONFIG_VIRTIO_PCI=m
 CONFIG_VIRTIO_BALLOON=m
 CONFIG_VIRTIO_INPUT=y
diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig
index 3efce05d7b57ca..d06da455253cdb 100644
--- a/drivers/gpu/drm/i915/Kconfig
+++ b/drivers/gpu/drm/i915/Kconfig
@@ -116,9 +116,9 @@ config DRM_I915_GVT_KVMGT
 	depends on X86
 	depends on 64BIT
 	depends on KVM
-	depends on VFIO_MDEV
 	select DRM_I915_GVT
 	select KVM_EXTERNAL_WRITE_TRACKING
+	select VFIO_MDEV
 
 	help
 	  Choose this option if you want to enable Intel GVT-g graphics
diff --git a/drivers/vfio/mdev/Kconfig b/drivers/vfio/mdev/Kconfig
index 646dbed44eb283..e5fb84e0796507 100644
--- a/drivers/vfio/mdev/Kconfig
+++ b/drivers/vfio/mdev/Kconfig
@@ -1,10 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0-only
 
 config VFIO_MDEV
-	tristate "Mediated device driver framework"
-	default n
-	help
-	  Provides a framework to virtualize devices.
-	  See Documentation/driver-api/vfio-mediated-device.rst for more details.
-
-	  If you don't know what do here, say N.
+	tristate
diff --git a/samples/Kconfig b/samples/Kconfig
index f1b8d4ff123036..56b191d128d88f 100644
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -185,14 +185,14 @@ config SAMPLE_UHID
 
 config SAMPLE_VFIO_MDEV_MTTY
 	tristate "Build VFIO mtty example mediated device sample code"
-	depends on VFIO_MDEV
+	select VFIO_MDEV
 	help
 	  Build a virtual tty sample driver for use as a VFIO
 	  mediated device
 
 config SAMPLE_VFIO_MDEV_MDPY
 	tristate "Build VFIO mdpy example mediated device sample code"
-	depends on VFIO_MDEV
+	select VFIO_MDEV
 	help
 	  Build a virtual display sample driver for use as a VFIO
 	  mediated device.  It is a simple framebuffer and supports
@@ -209,7 +209,7 @@ config SAMPLE_VFIO_MDEV_MDPY_FB
 
 config SAMPLE_VFIO_MDEV_MBOCHS
 	tristate "Build VFIO mdpy example mediated device sample code"
-	depends on VFIO_MDEV
+	select VFIO_MDEV
 	select DMA_SHARED_BUFFER
 	help
 	  Build a virtual display sample driver for use as a VFIO
-- 
2.35.1

Re: [PATCH 2/4] vfio-mdev: turn VFIO_MDEV into a selectable symbol

[Anthony Krowiak]

Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>

On 1/10/23 4:10 AM, Christoph Hellwig wrote:
> VFIO_MDEV is just a library with helpers for the drivers.  Stop making
> it a user choice and just select it by the drivers that use the helpers.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   Documentation/s390/vfio-ap.rst    | 1 -
>   arch/s390/Kconfig                 | 6 ++++--
>   arch/s390/configs/debug_defconfig | 1 -
>   arch/s390/configs/defconfig       | 1 -
>   drivers/gpu/drm/i915/Kconfig      | 2 +-
>   drivers/vfio/mdev/Kconfig         | 8 +-------
>   samples/Kconfig                   | 6 +++---
>   7 files changed, 9 insertions(+), 16 deletions(-)
>
> diff --git a/Documentation/s390/vfio-ap.rst b/Documentation/s390/vfio-ap.rst
> index 00f4a04f6d4c6a..d46e98c7c1ec6c 100644
> --- a/Documentation/s390/vfio-ap.rst
> +++ b/Documentation/s390/vfio-ap.rst
> @@ -553,7 +553,6 @@ These are the steps:
>      * ZCRYPT
>      * S390_AP_IOMMU
>      * VFIO
> -   * VFIO_MDEV
>      * KVM
>   
>      If using make menuconfig select the following to build the vfio_ap module::
> diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
> index 318fce77601d35..60fddcdad495e6 100644
> --- a/arch/s390/Kconfig
> +++ b/arch/s390/Kconfig
> @@ -705,7 +705,8 @@ config EADM_SCH
>   config VFIO_CCW
>   	def_tristate n
>   	prompt "Support for VFIO-CCW subchannels"
> -	depends on S390_CCW_IOMMU && VFIO_MDEV
> +	depends on S390_CCW_IOMMU
> +	select VFIO_MDEV
>   	help
>   	  This driver allows usage of I/O subchannels via VFIO-CCW.
>   
> @@ -715,7 +716,8 @@ config VFIO_CCW
>   config VFIO_AP
>   	def_tristate n
>   	prompt "VFIO support for AP devices"
> -	depends on S390_AP_IOMMU && VFIO_MDEV && KVM
> +	depends on S390_AP_IOMMU && KVM
> +	select VFIO_MDEV
>   	depends on ZCRYPT
>   	help
>   	  This driver grants access to Adjunct Processor (AP) devices
> diff --git a/arch/s390/configs/debug_defconfig b/arch/s390/configs/debug_defconfig
> index 2a827002934bc6..e78fc3ba7d442a 100644
> --- a/arch/s390/configs/debug_defconfig
> +++ b/arch/s390/configs/debug_defconfig
> @@ -596,7 +596,6 @@ CONFIG_SYNC_FILE=y
>   CONFIG_VFIO=m
>   CONFIG_VFIO_PCI=m
>   CONFIG_MLX5_VFIO_PCI=m
> -CONFIG_VFIO_MDEV=m
>   CONFIG_VIRTIO_PCI=m
>   CONFIG_VIRTIO_BALLOON=m
>   CONFIG_VIRTIO_INPUT=y
> diff --git a/arch/s390/configs/defconfig b/arch/s390/configs/defconfig
> index fb780e80e4c8f7..f7eb2e527b6e65 100644
> --- a/arch/s390/configs/defconfig
> +++ b/arch/s390/configs/defconfig
> @@ -585,7 +585,6 @@ CONFIG_SYNC_FILE=y
>   CONFIG_VFIO=m
>   CONFIG_VFIO_PCI=m
>   CONFIG_MLX5_VFIO_PCI=m
> -CONFIG_VFIO_MDEV=m
>   CONFIG_VIRTIO_PCI=m
>   CONFIG_VIRTIO_BALLOON=m
>   CONFIG_VIRTIO_INPUT=y
> diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig
> index 3efce05d7b57ca..d06da455253cdb 100644
> --- a/drivers/gpu/drm/i915/Kconfig
> +++ b/drivers/gpu/drm/i915/Kconfig
> @@ -116,9 +116,9 @@ config DRM_I915_GVT_KVMGT
>   	depends on X86
>   	depends on 64BIT
>   	depends on KVM
> -	depends on VFIO_MDEV
>   	select DRM_I915_GVT
>   	select KVM_EXTERNAL_WRITE_TRACKING
> +	select VFIO_MDEV
>   
>   	help
>   	  Choose this option if you want to enable Intel GVT-g graphics
> diff --git a/drivers/vfio/mdev/Kconfig b/drivers/vfio/mdev/Kconfig
> index 646dbed44eb283..e5fb84e0796507 100644
> --- a/drivers/vfio/mdev/Kconfig
> +++ b/drivers/vfio/mdev/Kconfig
> @@ -1,10 +1,4 @@
>   # SPDX-License-Identifier: GPL-2.0-only
>   
>   config VFIO_MDEV
> -	tristate "Mediated device driver framework"
> -	default n
> -	help
> -	  Provides a framework to virtualize devices.
> -	  See Documentation/driver-api/vfio-mediated-device.rst for more details.
> -
> -	  If you don't know what do here, say N.
> +	tristate
> diff --git a/samples/Kconfig b/samples/Kconfig
> index f1b8d4ff123036..56b191d128d88f 100644
> --- a/samples/Kconfig
> +++ b/samples/Kconfig
> @@ -185,14 +185,14 @@ config SAMPLE_UHID
>   
>   config SAMPLE_VFIO_MDEV_MTTY
>   	tristate "Build VFIO mtty example mediated device sample code"
> -	depends on VFIO_MDEV
> +	select VFIO_MDEV
>   	help
>   	  Build a virtual tty sample driver for use as a VFIO
>   	  mediated device
>   
>   config SAMPLE_VFIO_MDEV_MDPY
>   	tristate "Build VFIO mdpy example mediated device sample code"
> -	depends on VFIO_MDEV
> +	select VFIO_MDEV
>   	help
>   	  Build a virtual display sample driver for use as a VFIO
>   	  mediated device.  It is a simple framebuffer and supports
> @@ -209,7 +209,7 @@ config SAMPLE_VFIO_MDEV_MDPY_FB
>   
>   config SAMPLE_VFIO_MDEV_MBOCHS
>   	tristate "Build VFIO mdpy example mediated device sample code"
> -	depends on VFIO_MDEV
> +	select VFIO_MDEV
>   	select DMA_SHARED_BUFFER
>   	help
>   	  Build a virtual display sample driver for use as a VFIO

Re: [PATCH 2/4] vfio-mdev: turn VFIO_MDEV into a selectable symbol

[Jason Gunthorpe]

On Tue, Jan 10, 2023 at 10:10:07AM +0100, Christoph Hellwig wrote:
> VFIO_MDEV is just a library with helpers for the drivers.  Stop making
> it a user choice and just select it by the drivers that use the helpers.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  Documentation/s390/vfio-ap.rst    | 1 -
>  arch/s390/Kconfig                 | 6 ++++--
>  arch/s390/configs/debug_defconfig | 1 -
>  arch/s390/configs/defconfig       | 1 -
>  drivers/gpu/drm/i915/Kconfig      | 2 +-
>  drivers/vfio/mdev/Kconfig         | 8 +-------
>  samples/Kconfig                   | 6 +++---
>  7 files changed, 9 insertions(+), 16 deletions(-)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason

[PATCH 3/4] vfio-mdev: move the mtty usage documentation

[Christoph Hellwig]

Move the documentation on how to use mtty to samples/vfio-mdev/README.rst
as it is in no way related to the vfio API.  This matches how the bpf
and pktgen samples are documented.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 .../driver-api/vfio-mediated-device.rst       | 100 ------------------
 samples/vfio-mdev/README.rst                  | 100 ++++++++++++++++++
 2 files changed, 100 insertions(+), 100 deletions(-)
 create mode 100644 samples/vfio-mdev/README.rst

diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst
index fdf7d69378ec4a..d4267243b4f525 100644
--- a/Documentation/driver-api/vfio-mediated-device.rst
+++ b/Documentation/driver-api/vfio-mediated-device.rst
@@ -270,106 +270,6 @@ these callbacks are supported in the TYPE1 IOMMU module. To enable them for
 other IOMMU backend modules, such as PPC64 sPAPR module, they need to provide
 these two callback functions.
 
-Using the Sample Code
-=====================
-
-mtty.c in samples/vfio-mdev/ directory is a sample driver program to
-demonstrate how to use the mediated device framework.
-
-The sample driver creates an mdev device that simulates a serial port over a PCI
-card.
-
-1. Build and load the mtty.ko module.
-
-   This step creates a dummy device, /sys/devices/virtual/mtty/mtty/
-
-   Files in this device directory in sysfs are similar to the following::
-
-     # tree /sys/devices/virtual/mtty/mtty/
-        /sys/devices/virtual/mtty/mtty/
-        |-- mdev_supported_types
-        |   |-- mtty-1
-        |   |   |-- available_instances
-        |   |   |-- create
-        |   |   |-- device_api
-        |   |   |-- devices
-        |   |   `-- name
-        |   `-- mtty-2
-        |       |-- available_instances
-        |       |-- create
-        |       |-- device_api
-        |       |-- devices
-        |       `-- name
-        |-- mtty_dev
-        |   `-- sample_mtty_dev
-        |-- power
-        |   |-- autosuspend_delay_ms
-        |   |-- control
-        |   |-- runtime_active_time
-        |   |-- runtime_status
-        |   `-- runtime_suspended_time
-        |-- subsystem -> ../../../../class/mtty
-        `-- uevent
-
-2. Create a mediated device by using the dummy device that you created in the
-   previous step::
-
-     # echo "83b8f4f2-509f-382f-3c1e-e6bfe0fa1001" >	\
-              /sys/devices/virtual/mtty/mtty/mdev_supported_types/mtty-2/create
-
-3. Add parameters to qemu-kvm::
-
-     -device vfio-pci,\
-      sysfsdev=/sys/bus/mdev/devices/83b8f4f2-509f-382f-3c1e-e6bfe0fa1001
-
-4. Boot the VM.
-
-   In the Linux guest VM, with no hardware on the host, the device appears
-   as  follows::
-
-     # lspci -s 00:05.0 -xxvv
-     00:05.0 Serial controller: Device 4348:3253 (rev 10) (prog-if 02 [16550])
-             Subsystem: Device 4348:3253
-             Physical Slot: 5
-             Control: I/O+ Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr-
-     Stepping- SERR- FastB2B- DisINTx-
-             Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=medium >TAbort-
-     <TAbort- <MAbort- >SERR- <PERR- INTx-
-             Interrupt: pin A routed to IRQ 10
-             Region 0: I/O ports at c150 [size=8]
-             Region 1: I/O ports at c158 [size=8]
-             Kernel driver in use: serial
-     00: 48 43 53 32 01 00 00 02 10 02 00 07 00 00 00 00
-     10: 51 c1 00 00 59 c1 00 00 00 00 00 00 00 00 00 00
-     20: 00 00 00 00 00 00 00 00 00 00 00 00 48 43 53 32
-     30: 00 00 00 00 00 00 00 00 00 00 00 00 0a 01 00 00
-
-     In the Linux guest VM, dmesg output for the device is as follows:
-
-     serial 0000:00:05.0: PCI INT A -> Link[LNKA] -> GSI 10 (level, high) -> IRQ 10
-     0000:00:05.0: ttyS1 at I/O 0xc150 (irq = 10) is a 16550A
-     0000:00:05.0: ttyS2 at I/O 0xc158 (irq = 10) is a 16550A
-
-
-5. In the Linux guest VM, check the serial ports::
-
-     # setserial -g /dev/ttyS*
-     /dev/ttyS0, UART: 16550A, Port: 0x03f8, IRQ: 4
-     /dev/ttyS1, UART: 16550A, Port: 0xc150, IRQ: 10
-     /dev/ttyS2, UART: 16550A, Port: 0xc158, IRQ: 10
-
-6. Using minicom or any terminal emulation program, open port /dev/ttyS1 or
-   /dev/ttyS2 with hardware flow control disabled.
-
-7. Type data on the minicom terminal or send data to the terminal emulation
-   program and read the data.
-
-   Data is loop backed from hosts mtty driver.
-
-8. Destroy the mediated device that you created::
-
-     # echo 1 > /sys/bus/mdev/devices/83b8f4f2-509f-382f-3c1e-e6bfe0fa1001/remove
-
 References
 ==========
 
diff --git a/samples/vfio-mdev/README.rst b/samples/vfio-mdev/README.rst
new file mode 100644
index 00000000000000..b52eb37739c039
--- /dev/null
+++ b/samples/vfio-mdev/README.rst
@@ -0,0 +1,100 @@
+Using the mtty vfio-mdev sample code
+====================================
+
+mtty is a sample vfio-mdev driver that demonstrates how to use the mediated
+device framework.
+
+The sample driver creates an mdev device that simulates a serial port over a PCI
+card.
+
+1. Build and load the mtty.ko module.
+
+   This step creates a dummy device, /sys/devices/virtual/mtty/mtty/
+
+   Files in this device directory in sysfs are similar to the following::
+
+     # tree /sys/devices/virtual/mtty/mtty/
+        /sys/devices/virtual/mtty/mtty/
+        |-- mdev_supported_types
+        |   |-- mtty-1
+        |   |   |-- available_instances
+        |   |   |-- create
+        |   |   |-- device_api
+        |   |   |-- devices
+        |   |   `-- name
+        |   `-- mtty-2
+        |       |-- available_instances
+        |       |-- create
+        |       |-- device_api
+        |       |-- devices
+        |       `-- name
+        |-- mtty_dev
+        |   `-- sample_mtty_dev
+        |-- power
+        |   |-- autosuspend_delay_ms
+        |   |-- control
+        |   |-- runtime_active_time
+        |   |-- runtime_status
+        |   `-- runtime_suspended_time
+        |-- subsystem -> ../../../../class/mtty
+        `-- uevent
+
+2. Create a mediated device by using the dummy device that you created in the
+   previous step::
+
+     # echo "83b8f4f2-509f-382f-3c1e-e6bfe0fa1001" >	\
+              /sys/devices/virtual/mtty/mtty/mdev_supported_types/mtty-2/create
+
+3. Add parameters to qemu-kvm::
+
+     -device vfio-pci,\
+      sysfsdev=/sys/bus/mdev/devices/83b8f4f2-509f-382f-3c1e-e6bfe0fa1001
+
+4. Boot the VM.
+
+   In the Linux guest VM, with no hardware on the host, the device appears
+   as  follows::
+
+     # lspci -s 00:05.0 -xxvv
+     00:05.0 Serial controller: Device 4348:3253 (rev 10) (prog-if 02 [16550])
+             Subsystem: Device 4348:3253
+             Physical Slot: 5
+             Control: I/O+ Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr-
+     Stepping- SERR- FastB2B- DisINTx-
+             Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=medium >TAbort-
+     <TAbort- <MAbort- >SERR- <PERR- INTx-
+             Interrupt: pin A routed to IRQ 10
+             Region 0: I/O ports at c150 [size=8]
+             Region 1: I/O ports at c158 [size=8]
+             Kernel driver in use: serial
+     00: 48 43 53 32 01 00 00 02 10 02 00 07 00 00 00 00
+     10: 51 c1 00 00 59 c1 00 00 00 00 00 00 00 00 00 00
+     20: 00 00 00 00 00 00 00 00 00 00 00 00 48 43 53 32
+     30: 00 00 00 00 00 00 00 00 00 00 00 00 0a 01 00 00
+
+     In the Linux guest VM, dmesg output for the device is as follows:
+
+     serial 0000:00:05.0: PCI INT A -> Link[LNKA] -> GSI 10 (level, high) -> IRQ 10
+     0000:00:05.0: ttyS1 at I/O 0xc150 (irq = 10) is a 16550A
+     0000:00:05.0: ttyS2 at I/O 0xc158 (irq = 10) is a 16550A
+
+
+5. In the Linux guest VM, check the serial ports::
+
+     # setserial -g /dev/ttyS*
+     /dev/ttyS0, UART: 16550A, Port: 0x03f8, IRQ: 4
+     /dev/ttyS1, UART: 16550A, Port: 0xc150, IRQ: 10
+     /dev/ttyS2, UART: 16550A, Port: 0xc158, IRQ: 10
+
+6. Using minicom or any terminal emulation program, open port /dev/ttyS1 or
+   /dev/ttyS2 with hardware flow control disabled.
+
+7. Type data on the minicom terminal or send data to the terminal emulation
+   program and read the data.
+
+   Data is loop backed from hosts mtty driver.
+
+8. Destroy the mediated device that you created::
+
+     # echo 1 > /sys/bus/mdev/devices/83b8f4f2-509f-382f-3c1e-e6bfe0fa1001/remove
+
-- 
2.35.1

Re: [PATCH 3/4] vfio-mdev: move the mtty usage documentation

[Jason Gunthorpe]

On Tue, Jan 10, 2023 at 10:10:08AM +0100, Christoph Hellwig wrote:
> Move the documentation on how to use mtty to samples/vfio-mdev/README.rst
> as it is in no way related to the vfio API.  This matches how the bpf
> and pktgen samples are documented.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  .../driver-api/vfio-mediated-device.rst       | 100 ------------------
>  samples/vfio-mdev/README.rst                  | 100 ++++++++++++++++++
>  2 files changed, 100 insertions(+), 100 deletions(-)
>  create mode 100644 samples/vfio-mdev/README.rst

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason

[PATCH 4/4] vfio-mdev: remove an non-existing driver from vfio-mediated-device

[Christoph Hellwig]

The nvidia mdev driver does not actually exist anywhere in the tree.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 Documentation/driver-api/vfio-mediated-device.rst | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst
index d4267243b4f525..bbd548b66b4255 100644
--- a/Documentation/driver-api/vfio-mediated-device.rst
+++ b/Documentation/driver-api/vfio-mediated-device.rst
@@ -60,7 +60,7 @@ devices as examples, as these devices are the first devices to use this module::
      |   mdev.ko     |
      | +-----------+ |  mdev_register_parent() +--------------+
      | |           | +<------------------------+              |
-     | |           | |                         |  nvidia.ko   |<-> physical
+     | |           | |                         | ccw_device.ko|<-> physical
      | |           | +------------------------>+              |    device
      | |           | |        callbacks        +--------------+
      | | Physical  | |
@@ -69,12 +69,6 @@ devices as examples, as these devices are the first devices to use this module::
      | |           | |                         |  i915.ko     |<-> physical
      | |           | +------------------------>+              |    device
      | |           | |        callbacks        +--------------+
-     | |           | |
-     | |           | |  mdev_register_parent() +--------------+
-     | |           | +<------------------------+              |
-     | |           | |                         | ccw_device.ko|<-> physical
-     | |           | +------------------------>+              |    device
-     | |           | |        callbacks        +--------------+
      | +-----------+ |
      +---------------+
 
-- 
2.35.1

Re: [PATCH 4/4] vfio-mdev: remove an non-existing driver from vfio-mediated-device

[Anthony Krowiak]

LGTM

Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>

On 1/10/23 4:10 AM, Christoph Hellwig wrote:
> The nvidia mdev driver does not actually exist anywhere in the tree.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   Documentation/driver-api/vfio-mediated-device.rst | 8 +-------
>   1 file changed, 1 insertion(+), 7 deletions(-)
>
> diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst
> index d4267243b4f525..bbd548b66b4255 100644
> --- a/Documentation/driver-api/vfio-mediated-device.rst
> +++ b/Documentation/driver-api/vfio-mediated-device.rst
> @@ -60,7 +60,7 @@ devices as examples, as these devices are the first devices to use this module::
>        |   mdev.ko     |
>        | +-----------+ |  mdev_register_parent() +--------------+
>        | |           | +<------------------------+              |
> -     | |           | |                         |  nvidia.ko   |<-> physical
> +     | |           | |                         | ccw_device.ko|<-> physical
>        | |           | +------------------------>+              |    device
>        | |           | |        callbacks        +--------------+
>        | | Physical  | |
> @@ -69,12 +69,6 @@ devices as examples, as these devices are the first devices to use this module::
>        | |           | |                         |  i915.ko     |<-> physical
>        | |           | +------------------------>+              |    device
>        | |           | |        callbacks        +--------------+
> -     | |           | |
> -     | |           | |  mdev_register_parent() +--------------+
> -     | |           | +<------------------------+              |
> -     | |           | |                         | ccw_device.ko|<-> physical
> -     | |           | +------------------------>+              |    device
> -     | |           | |        callbacks        +--------------+
>        | +-----------+ |
>        +---------------+
>   

Re: [PATCH 4/4] vfio-mdev: remove an non-existing driver from vfio-mediated-device

[Jason Gunthorpe]

On Tue, Jan 10, 2023 at 10:10:09AM +0100, Christoph Hellwig wrote:
> The nvidia mdev driver does not actually exist anywhere in the tree.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  Documentation/driver-api/vfio-mediated-device.rst | 8 +-------
>  1 file changed, 1 insertion(+), 7 deletions(-)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason

Re: misc mdev tidyups

[Alex Williamson]

On Tue, 10 Jan 2023 10:10:05 +0100
Christoph Hellwig <hch@lst.de> wrote:

> Hi all,
> 
> this series tidies up the mdev Kconfig interaction and documentation a bit.
> 
> Diffstat:
>  Documentation/driver-api/vfio-mediated-device.rst |  108 ----------------------
>  Documentation/s390/vfio-ap.rst                    |    1 
>  arch/s390/Kconfig                                 |    6 -
>  arch/s390/configs/debug_defconfig                 |    1 
>  arch/s390/configs/defconfig                       |    1 
>  drivers/gpu/drm/i915/Kconfig                      |    2 
>  drivers/vfio/mdev/Kconfig                         |    8 -
>  samples/Kconfig                                   |   16 +--
>  samples/vfio-mdev/README.rst                      |  100 ++++++++++++++++++++
>  9 files changed, 115 insertions(+), 128 deletions(-)
> 

Applied to vfio next branch for v6.3.  Thanks,

Alex