[PATCH 0/2] vfio/platform: Deprecate vfio-amba and reset drivers

[PATCH 0/2] vfio/platform: Deprecate vfio-amba and reset drivers

[Alex Williamson]

Based on discussion[1] there's still interest in keeping vfio-platform
itself, but the use case doesn't involve any of the current reset
drivers and doesn't include vfio-amba.  To give any users a chance to
speak up, let's mark these as deprecated and generate logs if they're
used.

I intend to pull the vfio/fsl-mc removal from the previous series given
there were no objections.  Thanks,

Alex

[1] https://lore.kernel.org/all/20250806170314.3768750-1-alex.williamson@redhat.com/

Alex Williamson (2):
  vfio/amba: Mark for removal
  vfio/platform: Mark reset drivers for removal

 drivers/vfio/platform/Kconfig                            | 5 ++++-
 drivers/vfio/platform/reset/Kconfig                      | 6 +++---
 drivers/vfio/platform/reset/vfio_platform_amdxgbe.c      | 2 ++
 drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c    | 2 ++
 drivers/vfio/platform/reset/vfio_platform_calxedaxgmac.c | 2 ++
 drivers/vfio/platform/vfio_amba.c                        | 2 ++
 6 files changed, 15 insertions(+), 4 deletions(-)

-- 
2.50.1

[PATCH 1/2] vfio/amba: Mark for removal

[Alex Williamson]

vfio-amba has only been touched to keep up with the rest of the code
base for the past 10 years.  We have no basis to believe that it's
currently tested or used.  Mark it for deprecation.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
 drivers/vfio/platform/Kconfig     | 5 ++++-
 drivers/vfio/platform/vfio_amba.c | 2 ++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/platform/Kconfig b/drivers/vfio/platform/Kconfig
index 88fcde51f024..c6be29b2c24b 100644
--- a/drivers/vfio/platform/Kconfig
+++ b/drivers/vfio/platform/Kconfig
@@ -17,10 +17,13 @@ config VFIO_PLATFORM
 	  If you don't know what to do here, say N.
 
 config VFIO_AMBA
-	tristate "VFIO support for AMBA devices"
+	tristate "VFIO support for AMBA devices (DEPRECATED)"
 	depends on ARM_AMBA || COMPILE_TEST
 	select VFIO_PLATFORM_BASE
 	help
+	  The vfio-amba driver is deprecated and will be removed in a
+	  future kernel release.
+
 	  Support for ARM AMBA devices with VFIO. This is required to make
 	  use of ARM AMBA devices present on the system using the VFIO
 	  framework.
diff --git a/drivers/vfio/platform/vfio_amba.c b/drivers/vfio/platform/vfio_amba.c
index ff8ff8480968..9f5c527baa8a 100644
--- a/drivers/vfio/platform/vfio_amba.c
+++ b/drivers/vfio/platform/vfio_amba.c
@@ -70,6 +70,8 @@ static int vfio_amba_probe(struct amba_device *adev, const struct amba_id *id)
 	struct vfio_platform_device *vdev;
 	int ret;
 
+	dev_err_once(&adev->dev, "DEPRECATION: vfio-amba is deprecated and will be removed in a future kernel release\n");
+
 	vdev = vfio_alloc_device(vfio_platform_device, vdev, &adev->dev,
 				 &vfio_amba_ops);
 	if (IS_ERR(vdev))
-- 
2.50.1

[PATCH 2/2] vfio/platform: Mark reset drivers for removal

[Alex Williamson]

While vfio-platform itself is on a reprieve from being removed[1],
these reset drivers don't support any current hardware, are not being
tested, and suggest a level of support that doesn't really exist.
Mark them for removal to surface any remaining user such that we can
potentially drop them and simplify the code if none appear.

Link: https://lore.kernel.org/all/20250806170314.3768750-3-alex.williamson@redhat.com [1]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
 drivers/vfio/platform/reset/Kconfig                      | 6 +++---
 drivers/vfio/platform/reset/vfio_platform_amdxgbe.c      | 2 ++
 drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c    | 2 ++
 drivers/vfio/platform/reset/vfio_platform_calxedaxgmac.c | 2 ++
 4 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/vfio/platform/reset/Kconfig b/drivers/vfio/platform/reset/Kconfig
index dcc08dc145a5..70af0dbe293b 100644
--- a/drivers/vfio/platform/reset/Kconfig
+++ b/drivers/vfio/platform/reset/Kconfig
@@ -1,21 +1,21 @@
 # SPDX-License-Identifier: GPL-2.0-only
 if VFIO_PLATFORM
 config VFIO_PLATFORM_CALXEDAXGMAC_RESET
-	tristate "VFIO support for calxeda xgmac reset"
+	tristate "VFIO support for calxeda xgmac reset (DEPRECATED)"
 	help
 	  Enables the VFIO platform driver to handle reset for Calxeda xgmac
 
 	  If you don't know what to do here, say N.
 
 config VFIO_PLATFORM_AMDXGBE_RESET
-	tristate "VFIO support for AMD XGBE reset"
+	tristate "VFIO support for AMD XGBE reset (DEPRECATED)"
 	help
 	  Enables the VFIO platform driver to handle reset for AMD XGBE
 
 	  If you don't know what to do here, say N.
 
 config VFIO_PLATFORM_BCMFLEXRM_RESET
-	tristate "VFIO support for Broadcom FlexRM reset"
+	tristate "VFIO support for Broadcom FlexRM reset (DEPRECATED)"
 	depends on ARCH_BCM_IPROC || COMPILE_TEST
 	default ARCH_BCM_IPROC
 	help
diff --git a/drivers/vfio/platform/reset/vfio_platform_amdxgbe.c b/drivers/vfio/platform/reset/vfio_platform_amdxgbe.c
index abdca900802d..45f386a042a9 100644
--- a/drivers/vfio/platform/reset/vfio_platform_amdxgbe.c
+++ b/drivers/vfio/platform/reset/vfio_platform_amdxgbe.c
@@ -52,6 +52,8 @@ static int vfio_platform_amdxgbe_reset(struct vfio_platform_device *vdev)
 	u32 dma_mr_value, pcs_value, value;
 	unsigned int count;
 
+	dev_err_once(vdev->device, "DEPRECATION: VFIO AMD XGBE platform reset is deprecated and will be removed in a future kernel release\n");
+
 	if (!xgmac_regs->ioaddr) {
 		xgmac_regs->ioaddr =
 			ioremap(xgmac_regs->addr, xgmac_regs->size);
diff --git a/drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c b/drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c
index 1131ebe4837d..51c9d156f307 100644
--- a/drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c
+++ b/drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c
@@ -72,6 +72,8 @@ static int vfio_platform_bcmflexrm_reset(struct vfio_platform_device *vdev)
 	int rc = 0, ret = 0, ring_num = 0;
 	struct vfio_platform_region *reg = &vdev->regions[0];
 
+	dev_err_once(vdev->device, "DEPRECATION: VFIO Broadcom FlexRM platform reset is deprecated and will be removed in a future kernel release\n");
+
 	/* Map FlexRM ring registers if not mapped */
 	if (!reg->ioaddr) {
 		reg->ioaddr = ioremap(reg->addr, reg->size);
diff --git a/drivers/vfio/platform/reset/vfio_platform_calxedaxgmac.c b/drivers/vfio/platform/reset/vfio_platform_calxedaxgmac.c
index 63cc7f0b2e4a..a298045a8e19 100644
--- a/drivers/vfio/platform/reset/vfio_platform_calxedaxgmac.c
+++ b/drivers/vfio/platform/reset/vfio_platform_calxedaxgmac.c
@@ -50,6 +50,8 @@ static int vfio_platform_calxedaxgmac_reset(struct vfio_platform_device *vdev)
 {
 	struct vfio_platform_region *reg = &vdev->regions[0];
 
+	dev_err_once(vdev->device, "DEPRECATION: VFIO Calxeda xgmac platform reset is deprecated and will be removed in a future kernel release\n");
+
 	if (!reg->ioaddr) {
 		reg->ioaddr =
 			ioremap(reg->addr, reg->size);
-- 
2.50.1

Re: [PATCH 0/2] vfio/platform: Deprecate vfio-amba and reset drivers

[Eric Auger]

On 8/25/25 7:57 PM, Alex Williamson wrote:
> Based on discussion[1] there's still interest in keeping vfio-platform
> itself, but the use case doesn't involve any of the current reset
> drivers and doesn't include vfio-amba.  To give any users a chance to
> speak up, let's mark these as deprecated and generate logs if they're
> used.
>
> I intend to pull the vfio/fsl-mc removal from the previous series given
> there were no objections.  Thanks,
>
> Alex
>
> [1] https://lore.kernel.org/all/20250806170314.3768750-1-alex.williamson@redhat.com/
for the series:
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Eric
>
> Alex Williamson (2):
>   vfio/amba: Mark for removal
>   vfio/platform: Mark reset drivers for removal
>
>  drivers/vfio/platform/Kconfig                            | 5 ++++-
>  drivers/vfio/platform/reset/Kconfig                      | 6 +++---
>  drivers/vfio/platform/reset/vfio_platform_amdxgbe.c      | 2 ++
>  drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c    | 2 ++
>  drivers/vfio/platform/reset/vfio_platform_calxedaxgmac.c | 2 ++
>  drivers/vfio/platform/vfio_amba.c                        | 2 ++
>  6 files changed, 15 insertions(+), 4 deletions(-)
>

Re: [PATCH 0/2] vfio/platform: Deprecate vfio-amba and reset drivers

[Mostafa Saleh]

Hi Alex,

On Mon, Aug 25, 2025 at 11:57:59AM -0600, Alex Williamson wrote:
> Based on discussion[1] there's still interest in keeping vfio-platform
> itself, but the use case doesn't involve any of the current reset
> drivers and doesn't include vfio-amba.  To give any users a chance to
> speak up, let's mark these as deprecated and generate logs if they're
> used.
> 
> I intend to pull the vfio/fsl-mc removal from the previous series given
> there were no objections.  Thanks,
> 
> Alex
> 
> [1] https://lore.kernel.org/all/20250806170314.3768750-1-alex.williamson@redhat.com/
> 
> Alex Williamson (2):
>   vfio/amba: Mark for removal
>   vfio/platform: Mark reset drivers for removal
> 
>  drivers/vfio/platform/Kconfig                            | 5 ++++-
>  drivers/vfio/platform/reset/Kconfig                      | 6 +++---
>  drivers/vfio/platform/reset/vfio_platform_amdxgbe.c      | 2 ++
>  drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c    | 2 ++
>  drivers/vfio/platform/reset/vfio_platform_calxedaxgmac.c | 2 ++
>  drivers/vfio/platform/vfio_amba.c                        | 2 ++
>  6 files changed, 15 insertions(+), 4 deletions(-)

For the series:
Reviewed-by: Mostafa Saleh <smostafa@google.com>

Thanks,
Mostafa

> 
> -- 
> 2.50.1
> 

Re: [PATCH 0/2] vfio/platform: Deprecate vfio-amba and reset drivers

[Pranjal Shrivastava]

On Mon, Aug 25, 2025 at 11:57:59AM -0600, Alex Williamson wrote:
> Based on discussion[1] there's still interest in keeping vfio-platform
> itself, but the use case doesn't involve any of the current reset
> drivers and doesn't include vfio-amba.  To give any users a chance to
> speak up, let's mark these as deprecated and generate logs if they're
> used.
> 
> I intend to pull the vfio/fsl-mc removal from the previous series given
> there were no objections.  Thanks,
> 
> Alex
> 
> [1] https://lore.kernel.org/all/20250806170314.3768750-1-alex.williamson@redhat.com/
> 
> Alex Williamson (2):
>   vfio/amba: Mark for removal
>   vfio/platform: Mark reset drivers for removal
> 
>  drivers/vfio/platform/Kconfig                            | 5 ++++-
>  drivers/vfio/platform/reset/Kconfig                      | 6 +++---
>  drivers/vfio/platform/reset/vfio_platform_amdxgbe.c      | 2 ++
>  drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c    | 2 ++
>  drivers/vfio/platform/reset/vfio_platform_calxedaxgmac.c | 2 ++
>  drivers/vfio/platform/vfio_amba.c                        | 2 ++
>  6 files changed, 15 insertions(+), 4 deletions(-)
> 

The series feels like a sensible compromise. The rationale for
deprecating vfio-amba and the obsolete reset drivers is sound, as it
cleans up code that can no longer be tested by the maintainers [1].

The changes to Kconfig and the addition of dev_err_once() handle this
deprecation cleanly.

For the series:
Reviewed-by: Pranjal Shrivastava <praan@google.com>

Thanks,
Praan

[1] https://kvm-forum.qemu.org/2024/vfio-platform-kvm-forum24-landscape_TtZ3SnC.pdf

> -- 
> 2.50.1
>