[PATCH v2 1/2] cdx: don't select CONFIG_GENERIC_MSI_IRQ

[PATCH v2 1/2] cdx: don't select CONFIG_GENERIC_MSI_IRQ

[Nipun Gupta]

From: Arnd Bergmann <arnd@kernel.org>

x86 does not use CONFIG_GENERIC_MSI_IRQ, and trying to enable it anyway
results in a build failure:

In file included from include/linux/ssb/ssb.h:10,
                 from drivers/ssb/pcihost_wrapper.c:18:
include/linux/gpio/driver.h:41:33: error: field 'msiinfo' has incomplete type
   41 |         msi_alloc_info_t        msiinfo;
      |                                 ^~~~~~~
In file included from include/linux/kvm_host.h:19,
                 from arch/x86/events/intel/core.c:17:
include/linux/msi.h:528:33: error: field 'alloc_info' has incomplete type
  528 |         msi_alloc_info_t        alloc_info;

Change the driver to actually build without this symbol and remove the
incorrect 'select' statements.

Fixes: e8b18c11731d ("cdx: Fix missing GENERIC_MSI_IRQ on compile test")
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Nikhil Agarwal <nikhil.agarwal@amd.com>
Signed-off-by: Arnd Bergmann <arnd@kernel.org>
---

No change in this patch from v1 -> v2 (change is in patch 2/2)

 drivers/cdx/Kconfig                     | 1 -
 drivers/cdx/cdx.c                       | 2 +-
 drivers/cdx/controller/Kconfig          | 1 -
 drivers/cdx/controller/cdx_controller.c | 3 ++-
 4 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/cdx/Kconfig b/drivers/cdx/Kconfig
index 3af41f51cf38..1f1e360507d7 100644
--- a/drivers/cdx/Kconfig
+++ b/drivers/cdx/Kconfig
@@ -8,7 +8,6 @@
 config CDX_BUS
 	bool "CDX Bus driver"
 	depends on OF && ARM64 || COMPILE_TEST
-	select GENERIC_MSI_IRQ
 	help
 	  Driver to enable Composable DMA Transfer(CDX) Bus. CDX bus
 	  exposes Fabric devices which uses composable DMA IP to the
diff --git a/drivers/cdx/cdx.c b/drivers/cdx/cdx.c
index 092306ca2541..1a5c95ba09ba 100644
--- a/drivers/cdx/cdx.c
+++ b/drivers/cdx/cdx.c
@@ -310,7 +310,7 @@ static int cdx_probe(struct device *dev)
 	 * Setup MSI device data so that generic MSI alloc/free can
 	 * be used by the device driver.
 	 */
-	if (cdx->msi_domain) {
+	if (IS_ENABLED(CONFIG_GENERIC_MSI_IRQ) && cdx->msi_domain) {
 		error = msi_setup_device_data(&cdx_dev->dev);
 		if (error)
 			return error;
diff --git a/drivers/cdx/controller/Kconfig b/drivers/cdx/controller/Kconfig
index 0641a4c21e66..a480b62cbd1f 100644
--- a/drivers/cdx/controller/Kconfig
+++ b/drivers/cdx/controller/Kconfig
@@ -10,7 +10,6 @@ if CDX_BUS
 config CDX_CONTROLLER
 	tristate "CDX bus controller"
 	depends on HAS_DMA
-	select GENERIC_MSI_IRQ
 	select REMOTEPROC
 	select RPMSG
 	help
diff --git a/drivers/cdx/controller/cdx_controller.c b/drivers/cdx/controller/cdx_controller.c
index fca83141e3e6..5e3fd89b6b56 100644
--- a/drivers/cdx/controller/cdx_controller.c
+++ b/drivers/cdx/controller/cdx_controller.c
@@ -193,7 +193,8 @@ static int xlnx_cdx_probe(struct platform_device *pdev)
 	cdx->ops = &cdx_ops;
 
 	/* Create MSI domain */
-	cdx->msi_domain = cdx_msi_domain_init(&pdev->dev);
+	if (IS_ENABLED(CONFIG_GENERIC_MSI_IRQ))
+		cdx->msi_domain = cdx_msi_domain_init(&pdev->dev);
 	if (!cdx->msi_domain) {
 		ret = dev_err_probe(&pdev->dev, -ENODEV, "cdx_msi_domain_init() failed");
 		goto cdx_msi_fail;
-- 
2.34.1

[PATCH v2 2/2] vfio/cdx: update driver to build without CONFIG_GENERIC_MSI_IRQ

[Nipun Gupta]

Define dummy MSI related APIs in VFIO CDX driver to build the
driver without enabling CONFIG_GENERIC_MSI_IRQ flag.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202508070308.opy5dIFX-lkp@intel.com/
Reviewed-by: Nikhil Agarwal <nikhil.agarwal@amd.com>
Signed-off-by: Nipun Gupta <nipun.gupta@amd.com>
---
Changes v1->v2:
- fix linking intr.c file in Makefile

 drivers/vfio/cdx/Makefile  |  6 +++++-
 drivers/vfio/cdx/private.h | 14 ++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/cdx/Makefile b/drivers/vfio/cdx/Makefile
index df92b320122a..dadbef2419ea 100644
--- a/drivers/vfio/cdx/Makefile
+++ b/drivers/vfio/cdx/Makefile
@@ -5,4 +5,8 @@
 
 obj-$(CONFIG_VFIO_CDX) += vfio-cdx.o
 
-vfio-cdx-objs := main.o intr.o
+vfio-cdx-objs := main.o
+
+ifdef CONFIG_GENERIC_MSI_IRQ
+vfio-cdx-objs += intr.o
+endif
diff --git a/drivers/vfio/cdx/private.h b/drivers/vfio/cdx/private.h
index dc56729b3114..0482a1516439 100644
--- a/drivers/vfio/cdx/private.h
+++ b/drivers/vfio/cdx/private.h
@@ -38,11 +38,25 @@ struct vfio_cdx_device {
 	u8			config_msi;
 };
 
+#ifdef CONFIG_GENERIC_MSI_IRQ
 int vfio_cdx_set_irqs_ioctl(struct vfio_cdx_device *vdev,
 			    u32 flags, unsigned int index,
 			    unsigned int start, unsigned int count,
 			    void *data);
 
 void vfio_cdx_irqs_cleanup(struct vfio_cdx_device *vdev);
+#else
+static int vfio_cdx_set_irqs_ioctl(struct vfio_cdx_device *vdev,
+				   u32 flags, unsigned int index,
+				   unsigned int start, unsigned int count,
+				   void *data)
+{
+	return 0;
+}
+
+static void vfio_cdx_irqs_cleanup(struct vfio_cdx_device *vdev)
+{
+}
+#endif
 
 #endif /* VFIO_CDX_PRIVATE_H */
-- 
2.34.1

Re: [PATCH v2 2/2] vfio/cdx: update driver to build without CONFIG_GENERIC_MSI_IRQ

[Alex Williamson]

On Thu, 21 Aug 2025 12:43:08 +0530
Nipun Gupta <nipun.gupta@amd.com> wrote:

> Define dummy MSI related APIs in VFIO CDX driver to build the
> driver without enabling CONFIG_GENERIC_MSI_IRQ flag.
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202508070308.opy5dIFX-lkp@intel.com/
> Reviewed-by: Nikhil Agarwal <nikhil.agarwal@amd.com>
> Signed-off-by: Nipun Gupta <nipun.gupta@amd.com>
> ---
> Changes v1->v2:
> - fix linking intr.c file in Makefile
> 
>  drivers/vfio/cdx/Makefile  |  6 +++++-
>  drivers/vfio/cdx/private.h | 14 ++++++++++++++
>  2 files changed, 19 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/vfio/cdx/Makefile b/drivers/vfio/cdx/Makefile
> index df92b320122a..dadbef2419ea 100644
> --- a/drivers/vfio/cdx/Makefile
> +++ b/drivers/vfio/cdx/Makefile
> @@ -5,4 +5,8 @@
>  
>  obj-$(CONFIG_VFIO_CDX) += vfio-cdx.o
>  
> -vfio-cdx-objs := main.o intr.o
> +vfio-cdx-objs := main.o
> +
> +ifdef CONFIG_GENERIC_MSI_IRQ
> +vfio-cdx-objs += intr.o
> +endif
> diff --git a/drivers/vfio/cdx/private.h b/drivers/vfio/cdx/private.h
> index dc56729b3114..0482a1516439 100644
> --- a/drivers/vfio/cdx/private.h
> +++ b/drivers/vfio/cdx/private.h
> @@ -38,11 +38,25 @@ struct vfio_cdx_device {
>  	u8			config_msi;
>  };
>  
> +#ifdef CONFIG_GENERIC_MSI_IRQ
>  int vfio_cdx_set_irqs_ioctl(struct vfio_cdx_device *vdev,
>  			    u32 flags, unsigned int index,
>  			    unsigned int start, unsigned int count,
>  			    void *data);
>  
>  void vfio_cdx_irqs_cleanup(struct vfio_cdx_device *vdev);
> +#else
> +static int vfio_cdx_set_irqs_ioctl(struct vfio_cdx_device *vdev,
> +				   u32 flags, unsigned int index,
> +				   unsigned int start, unsigned int count,
> +				   void *data)
> +{
> +	return 0;
> +}
> +
> +static void vfio_cdx_irqs_cleanup(struct vfio_cdx_device *vdev)
> +{
> +}
> +#endif
>  
>  #endif /* VFIO_CDX_PRIVATE_H */

Why are we returning success if we don't implement the function?  This
provides the wrong return value to the user.

Also, aren't we also missing in patch 1/ that cdx_dev->num_msi is
initialized and therefore vfio_cdx_ioctl_get_info() might return that
an interrupt is supported when it is not?  Thanks,

Alex