[PATCH v2 6/7] iommufd: Implement sw_msi support natively

[Jason Gunthorpe]

On Wed, Feb 19, 2025 at 05:31:41PM -0800, Nicolin Chen wrote:

> +/*
> + * Get a iommufd_sw_msi_map for the msi physical address requested by the irq
> + * layer. The mapping to IOVA is global to the iommufd file descriptor, every
> + * domain that is attached to a device using the same MSI parameters will use
> + * the same IOVA.
> + */
> +static struct iommufd_sw_msi_map *
> +iommufd_sw_msi_get_map(struct iommufd_ctx *ictx, phys_addr_t msi_addr,
> +		       phys_addr_t sw_msi_start)
> +{

This ends up being never called if !CONFIG_IRQ_MSI_IOMMU because the
sw_msi doesn't exist.

--- a/drivers/iommu/iommufd/device.c
+++ b/drivers/iommu/iommufd/device.c
@@ -300,7 +300,7 @@ EXPORT_SYMBOL_NS_GPL(iommufd_device_to_id, "IOMMUFD");
  * domain that is attached to a device using the same MSI parameters will use
  * the same IOVA.
  */
-static struct iommufd_sw_msi_map *
+static __maybe_unused struct iommufd_sw_msi_map *
 iommufd_sw_msi_get_map(struct iommufd_ctx *ictx, phys_addr_t msi_addr,
                       phys_addr_t sw_msi_start)
 {

Fixed it up

Jason