On Tue, Feb 25, 2025 at 06:25:27PM -0800, Nicolin Chen wrote:
On Fri, Feb 21, 2025 at 10:39:59AM -0400, Jason Gunthorpe wrote:
diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 99dd72998cb7f7..082274e8ba6a3d 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -1534,12 +1534,16 @@ void iommu_debugfs_setup(void); static inline void iommu_debugfs_setup(void) {} #endif -#ifdef CONFIG_IOMMU_DMA +#if defined(CONFIG_IOMMU_DMA) && IS_ENABLED(CONFIG_IRQ_MSI_IOMMU) int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base); +void iommu_put_msi_cookie(struct iommu_domain *domain); #else /* CONFIG_IOMMU_DMA */ static inline int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base) {
- return -ENODEV;
- return 0;
Should we keep the -ENODEV here for !CONFIG_IOMMU_DMA?
My feeling was if the system doesn't have an IRQ driver that needs MSI_IOMMU but does have a IOMMU driver that reports SW_MSI reserved regions then iommufd/vfio should not fail.
I don't think it is realistic that we'd ever hit this return.
Jason