This is a partial update aiming at enhancing the VFIO user API with IOMMU info capability chain, msi_geometry reporting and MSI IOVA window registration.
The kernel code is not yet upstreamed. It is available at https://github.com/eauger/linux/tree/generic-v7-passthrough-v13 ([PATCH v13 00/15] KVM PCIe/MSI passthrough on ARM/ARM64) Signed-off-by: Eric Auger <eric.au...@redhat.com> --- v2 -> v3: - features VFIO_IOMMU_TYPE1_INFO_CAP_MSI_GEOMETRY --- linux-headers/linux/vfio.h | 48 +++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 43 insertions(+), 5 deletions(-) diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h index 759b850..8dae013 100644 --- a/linux-headers/linux/vfio.h +++ b/linux-headers/linux/vfio.h @@ -8,8 +8,8 @@ * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ -#ifndef VFIO_H -#define VFIO_H +#ifndef _UAPIVFIO_H +#define _UAPIVFIO_H #include <linux/types.h> #include <linux/ioctl.h> @@ -488,7 +488,35 @@ struct vfio_iommu_type1_info { __u32 argsz; __u32 flags; #define VFIO_IOMMU_INFO_PGSIZES (1 << 0) /* supported page sizes info */ - __u64 iova_pgsizes; /* Bitmap of supported page sizes */ +#define VFIO_IOMMU_INFO_CAPS (1 << 1) /* Info supports caps */ + __u64 iova_pgsizes; /* Bitmap of supported page sizes */ + __u32 __resv; + __u32 cap_offset; /* Offset within info struct of first cap */ +}; + +#define VFIO_IOMMU_TYPE1_INFO_CAP_MSI_GEOMETRY 1 + +/* + * The MSI geometry capability allows to report the MSI IOVA geometry: + * - either the MSI IOVAs are constrained within a reserved IOVA aperture + * whose boundaries are given by [@aperture_start, @aperture_end]. + * this is typically the case on x86 host. The userspace is not allowed + * to map userspace memory at IOVAs intersecting this range using + * VFIO_IOMMU_MAP_DMA. + * - or the MSI IOVAs are not requested to belong to any reserved range; + * in that case the userspace must provide an IOVA window characterized by + * @size and @alignment using VFIO_IOMMU_MAP_DMA with RESERVED_MSI_IOVA flag. + */ +struct vfio_iommu_type1_info_cap_msi_geometry { + struct vfio_info_cap_header header; + __u32 flags; +#define VFIO_IOMMU_MSI_GEOMETRY_RESERVED (1 << 0) /* reserved geometry */ + /* not reserved */ + __u32 order; /* iommu page order used for aperture alignment*/ + __u64 size; /* IOVA aperture size (bytes) the userspace must provide */ + /* reserved */ + __u64 aperture_start; + __u64 aperture_end; }; #define VFIO_IOMMU_GET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12) @@ -498,12 +526,21 @@ struct vfio_iommu_type1_info { * * Map process virtual addresses to IO virtual addresses using the * provided struct vfio_dma_map. Caller sets argsz. READ &/ WRITE required. + * + * In case RESERVED_MSI_IOVA flag is set, the API only aims at registering an + * IOVA region that will be used on some platforms to map the host MSI frames. + * In that specific case, vaddr is ignored. Once registered, an MSI reserved + * IOVA region stays until the container is closed. + * The requirement for provisioning such reserved IOVA range can be checked by + * checking the VFIO_IOMMU_TYPE1_INFO_CAP_MSI_GEOMETRY capability. */ struct vfio_iommu_type1_dma_map { __u32 argsz; __u32 flags; #define VFIO_DMA_MAP_FLAG_READ (1 << 0) /* readable from device */ #define VFIO_DMA_MAP_FLAG_WRITE (1 << 1) /* writable from device */ +/* reserved iova for MSI vectors*/ +#define VFIO_DMA_MAP_FLAG_RESERVED_MSI_IOVA (1 << 2) __u64 vaddr; /* Process virtual address */ __u64 iova; /* IO virtual address */ __u64 size; /* Size of mapping (bytes) */ @@ -519,7 +556,8 @@ struct vfio_iommu_type1_dma_map { * Caller sets argsz. The actual unmapped size is returned in the size * field. No guarantee is made to the user that arbitrary unmaps of iova * or size different from those used in the original mapping call will - * succeed. + * succeed. Once registered, an MSI region cannot be unmapped and stays + * until the container is closed. */ struct vfio_iommu_type1_dma_unmap { __u32 argsz; @@ -688,4 +726,4 @@ struct vfio_iommu_spapr_tce_remove { /* ***************************************************************** */ -#endif /* VFIO_H */ +#endif /* _UAPIVFIO_H */ -- 1.9.1