@@ -310,6 +310,29 @@ static int vaddr_get_pfn(unsigned long vaddr, int prot, unsigned long *pfn)
}
/*
+ * vfio_domains_require_msi_mapping: return whether MSI doorbells must be
+ * iommu mapped
+ *
+ * returns true if msi mapping is requested
+ */
+static bool vfio_domains_require_msi_mapping(struct vfio_iommu *iommu)
+{
+ struct iommu_domain_msi_geometry msi_geometry;
+ struct vfio_domain *d;
+ bool flag;
+
+ mutex_lock(&iommu->lock);
+ /* All domains have same require_msi_map property, pick first */
+ d = list_first_entry(&iommu->domain_list, struct vfio_domain, next);
+ iommu_domain_get_attr(d->domain, DOMAIN_ATTR_MSI_GEOMETRY,
+ &msi_geometry);
+ flag = msi_geometry.programmable;
+
+ mutex_unlock(&iommu->lock);
+
+ return flag;
+}
+/*
* Attempt to pin pages. We really don't want to track all the pfns and
* the iommu can only map chunks of consecutive pfns anyway, so get the
* first page and all consecutive pages with the same locking.
@@ -1166,6 +1189,9 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
info.flags = VFIO_IOMMU_INFO_PGSIZES;
+ if (vfio_domains_require_msi_mapping(iommu))
+ info.flags |= VFIO_IOMMU_INFO_REQUIRE_MSI_MAP;
+
info.iova_pgsizes = vfio_pgsize_bitmap(iommu);
return copy_to_user((void __user *)arg, &info, minsz) ?
@@ -488,6 +488,7 @@ struct vfio_iommu_type1_info {
__u32 argsz;
__u32 flags;
#define VFIO_IOMMU_INFO_PGSIZES (1 << 0) /* supported page sizes info */
+#define VFIO_IOMMU_INFO_REQUIRE_MSI_MAP (1 << 1)/* MSI must be mapped */
__u64 iova_pgsizes; /* Bitmap of supported page sizes */
};
@@ -503,6 +504,9 @@ struct vfio_iommu_type1_info {
* 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
+ * calling VFIO_IOMMU_GET_INFO and testing the VFIO_IOMMU_INFO_REQUIRE_MSI_MAP
+ * flag.
*/
struct vfio_iommu_type1_dma_map {
__u32 argsz;
This patch allows the user-space to know whether MSI addresses need to be mapped in the IOMMU. The user-space uses VFIO_IOMMU_GET_INFO ioctl and IOMMU_INFO_REQUIRE_MSI_MAP gets set if they need to. The computation of the number of IOVA pages to be provided by the user space will be implemented in a separate patch using capability chains. Signed-off-by: Eric Auger <eric.auger@linaro.org> --- v6 -> v7: - remove the computation of the number of IOVA pages to be provisionned. This number depends on the domain/group/device topology which can dynamically change. Let's rely instead rely on an arbitrary max depending on the system v4 -> v5: - move msi_info and ret declaration within the conditional code v3 -> v4: - replace former vfio_domains_require_msi_mapping by more complex computation of MSI mapping requirements, especially the number of pages to be provided by the user-space. - reword patch title RFC v1 -> v1: - derived from [RFC PATCH 3/6] vfio: Extend iommu-info to return MSIs automap state - renamed allow_msi_reconfig into require_msi_mapping - fixed VFIO_IOMMU_GET_INFO --- drivers/vfio/vfio_iommu_type1.c | 26 ++++++++++++++++++++++++++ include/uapi/linux/vfio.h | 4 ++++ 2 files changed, 30 insertions(+) -- 1.9.1