vfio: selftests: Keep track of DMA regions mapped into the device

Keep track of the list of DMA regions that are mapped into the device
using a linked list and a new struct vfio_dma_region and use that to add
{__,}to_iova() for converting host virtual addresses into IOVAs.

This will be used in a subsequent commit to map multiple DMA regions
into a device that are then used by drivers.

Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-10-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

diff --git a/tools/testing/selftests/vfio/lib/include/vfio_util.h b/tools/testing/selftests/vfio/lib/include/vfio_util.h
index 234403b442af2ca1f295acace275b0ed71ad9f05..db08646c2819c60d3f66fcb43ff3755a5ca93d5c 100644 (file)
--- a/tools/testing/selftests/vfio/lib/include/vfio_util.h
+++ b/tools/testing/selftests/vfio/lib/include/vfio_util.h
@@ -51,6 +51,17 @@ struct vfio_pci_bar {
        void *vaddr;
 };
 
+typedef u64 iova_t;
+
+#define INVALID_IOVA UINT64_MAX
+
+struct vfio_dma_region {
+       struct list_head link;
+       void *vaddr;
+       iova_t iova;
+       u64 size;
+};
+
 struct vfio_pci_device {
        int fd;
        int group_fd;
@@ -63,6 +74,8 @@ struct vfio_pci_device {
        struct vfio_irq_info msi_info;
        struct vfio_irq_info msix_info;
 
+       struct list_head dma_regions;
+
        /* eventfds for MSI and MSI-x interrupts */
        int msi_eventfds[PCI_MSIX_FLAGS_QSIZE + 1];
 };
@@ -85,9 +98,10 @@ struct vfio_pci_device *vfio_pci_device_init(const char *bdf, int iommu_type);
 void vfio_pci_device_cleanup(struct vfio_pci_device *device);
 void vfio_pci_device_reset(struct vfio_pci_device *device);
 
-void vfio_pci_dma_map(struct vfio_pci_device *device, u64 iova, u64 size,
-                     void *vaddr);
-void vfio_pci_dma_unmap(struct vfio_pci_device *device, u64 iova, u64 size);
+void vfio_pci_dma_map(struct vfio_pci_device *device,
+                     struct vfio_dma_region *region);
+void vfio_pci_dma_unmap(struct vfio_pci_device *device,
+                       struct vfio_dma_region *region);
 
 void vfio_pci_config_access(struct vfio_pci_device *device, bool write,
                            size_t config, size_t size, void *data);
@@ -138,4 +152,7 @@ static inline void vfio_pci_msix_disable(struct vfio_pci_device *device)
        vfio_pci_irq_disable(device, VFIO_PCI_MSIX_IRQ_INDEX);
 }
 
+iova_t __to_iova(struct vfio_pci_device *device, void *vaddr);
+iova_t to_iova(struct vfio_pci_device *device, void *vaddr);
+
 #endif /* SELFTESTS_VFIO_LIB_INCLUDE_VFIO_UTIL_H */

diff --git a/tools/testing/selftests/vfio/lib/vfio_pci_device.c b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
index 98cce0a6ecd732c6f92715d4e7d8e3d06d785e28..36b4b30b75cfb85b253a6b6033723f1de1dffd43 100644 (file)
--- a/tools/testing/selftests/vfio/lib/vfio_pci_device.c
+++ b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
@@ -26,6 +26,33 @@
        VFIO_ASSERT_EQ(__ret, 0, "ioctl(%s, %s, %s) returned %d\n", #_fd, #_op, #_arg, __ret); \
 } while (0)
 
+iova_t __to_iova(struct vfio_pci_device *device, void *vaddr)
+{
+       struct vfio_dma_region *region;
+
+       list_for_each_entry(region, &device->dma_regions, link) {
+               if (vaddr < region->vaddr)
+                       continue;
+
+               if (vaddr >= region->vaddr + region->size)
+                       continue;
+
+               return region->iova + (vaddr - region->vaddr);
+       }
+
+       return INVALID_IOVA;
+}
+
+iova_t to_iova(struct vfio_pci_device *device, void *vaddr)
+{
+       iova_t iova;
+
+       iova = __to_iova(device, vaddr);
+       VFIO_ASSERT_NE(iova, INVALID_IOVA, "%p is not mapped into device.\n", vaddr);
+
+       return iova;
+}
+
 static void vfio_pci_irq_set(struct vfio_pci_device *device,
                             u32 index, u32 vector, u32 count, int *fds)
 {
@@ -112,28 +139,34 @@ static void vfio_pci_irq_get(struct vfio_pci_device *device, u32 index,
        ioctl_assert(device->fd, VFIO_DEVICE_GET_IRQ_INFO, irq_info);
 }
 
-void vfio_pci_dma_map(struct vfio_pci_device *device, u64 iova, u64 size, void *vaddr)
+void vfio_pci_dma_map(struct vfio_pci_device *device,
+                     struct vfio_dma_region *region)
 {
        struct vfio_iommu_type1_dma_map map = {
                .argsz = sizeof(map),
                .flags = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE,
-               .vaddr = (u64)vaddr,
-               .iova = iova,
-               .size = size,
+               .vaddr = (u64)region->vaddr,
+               .iova = region->iova,
+               .size = region->size,
        };
 
        ioctl_assert(device->container_fd, VFIO_IOMMU_MAP_DMA, &map);
+
+       list_add(&region->link, &device->dma_regions);
 }
 
-void vfio_pci_dma_unmap(struct vfio_pci_device *device, u64 iova, u64 size)
+void vfio_pci_dma_unmap(struct vfio_pci_device *device,
+                       struct vfio_dma_region *region)
 {
        struct vfio_iommu_type1_dma_unmap unmap = {
                .argsz = sizeof(unmap),
-               .iova = iova,
-               .size = size,
+               .iova = region->iova,
+               .size = region->size,
        };
 
        ioctl_assert(device->container_fd, VFIO_IOMMU_UNMAP_DMA, &unmap);
+
+       list_del(&region->link);
 }
 
 static void vfio_pci_region_get(struct vfio_pci_device *device, int index,
@@ -260,6 +293,8 @@ static void vfio_pci_iommu_setup(struct vfio_pci_device *device, unsigned long i
 {
        int ret;
 
+       INIT_LIST_HEAD(&device->dma_regions);
+
        ret = ioctl(device->container_fd, VFIO_CHECK_EXTENSION, iommu_type);
        VFIO_ASSERT_GT(ret, 0, "VFIO IOMMU type %lu not supported\n", iommu_type);
 

diff --git a/tools/testing/selftests/vfio/vfio_dma_mapping_test.c b/tools/testing/selftests/vfio/vfio_dma_mapping_test.c
index 2612f0cabea525c8cf37958e8d3e11976cf839cd..4578ee6df0e1431b274a8d1b8b8e59846f11f215 100644 (file)
--- a/tools/testing/selftests/vfio/vfio_dma_mapping_test.c
+++ b/tools/testing/selftests/vfio/vfio_dma_mapping_test.c
@@ -128,30 +128,32 @@ TEST_F(vfio_dma_mapping_test, dma_map_unmap)
 {
        const u64 size = variant->size ?: getpagesize();
        const int flags = variant->mmap_flags;
+       struct vfio_dma_region region;
        struct iommu_mapping mapping;
-       void *mem;
-       u64 iova;
        int rc;
 
-       mem = mmap(NULL, size, PROT_READ | PROT_WRITE, flags, -1, 0);
+       region.vaddr = mmap(NULL, size, PROT_READ | PROT_WRITE, flags, -1, 0);
 
        /* Skip the test if there aren't enough HugeTLB pages available. */
-       if (flags & MAP_HUGETLB && mem == MAP_FAILED)
+       if (flags & MAP_HUGETLB && region.vaddr == MAP_FAILED)
                SKIP(return, "mmap() failed: %s (%d)\n", strerror(errno), errno);
        else
-               ASSERT_NE(mem, MAP_FAILED);
+               ASSERT_NE(region.vaddr, MAP_FAILED);
 
-       iova = (u64)mem;
+       region.iova = (u64)region.vaddr;
+       region.size = size;
 
-       vfio_pci_dma_map(self->device, iova, size, mem);
-       printf("Mapped HVA %p (size 0x%lx) at IOVA 0x%lx\n", mem, size, iova);
+       vfio_pci_dma_map(self->device, &region);
+       printf("Mapped HVA %p (size 0x%lx) at IOVA 0x%lx\n", region.vaddr, size, region.iova);
 
-       rc = iommu_mapping_get(device_bdf, iova, &mapping);
+       ASSERT_EQ(region.iova, to_iova(self->device, region.vaddr));
+
+       rc = iommu_mapping_get(device_bdf, region.iova, &mapping);
        if (rc == -EOPNOTSUPP)
                goto unmap;
 
        ASSERT_EQ(0, rc);
-       printf("Found IOMMU mappings for IOVA 0x%lx:\n", iova);
+       printf("Found IOMMU mappings for IOVA 0x%lx:\n", region.iova);
        printf("PGD: 0x%016lx\n", mapping.pgd);
        printf("P4D: 0x%016lx\n", mapping.p4d);
        printf("PUD: 0x%016lx\n", mapping.pud);
@@ -176,11 +178,12 @@ TEST_F(vfio_dma_mapping_test, dma_map_unmap)
        }
 
 unmap:
-       vfio_pci_dma_unmap(self->device, iova, size);
-       printf("Unmapped IOVA 0x%lx\n", iova);
-       ASSERT_NE(0, iommu_mapping_get(device_bdf, iova, &mapping));
+       vfio_pci_dma_unmap(self->device, &region);
+       printf("Unmapped IOVA 0x%lx\n", region.iova);
+       ASSERT_EQ(INVALID_IOVA, __to_iova(self->device, region.vaddr));
+       ASSERT_NE(0, iommu_mapping_get(device_bdf, region.iova, &mapping));
 
-       ASSERT_TRUE(!munmap(mem, size));
+       ASSERT_TRUE(!munmap(region.vaddr, size));
 }
 
 int main(int argc, char *argv[])