[PATCH 14/33] vfio: selftests: Keep track of DMA regions mapped into the device

[David Matlack]

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.

Signed-off-by: David Matlack <dmatl...@google.com>
---
 .../selftests/vfio/lib/include/vfio_util.h    | 23 +++++++--
 .../selftests/vfio/lib/vfio_pci_device.c      | 49 ++++++++++++++++---
 .../selftests/vfio/vfio_dma_mapping_test.c    | 21 +++++---
 3 files changed, 75 insertions(+), 18 deletions(-)

diff --git a/tools/testing/selftests/vfio/lib/include/vfio_util.h 
b/tools/testing/selftests/vfio/lib/include/vfio_util.h
index 234403b442af..db08646c2819 100644
--- 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 98cce0a6ecd7..36b4b30b75cf 100644
--- 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 9cdf25b293c5..8cec09ba8ec3 100644
--- a/tools/testing/selftests/vfio/vfio_dma_mapping_test.c
+++ b/tools/testing/selftests/vfio/vfio_dma_mapping_test.c
@@ -128,21 +128,25 @@ 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;
        const u64 iova = 0;
-       void *mem;
        int rc;
 
-       mem = mmap(NULL, size, PROT_READ | PROT_WRITE, flags, -1, 0);
+       region.iova = iova;
+       region.size = size;
+       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);
 
-       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, iova);
+
+       ASSERT_EQ(iova, to_iova(self->device, region.vaddr));
 
        rc = iommu_mapping_get(device_bdf, iova, &mapping);
        if (rc == -EOPNOTSUPP)
@@ -174,11 +178,12 @@ TEST_F(vfio_dma_mapping_test, dma_map_unmap)
        }
 
 unmap:
-       vfio_pci_dma_unmap(self->device, iova, size);
+       vfio_pci_dma_unmap(self->device, &region);
        printf("Unmapped IOVA 0x%lx\n", iova);
+       ASSERT_EQ(INVALID_IOVA, __to_iova(self->device, region.vaddr));
        ASSERT_NE(0, iommu_mapping_get(device_bdf, iova, &mapping));
 
-       ASSERT_TRUE(!munmap(mem, size));
+       ASSERT_TRUE(!munmap(region.vaddr, size));
 }
 
 int main(int argc, char *argv[])
-- 
2.50.0.rc2.701.gf1e915cc24-goog