Hello John,
On 11/9/22 00:13, John Johnson wrote:
Used for communication with VFIO driver
(prep work for vfio-user, which will communicate over a socket)
Signed-off-by: John G Johnson <john.g.john...@oracle.com>
---
hw/vfio/common.c | 126 ++++++++++++++++++++++++++++--------------
include/hw/vfio/vfio-common.h | 33 +++++++++++
2 files changed, 117 insertions(+), 42 deletions(-)
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index ace9562..83d69b9 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -432,12 +432,12 @@ static int vfio_dma_unmap_bitmap(VFIOContainer *container,
goto unmap_exit;
}
- ret = ioctl(container->fd, VFIO_IOMMU_UNMAP_DMA, unmap);
+ ret = CONT_DMA_UNMAP(container, unmap, bitmap);
I am not sure these macros are very useful, compared to :
container->ops->dma_unmap(container, unmap, bitmap);
if (!ret) {
cpu_physical_memory_set_dirty_lebitmap((unsigned long *)bitmap->data,
iotlb->translated_addr, pages);
} else {
- error_report("VFIO_UNMAP_DMA with DIRTY_BITMAP : %m");
+ error_report("VFIO_UNMAP_DMA with DIRTY_BITMAP : %s", strerror(-ret));
}
g_free(bitmap->data);
@@ -465,30 +465,7 @@ static int vfio_dma_unmap(VFIOContainer *container,
return vfio_dma_unmap_bitmap(container, iova, size, iotlb);
}
- while (ioctl(container->fd, VFIO_IOMMU_UNMAP_DMA, &unmap)) {
- /*
- * The type1 backend has an off-by-one bug in the kernel (71a7d3d78e3c
- * v4.15) where an overflow in its wrap-around check prevents us from
- * unmapping the last page of the address space. Test for the error
- * condition and re-try the unmap excluding the last page. The
- * expectation is that we've never mapped the last page anyway and this
- * unmap request comes via vIOMMU support which also makes it unlikely
- * that this page is used. This bug was introduced well after type1 v2
- * support was introduced, so we shouldn't need to test for v1. A fix
- * is queued for kernel v5.0 so this workaround can be removed once
- * affected kernels are sufficiently deprecated.
- */
- if (errno == EINVAL && unmap.size && !(unmap.iova + unmap.size) &&
- container->iommu_type == VFIO_TYPE1v2_IOMMU) {
- trace_vfio_dma_unmap_overflow_workaround();
- unmap.size -= 1ULL << ctz64(container->pgsizes);
- continue;
- }
- error_report("VFIO_UNMAP_DMA failed: %s", strerror(errno));
- return -errno;
- }
-
- return 0;
+ return CONT_DMA_UNMAP(container, &unmap, NULL);
}
static int vfio_dma_map(VFIOContainer *container, hwaddr iova,
@@ -501,24 +478,18 @@ static int vfio_dma_map(VFIOContainer *container, hwaddr
iova,
.iova = iova,
.size = size,
};
+ int ret;
if (!readonly) {
map.flags |= VFIO_DMA_MAP_FLAG_WRITE;
}
- /*
- * Try the mapping, if it fails with EBUSY, unmap the region and try
- * again. This shouldn't be necessary, but we sometimes see it in
- * the VGA ROM space.
- */
- if (ioctl(container->fd, VFIO_IOMMU_MAP_DMA, &map) == 0 ||
- (errno == EBUSY && vfio_dma_unmap(container, iova, size, NULL) == 0 &&
- ioctl(container->fd, VFIO_IOMMU_MAP_DMA, &map) == 0)) {
- return 0;
- }
+ ret = CONT_DMA_MAP(container, &map);
- error_report("VFIO_MAP_DMA failed: %s", strerror(errno));
- return -errno;
+ if (ret < 0) {
+ error_report("VFIO_MAP_DMA failed: %s", strerror(-ret));
+ }
+ return ret;
}
static void vfio_host_win_add(VFIOContainer *container,
@@ -1263,10 +1234,10 @@ static void vfio_set_dirty_page_tracking(VFIOContainer
*container, bool start)
dirty.flags = VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP;
}
- ret = ioctl(container->fd, VFIO_IOMMU_DIRTY_PAGES, &dirty);
+ ret = CONT_DIRTY_BITMAP(container, &dirty, NULL);
if (ret) {
error_report("Failed to set dirty tracking flag 0x%x errno: %d",
- dirty.flags, errno);
+ dirty.flags, -ret);
}
}
@@ -1316,11 +1287,11 @@ static int vfio_get_dirty_bitmap(VFIOContainer *container, uint64_t iova,
goto err_out;
}
- ret = ioctl(container->fd, VFIO_IOMMU_DIRTY_PAGES, dbitmap);
+ ret = CONT_DIRTY_BITMAP(container, dbitmap, range);
if (ret) {
error_report("Failed to get dirty bitmap for iova: 0x%"PRIx64
" size: 0x%"PRIx64" err: %d", (uint64_t)range->iova,
- (uint64_t)range->size, errno);
+ (uint64_t)range->size, -ret);
goto err_out;
}
@@ -2090,6 +2061,7 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
container->error = NULL;
container->dirty_pages_supported = false;
container->dma_max_mappings = 0;
+ container->io_ops = &vfio_cont_io_ioctl;
QLIST_INIT(&container->giommu_list);
QLIST_INIT(&container->hostwin_list);
QLIST_INIT(&container->vrdl_list);
@@ -2626,3 +2598,73 @@ int vfio_eeh_as_op(AddressSpace *as, uint32_t op)
}
return vfio_eeh_container_op(container, op);
}
+
+/*
+ * Traditional ioctl() based io_ops
+ */
+
+static int vfio_io_dma_map(VFIOContainer *container,
+ struct vfio_iommu_type1_dma_map *map)
+{
+
+ /*
+ * Try the mapping, if it fails with EBUSY, unmap the region and try
+ * again. This shouldn't be necessary, but we sometimes see it in
+ * the VGA ROM space.
+ */
+ if (ioctl(container->fd, VFIO_IOMMU_MAP_DMA, map) == 0 ||
+ (errno == EBUSY &&
+ vfio_dma_unmap(container, map->iova, map->size, NULL) == 0 &&
+ ioctl(container->fd, VFIO_IOMMU_MAP_DMA, map) == 0)) {
+ return 0;
+ }
+ return -errno;
+}
+
+static int vfio_io_dma_unmap(VFIOContainer *container,
+ struct vfio_iommu_type1_dma_unmap *unmap,
+ struct vfio_bitmap *bitmap)
+{
+
+ while (ioctl(container->fd, VFIO_IOMMU_UNMAP_DMA, unmap)) {
+ /*
+ * The type1 backend has an off-by-one bug in the kernel (71a7d3d78e3c
+ * v4.15) where an overflow in its wrap-around check prevents us from
+ * unmapping the last page of the address space. Test for the error
+ * condition and re-try the unmap excluding the last page. The
+ * expectation is that we've never mapped the last page anyway and this
+ * unmap request comes via vIOMMU support which also makes it unlikely
+ * that this page is used. This bug was introduced well after type1 v2
+ * support was introduced, so we shouldn't need to test for v1. A fix
+ * is queued for kernel v5.0 so this workaround can be removed once
+ * affected kernels are sufficiently deprecated.
+ */
+ if (errno == EINVAL && unmap->size && !(unmap->iova + unmap->size) &&
+ container->iommu_type == VFIO_TYPE1v2_IOMMU) {
+ trace_vfio_dma_unmap_overflow_workaround();
+ unmap->size -= 1ULL << ctz64(container->pgsizes);
+ continue;
+ }
+ error_report("VFIO_UNMAP_DMA failed: %s", strerror(errno));
+ return -errno;
+ }
+
+ return 0;
+}
+
+static int vfio_io_dirty_bitmap(VFIOContainer *container,
+ struct vfio_iommu_type1_dirty_bitmap *bitmap,
+ struct vfio_iommu_type1_dirty_bitmap_get
*range)
+{
+ int ret;
+
+ ret = ioctl(container->fd, VFIO_IOMMU_DIRTY_PAGES, bitmap);
+
+ return ret < 0 ? -errno : ret;
+}
+
+VFIOContIO vfio_cont_io_ioctl = {
+ .dma_map = vfio_io_dma_map,
+ .dma_unmap = vfio_io_dma_unmap,
+ .dirty_bitmap = vfio_io_dirty_bitmap,
+};
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index e573f5a..6fd40f1 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -75,6 +75,7 @@ typedef struct VFIOAddressSpace {
} VFIOAddressSpace;
struct VFIOGroup;
+typedef struct VFIOContIO VFIOContIO;
typedef struct VFIOContainer {
VFIOAddressSpace *space;
@@ -83,6 +84,7 @@ typedef struct VFIOContainer {
MemoryListener prereg_listener;
unsigned iommu_type;
Error *error;
+ VFIOContIO *io_ops;
ops should be enough.
bool initialized;
bool dirty_pages_supported;
uint64_t dirty_pgsizes;
@@ -154,6 +156,37 @@ struct VFIODeviceOps {
int (*vfio_load_config)(VFIODevice *vdev, QEMUFile *f);
};
+#ifdef CONFIG_LINUX
+
+/*
+ * The next 2 ops vectors are how Devices and Containers
+ * communicate with the server. The default option is
+ * through ioctl() to the kernel VFIO driver, but vfio-user
+ * can use a socket to a remote process.
+ */
+
+struct VFIOContIO {
VFIOContainerOps seems more adequate with the current VFIO terminology
in QEMU.
Thanks,
C.
+ int (*dma_map)(VFIOContainer *container,
+ struct vfio_iommu_type1_dma_map *map);
+ int (*dma_unmap)(VFIOContainer *container,
+ struct vfio_iommu_type1_dma_unmap *unmap,
+ struct vfio_bitmap *bitmap);
+ int (*dirty_bitmap)(VFIOContainer *container,
+ struct vfio_iommu_type1_dirty_bitmap *bitmap,
+ struct vfio_iommu_type1_dirty_bitmap_get *range);
+};
+
+#define CONT_DMA_MAP(cont, map) \
+ ((cont)->io_ops->dma_map((cont), (map)))
+#define CONT_DMA_UNMAP(cont, unmap, bitmap) \
+ ((cont)->io_ops->dma_unmap((cont), (unmap), (bitmap)))
+#define CONT_DIRTY_BITMAP(cont, bitmap, range) \
+ ((cont)->io_ops->dirty_bitmap((cont), (bitmap), (range)))
+
+extern VFIOContIO vfio_cont_io_ioctl;
+
+#endif /* CONFIG_LINUX */
+
typedef struct VFIOGroup {
int fd;
int groupid;
