> -----Original Message-----
> From: Ding, Xuan <xuan.ding@intel.com>
> Sent: Monday, October 11, 2021 4:00 PM
> To: dev@dpdk.org; Burakov, Anatoly <anatoly.burakov@intel.com>;
> maxime.coquelin@redhat.com; Xia, Chenbo <chenbo.xia@intel.com>
> Cc: Hu, Jiayu <jiayu.hu@intel.com>; Jiang, Cheng1 <cheng1.jiang@intel.com>;
> Richardson, Bruce <bruce.richardson@intel.com>; Pai G, Sunil
> <sunil.pai.g@intel.com>; Wang, Yinan <yinan.wang@intel.com>; Yang,
> YvonneX <yvonnex.yang@intel.com>; Ding, Xuan <xuan.ding@intel.com>
> Subject: [PATCH v7 2/2] vhost: enable IOMMU for async vhost
>
> The use of IOMMU has many advantages, such as isolation and address
> translation. This patch extends the capbility of DMA engine to use IOMMU if
> the DMA engine is bound to vfio.
>
> When set memory table, the guest memory will be mapped into the default
> container of DPDK.
>
> Signed-off-by: Xuan Ding <xuan.ding@intel.com>
> ---
Tested-by: Yvonne Yang <yvonnex.yang@intel.com>
@@ -370,6 +370,10 @@ struct virtio_net {
int16_t broadcast_rarp;
uint32_t nr_vring;
int async_copy;
+
+ /* Record the dma map status for each region. */
+ bool *async_map_status;
+
int extbuf;
int linearbuf;
struct vhost_virtqueue *virtqueue[VHOST_MAX_QUEUE_PAIRS * 2];
@@ -45,6 +45,8 @@
#include <rte_common.h>
#include <rte_malloc.h>
#include <rte_log.h>
+#include <rte_vfio.h>
+#include <rte_errno.h>
#include "iotlb.h"
#include "vhost.h"
@@ -141,6 +143,63 @@ get_blk_size(int fd)
return ret == -1 ? (uint64_t)-1 : (uint64_t)stat.st_blksize;
}
+static int
+async_dma_map(struct rte_vhost_mem_region *region, bool *dma_map_success, bool do_map)
+{
+ uint64_t host_iova;
+ int ret = 0;
+
+ host_iova = rte_mem_virt2iova((void *)(uintptr_t)region->host_user_addr);
+ if (do_map) {
+ /* Add mapped region into the default container of DPDK. */
+ ret = rte_vfio_container_dma_map(RTE_VFIO_DEFAULT_CONTAINER_FD,
+ region->host_user_addr,
+ host_iova,
+ region->size);
+ *dma_map_success = ret == 0;
+
+ if (ret) {
+ /*
+ * DMA device may bind with kernel driver, in this case,
+ * we don't need to program IOMMU manually. However, if no
+ * device is bound with vfio/uio in DPDK, and vfio kernel
+ * module is loaded, the API will still be called and return
+ * with ENODEV/ENOSUP.
+ *
+ * DPDK vfio only returns ENODEV/ENOSUP in very similar
+ * situations(vfio either unsupported, or supported
+ * but no devices found). Either way, no mappings could be
+ * performed. We treat it as normal case in async path.
+ */
+ if (rte_errno == ENODEV || rte_errno == ENOTSUP)
+ return 0;
+
+ VHOST_LOG_CONFIG(ERR, "DMA engine map failed\n");
+ return ret;
+
+ }
+
+ } else {
+ /* No need to do vfio unmap if the map failed. */
+ if (!*dma_map_success)
+ return 0;
+
+ /* Remove mapped region from the default container of DPDK. */
+ ret = rte_vfio_container_dma_unmap(RTE_VFIO_DEFAULT_CONTAINER_FD,
+ region->host_user_addr,
+ host_iova,
+ region->size);
+ if (ret) {
+ VHOST_LOG_CONFIG(ERR, "DMA engine unmap failed\n");
+ return ret;
+ }
+ /* Clear the flag once the unmap succeeds. */
+ *dma_map_success = 0;
+ }
+
+ return ret;
+}
+
static void
free_mem_region(struct virtio_net *dev)
{
@@ -153,6 +212,9 @@ free_mem_region(struct virtio_net *dev)
for (i = 0; i < dev->mem->nregions; i++) {
reg = &dev->mem->regions[i];
if (reg->host_user_addr) {
+ if (dev->async_copy && rte_vfio_is_enabled("vfio"))
+ async_dma_map(reg, &dev->async_map_status[i], false);
+
munmap(reg->mmap_addr, reg->mmap_size);
close(reg->fd);
}
@@ -166,6 +228,11 @@ vhost_backend_cleanup(struct virtio_net *dev)
free_mem_region(dev);
rte_free(dev->mem);
dev->mem = NULL;
+
+ if (dev->async_map_status) {
+ rte_free(dev->async_map_status);
+ dev->async_map_status = NULL;
+ }
}
rte_free(dev->guest_pages);
@@ -621,6 +688,19 @@ numa_realloc(struct virtio_net *dev, int index)
}
dev->mem = mem;
+ if (dev->async_copy && rte_vfio_is_enabled("vfio")) {
+ if (dev->async_map_status == NULL) {
+ dev->async_map_status = rte_zmalloc_socket("async-dma-map-status",
+ sizeof(bool) * dev->mem->nregions, 0, node);
+ if (!dev->async_map_status) {
+ VHOST_LOG_CONFIG(ERR,
+ "(%d) failed to realloc dma mapping status on node\n",
+ dev->vid);
+ return dev;
+ }
+ }
+ }
+
gp = rte_realloc_socket(dev->guest_pages, dev->max_guest_pages * sizeof(*gp),
RTE_CACHE_LINE_SIZE, node);
if (!gp) {
@@ -1151,12 +1231,14 @@ vhost_user_postcopy_register(struct virtio_net *dev, int main_fd,
static int
vhost_user_mmap_region(struct virtio_net *dev,
struct rte_vhost_mem_region *region,
+ uint32_t region_index,
uint64_t mmap_offset)
{
void *mmap_addr;
uint64_t mmap_size;
uint64_t alignment;
int populate;
+ int ret;
/* Check for memory_size + mmap_offset overflow */
if (mmap_offset >= -region->size) {
@@ -1210,13 +1292,23 @@ vhost_user_mmap_region(struct virtio_net *dev,
region->mmap_size = mmap_size;
region->host_user_addr = (uint64_t)(uintptr_t)mmap_addr + mmap_offset;
- if (dev->async_copy)
+ if (dev->async_copy) {
if (add_guest_pages(dev, region, alignment) < 0) {
VHOST_LOG_CONFIG(ERR,
"adding guest pages to region failed.\n");
return -1;
}
+ if (rte_vfio_is_enabled("vfio")) {
+ ret = async_dma_map(region, &dev->async_map_status[region_index], true);
+ if (ret) {
+ VHOST_LOG_CONFIG(ERR, "Configure IOMMU for DMA "
+ "engine failed\n");
+ return -1;
+ }
+ }
+ }
+
VHOST_LOG_CONFIG(INFO,
"guest memory region size: 0x%" PRIx64 "\n"
"\t guest physical addr: 0x%" PRIx64 "\n"
@@ -1289,6 +1381,11 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
free_mem_region(dev);
rte_free(dev->mem);
dev->mem = NULL;
+
+ if (dev->async_map_status) {
+ rte_free(dev->async_map_status);
+ dev->async_map_status = NULL;
+ }
}
/* Flush IOTLB cache as previous HVAs are now invalid */
@@ -1329,6 +1426,17 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
goto free_guest_pages;
}
+ if (dev->async_copy) {
+ dev->async_map_status = rte_zmalloc_socket("async-dma-map-status",
+ sizeof(bool) * memory->nregions, 0, numa_node);
+ if (!dev->async_map_status) {
+ VHOST_LOG_CONFIG(ERR,
+ "(%d) failed to allocate memory for dma mapping status\n",
+ dev->vid);
+ goto free_mem_table;
+ }
+ }
+
for (i = 0; i < memory->nregions; i++) {
reg = &dev->mem->regions[i];
@@ -1345,7 +1453,7 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
mmap_offset = memory->regions[i].mmap_offset;
- if (vhost_user_mmap_region(dev, reg, mmap_offset) < 0) {
+ if (vhost_user_mmap_region(dev, reg, i, mmap_offset) < 0) {
VHOST_LOG_CONFIG(ERR, "Failed to mmap region %u\n", i);
goto free_mem_table;
}
@@ -1393,6 +1501,10 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
free_mem_region(dev);
rte_free(dev->mem);
dev->mem = NULL;
+ if (dev->async_map_status) {
+ rte_free(dev->async_map_status);
+ dev->async_map_status = NULL;
+ }
free_guest_pages:
rte_free(dev->guest_pages);
dev->guest_pages = NULL;