diff mbox series

[v5,2/2] vhost: enable IOMMU for async vhost

Message ID 20210927074806.90020-3-xuan.ding@intel.com (mailing list archive)
State Superseded
Delegated to: Maxime Coquelin
Headers show
Series support IOMMU for DMA device | expand

Checks

Context Check Description
ci/intel-Testing fail Testing issues
ci/Intel-compilation success Compilation OK
ci/checkpatch success coding style OK

Commit Message

Xuan Ding Sept. 27, 2021, 7:48 a.m. UTC
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>
---
 lib/vhost/vhost.h      |   4 ++
 lib/vhost/vhost_user.c | 114 ++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 116 insertions(+), 2 deletions(-)

Comments

Anatoly Burakov Sept. 27, 2021, 12:13 p.m. UTC | #1
On 27-Sep-21 8:48 AM, Xuan Ding wrote:
> 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>
> ---


>   	/* Flush IOTLB cache as previous HVAs are now invalid */
> @@ -1329,6 +1424,17 @@ 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);

Would it be useful to sanity check this to make sure we're not leaking 
memory?
Xuan Ding Sept. 28, 2021, 9:03 a.m. UTC | #2
Hi Anatoly,

> -----Original Message-----
> From: Burakov, Anatoly <anatoly.burakov@intel.com>
> Sent: Monday, September 27, 2021 8:14 PM
> To: Ding, Xuan <xuan.ding@intel.com>; dev@dpdk.org;
> 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>
> Subject: Re: [PATCH v5 2/2] vhost: enable IOMMU for async vhost
> 
> On 27-Sep-21 8:48 AM, Xuan Ding wrote:
> > 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>
> > ---
> 
> 
> >   	/* Flush IOTLB cache as previous HVAs are now invalid */
> > @@ -1329,6 +1424,17 @@ 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);
> 
> Would it be useful to sanity check this to make sure we're not leaking
> memory?

Thanks for the catch, will add the check in next version.

Regards,
Xuan

> 
> --
> Thanks,
> Anatoly
diff mbox series

Patch

diff --git a/lib/vhost/vhost.h b/lib/vhost/vhost.h
index d98ca8adfa..8b8df3897b 100644
--- a/lib/vhost/vhost.h
+++ b/lib/vhost/vhost.h
@@ -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];
diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
index 29a4c9af60..7ffb679304 100644
--- a/lib/vhost/vhost_user.c
+++ b/lib/vhost/vhost_user.c
@@ -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);
 		}
@@ -203,6 +265,11 @@  vhost_backend_cleanup(struct virtio_net *dev)
 	}
 
 	dev->postcopy_listening = 0;
+
+	if (dev->async_map_status) {
+		rte_free(dev->async_map_status);
+		dev->async_map_status = NULL;
+	}
 }
 
 static void
@@ -621,6 +688,17 @@  numa_realloc(struct virtio_net *dev, int index)
 	}
 	dev->mem = mem;
 
+	if (dev->async_copy && rte_vfio_is_enabled("vfio")) {
+		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 +1229,14 @@  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 +1290,23 @@  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 +1379,11 @@  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 +1424,17 @@  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 +1451,7 @@  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 +1499,10 @@  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;