[PATCH v4 3/5] vhost_user: support function defines for back-end

[Pravin M Bathija <pravin.bathija@dell.com>]

Here we define support functions which are called from the various
vhost-user back-end message functions like set memory table, get
memory slots, add memory region, remove memory region.  These are
essentially common functions to initialize memory, unmap a set of
memory regions, perform register copy, align memory addresses and
dma map/unmap a single memory region.

Signed-off-by: Pravin M Bathija <pravin.bathija@dell.com>
---
 lib/vhost/vhost_user.c | 150 ++++++++++++++++++++++++++++++++++++++---
 1 file changed, 140 insertions(+), 10 deletions(-)

diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
index 4bfb13fb98..7dc21fe42a 100644
--- a/lib/vhost/vhost_user.c
+++ b/lib/vhost/vhost_user.c
@@ -171,6 +171,80 @@ get_blk_size(int fd)
 	return ret == -1 ? (uint64_t)-1 : (uint64_t)stat.st_blksize;
 }
 
+static void
+async_dma_map_region(struct virtio_net *dev, struct rte_vhost_mem_region *reg, bool do_map)
+{
+	uint32_t i;
+	int ret = 0;
+	int found = 0;
+	struct guest_page *page;
+
+	uint64_t reg_size = reg->size;
+	uint64_t host_user_addr  = reg->host_user_addr;
+
+	for (i = 0; i < dev->nr_guest_pages; i++) {
+		page = &dev->guest_pages[i];
+		if (host_user_addr == page->host_user_addr) {
+			found = 1;
+			break;
+		}
+	}
+
+	if (!found) {
+		VHOST_CONFIG_LOG(dev->ifname, ERR, "DMA engine map: region not found");
+		return;
+	}
+
+	if (do_map) {
+		while (reg_size) {
+			page = &dev->guest_pages[i];
+			ret = rte_vfio_container_dma_map(RTE_VFIO_DEFAULT_CONTAINER_FD,
+					page->host_user_addr,
+					page->host_iova,
+					page->size);
+			if (ret) {
+				if (rte_errno == ENODEV)
+					return;
+
+				/* DMA mapping errors won't stop VHOST_USER_SET_MEM_TABLE. */
+				VHOST_CONFIG_LOG(dev->ifname, ERR, "DMA engine map failed");
+			}
+
+			reg_size -= page->size;
+			++i;
+			if (i >= dev->nr_guest_pages) {
+				/* shouldn't get here */
+				VHOST_CONFIG_LOG(dev->ifname, ERR, "DMA engine map: No more pages");
+				return;
+			}
+		}
+	} else {
+		while (reg_size) {
+			page = &dev->guest_pages[i];
+			ret = rte_vfio_container_dma_unmap(RTE_VFIO_DEFAULT_CONTAINER_FD,
+					page->host_user_addr,
+					page->host_iova,
+					page->size);
+			if (ret) {
+				if (rte_errno == EINVAL)
+					return;
+
+				/* DMA mapping errors won't stop VHOST_USER_SET_MEM_TABLE. */
+				VHOST_CONFIG_LOG(dev->ifname, ERR, "DMA engine unmap failed");
+			}
+
+			reg_size -= page->size;
+			++i;
+			if (i >= dev->nr_guest_pages) {
+				/* shouldn't get here */
+				VHOST_CONFIG_LOG(dev->ifname, ERR, "DMA engine unmap: No more pages");
+				return;
+			}
+		}
+	}
+
+}
+
 static void
 async_dma_map(struct virtio_net *dev, bool do_map)
 {
@@ -225,7 +299,17 @@ async_dma_map(struct virtio_net *dev, bool do_map)
 }
 
 static void
-free_mem_region(struct virtio_net *dev)
+free_mem_region(struct rte_vhost_mem_region *reg)
+{
+	if (reg != NULL && reg->host_user_addr) {
+		munmap(reg->mmap_addr, reg->mmap_size);
+		close(reg->fd);
+		memset(reg, 0, sizeof(struct rte_vhost_mem_region));
+	}
+}
+
+static void
+free_all_mem_regions(struct virtio_net *dev)
 {
 	uint32_t i;
 	struct rte_vhost_mem_region *reg;
@@ -236,12 +320,10 @@ free_mem_region(struct virtio_net *dev)
 	if (dev->async_copy && rte_vfio_is_enabled("vfio"))
 		async_dma_map(dev, false);
 
-	for (i = 0; i < dev->mem->nregions; i++) {
+	for (i = 0; i < VHOST_MEMORY_MAX_NREGIONS; i++) {
 		reg = &dev->mem->regions[i];
-		if (reg->host_user_addr) {
-			munmap(reg->mmap_addr, reg->mmap_size);
-			close(reg->fd);
-		}
+		if (reg->mmap_addr)
+			free_mem_region(reg);
 	}
 }
 
@@ -255,7 +337,7 @@ vhost_backend_cleanup(struct virtio_net *dev)
 		vdpa_dev->ops->dev_cleanup(dev->vid);
 
 	if (dev->mem) {
-		free_mem_region(dev);
+		free_all_mem_regions(dev);
 		rte_free(dev->mem);
 		dev->mem = NULL;
 	}
@@ -704,7 +786,7 @@ numa_realloc(struct virtio_net **pdev, struct vhost_virtqueue **pvq)
 	vhost_devices[dev->vid] = dev;
 
 	mem_size = sizeof(struct rte_vhost_memory) +
-		sizeof(struct rte_vhost_mem_region) * dev->mem->nregions;
+		sizeof(struct rte_vhost_mem_region) * VHOST_MEMORY_MAX_NREGIONS;
 	mem = rte_realloc_socket(dev->mem, mem_size, 0, node);
 	if (!mem) {
 		VHOST_CONFIG_LOG(dev->ifname, ERR,
@@ -808,8 +890,10 @@ hua_to_alignment(struct rte_vhost_memory *mem, void *ptr)
 	uint32_t i;
 	uintptr_t hua = (uintptr_t)ptr;
 
-	for (i = 0; i < mem->nregions; i++) {
+	for (i = 0; i < VHOST_MEMORY_MAX_NREGIONS; i++) {
 		r = &mem->regions[i];
+		if (r->host_user_addr == 0)
+			continue;
 		if (hua >= r->host_user_addr &&
 			hua < r->host_user_addr + r->size) {
 			return get_blk_size(r->fd);
@@ -1248,8 +1332,12 @@ vhost_user_postcopy_register(struct virtio_net *dev, int main_fd,
 	 */
 	memory = &ctx->msg.payload.memory;
 	for (i = 0; i < memory->nregions; i++) {
+		int reg_msg_index = 0;
 		reg = &dev->mem->regions[i];
-		memory->regions[i].userspace_addr = reg->host_user_addr;
+		if (reg->host_user_addr == 0)
+			continue;
+		memory->regions[reg_msg_index].userspace_addr = reg->host_user_addr;
+		reg_msg_index++;
 	}
 
 	/* Send the addresses back to qemu */
@@ -1278,6 +1366,8 @@ vhost_user_postcopy_register(struct virtio_net *dev, int main_fd,
 	/* Now userfault register and we can use the memory */
 	for (i = 0; i < memory->nregions; i++) {
 		reg = &dev->mem->regions[i];
+		if (reg->host_user_addr == 0)
+			continue;
 		if (vhost_user_postcopy_region_register(dev, reg) < 0)
 			return -1;
 	}
@@ -1382,6 +1472,46 @@ vhost_user_mmap_region(struct virtio_net *dev,
 	return 0;
 }
 
+static int
+vhost_user_initialize_memory(struct virtio_net **pdev)
+{
+	struct virtio_net *dev = *pdev;
+	int numa_node = SOCKET_ID_ANY;
+
+	/*
+	 * If VQ 0 has already been allocated, try to allocate on the same
+	 * NUMA node. It can be reallocated later in numa_realloc().
+	 */
+	if (dev->nr_vring > 0)
+		numa_node = dev->virtqueue[0]->numa_node;
+
+	dev->nr_guest_pages = 0;
+	if (dev->guest_pages == NULL) {
+		dev->max_guest_pages = VHOST_MEMORY_MAX_NREGIONS;
+		dev->guest_pages = rte_zmalloc_socket(NULL,
+					dev->max_guest_pages *
+					sizeof(struct guest_page),
+					RTE_CACHE_LINE_SIZE,
+					numa_node);
+		if (dev->guest_pages == NULL) {
+			VHOST_CONFIG_LOG(dev->ifname, ERR,
+				"failed to allocate memory for dev->guest_pages");
+			return -1;
+		}
+	}
+
+	dev->mem = rte_zmalloc_socket("vhost-mem-table", sizeof(struct rte_vhost_memory) +
+		sizeof(struct rte_vhost_mem_region) * VHOST_MEMORY_MAX_NREGIONS, 0, numa_node);
+	if (dev->mem == NULL) {
+		VHOST_CONFIG_LOG(dev->ifname, ERR, "failed to allocate memory for dev->mem");
+		rte_free(dev->guest_pages);
+		dev->guest_pages = NULL;
+		return -1;
+	}
+
+	return 0;
+}
+
 static int
 vhost_user_set_mem_table(struct virtio_net **pdev,
 			struct vhu_msg_context *ctx,
-- 
2.43.0