vhost: refactor memory regions mapping

This patch moves memory region mmaping and related
preparation in a dedicated function in order to simplify
VHOST_USER_SET_MEM_TABLE request handling function.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index e3ae85c..4fb1924 100644 (file)
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -1097,6 +1097,96 @@ vhost_user_postcopy_register(struct virtio_net *dev, int main_fd,
        return 0;
 }
 
+static int
+vhost_user_mmap_region(struct virtio_net *dev,
+               struct rte_vhost_mem_region *region,
+               uint64_t mmap_offset)
+{
+       void *mmap_addr;
+       uint64_t mmap_size;
+       uint64_t alignment;
+       int populate;
+
+       /* Check for memory_size + mmap_offset overflow */
+       if (mmap_offset >= -region->size) {
+               VHOST_LOG_CONFIG(ERR,
+                               "mmap_offset (%#"PRIx64") and memory_size "
+                               "(%#"PRIx64") overflow\n",
+                               mmap_offset, region->size);
+               return -1;
+       }
+
+       mmap_size = region->size + mmap_offset;
+
+       /* mmap() without flag of MAP_ANONYMOUS, should be called with length
+        * argument aligned with hugepagesz at older longterm version Linux,
+        * like 2.6.32 and 3.2.72, or mmap() will fail with EINVAL.
+        *
+        * To avoid failure, make sure in caller to keep length aligned.
+        */
+       alignment = get_blk_size(region->fd);
+       if (alignment == (uint64_t)-1) {
+               VHOST_LOG_CONFIG(ERR,
+                               "couldn't get hugepage size through fstat\n");
+               return -1;
+       }
+       mmap_size = RTE_ALIGN_CEIL(mmap_size, alignment);
+       if (mmap_size == 0) {
+               /*
+                * It could happen if initial mmap_size + alignment overflows
+                * the sizeof uint64, which could happen if either mmap_size or
+                * alignment value is wrong.
+                *
+                * mmap() kernel implementation would return an error, but
+                * better catch it before and provide useful info in the logs.
+                */
+               VHOST_LOG_CONFIG(ERR, "mmap size (0x%" PRIx64 ") "
+                               "or alignment (0x%" PRIx64 ") is invalid\n",
+                               region->size + mmap_offset, alignment);
+               return -1;
+       }
+
+       populate = dev->async_copy ? MAP_POPULATE : 0;
+       mmap_addr = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE,
+                       MAP_SHARED | populate, region->fd, 0);
+
+       if (mmap_addr == MAP_FAILED) {
+               VHOST_LOG_CONFIG(ERR, "mmap failed (%s).\n", strerror(errno));
+               return -1;
+       }
+
+       region->mmap_addr = mmap_addr;
+       region->mmap_size = mmap_size;
+       region->host_user_addr = (uint64_t)(uintptr_t)mmap_addr + mmap_offset;
+
+       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;
+               }
+
+       VHOST_LOG_CONFIG(INFO,
+                       "guest memory region size: 0x%" PRIx64 "\n"
+                       "\t guest physical addr: 0x%" PRIx64 "\n"
+                       "\t guest virtual  addr: 0x%" PRIx64 "\n"
+                       "\t host  virtual  addr: 0x%" PRIx64 "\n"
+                       "\t mmap addr : 0x%" PRIx64 "\n"
+                       "\t mmap size : 0x%" PRIx64 "\n"
+                       "\t mmap align: 0x%" PRIx64 "\n"
+                       "\t mmap off  : 0x%" PRIx64 "\n",
+                       region->size,
+                       region->guest_phys_addr,
+                       region->guest_user_addr,
+                       region->host_user_addr,
+                       (uint64_t)(uintptr_t)mmap_addr,
+                       mmap_size,
+                       alignment,
+                       mmap_offset);
+
+       return 0;
+}
+
 static int
 vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
                        int main_fd)
@@ -1104,12 +1194,9 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
        struct virtio_net *dev = *pdev;
        struct VhostUserMemory *memory = &msg->payload.memory;
        struct rte_vhost_mem_region *reg;
-       void *mmap_addr;
-       uint64_t mmap_size;
+
        uint64_t mmap_offset;
-       uint64_t alignment;
        uint32_t i;
-       int populate;
 
        if (validate_msg_fds(msg, memory->nregions) != 0)
                return RTE_VHOST_MSG_RESULT_ERR;
@@ -1171,7 +1258,6 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
                        dev->vid);
                goto free_guest_pages;
        }
-       dev->mem->nregions = memory->nregions;
 
        for (i = 0; i < memory->nregions; i++) {
                reg = &dev->mem->regions[i];
@@ -1189,88 +1275,12 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
 
                mmap_offset = memory->regions[i].mmap_offset;
 
-               /* Check for memory_size + mmap_offset overflow */
-               if (mmap_offset >= -reg->size) {
-                       VHOST_LOG_CONFIG(ERR,
-                               "mmap_offset (%#"PRIx64") and memory_size "
-                               "(%#"PRIx64") overflow\n",
-                               mmap_offset, reg->size);
-                       goto free_mem_table;
-               }
-
-               mmap_size = reg->size + mmap_offset;
-
-               /* mmap() without flag of MAP_ANONYMOUS, should be called
-                * with length argument aligned with hugepagesz at older
-                * longterm version Linux, like 2.6.32 and 3.2.72, or
-                * mmap() will fail with EINVAL.
-                *
-                * to avoid failure, make sure in caller to keep length
-                * aligned.
-                */
-               alignment = get_blk_size(reg->fd);
-               if (alignment == (uint64_t)-1) {
-                       VHOST_LOG_CONFIG(ERR,
-                               "couldn't get hugepage size through fstat\n");
-                       goto free_mem_table;
-               }
-               mmap_size = RTE_ALIGN_CEIL(mmap_size, alignment);
-               if (mmap_size == 0) {
-                       /*
-                        * It could happen if initial mmap_size + alignment
-                        * overflows the sizeof uint64, which could happen if
-                        * either mmap_size or alignment value is wrong.
-                        *
-                        * mmap() kernel implementation would return an error,
-                        * but better catch it before and provide useful info
-                        * in the logs.
-                        */
-                       VHOST_LOG_CONFIG(ERR, "mmap size (0x%" PRIx64 ") "
-                                       "or alignment (0x%" PRIx64 ") is invalid\n",
-                                       reg->size + mmap_offset, alignment);
-                       goto free_mem_table;
-               }
-
-               populate = dev->async_copy ? MAP_POPULATE : 0;
-               mmap_addr = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE,
-                                MAP_SHARED | populate, reg->fd, 0);
-
-               if (mmap_addr == MAP_FAILED) {
-                       VHOST_LOG_CONFIG(ERR,
-                               "mmap region %u failed.\n", i);
+               if (vhost_user_mmap_region(dev, reg, mmap_offset) < 0) {
+                       VHOST_LOG_CONFIG(ERR, "Failed to mmap region %u\n", i);
                        goto free_mem_table;
                }
 
-               reg->mmap_addr = mmap_addr;
-               reg->mmap_size = mmap_size;
-               reg->host_user_addr = (uint64_t)(uintptr_t)mmap_addr +
-                                     mmap_offset;
-
-               if (dev->async_copy)
-                       if (add_guest_pages(dev, reg, alignment) < 0) {
-                               VHOST_LOG_CONFIG(ERR,
-                                       "adding guest pages to region %u failed.\n",
-                                       i);
-                               goto free_mem_table;
-                       }
-
-               VHOST_LOG_CONFIG(INFO,
-                       "guest memory region %u, size: 0x%" PRIx64 "\n"
-                       "\t guest physical addr: 0x%" PRIx64 "\n"
-                       "\t guest virtual  addr: 0x%" PRIx64 "\n"
-                       "\t host  virtual  addr: 0x%" PRIx64 "\n"
-                       "\t mmap addr : 0x%" PRIx64 "\n"
-                       "\t mmap size : 0x%" PRIx64 "\n"
-                       "\t mmap align: 0x%" PRIx64 "\n"
-                       "\t mmap off  : 0x%" PRIx64 "\n",
-                       i, reg->size,
-                       reg->guest_phys_addr,
-                       reg->guest_user_addr,
-                       reg->host_user_addr,
-                       (uint64_t)(uintptr_t)mmap_addr,
-                       mmap_size,
-                       alignment,
-                       mmap_offset);
+               dev->mem->nregions++;
        }
 
        if (vhost_user_postcopy_register(dev, main_fd, msg) < 0)