* [PATCH v15 1/5] vhost: add user to mailmap and define to vhost hdr
2026-06-04 23:57 [PATCH v15 0/5] Support add/remove memory region and get-max-slots pravin.bathija
@ 2026-06-04 23:57 ` pravin.bathija
2026-06-04 23:57 ` [PATCH v15 2/5] vhost: header defines for add/rem mem region pravin.bathija
` (5 subsequent siblings)
6 siblings, 0 replies; 9+ messages in thread
From: pravin.bathija @ 2026-06-04 23:57 UTC (permalink / raw)
To: dev, fengchengwen, stephen, maxime.coquelin
Cc: pravin.bathija, thomas, Stephen Hemminger
From: Pravin M Bathija <pravin.bathija@dell.com>
- add user to mailmap file.
- define a bit-field called VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS
that depicts if the feature/capability to add/remove memory regions
is supported. This is a part of the overall support for add/remove
memory region feature in this patchset.
Signed-off-by: Pravin M Bathija <pravin.bathija@dell.com>
Acked-by: Fengchengwen <fengchengwen@huawei.com>
Reviewed-by: Stephen Hemminger <stephen@networkplumber.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
.mailmap | 1 +
lib/vhost/rte_vhost.h | 4 ++++
2 files changed, 5 insertions(+)
diff --git a/.mailmap b/.mailmap
index 0e0d83e1c6..cc44e27036 100644
--- a/.mailmap
+++ b/.mailmap
@@ -1295,6 +1295,7 @@ Prateek Agarwal <prateekag@cse.iitb.ac.in>
Prathisna Padmasanan <prathisna.padmasanan@intel.com>
Praveen Kaligineedi <pkaligineedi@google.com>
Praveen Shetty <praveen.shetty@intel.com>
+Pravin M Bathija <pravin.bathija@dell.com>
Pravin Pathak <pravin.pathak.dev@gmail.com> <pravin.pathak@intel.com>
Prince Takkar <ptakkar@marvell.com>
Priyalee Kushwaha <priyalee.kushwaha@intel.com>
diff --git a/lib/vhost/rte_vhost.h b/lib/vhost/rte_vhost.h
index 2f7c4c0080..a7f9700538 100644
--- a/lib/vhost/rte_vhost.h
+++ b/lib/vhost/rte_vhost.h
@@ -109,6 +109,10 @@ extern "C" {
#define VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD 12
#endif
+#ifndef VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS
+#define VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS 15
+#endif
+
#ifndef VHOST_USER_PROTOCOL_F_STATUS
#define VHOST_USER_PROTOCOL_F_STATUS 16
#endif
--
2.43.0
^ permalink raw reply related [flat|nested] 9+ messages in thread* [PATCH v15 2/5] vhost: header defines for add/rem mem region
2026-06-04 23:57 [PATCH v15 0/5] Support add/remove memory region and get-max-slots pravin.bathija
2026-06-04 23:57 ` [PATCH v15 1/5] vhost: add user to mailmap and define to vhost hdr pravin.bathija
@ 2026-06-04 23:57 ` pravin.bathija
2026-06-04 23:57 ` [PATCH v15 3/5] vhost: refactor memory helper functions pravin.bathija
` (4 subsequent siblings)
6 siblings, 0 replies; 9+ messages in thread
From: pravin.bathija @ 2026-06-04 23:57 UTC (permalink / raw)
To: dev, fengchengwen, stephen, maxime.coquelin
Cc: pravin.bathija, thomas, Stephen Hemminger
From: Pravin M Bathija <pravin.bathija@dell.com>
The changes in this file cover the enum message requests for
supporting add/remove memory regions. The front-end vhost-user
client sends messages like get max memory slots, add memory region
and remove memory region which are covered in these changes which
are on the vhost-user back-end. The changes also include data structure
definition of memory region to be added/removed. The data structure
VhostUserMsg has been changed to include the memory region.
Signed-off-by: Pravin M Bathija <pravin.bathija@dell.com>
Reviewed-by: Fengchengwen <fengchengwen@huawei.com>
Reviewed-by: Stephen Hemminger <stephen@networkplumber.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
lib/vhost/vhost_user.h | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/lib/vhost/vhost_user.h b/lib/vhost/vhost_user.h
index ef486545ba..6435816534 100644
--- a/lib/vhost/vhost_user.h
+++ b/lib/vhost/vhost_user.h
@@ -67,6 +67,9 @@ typedef enum VhostUserRequest {
VHOST_USER_POSTCOPY_END = 30,
VHOST_USER_GET_INFLIGHT_FD = 31,
VHOST_USER_SET_INFLIGHT_FD = 32,
+ VHOST_USER_GET_MAX_MEM_SLOTS = 36,
+ VHOST_USER_ADD_MEM_REG = 37,
+ VHOST_USER_REM_MEM_REG = 38,
VHOST_USER_SET_STATUS = 39,
VHOST_USER_GET_STATUS = 40,
} VhostUserRequest;
@@ -91,6 +94,11 @@ typedef struct VhostUserMemory {
VhostUserMemoryRegion regions[VHOST_MEMORY_MAX_NREGIONS];
} VhostUserMemory;
+typedef struct VhostUserMemRegMsg {
+ uint64_t padding;
+ VhostUserMemoryRegion region;
+} VhostUserMemRegMsg;
+
typedef struct VhostUserLog {
uint64_t mmap_size;
uint64_t mmap_offset;
@@ -186,6 +194,7 @@ typedef struct __rte_packed_begin VhostUserMsg {
struct vhost_vring_state state;
struct vhost_vring_addr addr;
VhostUserMemory memory;
+ VhostUserMemRegMsg memreg;
VhostUserLog log;
struct vhost_iotlb_msg iotlb;
VhostUserCryptoSessionParam crypto_session;
--
2.43.0
^ permalink raw reply related [flat|nested] 9+ messages in thread* [PATCH v15 3/5] vhost: refactor memory helper functions
2026-06-04 23:57 [PATCH v15 0/5] Support add/remove memory region and get-max-slots pravin.bathija
2026-06-04 23:57 ` [PATCH v15 1/5] vhost: add user to mailmap and define to vhost hdr pravin.bathija
2026-06-04 23:57 ` [PATCH v15 2/5] vhost: header defines for add/rem mem region pravin.bathija
@ 2026-06-04 23:57 ` pravin.bathija
2026-06-04 23:57 ` [PATCH v15 4/5] vhost: add mem region add/remove handlers pravin.bathija
` (3 subsequent siblings)
6 siblings, 0 replies; 9+ messages in thread
From: pravin.bathija @ 2026-06-04 23:57 UTC (permalink / raw)
To: dev, fengchengwen, stephen, maxime.coquelin
Cc: pravin.bathija, thomas, Stephen Hemminger
From: Pravin M Bathija <pravin.bathija@dell.com>
- Extract reusable helper routines for vhost-user backend memory
operations.
- Split DMA map/unmap into per-region logic.
- Decouple and rework memory region free routines.
- Iterate over VHOST_MEMORY_MAX_NREGIONS uniformly
across related functions to simplify code reuse
Signed-off-by: Pravin M Bathija <pravin.bathija@dell.com>
Reviewed-by: Stephen Hemminger <stephen@networkplumber.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
lib/vhost/vhost_user.c | 172 ++++++++++++++++++++++++++---------------
1 file changed, 110 insertions(+), 62 deletions(-)
diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
index 4bfb13fb98..94fca8b589 100644
--- a/lib/vhost/vhost_user.c
+++ b/lib/vhost/vhost_user.c
@@ -171,20 +171,27 @@ get_blk_size(int fd)
return ret == -1 ? (uint64_t)-1 : (uint64_t)stat.st_blksize;
}
-static void
-async_dma_map(struct virtio_net *dev, bool do_map)
+static int
+async_dma_map_region(struct virtio_net *dev, struct rte_vhost_mem_region *reg, bool do_map)
{
- int ret = 0;
uint32_t i;
- struct guest_page *page;
+ int ret;
+ uint64_t reg_start = reg->host_user_addr;
+ uint64_t reg_end = reg_start + reg->size;
- if (do_map) {
- for (i = 0; i < dev->nr_guest_pages; i++) {
- page = &dev->guest_pages[i];
+ for (i = 0; i < dev->nr_guest_pages; i++) {
+ struct guest_page *page = &dev->guest_pages[i];
+
+ /* Only process pages belonging to this region */
+ if (page->host_user_addr < reg_start ||
+ page->host_user_addr >= reg_end)
+ continue;
+
+ if (do_map) {
ret = rte_vfio_container_dma_map(RTE_VFIO_DEFAULT_CONTAINER_FD,
- page->host_user_addr,
- page->host_iova,
- page->size);
+ page->host_user_addr,
+ page->host_iova,
+ page->size);
if (ret) {
/*
* DMA device may bind with kernel driver, in this case,
@@ -199,33 +206,57 @@ async_dma_map(struct virtio_net *dev, bool do_map)
* normal case in async path. This is a workaround.
*/
if (rte_errno == ENODEV)
- return;
+ return 0;
/* DMA mapping errors won't stop VHOST_USER_SET_MEM_TABLE. */
VHOST_CONFIG_LOG(dev->ifname, ERR, "DMA engine map failed");
+ return -1;
}
- }
-
- } else {
- for (i = 0; i < dev->nr_guest_pages; i++) {
- page = &dev->guest_pages[i];
+ } else {
ret = rte_vfio_container_dma_unmap(RTE_VFIO_DEFAULT_CONTAINER_FD,
- page->host_user_addr,
- page->host_iova,
- page->size);
+ page->host_user_addr,
+ page->host_iova,
+ page->size);
if (ret) {
/* like DMA map, ignore the kernel driver case when unmap. */
if (rte_errno == EINVAL)
- return;
+ return 0;
VHOST_CONFIG_LOG(dev->ifname, ERR, "DMA engine unmap failed");
+ return -1;
}
}
}
+
+ return 0;
+}
+
+static void
+async_dma_map(struct virtio_net *dev, bool do_map)
+{
+ uint32_t i;
+ struct rte_vhost_mem_region *reg;
+
+ for (i = 0; i < VHOST_MEMORY_MAX_NREGIONS; i++) {
+ reg = &dev->mem->regions[i];
+ if (reg->host_user_addr == 0)
+ continue;
+ async_dma_map_region(dev, reg, do_map);
+ }
}
static void
-free_mem_region(struct virtio_net *dev)
+free_mem_region(struct rte_vhost_mem_region *reg)
+{
+ if (reg != NULL && reg->mmap_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 +267,10 @@ 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 +284,7 @@ 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 +733,7 @@ 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 +837,10 @@ 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);
@@ -1382,6 +1413,52 @@ 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 (dev->mem != NULL) {
+ VHOST_CONFIG_LOG(dev->ifname, ERR,
+ "memory already initialized, free it first");
+ return -1;
+ }
+
+ /*
+ * 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 = 8;
+ 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,
@@ -1390,7 +1467,6 @@ vhost_user_set_mem_table(struct virtio_net **pdev,
struct virtio_net *dev = *pdev;
struct VhostUserMemory *memory = &ctx->msg.payload.memory;
struct rte_vhost_mem_region *reg;
- int numa_node = SOCKET_ID_ANY;
uint64_t mmap_offset;
uint32_t i;
bool async_notify = false;
@@ -1435,39 +1511,13 @@ vhost_user_set_mem_table(struct virtio_net **pdev,
if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
vhost_user_iotlb_flush_all(dev);
- free_mem_region(dev);
+ free_all_mem_regions(dev);
rte_free(dev->mem);
dev->mem = NULL;
}
- /*
- * 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 = 8;
- 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");
- goto close_msg_fds;
- }
- }
-
- dev->mem = rte_zmalloc_socket("vhost-mem-table", sizeof(struct rte_vhost_memory) +
- sizeof(struct rte_vhost_mem_region) * memory->nregions, 0, numa_node);
- if (dev->mem == NULL) {
- VHOST_CONFIG_LOG(dev->ifname, ERR, "failed to allocate memory for dev->mem");
- goto free_guest_pages;
- }
+ if (vhost_user_initialize_memory(pdev) < 0)
+ goto close_msg_fds;
for (i = 0; i < memory->nregions; i++) {
reg = &dev->mem->regions[i];
@@ -1531,11 +1581,9 @@ vhost_user_set_mem_table(struct virtio_net **pdev,
return RTE_VHOST_MSG_RESULT_OK;
free_mem_table:
- free_mem_region(dev);
+ free_all_mem_regions(dev);
rte_free(dev->mem);
dev->mem = NULL;
-
-free_guest_pages:
rte_free(dev->guest_pages);
dev->guest_pages = NULL;
close_msg_fds:
--
2.43.0
^ permalink raw reply related [flat|nested] 9+ messages in thread* [PATCH v15 4/5] vhost: add mem region add/remove handlers
2026-06-04 23:57 [PATCH v15 0/5] Support add/remove memory region and get-max-slots pravin.bathija
` (2 preceding siblings ...)
2026-06-04 23:57 ` [PATCH v15 3/5] vhost: refactor memory helper functions pravin.bathija
@ 2026-06-04 23:57 ` pravin.bathija
2026-06-05 11:32 ` Maxime Coquelin
2026-06-04 23:57 ` [PATCH v15 5/5] vhost: enable configure memory slots pravin.bathija
` (2 subsequent siblings)
6 siblings, 1 reply; 9+ messages in thread
From: pravin.bathija @ 2026-06-04 23:57 UTC (permalink / raw)
To: dev, fengchengwen, stephen, maxime.coquelin; +Cc: pravin.bathija, thomas
From: Pravin M Bathija <pravin.bathija@dell.com>
Add support for VHOST_USER_ADD_MEM_REG, VHOST_USER_REM_MEM_REG and
VHOST_USER_GET_MAX_MEM_SLOTS. Refactor memory initialization into
common helper and add supporting functions for dynamic memory management.
Signed-off-by: Pravin M Bathija <pravin.bathija@dell.com>
---
lib/vhost/vhost_user.c | 253 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 253 insertions(+)
diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
index 94fca8b589..b13c23ccf8 100644
--- a/lib/vhost/vhost_user.c
+++ b/lib/vhost/vhost_user.c
@@ -71,6 +71,9 @@ VHOST_MESSAGE_HANDLER(VHOST_USER_SET_FEATURES, vhost_user_set_features, false, t
VHOST_MESSAGE_HANDLER(VHOST_USER_SET_OWNER, vhost_user_set_owner, false, true) \
VHOST_MESSAGE_HANDLER(VHOST_USER_RESET_OWNER, vhost_user_reset_owner, false, false) \
VHOST_MESSAGE_HANDLER(VHOST_USER_SET_MEM_TABLE, vhost_user_set_mem_table, true, true) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_GET_MAX_MEM_SLOTS, vhost_user_get_max_mem_slots, false, false) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_ADD_MEM_REG, vhost_user_add_mem_reg, true, true) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_REM_MEM_REG, vhost_user_rem_mem_reg, false, true) \
VHOST_MESSAGE_HANDLER(VHOST_USER_SET_LOG_BASE, vhost_user_set_log_base, true, true) \
VHOST_MESSAGE_HANDLER(VHOST_USER_SET_LOG_FD, vhost_user_set_log_fd, true, true) \
VHOST_MESSAGE_HANDLER(VHOST_USER_SET_VRING_NUM, vhost_user_set_vring_num, false, true) \
@@ -1167,6 +1170,24 @@ add_guest_pages(struct virtio_net *dev, struct rte_vhost_mem_region *reg,
return 0;
}
+static void
+remove_guest_pages(struct virtio_net *dev, struct rte_vhost_mem_region *reg)
+{
+ uint64_t reg_start = reg->host_user_addr;
+ uint64_t reg_end = reg_start + reg->size;
+ uint32_t i, j = 0;
+
+ for (i = 0; i < dev->nr_guest_pages; i++) {
+ if (dev->guest_pages[i].host_user_addr >= reg_start &&
+ dev->guest_pages[i].host_user_addr < reg_end)
+ continue;
+ if (j != i)
+ dev->guest_pages[j] = dev->guest_pages[i];
+ j++;
+ }
+ dev->nr_guest_pages = j;
+}
+
#ifdef RTE_LIBRTE_VHOST_DEBUG
/* TODO: enable it only in debug mode? */
static void
@@ -1591,6 +1612,238 @@ vhost_user_set_mem_table(struct virtio_net **pdev,
return RTE_VHOST_MSG_RESULT_ERR;
}
+
+static int
+vhost_user_get_max_mem_slots(struct virtio_net **pdev __rte_unused,
+ struct vhu_msg_context *ctx,
+ int main_fd __rte_unused)
+{
+ uint32_t max_mem_slots = VHOST_MEMORY_MAX_NREGIONS;
+
+ ctx->msg.payload.u64 = max_mem_slots;
+ ctx->msg.size = sizeof(ctx->msg.payload.u64);
+ ctx->fd_num = 0;
+
+ return RTE_VHOST_MSG_RESULT_REPLY;
+}
+
+/*
+ * Invalidate and re-translate all vring addresses after the memory table
+ * has been modified (add/remove region).
+ *
+ * translate_ring_addresses() may call numa_realloc(), which can reallocate
+ * the device structure. The updated pointer is written back through *pdev
+ * so callers must refresh their local "dev" afterwards: dev = *pdev.
+ */
+static void
+vhost_user_invalidate_vrings(struct virtio_net **pdev)
+{
+ struct virtio_net *dev = *pdev;
+ uint32_t i;
+
+ for (i = 0; i < dev->nr_vring; i++) {
+ struct vhost_virtqueue *vq = dev->virtqueue[i];
+
+ if (!vq)
+ continue;
+
+ if (vq->desc || vq->avail || vq->used) {
+ vq_assert_lock(dev, vq);
+
+ vring_invalidate(dev, vq);
+
+ translate_ring_addresses(&dev, &vq);
+ }
+ }
+
+ *pdev = dev;
+}
+
+/*
+ * Macro wrapper that performs the compile-time lock assertion with the
+ * correct message ID at the call site, then calls the implementation.
+ */
+#define dev_invalidate_vrings(pdev, id) do { \
+ static_assert(id ## _LOCK_ALL_QPS, \
+ #id " handler is not declared as locking all queue pairs"); \
+ vhost_user_invalidate_vrings(pdev); \
+} while (0)
+
+static int
+vhost_user_add_mem_reg(struct virtio_net **pdev,
+ struct vhu_msg_context *ctx,
+ int main_fd __rte_unused)
+{
+ struct VhostUserMemoryRegion *region = &ctx->msg.payload.memreg.region;
+ struct virtio_net *dev = *pdev;
+ uint32_t i;
+
+ /* convert first region add to normal memory table set */
+ if (dev->mem == NULL) {
+ if (vhost_user_initialize_memory(pdev) < 0)
+ goto close_msg_fds;
+ }
+
+ /* make sure new region will fit */
+ if (dev->mem->nregions >= VHOST_MEMORY_MAX_NREGIONS) {
+ VHOST_CONFIG_LOG(dev->ifname, ERR, "too many memory regions already (%u)",
+ dev->mem->nregions);
+ goto close_msg_fds;
+ }
+
+ /* make sure supplied memory fd present */
+ if (ctx->fd_num != 1) {
+ VHOST_CONFIG_LOG(dev->ifname, ERR, "fd count makes no sense (%u)", ctx->fd_num);
+ goto close_msg_fds;
+ }
+
+ /* Make sure no overlap in guest virtual address space */
+ for (i = 0; i < dev->mem->nregions; i++) {
+ struct rte_vhost_mem_region *cur = &dev->mem->regions[i];
+ uint64_t cur_start = cur->guest_user_addr;
+ uint64_t cur_end = cur_start + cur->size - 1;
+ uint64_t new_start = region->userspace_addr;
+ uint64_t new_end = new_start + region->memory_size - 1;
+
+ if (new_end >= cur_start && new_start <= cur_end) {
+ VHOST_CONFIG_LOG(dev->ifname, ERR,
+ "requested memory region overlaps with another region");
+ VHOST_CONFIG_LOG(dev->ifname, ERR,
+ "\tRequested region address:0x%" PRIx64,
+ region->userspace_addr);
+ VHOST_CONFIG_LOG(dev->ifname, ERR,
+ "\tRequested region size:0x%" PRIx64,
+ region->memory_size);
+ VHOST_CONFIG_LOG(dev->ifname, ERR,
+ "\tOverlapping region address:0x%" PRIx64,
+ cur->guest_user_addr);
+ VHOST_CONFIG_LOG(dev->ifname, ERR,
+ "\tOverlapping region size:0x%" PRIx64,
+ cur->size);
+ goto close_msg_fds;
+ }
+ }
+
+ /* New region goes at the end of the contiguous array */
+ struct rte_vhost_mem_region *reg = &dev->mem->regions[dev->mem->nregions];
+
+ reg->guest_phys_addr = region->guest_phys_addr;
+ reg->guest_user_addr = region->userspace_addr;
+ reg->size = region->memory_size;
+ reg->fd = ctx->fds[0];
+ ctx->fds[0] = -1;
+
+ if (vhost_user_mmap_region(dev, reg, region->mmap_offset) < 0) {
+ VHOST_CONFIG_LOG(dev->ifname, ERR, "failed to mmap region");
+ if (reg->mmap_addr) {
+ /* mmap succeeded but a later step (e.g. add_guest_pages)
+ * failed; undo the mapping and any guest-page entries.
+ */
+ remove_guest_pages(dev, reg);
+ free_mem_region(reg);
+ } else {
+ close(reg->fd);
+ reg->fd = -1;
+ }
+ goto close_msg_fds;
+ }
+
+ dev->mem->nregions++;
+
+ if (dev->async_copy && rte_vfio_is_enabled("vfio")) {
+ if (async_dma_map_region(dev, reg, true) < 0)
+ goto free_new_region_no_dma;
+ }
+
+ if (dev->postcopy_listening) {
+ /*
+ * Cannot use vhost_user_postcopy_register() here because it
+ * reads ctx->msg.payload.memory (SET_MEM_TABLE layout), but
+ * ADD_MEM_REG uses the memreg payload. Register the
+ * single new region directly instead.
+ */
+ if (vhost_user_postcopy_region_register(dev, reg) < 0)
+ goto free_new_region;
+ }
+
+ dev_invalidate_vrings(pdev, VHOST_USER_ADD_MEM_REG);
+ dev = *pdev;
+ dump_guest_pages(dev);
+
+ /* Reply with the back-end's mapping address per vhost-user spec */
+ ctx->msg.payload.memreg.region.userspace_addr = reg->host_user_addr;
+ ctx->msg.size = sizeof(ctx->msg.payload.memreg);
+ ctx->fd_num = 0;
+
+ return RTE_VHOST_MSG_RESULT_REPLY;
+
+free_new_region:
+ if (dev->async_copy && rte_vfio_is_enabled("vfio"))
+ async_dma_map_region(dev, reg, false);
+free_new_region_no_dma:
+ remove_guest_pages(dev, reg);
+ free_mem_region(reg);
+ dev->mem->nregions--;
+close_msg_fds:
+ close_msg_fds(ctx);
+ return RTE_VHOST_MSG_RESULT_ERR;
+}
+
+static int
+vhost_user_rem_mem_reg(struct virtio_net **pdev,
+ struct vhu_msg_context *ctx,
+ int main_fd __rte_unused)
+{
+ struct VhostUserMemoryRegion *region = &ctx->msg.payload.memreg.region;
+ struct virtio_net *dev = *pdev;
+ uint32_t i;
+
+ if (dev->mem == NULL || dev->mem->nregions == 0) {
+ VHOST_CONFIG_LOG(dev->ifname, ERR, "no memory regions to remove");
+ return RTE_VHOST_MSG_RESULT_ERR;
+ }
+
+ for (i = 0; i < dev->mem->nregions; i++) {
+ struct rte_vhost_mem_region *current_region = &dev->mem->regions[i];
+
+ /*
+ * According to the vhost-user specification:
+ * The memory region to be removed is identified by its GPA,
+ * user address and size. The mmap offset is ignored.
+ */
+ if (region->userspace_addr == current_region->guest_user_addr
+ && region->guest_phys_addr == current_region->guest_phys_addr
+ && region->memory_size == current_region->size) {
+ if (dev->async_copy && rte_vfio_is_enabled("vfio"))
+ async_dma_map_region(dev, current_region, false);
+ if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
+ vhost_user_iotlb_cache_remove(dev,
+ current_region->guest_phys_addr,
+ current_region->size);
+ remove_guest_pages(dev, current_region);
+ free_mem_region(current_region);
+
+ /* Compact the regions array to keep it contiguous */
+ if (i < dev->mem->nregions - 1) {
+ memmove(&dev->mem->regions[i],
+ &dev->mem->regions[i + 1],
+ (dev->mem->nregions - 1 - i) *
+ sizeof(struct rte_vhost_mem_region));
+ memset(&dev->mem->regions[dev->mem->nregions - 1],
+ 0, sizeof(struct rte_vhost_mem_region));
+ }
+
+ dev->mem->nregions--;
+ dev_invalidate_vrings(pdev, VHOST_USER_REM_MEM_REG);
+ dev = *pdev;
+ return RTE_VHOST_MSG_RESULT_OK;
+ }
+ }
+
+ VHOST_CONFIG_LOG(dev->ifname, ERR, "failed to find region");
+ return RTE_VHOST_MSG_RESULT_ERR;
+}
+
static bool
vq_is_ready(struct virtio_net *dev, struct vhost_virtqueue *vq)
{
--
2.43.0
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [PATCH v15 4/5] vhost: add mem region add/remove handlers
2026-06-04 23:57 ` [PATCH v15 4/5] vhost: add mem region add/remove handlers pravin.bathija
@ 2026-06-05 11:32 ` Maxime Coquelin
0 siblings, 0 replies; 9+ messages in thread
From: Maxime Coquelin @ 2026-06-05 11:32 UTC (permalink / raw)
To: pravin.bathija; +Cc: dev, fengchengwen, stephen, thomas
On Fri, Jun 5, 2026 at 1:58 AM <pravin.bathija@dell.com> wrote:
>
> From: Pravin M Bathija <pravin.bathija@dell.com>
>
> Add support for VHOST_USER_ADD_MEM_REG, VHOST_USER_REM_MEM_REG and
> VHOST_USER_GET_MAX_MEM_SLOTS. Refactor memory initialization into
> common helper and add supporting functions for dynamic memory management.
>
> Signed-off-by: Pravin M Bathija <pravin.bathija@dell.com>
> ---
> lib/vhost/vhost_user.c | 253 +++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 253 insertions(+)
>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Thanks,
Maxime
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH v15 5/5] vhost: enable configure memory slots
2026-06-04 23:57 [PATCH v15 0/5] Support add/remove memory region and get-max-slots pravin.bathija
` (3 preceding siblings ...)
2026-06-04 23:57 ` [PATCH v15 4/5] vhost: add mem region add/remove handlers pravin.bathija
@ 2026-06-04 23:57 ` pravin.bathija
2026-06-05 13:14 ` [PATCH v15 0/5] Support add/remove memory region and get-max-slots Maxime Coquelin
2026-06-05 16:45 ` Stephen Hemminger
6 siblings, 0 replies; 9+ messages in thread
From: pravin.bathija @ 2026-06-04 23:57 UTC (permalink / raw)
To: dev, fengchengwen, stephen, maxime.coquelin
Cc: pravin.bathija, thomas, Stephen Hemminger
From: Pravin M Bathija <pravin.bathija@dell.com>
This patch enables configure memory slots in the header define
VHOST_USER_PROTOCOL_FEATURES.
Signed-off-by: Pravin M Bathija <pravin.bathija@dell.com>
Reviewed-by: Stephen Hemminger <stephen@networkplumber.com>
Reviewed-by: Fengchengwen <fengchengwen@huawei.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
lib/vhost/vhost_user.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/lib/vhost/vhost_user.h b/lib/vhost/vhost_user.h
index 6435816534..732aa4dc02 100644
--- a/lib/vhost/vhost_user.h
+++ b/lib/vhost/vhost_user.h
@@ -32,6 +32,7 @@
(1ULL << VHOST_USER_PROTOCOL_F_BACKEND_SEND_FD) | \
(1ULL << VHOST_USER_PROTOCOL_F_HOST_NOTIFIER) | \
(1ULL << VHOST_USER_PROTOCOL_F_PAGEFAULT) | \
+ (1ULL << VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS) | \
(1ULL << VHOST_USER_PROTOCOL_F_STATUS))
typedef enum VhostUserRequest {
--
2.43.0
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [PATCH v15 0/5] Support add/remove memory region and get-max-slots
2026-06-04 23:57 [PATCH v15 0/5] Support add/remove memory region and get-max-slots pravin.bathija
` (4 preceding siblings ...)
2026-06-04 23:57 ` [PATCH v15 5/5] vhost: enable configure memory slots pravin.bathija
@ 2026-06-05 13:14 ` Maxime Coquelin
2026-06-05 16:45 ` Stephen Hemminger
6 siblings, 0 replies; 9+ messages in thread
From: Maxime Coquelin @ 2026-06-05 13:14 UTC (permalink / raw)
To: pravin.bathija; +Cc: dev, fengchengwen, stephen, thomas
On Fri, Jun 5, 2026 at 1:57 AM <pravin.bathija@dell.com> wrote:
>
> From: Pravin M Bathija <pravin.bathija@dell.com>
>
> This is version v15 of the patchset and it incorporates the
> recommendations made by Maxime Coquelin.
>
> Patch 4/5
> - Changed VHOST_USER_REM_MEM_REG handler declaration from
> accepts_fd=true to accepts_fd=false, as the remove request does not
> expect FDs in ancillary data.
> - Removed all close_msg_fds(ctx) calls from vhost_user_rem_mem_reg(), no
> longer needed since the handler is declared as not accepting FDs.
> - Removed validate_msg_fds(dev, ctx, 0) check from
> vhost_user_rem_mem_reg(), as FD validation is now handled generically
> by the framework.
> - Added targeted IOTLB cache invalidation in vhost_user_rem_mem_reg()
> using vhost_user_iotlb_cache_remove() for the removed region's GPA
> range, instead of the nuclear iotlb_flush_all() used by set_mem_table.
>
> This implementation has been extensively tested by doing Read/Write I/O
> from multiple instances of fio + libblkio (front-end) talking to
> spdk/dpdk (back-end) based drives. Tested with qemu front-end talking to
> dpdk testpmd (back-end) performing add/removal of memory regions. Also
> tested post-copy live migration after doing add_memory_region.
>
> Version Log:
> Version v15 (Current version): Incorporate code review suggestions from
> Maxime Coquelin as described above.
>
> Version v14: Incorporate code review suggestions from Stephen Hemminger
> and Fengcheng Wen.
> Changes from Fengcheng Wen review:
> Patch 3/5
> - Moved free_all_mem_regions() call sites in vhost_user_set_mem_table()
> from patch 4/5 to patch 3/5 so each commit compiles independently
> Patch 4/5
> - Renamed _dev_invalidate_vrings() to vhost_user_invalidate_vrings() to
> follow vhost naming convention
> - Added comment explaining *pdev propagation through
> translate_ring_addresses / numa_realloc()
> - Reordered local variables in vhost_user_add_mem_reg() and
> vhost_user_rem_mem_reg() by descending line length
> - Shortened overlap check variable names (current_region_guest_start/end
> --> cur_start/end, proposed_region_guest_start/end -> new_start/end)
> - Fixed DMA error path in vhost_user_add_mem_reg(): added
> free_new_region_no_dma label so async_dma_map_region(false) is not
> called when the map itself failed.
> Changes from Stephen Hemminger review:
> Patch 4/5
> - vhost_user_add_mem_reg() now constructs a reply with the back-end's
> host mapping address in userspace_addr and returns
> RTE_VHOST_MSG_RESULT_REPLY per the vhost-user spec
> - Added validate_msg_fds(dev, ctx, 0) in vhost_user_rem_mem_reg() to
> reject malformed messages with unexpected file descriptors
> - Dropped unnecessary (uint64_t) cast in vhost_user_get_max_mem_slots()
>
> Version v13: Incorporate code review suggestions from Fengcheng Wen
> Patch 2/5
> Renamed VhostUserSingleMemReg to VhostUserMemRegMsg and memory_single
> to memreg
> Patches 3/5 and 4/5
> Relocated function remove_guest_pages from patch 3/5 to 4/5
>
> Version v12: Incorporate code review suggestions from Maxime Coquelin
> and ai-code-review.
> Patch 3/5
> Refactored async_dma_map() to delegate to async_dma_map_region(),
> eliminating code duplication between the two functions.
> Restored original comments in async_dma_map_region() explaining why
> ENODEV and EINVAL errors are ignored (these were stripped in v10)
> Reverted unnecessary changes to vhost_user_postcopy_register() --
> removed the host_user_addr == 0 checks and reg_msg_index indirection
> that were added in v10, since this function is only called from
> vhost_user_set_mem_table() where regions are always contiguous.
>
> Version v11: Incorporate code review suggestions from Stephen Hemminger.
> Patch 4/5
> Fix incomplete cleanup in vhost_user_add_mem_reg() when
> vhost_user_mmap_region() fails after the mmap succeeds (e.g.
> add_guest_pages() realloc failure) realloc failure). The error path now
> calls remove_guest_pages() and free_mem_region() to undo the mapping
> and stale guest-page entries, preventing a leaked mmap and slot reuse
> corruption. The plain close(fd) path is kept for pre-mmap failures.
>
> Version v10: Incorporate code review suggestions from Stephen Hemminger.
> Patch 4/5
> Moved dev_invalidate_vrings after free_mem_region, array compaction, and
> nregions decrement. This ensures translate_ring_addresses only sees
> surviving memory regions, preventing vring pointers from resolving into
> a region that is about to be unmapped.
>
> Version v9: Incorporate code review suggestions from Stephen Hemminger.
> Patch 3/5
> Restored max_guest_pages initial value to hardcoded 8 instead of
> VHOST_MEMORY_MAX_NREGIONS, matching upstream semantics.
> Patch 4/5
> Added close(reg->fd) and reg->fd = -1 before goto close_msg_fds in the
> mmap failure path to fix fd leak after fd was moved from ctx->fds[0].
> Converted dev_invalidate_vrings from a plain function to a macro +
> implementation function pair, accepting message ID as a parameter so
> the static_assert reports the correct handler at each call site.
> Updated dev_invalidate_vrings call in add_mem_reg to pass
> VHOST_USER_ADD_MEM_REG as message ID.
> Updated dev_invalidate_vrings call in rem_mem_reg to pass
> VHOST_USER_REM_MEM_REG as message ID.
>
> Version v8: Incorporate code review suggestions from Stephen Hemminger.
> rewrite async_dma_map_region function to iterate guest pages by host
> address range matching
> change function dev_invalidate_vrings to accept a double pointer to
> propagate pointer updates
> new function remove_guest_pages was added
> add_mem_reg error path was narrowed to only clean up the single failed
> region instead of destroting all existing regions
>
> Version v7: Incorporate code review suggestions from Maxime Coquelin.
> Add debug messages to vhost_postcopy_register function.
>
> Version v6: Added the enablement of this feature as a final patch in
> this patch-set and other code optimizations as suggested by Maxime
> Coquelin.
>
> Version v5: removed the patch that increased the number of memory regions
> from 8 to 128. This will be submitted as a separate feature at a later
> point after incorporating additional optimizations. Also includes code
> optimizations as suggested by Feng Cheng Wen.
>
> Version v4: code optimizations as suggested by Feng Cheng Wen.
>
> Version v3: code optimizations as suggested by Maxime Coquelin
> and Thomas Monjalon.
>
> Version v2: code optimizations as suggested by Maxime Coquelin.
>
> Version v1: Initial patch set.
>
> Pravin M Bathija (5):
> vhost: add user to mailmap and define to vhost hdr
> vhost: header defines for add/rem mem region
> vhost: refactor memory helper functions
> vhost: add mem region add/remove handlers
> vhost: enable configure memory slots
>
> .mailmap | 1 +
> lib/vhost/rte_vhost.h | 4 +
> lib/vhost/vhost_user.c | 425 +++++++++++++++++++++++++++++++++++------
> lib/vhost/vhost_user.h | 10 +
> 4 files changed, 378 insertions(+), 62 deletions(-)
>
> --
> 2.43.0
>
Applied to next-virtio/for-next-net.
Thanks,
Maxime
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH v15 0/5] Support add/remove memory region and get-max-slots
2026-06-04 23:57 [PATCH v15 0/5] Support add/remove memory region and get-max-slots pravin.bathija
` (5 preceding siblings ...)
2026-06-05 13:14 ` [PATCH v15 0/5] Support add/remove memory region and get-max-slots Maxime Coquelin
@ 2026-06-05 16:45 ` Stephen Hemminger
6 siblings, 0 replies; 9+ messages in thread
From: Stephen Hemminger @ 2026-06-05 16:45 UTC (permalink / raw)
To: pravin.bathija; +Cc: dev, fengchengwen, maxime.coquelin, thomas
On Thu, 4 Jun 2026 23:57:18 +0000
<pravin.bathija@dell.com> wrote:
> From: Pravin M Bathija <pravin.bathija@dell.com>
>
> This is version v15 of the patchset and it incorporates the
> recommendations made by Maxime Coquelin.
>
> Patch 4/5
> - Changed VHOST_USER_REM_MEM_REG handler declaration from
> accepts_fd=true to accepts_fd=false, as the remove request does not
> expect FDs in ancillary data.
> - Removed all close_msg_fds(ctx) calls from vhost_user_rem_mem_reg(), no
> longer needed since the handler is declared as not accepting FDs.
> - Removed validate_msg_fds(dev, ctx, 0) check from
> vhost_user_rem_mem_reg(), as FD validation is now handled generically
> by the framework.
> - Added targeted IOTLB cache invalidation in vhost_user_rem_mem_reg()
> using vhost_user_iotlb_cache_remove() for the removed region's GPA
> range, instead of the nuclear iotlb_flush_all() used by set_mem_table.
>
> This implementation has been extensively tested by doing Read/Write I/O
> from multiple instances of fio + libblkio (front-end) talking to
> spdk/dpdk (back-end) based drives. Tested with qemu front-end talking to
> dpdk testpmd (back-end) performing add/removal of memory regions. Also
> tested post-copy live migration after doing add_memory_region.
>
> Version Log:
> Version v15 (Current version): Incorporate code review suggestions from
> Maxime Coquelin as described above.
>
> Version v14: Incorporate code review suggestions from Stephen Hemminger
> and Fengcheng Wen.
> Changes from Fengcheng Wen review:
> Patch 3/5
> - Moved free_all_mem_regions() call sites in vhost_user_set_mem_table()
> from patch 4/5 to patch 3/5 so each commit compiles independently
> Patch 4/5
> - Renamed _dev_invalidate_vrings() to vhost_user_invalidate_vrings() to
> follow vhost naming convention
> - Added comment explaining *pdev propagation through
> translate_ring_addresses / numa_realloc()
> - Reordered local variables in vhost_user_add_mem_reg() and
> vhost_user_rem_mem_reg() by descending line length
> - Shortened overlap check variable names (current_region_guest_start/end
> --> cur_start/end, proposed_region_guest_start/end -> new_start/end)
> - Fixed DMA error path in vhost_user_add_mem_reg(): added
> free_new_region_no_dma label so async_dma_map_region(false) is not
> called when the map itself failed.
> Changes from Stephen Hemminger review:
> Patch 4/5
> - vhost_user_add_mem_reg() now constructs a reply with the back-end's
> host mapping address in userspace_addr and returns
> RTE_VHOST_MSG_RESULT_REPLY per the vhost-user spec
> - Added validate_msg_fds(dev, ctx, 0) in vhost_user_rem_mem_reg() to
> reject malformed messages with unexpected file descriptors
> - Dropped unnecessary (uint64_t) cast in vhost_user_get_max_mem_slots()
>
> Version v13: Incorporate code review suggestions from Fengcheng Wen
> Patch 2/5
> Renamed VhostUserSingleMemReg to VhostUserMemRegMsg and memory_single
> to memreg
> Patches 3/5 and 4/5
> Relocated function remove_guest_pages from patch 3/5 to 4/5
>
> Version v12: Incorporate code review suggestions from Maxime Coquelin
> and ai-code-review.
> Patch 3/5
> Refactored async_dma_map() to delegate to async_dma_map_region(),
> eliminating code duplication between the two functions.
> Restored original comments in async_dma_map_region() explaining why
> ENODEV and EINVAL errors are ignored (these were stripped in v10)
> Reverted unnecessary changes to vhost_user_postcopy_register() --
> removed the host_user_addr == 0 checks and reg_msg_index indirection
> that were added in v10, since this function is only called from
> vhost_user_set_mem_table() where regions are always contiguous.
>
> Version v11: Incorporate code review suggestions from Stephen Hemminger.
> Patch 4/5
> Fix incomplete cleanup in vhost_user_add_mem_reg() when
> vhost_user_mmap_region() fails after the mmap succeeds (e.g.
> add_guest_pages() realloc failure) realloc failure). The error path now
> calls remove_guest_pages() and free_mem_region() to undo the mapping
> and stale guest-page entries, preventing a leaked mmap and slot reuse
> corruption. The plain close(fd) path is kept for pre-mmap failures.
>
> Version v10: Incorporate code review suggestions from Stephen Hemminger.
> Patch 4/5
> Moved dev_invalidate_vrings after free_mem_region, array compaction, and
> nregions decrement. This ensures translate_ring_addresses only sees
> surviving memory regions, preventing vring pointers from resolving into
> a region that is about to be unmapped.
>
> Version v9: Incorporate code review suggestions from Stephen Hemminger.
> Patch 3/5
> Restored max_guest_pages initial value to hardcoded 8 instead of
> VHOST_MEMORY_MAX_NREGIONS, matching upstream semantics.
> Patch 4/5
> Added close(reg->fd) and reg->fd = -1 before goto close_msg_fds in the
> mmap failure path to fix fd leak after fd was moved from ctx->fds[0].
> Converted dev_invalidate_vrings from a plain function to a macro +
> implementation function pair, accepting message ID as a parameter so
> the static_assert reports the correct handler at each call site.
> Updated dev_invalidate_vrings call in add_mem_reg to pass
> VHOST_USER_ADD_MEM_REG as message ID.
> Updated dev_invalidate_vrings call in rem_mem_reg to pass
> VHOST_USER_REM_MEM_REG as message ID.
>
> Version v8: Incorporate code review suggestions from Stephen Hemminger.
> rewrite async_dma_map_region function to iterate guest pages by host
> address range matching
> change function dev_invalidate_vrings to accept a double pointer to
> propagate pointer updates
> new function remove_guest_pages was added
> add_mem_reg error path was narrowed to only clean up the single failed
> region instead of destroting all existing regions
>
> Version v7: Incorporate code review suggestions from Maxime Coquelin.
> Add debug messages to vhost_postcopy_register function.
>
> Version v6: Added the enablement of this feature as a final patch in
> this patch-set and other code optimizations as suggested by Maxime
> Coquelin.
>
> Version v5: removed the patch that increased the number of memory regions
> from 8 to 128. This will be submitted as a separate feature at a later
> point after incorporating additional optimizations. Also includes code
> optimizations as suggested by Feng Cheng Wen.
>
> Version v4: code optimizations as suggested by Feng Cheng Wen.
>
> Version v3: code optimizations as suggested by Maxime Coquelin
> and Thomas Monjalon.
>
> Version v2: code optimizations as suggested by Maxime Coquelin.
>
> Version v1: Initial patch set.
>
> Pravin M Bathija (5):
> vhost: add user to mailmap and define to vhost hdr
> vhost: header defines for add/rem mem region
> vhost: refactor memory helper functions
> vhost: add mem region add/remove handlers
> vhost: enable configure memory slots
>
> .mailmap | 1 +
> lib/vhost/rte_vhost.h | 4 +
> lib/vhost/vhost_user.c | 425 +++++++++++++++++++++++++++++++++++------
> lib/vhost/vhost_user.h | 10 +
> 4 files changed, 378 insertions(+), 62 deletions(-)
>
I don't think this is ready to merge based on AI review.
Did AI review with Opus 4.8 on a chat which has past context.
Summary of v15 findings
New in v15 (both patch 4/5, both errors):
Use-after-free on the reply path: reg points into dev->mem->regions[], but dev_invalidate_vrings() -> translate_ring_addresses() -> numa_realloc() can relocate dev->mem. dev is refreshed via *pdev, reg is not, then reg->host_user_addr is read for the reply. Re-derive reg (or capture host_user_addr) after dev = *pdev.
ADD_MEM_REG reply sent unconditionally: handler always returns RESULT_REPLY, but the spec makes the mapping-address reply postcopy- only. In non-postcopy mode this desyncs the channel (no REPLY_ACK: the front-end never reads it; with REPLY_ACK: it expects a u64 ack, not a memreg). Gate the reply on dev->postcopy_listening, else return RESULT_OK -- same as SET_MEM_TABLE.
Carried over from v13 (now in a different form):
The v13 Warning (missing postcopy mapping-address reply) is addressed but mis-gated; correct fix is the conditional reply above. Until then postcopy correctness still isn't right.
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