Responses inline.
Internal Use - Confidential > -----Original Message----- > From: fengchengwen <[email protected]> > Sent: Tuesday, November 4, 2025 12:06 AM > To: Bathija, Pravin <[email protected]>; [email protected] > Cc: [email protected] > Subject: Re: [PATCH v3 4/5] vhost_user: support function defines for back-end > > > [EXTERNAL EMAIL] > > On 11/4/2025 12:21 PM, Pravin M Bathija wrote: > > 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 > > essetially common functions to initialize memory, unmap a set of > > memory regions, perform register copy and align memory addresses. > > > > Signed-off-by: Pravin M Bathija <[email protected]> > > --- > > lib/vhost/vhost_user.c | 80 > > +++++++++++++++++++++++++++++++++++------- > > 1 file changed, 68 insertions(+), 12 deletions(-) > > > > diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c index > > 168432e7d1..9a85f2fc92 100644 > > --- a/lib/vhost/vhost_user.c > > +++ b/lib/vhost/vhost_user.c > > @@ -228,7 +228,17 @@ 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; > > @@ -239,12 +249,10 @@ 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); > > } > > } > > > > @@ -258,7 +266,7 @@ 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; > > } > > @@ -707,7 +715,7 @@ 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, > > @@ -811,8 +819,10 @@ 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); > > @@ -1250,9 +1260,13 @@ vhost_user_postcopy_register(struct virtio_net > *dev, int main_fd, > > * retrieve the region offset when handling userfaults. > > */ > > memory = &ctx->msg.payload.memory; > > - for (i = 0; i < memory->nregions; i++) { > > + for (i = 0; i < VHOST_MEMORY_MAX_NREGIONS; i++) { > > I think the using MAX_NREGIONS are most for convienent, but it will impact > the performance, because the rte_vhost_va_from_guest_pa() should iter the > entire array. > Replaced VHOST_MEMORY_MAX_NREGIONS with memory->nregions. Please review v4. > I think we should keep the original impl: make sure the nregions entry of > memory-region is always valid. > > Beside, where is the modification for rte_vhost_va_from_guest_pa()??? Could you please provide more detail ? rte_vhost_va_from_guest_pa() was never called from here before. > > > + 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 */ @@ -1279,8 +1293,10 @@ > > 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++) { > > + for (i = 0; i < VHOST_MEMORY_MAX_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; > > } > > @@ -1385,6 +1401,46 @@ vhost_user_mmap_region(struct virtio_net *dev, > > return 0; > > } > > > > +static int > > +vhost_user_initialize_memory(struct virtio_net **pdev) > > This function should be part of 3/5, else the 3/5 will compile fail I have moved support functions to patch-3. Please review v4. > > > +{ > > + 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 = 8; > > It should be VHOST_MEMORY_MAX_NREGIONS Done. Please review v4. > > > + 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,
