+#define VHOST_LOG_PAGE 4096
+
+/*
+ * Atomically set a bit in memory.
+ */
+static __rte_always_inline void
+vhost_set_bit(unsigned int nr, volatile uint8_t *addr)
+{
+#if defined(RTE_TOOLCHAIN_GCC) && (GCC_VERSION < 70100)
+ /*
+ * __sync_ built-ins are deprecated, but __atomic_ ones
+ * are sub-optimized in older GCC versions.
+ */
+ __sync_fetch_and_or_1(addr, (1U << nr));
+#else
+ __atomic_fetch_or(addr, (1U << nr), __ATOMIC_RELAXED);
+#endif
+}
+
+static __rte_always_inline void
+vhost_log_page(uint8_t *log_base, uint64_t page)
+{
+ vhost_set_bit(page % 8, &log_base[page / 8]);
+}
+
+void
+__vhost_log_write(struct virtio_net *dev, uint64_t addr, uint64_t len)
+{
+ uint64_t page;
+
+ if (unlikely(!dev->log_base || !len))
+ return;
+
+ if (unlikely(dev->log_size <= ((addr + len - 1) / VHOST_LOG_PAGE / 8)))
+ return;
+
+ /* To make sure guest memory updates are committed before logging */
+ rte_smp_wmb();
+
+ page = addr / VHOST_LOG_PAGE;
+ while (page * VHOST_LOG_PAGE < addr + len) {
+ vhost_log_page((uint8_t *)(uintptr_t)dev->log_base, page);
+ page += 1;
+ }
+}
+
+void
+__vhost_log_write_iova(struct virtio_net *dev, struct vhost_virtqueue *vq,
+ uint64_t iova, uint64_t len)
+{
+ uint64_t hva, gpa, map_len;
+ map_len = len;
+
+ hva = __vhost_iova_to_vva(dev, vq, iova, &map_len, VHOST_ACCESS_RW);
+ if (map_len != len) {
+ VHOST_LOG_DATA(ERR,
+ "Failed to write log for IOVA 0x%" PRIx64 ". No IOTLB entry found\n",
+ iova);
+ return;
+ }
+
+ gpa = hva_to_gpa(dev, hva, len);
+ if (gpa)
+ __vhost_log_write(dev, gpa, len);
+}
+
+void
+__vhost_log_cache_sync(struct virtio_net *dev, struct vhost_virtqueue *vq)
+{
+ unsigned long *log_base;
+ int i;
+
+ if (unlikely(!dev->log_base))
+ return;
+
+ rte_smp_wmb();
+
+ log_base = (unsigned long *)(uintptr_t)dev->log_base;
+
+ for (i = 0; i < vq->log_cache_nb_elem; i++) {
+ struct log_cache_entry *elem = vq->log_cache + i;
+
+#if defined(RTE_TOOLCHAIN_GCC) && (GCC_VERSION < 70100)
+ /*
+ * '__sync' builtins are deprecated, but '__atomic' ones
+ * are sub-optimized in older GCC versions.
+ */
+ __sync_fetch_and_or(log_base + elem->offset, elem->val);
+#else
+ __atomic_fetch_or(log_base + elem->offset, elem->val,
+ __ATOMIC_RELAXED);
+#endif
+ }
+
+ rte_smp_wmb();
+
+ vq->log_cache_nb_elem = 0;
+}
+
+static __rte_always_inline void
+vhost_log_cache_page(struct virtio_net *dev, struct vhost_virtqueue *vq,
+ uint64_t page)
+{
+ uint32_t bit_nr = page % (sizeof(unsigned long) << 3);
+ uint32_t offset = page / (sizeof(unsigned long) << 3);
+ int i;
+
+ for (i = 0; i < vq->log_cache_nb_elem; i++) {
+ struct log_cache_entry *elem = vq->log_cache + i;
+
+ if (elem->offset == offset) {
+ elem->val |= (1UL << bit_nr);
+ return;
+ }
+ }
+
+ if (unlikely(i >= VHOST_LOG_CACHE_NR)) {
+ /*
+ * No more room for a new log cache entry,
+ * so write the dirty log map directly.
+ */
+ rte_smp_wmb();
+ vhost_log_page((uint8_t *)(uintptr_t)dev->log_base, page);
+
+ return;
+ }
+
+ vq->log_cache[i].offset = offset;
+ vq->log_cache[i].val = (1UL << bit_nr);
+ vq->log_cache_nb_elem++;
+}
+
+void
+__vhost_log_cache_write(struct virtio_net *dev, struct vhost_virtqueue *vq,
+ uint64_t addr, uint64_t len)
+{
+ uint64_t page;
+
+ if (unlikely(!dev->log_base || !len))
+ return;
+
+ if (unlikely(dev->log_size <= ((addr + len - 1) / VHOST_LOG_PAGE / 8)))
+ return;
+
+ page = addr / VHOST_LOG_PAGE;
+ while (page * VHOST_LOG_PAGE < addr + len) {
+ vhost_log_cache_page(dev, vq, page);
+ page += 1;
+ }
+}
+
+void
+__vhost_log_cache_write_iova(struct virtio_net *dev, struct vhost_virtqueue *vq,
+ uint64_t iova, uint64_t len)
+{
+ uint64_t hva, gpa, map_len;
+ map_len = len;
+
+ hva = __vhost_iova_to_vva(dev, vq, iova, &map_len, VHOST_ACCESS_RW);
+ if (map_len != len) {
+ VHOST_LOG_DATA(ERR,
+ "Failed to write log for IOVA 0x%" PRIx64 ". No IOTLB entry found\n",
+ iova);
+ return;
+ }
+
+ gpa = hva_to_gpa(dev, hva, len);
+ if (gpa)
+ __vhost_log_cache_write(dev, vq, gpa, len);
+}
+
+void *
+vhost_alloc_copy_ind_table(struct virtio_net *dev, struct vhost_virtqueue *vq,
+ uint64_t desc_addr, uint64_t desc_len)
+{
+ void *idesc;
+ uint64_t src, dst;
+ uint64_t len, remain = desc_len;
+
+ idesc = rte_malloc(__func__, desc_len, 0);
+ if (unlikely(!idesc))
+ return NULL;
+
+ dst = (uint64_t)(uintptr_t)idesc;
+
+ while (remain) {
+ len = remain;
+ src = vhost_iova_to_vva(dev, vq, desc_addr, &len,
+ VHOST_ACCESS_RO);
+ if (unlikely(!src || !len)) {
+ rte_free(idesc);
+ return NULL;
+ }
+
+ rte_memcpy((void *)(uintptr_t)dst, (void *)(uintptr_t)src, len);
+
+ remain -= len;
+ dst += len;
+ desc_addr += len;
+ }
+
+ return idesc;
+}
+
+void