Introduce vhost_log_write() helper function to log the dirty pages we
touched. Page size is harded code to 4096 (VHOST_LOG_PAGE), and each
log is presented by 1 bit.
Therefore, vhost_log_write() simply finds the right bit for related
page we are gonna change, and set it to 1. dev->log_base denotes the
start of the dirty page bitmap.
The page address is biased by log_guest_addr, which is derived from
SET_VRING_ADDR request as part of the vring related addresses.
Signed-off-by: Yuanhan Liu <yuanhan.liu at linux.intel.com>
---
lib/librte_vhost/rte_virtio_net.h | 34 ++++++++++++++++++++++++++++++++++
lib/librte_vhost/virtio-net.c | 4 ++++
2 files changed, 38 insertions(+)
diff --git a/lib/librte_vhost/rte_virtio_net.h
b/lib/librte_vhost/rte_virtio_net.h
index 416dac2..191c1be 100644
--- a/lib/librte_vhost/rte_virtio_net.h
+++ b/lib/librte_vhost/rte_virtio_net.h
@@ -40,6 +40,7 @@
*/
#include <stdint.h>
+#include <linux/vhost.h>
#include <linux/virtio_ring.h>
#include <linux/virtio_net.h>
#include <sys/eventfd.h>
@@ -59,6 +60,8 @@ struct rte_mbuf;
/* Backend value set by guest. */
#define VIRTIO_DEV_STOPPED -1
+#define VHOST_LOG_PAGE 4096
+
/* Enum for virtqueue management. */
enum {VIRTIO_RXQ, VIRTIO_TXQ, VIRTIO_QNUM};
@@ -82,6 +85,7 @@ struct vhost_virtqueue {
struct vring_desc *desc; /**< Virtqueue
descriptor ring. */
struct vring_avail *avail; /**< Virtqueue
available ring. */
struct vring_used *used; /**< Virtqueue used
ring. */
+ uint64_t log_guest_addr; /**< Physical address
of used ring, for logging */
uint32_t size; /**< Size of descriptor
ring. */
uint32_t backend; /**< Backend value to
determine if device should started/stopped. */
uint16_t vhost_hlen; /**< Vhost header
length (varies depending on RX merge buffers. */
@@ -203,6 +207,36 @@ gpa_to_vva(struct virtio_net *dev, uint64_t guest_pa)
return vhost_va;
}
+static inline void __attribute__((always_inline))
+vhost_log_page(uint8_t *log_base, uint64_t page)
+{
+ /* TODO: to make it atomic? */
+ log_base[page / 8] |= 1 << (page % 8);
+}
+
+static inline void __attribute__((always_inline))
+vhost_log_write(struct virtio_net *dev, struct vhost_virtqueue *vq,
+ uint64_t offset, uint64_t len)
+{
+ uint64_t addr = vq->log_guest_addr;
+ uint64_t page;
+
+ if (unlikely(((dev->features & (1ULL << VHOST_F_LOG_ALL)) == 0) ||
+ !dev->log_base || !len))
+ return;
+
+ addr += offset;
+ if (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_page(dev->log_base, page);
+ page += VHOST_LOG_PAGE;
+ }
+}
+
+
/**
* Disable features in feature_mask. Returns 0 on success.
*/
diff --git a/lib/librte_vhost/virtio-net.c b/lib/librte_vhost/virtio-net.c
index 8364938..4481827 100644
--- a/lib/librte_vhost/virtio-net.c
+++ b/lib/librte_vhost/virtio-net.c
@@ -666,12 +666,16 @@ set_vring_addr(struct vhost_device_ctx ctx, struct
vhost_vring_addr *addr)
return -1;
}
+ vq->log_guest_addr = addr->log_guest_addr;
+
LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") mapped address desc: %p\n",
dev->device_fh, vq->desc);
LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") mapped address avail: %p\n",
dev->device_fh, vq->avail);
LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") mapped address used: %p\n",
dev->device_fh, vq->used);
+ LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") log_guest_addr: %p\n",
+ dev->device_fh, (void *)(uintptr_t)vq->log_guest_addr);
return 0;
}
--
1.9.0
