[dpdk-dev,v5,3/3] net/virtio: support GUEST ANNOUNCE
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Commit Message
When live migration is done, for the backup VM, either the virtio
frontend or the vhost backend needs to send out gratuitous RARP packet
to announce its new network location.
This patch enables VIRTIO_NET_F_GUEST_ANNOUNCE feature to support live
migration scenario where the vhost backend doesn't have the ability to
generate RARP packet.
Brief introduction of the work flow:
1. QEMU finishes live migration, pokes the backup VM with an interrupt.
2. Virtio interrupt handler reads out the interrupt status value, and
realizes it needs to send out RARP packet to announce its location.
3. Pause device to stop worker thread touching the queues.
4. Inject a RARP packet into a Tx Queue.
5. Ack the interrupt via control queue.
6. Resume device to continue packet processing.
Signed-off-by: Xiao Wang <xiao.w.wang@intel.com>
---
drivers/net/virtio/virtio_ethdev.c | 97 +++++++++++++++++++++++++++++++++++++-
drivers/net/virtio/virtio_ethdev.h | 1 +
drivers/net/virtio/virtqueue.h | 11 +++++
3 files changed, 107 insertions(+), 2 deletions(-)
Comments
On Fri, Jan 05, 2018 at 08:46:57AM -0800, Xiao Wang wrote:
[...]
> +static int
> +make_rarp_packet(struct rte_mbuf *rarp_mbuf, const struct ether_addr *mac)
> +{
> + struct ether_hdr *eth_hdr;
> + struct arp_hdr *rarp;
Please just use one space between the type and var instead of two.
> +
[...]
> +static void
> +virtio_notify_peers(struct rte_eth_dev *dev)
> +{
> + struct virtio_hw *hw = dev->data->dev_private;
> + struct virtnet_rx *rxvq = dev->data->rx_queues[0];
> + struct rte_mbuf *rarp_mbuf;
> +
> + rarp_mbuf = rte_mbuf_raw_alloc(rxvq->mpool);
It's not necessary to use rte_mbuf_raw_alloc() here and
you forgot to initialize the allocated mbuf. I think you
can use rte_pktmbuf_alloc() directly as what I showed in
the example in my previous mail.
> + if (rarp_mbuf == NULL) {
> + PMD_DRV_LOG(ERR, "first mbuf allocate free_bufed");
Typos:
first?
free_bufed?
> + return;
> + }
[...]
> +static void
> +virtio_ack_link_announce(struct rte_eth_dev *dev)
> +{
> + struct virtio_hw *hw = dev->data->dev_private;
> + struct virtio_pmd_ctrl ctrl;
> + int len;
> +
> + ctrl.hdr.class = VIRTIO_NET_CTRL_ANNOUNCE;
> + ctrl.hdr.cmd = VIRTIO_NET_CTRL_ANNOUNCE_ACK;
> + len = 0;
> +
> + virtio_send_command(hw->cvq, &ctrl, &len, 0);
If the last param is 0, then the third param could be NULL,
i.e. you don't need to define `len`.
> +}
> +
[...]
> diff --git a/drivers/net/virtio/virtio_ethdev.h b/drivers/net/virtio/virtio_ethdev.h
> index 4a2a2f0..04b6a37 100644
> --- a/drivers/net/virtio/virtio_ethdev.h
> +++ b/drivers/net/virtio/virtio_ethdev.h
> @@ -68,6 +68,7 @@
> 1u << VIRTIO_NET_F_HOST_TSO6 | \
> 1u << VIRTIO_NET_F_MRG_RXBUF | \
> 1u << VIRTIO_NET_F_MTU | \
> + 1ULL << VIRTIO_NET_F_GUEST_ANNOUNCE | \
Please use one space before '|' instead of two.
Thanks,
Tiwei
Hi
> -----Original Message-----
> From: Bie, Tiwei
> Sent: Saturday, January 6, 2018 1:57 AM
> To: Wang, Xiao W <xiao.w.wang@intel.com>
> Cc: dev@dpdk.org; yliu@fridaylinux.org; stephen@networkplumber.org
> Subject: Re: [PATCH v5 3/3] net/virtio: support GUEST ANNOUNCE
>
> On Fri, Jan 05, 2018 at 08:46:57AM -0800, Xiao Wang wrote:
> [...]
> > +static int
> > +make_rarp_packet(struct rte_mbuf *rarp_mbuf, const struct ether_addr
> *mac)
> > +{
> > + struct ether_hdr *eth_hdr;
> > + struct arp_hdr *rarp;
>
> Please just use one space between the type and var instead of two.
Yes.
>
> > +
> [...]
> > +static void
> > +virtio_notify_peers(struct rte_eth_dev *dev)
> > +{
> > + struct virtio_hw *hw = dev->data->dev_private;
> > + struct virtnet_rx *rxvq = dev->data->rx_queues[0];
> > + struct rte_mbuf *rarp_mbuf;
> > +
> > + rarp_mbuf = rte_mbuf_raw_alloc(rxvq->mpool);
>
> It's not necessary to use rte_mbuf_raw_alloc() here and
> you forgot to initialize the allocated mbuf. I think you
> can use rte_pktmbuf_alloc() directly as what I showed in
> the example in my previous mail.
You are right.
>
> > + if (rarp_mbuf == NULL) {
> > + PMD_DRV_LOG(ERR, "first mbuf allocate free_bufed");
>
> Typos:
> first?
> free_bufed?
Sorry for typo.
>
> > + return;
> > + }
> [...]
> > +static void
> > +virtio_ack_link_announce(struct rte_eth_dev *dev)
> > +{
> > + struct virtio_hw *hw = dev->data->dev_private;
> > + struct virtio_pmd_ctrl ctrl;
> > + int len;
> > +
> > + ctrl.hdr.class = VIRTIO_NET_CTRL_ANNOUNCE;
> > + ctrl.hdr.cmd = VIRTIO_NET_CTRL_ANNOUNCE_ACK;
> > + len = 0;
> > +
> > + virtio_send_command(hw->cvq, &ctrl, &len, 0);
>
> If the last param is 0, then the third param could be NULL,
> i.e. you don't need to define `len`.
>
Just checked the code, when pkt_num is 0, len field won't be used.
Will make it NULL in v6.
> > +}
> > +
> [...]
> > diff --git a/drivers/net/virtio/virtio_ethdev.h
> b/drivers/net/virtio/virtio_ethdev.h
> > index 4a2a2f0..04b6a37 100644
> > --- a/drivers/net/virtio/virtio_ethdev.h
> > +++ b/drivers/net/virtio/virtio_ethdev.h
> > @@ -68,6 +68,7 @@
> > 1u << VIRTIO_NET_F_HOST_TSO6 | \
> > 1u << VIRTIO_NET_F_MRG_RXBUF | \
> > 1u << VIRTIO_NET_F_MTU | \
> > + 1ULL << VIRTIO_NET_F_GUEST_ANNOUNCE | \
>
> Please use one space before '|' instead of two.
Yes, will keep it aligned with the above lines.
Thanks a lot,
Xiao
v6:
- Use rte_pktmbuf_alloc() instead of rte_mbuf_raw_alloc().
- Remove the 'len' parameter in calling virtio_send_command().
- Remove extra space between typo and var.
- Improve comment and alignment.
- Remove the unnecessary header file.
- A better usage of 'unlikely' indication.
v5:
- Remove txvq parameter in virtio_inject_pkts.
- Zero hw->special_buf after using it.
- Return the retval of tx_pkt_burst().
- Allocate a mbuf pointer on stack directly.
v4:
- Move spinlock lock/unlock into dev_pause/resume.
- Separate out a patch for packet injection.
v3:
- Remove Tx function code duplication, use a special pointer for rarp
injection.
- Rename function generate_rarp to virtio_notify_peers, replace
'virtnet_' with 'virtio_'.
- Add comment for state_lock.
- Typo fix and comment improvement.
v2:
- Use spaces instead of tabs between the code and comments.
- Remove unnecessary parentheses.
- Use rte_pktmbuf_mtod directly to get eth_hdr addr.
- Fix virtio_dev_pause return value check.
Xiao Wang (3):
net/virtio: make control queue thread-safe
net/virtio: add packet injection method
net/virtio: support GUEST ANNOUNCE
drivers/net/virtio/virtio_ethdev.c | 158 +++++++++++++++++++++++++++++++-
drivers/net/virtio/virtio_ethdev.h | 6 ++
drivers/net/virtio/virtio_pci.h | 7 ++
drivers/net/virtio/virtio_rxtx.c | 3 +-
drivers/net/virtio/virtio_rxtx.h | 1 +
drivers/net/virtio/virtio_rxtx_simple.c | 2 +-
drivers/net/virtio/virtqueue.h | 11 +++
7 files changed, 183 insertions(+), 5 deletions(-)
@@ -48,6 +48,8 @@
#include <rte_pci.h>
#include <rte_bus_pci.h>
#include <rte_ether.h>
+#include <rte_ip.h>
+#include <rte_arp.h>
#include <rte_common.h>
#include <rte_errno.h>
#include <rte_cpuflags.h>
@@ -107,6 +109,11 @@ static int virtio_dev_queue_stats_mapping_set(
uint8_t stat_idx,
uint8_t is_rx);
+static int make_rarp_packet(struct rte_mbuf *rarp_mbuf,
+ const struct ether_addr *mac);
+static void virtio_notify_peers(struct rte_eth_dev *dev);
+static void virtio_ack_link_announce(struct rte_eth_dev *dev);
+
/*
* The set of PCI devices this driver supports
*/
@@ -1296,9 +1303,91 @@ static int virtio_dev_xstats_get_names(struct rte_eth_dev *dev,
return ret;
}
+#define RARP_PKT_SIZE 64
+static int
+make_rarp_packet(struct rte_mbuf *rarp_mbuf, const struct ether_addr *mac)
+{
+ struct ether_hdr *eth_hdr;
+ struct arp_hdr *rarp;
+
+ if (rarp_mbuf->buf_len < RARP_PKT_SIZE) {
+ PMD_DRV_LOG(ERR, "mbuf size too small %u (< %d)",
+ rarp_mbuf->buf_len, RARP_PKT_SIZE);
+ return -1;
+ }
+
+ /* Ethernet header. */
+ eth_hdr = rte_pktmbuf_mtod(rarp_mbuf, struct ether_hdr *);
+ memset(eth_hdr->d_addr.addr_bytes, 0xff, ETHER_ADDR_LEN);
+ ether_addr_copy(mac, ð_hdr->s_addr);
+ eth_hdr->ether_type = htons(ETHER_TYPE_RARP);
+
+ /* RARP header. */
+ rarp = (struct arp_hdr *)(eth_hdr + 1);
+ rarp->arp_hrd = htons(ARP_HRD_ETHER);
+ rarp->arp_pro = htons(ETHER_TYPE_IPv4);
+ rarp->arp_hln = ETHER_ADDR_LEN;
+ rarp->arp_pln = 4;
+ rarp->arp_op = htons(ARP_OP_REVREQUEST);
+
+ ether_addr_copy(mac, &rarp->arp_data.arp_sha);
+ ether_addr_copy(mac, &rarp->arp_data.arp_tha);
+ memset(&rarp->arp_data.arp_sip, 0x00, 4);
+ memset(&rarp->arp_data.arp_tip, 0x00, 4);
+
+ rarp_mbuf->data_len = RARP_PKT_SIZE;
+ rarp_mbuf->pkt_len = RARP_PKT_SIZE;
+
+ return 0;
+}
+
+static void
+virtio_notify_peers(struct rte_eth_dev *dev)
+{
+ struct virtio_hw *hw = dev->data->dev_private;
+ struct virtnet_rx *rxvq = dev->data->rx_queues[0];
+ struct rte_mbuf *rarp_mbuf;
+
+ rarp_mbuf = rte_mbuf_raw_alloc(rxvq->mpool);
+ if (rarp_mbuf == NULL) {
+ PMD_DRV_LOG(ERR, "first mbuf allocate free_bufed");
+ return;
+ }
+
+ if (make_rarp_packet(rarp_mbuf,
+ (struct ether_addr *)hw->mac_addr) < 0) {
+ rte_pktmbuf_free(rarp_mbuf);
+ return;
+ }
+
+ /* If virtio port just stopped, no need to send RARP */
+ if (virtio_dev_pause(dev) < 0) {
+ rte_pktmbuf_free(rarp_mbuf);
+ return;
+ }
+
+ virtio_inject_pkts(dev, &rarp_mbuf, 1);
+ virtio_dev_resume(dev);
+}
+
+static void
+virtio_ack_link_announce(struct rte_eth_dev *dev)
+{
+ struct virtio_hw *hw = dev->data->dev_private;
+ struct virtio_pmd_ctrl ctrl;
+ int len;
+
+ ctrl.hdr.class = VIRTIO_NET_CTRL_ANNOUNCE;
+ ctrl.hdr.cmd = VIRTIO_NET_CTRL_ANNOUNCE_ACK;
+ len = 0;
+
+ virtio_send_command(hw->cvq, &ctrl, &len, 0);
+}
+
/*
- * Process Virtio Config changed interrupt and call the callback
- * if link state changed.
+ * Process virtio config changed interrupt. Call the callback
+ * if link state changed, generate gratuitous RARP packet if
+ * the status indicates an ANNOUNCE.
*/
void
virtio_interrupt_handler(void *param)
@@ -1321,6 +1410,10 @@ static int virtio_dev_xstats_get_names(struct rte_eth_dev *dev,
NULL, NULL);
}
+ if (isr & VIRTIO_NET_S_ANNOUNCE) {
+ virtio_notify_peers(dev);
+ virtio_ack_link_announce(dev);
+ }
}
/* set rx and tx handlers according to what is supported */
@@ -68,6 +68,7 @@
1u << VIRTIO_NET_F_HOST_TSO6 | \
1u << VIRTIO_NET_F_MRG_RXBUF | \
1u << VIRTIO_NET_F_MTU | \
+ 1ULL << VIRTIO_NET_F_GUEST_ANNOUNCE | \
1u << VIRTIO_RING_F_INDIRECT_DESC | \
1ULL << VIRTIO_F_VERSION_1 | \
1ULL << VIRTIO_F_IOMMU_PLATFORM)
@@ -158,6 +158,17 @@ struct virtio_net_ctrl_mac {
#define VIRTIO_NET_CTRL_VLAN_ADD 0
#define VIRTIO_NET_CTRL_VLAN_DEL 1
+/*
+ * Control link announce acknowledgement
+ *
+ * The command VIRTIO_NET_CTRL_ANNOUNCE_ACK is used to indicate that
+ * driver has recevied the notification; device would clear the
+ * VIRTIO_NET_S_ANNOUNCE bit in the status field after it receives
+ * this command.
+ */
+#define VIRTIO_NET_CTRL_ANNOUNCE 3
+#define VIRTIO_NET_CTRL_ANNOUNCE_ACK 0
+
struct virtio_net_ctrl_hdr {
uint8_t class;
uint8_t cmd;