We send packets using a copy-free mechanism (this is the Guest to Host transport
via VMBUS). While this is obviously optimal for large packets,
it may not be optimal for small packets. Hyper-V host supports
a second mechanism for sending packets that is "copy based". We implement that
mechanism in this patch.
In this version of the patch I have addressed a comment from David Miller.
With this patch (and all of the other offload and VRSS patches), we are now able
to almost saturate a 10G interface between Linux VMs on Hyper-V
on different hosts - close to 9 Gbps as measured via iperf.
Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
Reviewed-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
---
drivers/net/hyperv/hyperv_net.h | 14 +++
drivers/net/hyperv/netvsc.c | 226 +++++++++++++++++++++++++++++++++++++--
drivers/net/hyperv/netvsc_drv.c | 3 +-
3 files changed, 234 insertions(+), 9 deletions(-)
diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index d1f7826..4b7df5a 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -140,6 +140,8 @@ struct hv_netvsc_packet {
void *send_completion_ctx;
void (*send_completion)(void *context);
+ u32 send_buf_index;
+
/* This points to the memory after page_buf */
struct rndis_message *rndis_msg;
@@ -582,6 +584,9 @@ struct nvsp_message {
#define NETVSC_RECEIVE_BUFFER_SIZE (1024*1024*16) /* 16MB */
#define NETVSC_RECEIVE_BUFFER_SIZE_LEGACY (1024*1024*15) /* 15MB */
+#define NETVSC_SEND_BUFFER_SIZE (1024 * 1024) /* 1MB */
+#define NETVSC_INVALID_INDEX -1
+
#define NETVSC_RECEIVE_BUFFER_ID 0xcafe
@@ -607,6 +612,15 @@ struct netvsc_device {
u32 recv_section_cnt;
struct nvsp_1_receive_buffer_section *recv_section;
+ /* Send buffer allocated by us */
+ void *send_buf;
+ u32 send_buf_size;
+ u32 send_buf_gpadl_handle;
+ u32 send_section_cnt;
+ u32 send_section_size;
+ unsigned long *send_section_map;
+ int map_words;
+
/* Used for NetVSP initialization protocol */
struct completion channel_init_wait;
struct nvsp_message channel_init_pkt;
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index bbee446..c041f63 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -28,6 +28,7 @@
#include <linux/slab.h>
#include <linux/netdevice.h>
#include <linux/if_ether.h>
+#include <asm/sync_bitops.h>
#include "hyperv_net.h"
@@ -80,7 +81,7 @@ get_in_err:
}
-static int netvsc_destroy_recv_buf(struct netvsc_device *net_device)
+static int netvsc_destroy_buf(struct netvsc_device *net_device)
{
struct nvsp_message *revoke_packet;
int ret = 0;
@@ -146,10 +147,62 @@ static int netvsc_destroy_recv_buf(struct netvsc_device *net_device)
net_device->recv_section = NULL;
}
+ /* Deal with the send buffer we may have setup.
+ * If we got a send section size, it means we received a
+ * SendsendBufferComplete msg (ie sent
+ * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
+ * to send a revoke msg here
+ */
+ if (net_device->send_section_size) {
+ /* Send the revoke receive buffer */
+ revoke_packet = &net_device->revoke_packet;
+ memset(revoke_packet, 0, sizeof(struct nvsp_message));
+
+ revoke_packet->hdr.msg_type =
+ NVSP_MSG1_TYPE_REVOKE_SEND_BUF;
+ revoke_packet->msg.v1_msg.revoke_recv_buf.id = 0;
+
+ ret = vmbus_sendpacket(net_device->dev->channel,
+ revoke_packet,
+ sizeof(struct nvsp_message),
+ (unsigned long)revoke_packet,
+ VM_PKT_DATA_INBAND, 0);
+ /* If we failed here, we might as well return and
+ * have a leak rather than continue and a bugchk
+ */
+ if (ret != 0) {
+ netdev_err(ndev, "unable to send "
+ "revoke send buffer to netvsp\n");
+ return ret;
+ }
+ }
+ /* Teardown the gpadl on the vsp end */
+ if (net_device->send_buf_gpadl_handle) {
+ ret = vmbus_teardown_gpadl(net_device->dev->channel,
+ net_device->send_buf_gpadl_handle);
+
+ /* If we failed here, we might as well return and have a leak
+ * rather than continue and a bugchk
+ */
+ if (ret != 0) {
+ netdev_err(ndev,
+ "unable to teardown send buffer's gpadl\n");
+ return ret;
+ }
+ net_device->recv_buf_gpadl_handle = 0;
+ }
+ if (net_device->send_buf) {
+ /* Free up the receive buffer */
+ free_pages((unsigned long)net_device->send_buf,
+ get_order(net_device->send_buf_size));
+ net_device->send_buf = NULL;
+ }
+ kfree(net_device->send_section_map);
+
return ret;
}
-static int netvsc_init_recv_buf(struct hv_device *device)
+static int netvsc_init_buf(struct hv_device *device)
{
int ret = 0;
int t;
@@ -248,10 +301,90 @@ static int netvsc_init_recv_buf(struct hv_device *device)
goto cleanup;
}
+ /* Now setup the send buffer.
+ */
+ net_device->send_buf =
+ (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
+ get_order(net_device->send_buf_size));
+ if (!net_device->send_buf) {
+ netdev_err(ndev, "unable to allocate send "
+ "buffer of size %d\n", net_device->send_buf_size);
+ ret = -ENOMEM;
+ goto cleanup;
+ }
+
+ /* Establish the gpadl handle for this buffer on this
+ * channel. Note: This call uses the vmbus connection rather
+ * than the channel to establish the gpadl handle.
+ */
+ ret = vmbus_establish_gpadl(device->channel, net_device->send_buf,
+ net_device->send_buf_size,
+ &net_device->send_buf_gpadl_handle);
+ if (ret != 0) {
+ netdev_err(ndev,
+ "unable to establish send buffer's gpadl\n");
+ goto cleanup;
+ }
+
+ /* Notify the NetVsp of the gpadl handle */
+ init_packet = &net_device->channel_init_pkt;
+ memset(init_packet, 0, sizeof(struct nvsp_message));
+ init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_SEND_BUF;
+ init_packet->msg.v1_msg.send_recv_buf.gpadl_handle =
+ net_device->send_buf_gpadl_handle;
+ init_packet->msg.v1_msg.send_recv_buf.id = 0;
+
+ /* Send the gpadl notification request */
+ ret = vmbus_sendpacket(device->channel, init_packet,
+ sizeof(struct nvsp_message),
+ (unsigned long)init_packet,
+ VM_PKT_DATA_INBAND,
+ VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+ if (ret != 0) {
+ netdev_err(ndev,
+ "unable to send send buffer's gpadl to netvsp\n");
+ goto cleanup;
+ }
+
+ t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
+ BUG_ON(t == 0);
+
+ /* Check the response */
+ if (init_packet->msg.v1_msg.
+ send_send_buf_complete.status != NVSP_STAT_SUCCESS) {
+ netdev_err(ndev, "Unable to complete send buffer "
+ "initialization with NetVsp - status %d\n",
+ init_packet->msg.v1_msg.
+ send_recv_buf_complete.status);
+ ret = -EINVAL;
+ goto cleanup;
+ }
+
+ /* Parse the response */
+ net_device->send_section_size = init_packet->msg.
+ v1_msg.send_send_buf_complete.section_size;
+
+ /* Section count is simply the size divided by the section size.
+ */
+ net_device->send_section_cnt =
+ net_device->send_buf_size/net_device->send_section_size;
+
+ dev_info(&device->device, "Send section size: %d, Section count:%d\n",
+ net_device->send_section_size, net_device->send_section_cnt);
+
+ /* Setup state for managing the send buffer. */
+ net_device->map_words = DIV_ROUND_UP(net_device->send_section_cnt,
+ BITS_PER_LONG);
+
+ net_device->send_section_map =
+ kzalloc(net_device->map_words * sizeof(ulong), GFP_KERNEL);
+ if (net_device->send_section_map == NULL)
+ goto cleanup;
+
goto exit;
cleanup:
- netvsc_destroy_recv_buf(net_device);
+ netvsc_destroy_buf(net_device);
exit:
return ret;
@@ -369,8 +502,9 @@ static int netvsc_connect_vsp(struct hv_device *device)
net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE_LEGACY;
else
net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
+ net_device->send_buf_size = NETVSC_SEND_BUFFER_SIZE;
- ret = netvsc_init_recv_buf(device);
+ ret = netvsc_init_buf(device);
cleanup:
return ret;
@@ -378,7 +512,7 @@ cleanup:
static void netvsc_disconnect_vsp(struct netvsc_device *net_device)
{
- netvsc_destroy_recv_buf(net_device);
+ netvsc_destroy_buf(net_device);
}
/*
@@ -440,6 +574,12 @@ static inline u32 hv_ringbuf_avail_percent(
return avail_write * 100 / ring_info->ring_datasize;
}
+static inline void netvsc_free_send_slot(struct netvsc_device *net_device,
+ u32 index)
+{
+ sync_change_bit(index, net_device->send_section_map);
+}
+
static void netvsc_send_completion(struct netvsc_device *net_device,
struct hv_device *device,
struct vmpacket_descriptor *packet)
@@ -447,6 +587,7 @@ static void netvsc_send_completion(struct netvsc_device *net_device,
struct nvsp_message *nvsp_packet;
struct hv_netvsc_packet *nvsc_packet;
struct net_device *ndev;
+ u32 send_index;
ndev = net_device->ndev;
@@ -477,6 +618,9 @@ static void netvsc_send_completion(struct netvsc_device *net_device,
/* Notify the layer above us */
if (nvsc_packet) {
+ send_index = nvsc_packet->send_buf_index;
+ if (send_index != NETVSC_INVALID_INDEX)
+ netvsc_free_send_slot(net_device, send_index);
q_idx = nvsc_packet->q_idx;
channel = nvsc_packet->channel;
nvsc_packet->send_completion(nvsc_packet->
@@ -504,6 +648,52 @@ static void netvsc_send_completion(struct netvsc_device *net_device,
}
+static u32 netvsc_get_next_send_section(struct netvsc_device *net_device)
+{
+ unsigned long index;
+ u32 max_words = net_device->map_words;
+ unsigned long *map_addr = (unsigned long *)net_device->send_section_map;
+ u32 section_cnt = net_device->send_section_cnt;
+ int ret_val = NETVSC_INVALID_INDEX;
+ int i;
+ int prev_val;
+
+ for (i = 0; i < max_words; i++) {
+ if (!~(map_addr[i]))
+ continue;
+ index = ffz(map_addr[i]);
+ prev_val = sync_test_and_set_bit(index, &map_addr[i]);
+ if (prev_val)
+ continue;
+ if ((index + (i * BITS_PER_LONG)) >= section_cnt)
+ break;
+ ret_val = (index + (i * BITS_PER_LONG));
+ break;
+ }
+ return ret_val;
+}
+
+u32 netvsc_copy_to_send_buf(struct netvsc_device *net_device,
+ unsigned int section_index,
+ struct hv_netvsc_packet *packet)
+{
+ char *start = net_device->send_buf;
+ char *dest = (start + (section_index * net_device->send_section_size));
+ int i;
+ u32 msg_size = 0;
+
+ for (i = 0; i < packet->page_buf_cnt; i++) {
+ char *src = phys_to_virt(packet->page_buf[i].pfn << PAGE_SHIFT);
+ u32 offset = packet->page_buf[i].offset;
+ u32 len = packet->page_buf[i].len;
+
+ memcpy(dest, (src + offset), len);
+ msg_size += len;
+ dest += len;
+ }
+ return msg_size;
+}
+
int netvsc_send(struct hv_device *device,
struct hv_netvsc_packet *packet)
{
@@ -513,6 +703,10 @@ int netvsc_send(struct hv_device *device,
struct net_device *ndev;
struct vmbus_channel *out_channel = NULL;
u64 req_id;
+ unsigned int section_index = NETVSC_INVALID_INDEX;
+ u32 msg_size = 0;
+ struct sk_buff *skb;
+
net_device = get_outbound_net_device(device);
if (!net_device)
@@ -528,10 +722,26 @@ int netvsc_send(struct hv_device *device,
sendMessage.msg.v1_msg.send_rndis_pkt.channel_type = 1;
}
- /* Not using send buffer section */
+ /* Attempt to send via sendbuf */
+ if (packet->total_data_buflen < net_device->send_section_size) {
+ section_index = netvsc_get_next_send_section(net_device);
+ if (section_index != NETVSC_INVALID_INDEX) {
+ msg_size = netvsc_copy_to_send_buf(net_device,
+ section_index,
+ packet);
+ skb = (struct sk_buff *)
+ (unsigned long)packet->send_completion_tid;
+ if (skb)
+ dev_kfree_skb_any(skb);
+ packet->page_buf_cnt = 0;
+ }
+ }
+ packet->send_buf_index = section_index;
+
+
sendMessage.msg.v1_msg.send_rndis_pkt.send_buf_section_index =
- 0xFFFFFFFF;
- sendMessage.msg.v1_msg.send_rndis_pkt.send_buf_section_size = 0;
+ section_index;
+ sendMessage.msg.v1_msg.send_rndis_pkt.send_buf_section_size = msg_size;
if (packet->send_completion)
req_id = (ulong)packet;
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index c76b665..939e3af 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -236,10 +236,11 @@ static void netvsc_xmit_completion(void *context)
struct hv_netvsc_packet *packet = (struct hv_netvsc_packet *)context;
struct sk_buff *skb = (struct sk_buff *)
(unsigned long)packet->send_completion_tid;
+ u32 index = packet->send_buf_index;
kfree(packet);
- if (skb)
+ if (skb && (index == NETVSC_INVALID_INDEX))
dev_kfree_skb_any(skb);
}
--
1.7.4.1
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