We need to be able to send fragmented packets in KVM to avoid an extra copy
in the TX path. This patch adds a qemu_sendv_packet() function to send
fragemented packets. It also provides backwards compatibility for old clients
that don't support the new interface.
Signed-off-by: Anthony Liguori <[EMAIL PROTECTED]>
diff --git a/qemu/net.h b/qemu/net.h
index 13daa27..5fb190e 100644
--- a/qemu/net.h
+++ b/qemu/net.h
@@ -1,12 +1,17 @@
#ifndef QEMU_NET_H
#define QEMU_NET_H
+#include <sys/uio.h>
+
/* VLANs support */
+typedef ssize_t (IOReadvHandler)(void *, const struct iovec *, int);
+
typedef struct VLANClientState VLANClientState;
struct VLANClientState {
IOReadHandler *fd_read;
+ IOReadvHandler *fd_readv;
/* Packets may still be sent if this returns zero. It's used to
rate-limit the slirp code. */
IOCanRWHandler *fd_can_read;
@@ -30,6 +35,8 @@ VLANClientState *qemu_new_vlan_client(VLANState *vlan,
void *opaque);
int qemu_can_send_packet(VLANClientState *vc);
void qemu_send_packet(VLANClientState *vc, const uint8_t *buf, int size);
+ssize_t qemu_sendv_packet(VLANClientState *vc, const struct iovec *iov,
+ int iovcnt);
void qemu_handler_true(void *opaque);
void do_info_network(void);
diff --git a/qemu/vl.c b/qemu/vl.c
index 45c97af..1f0a6ac 100644
--- a/qemu/vl.c
+++ b/qemu/vl.c
@@ -3820,6 +3820,50 @@ void qemu_send_packet(VLANClientState *vc1, const
uint8_t *buf, int size)
}
}
+static ssize_t vc_sendv_compat(VLANClientState *vc, const struct iovec *iov,
+ int iovcnt)
+{
+ char buffer[4096];
+ size_t offset = 0;
+ int i;
+
+ for (i = 0; i < iovcnt; i++) {
+ size_t len;
+
+ len = MIN(sizeof(buffer) - offset, iov[i].iov_len);
+ memcpy(buffer + offset, iov[i].iov_base, len);
+ offset += len;
+ }
+
+ vc->fd_read(vc->opaque, buffer, offset);
+
+ return offset;
+}
+
+ssize_t qemu_sendv_packet(VLANClientState *vc1, const struct iovec *iov,
+ int iovcnt)
+{
+ VLANState *vlan = vc1->vlan;
+ VLANClientState *vc;
+ ssize_t max_len = 0;
+
+ for (vc = vlan->first_client; vc != NULL; vc = vc->next) {
+ ssize_t len = 0;
+
+ if (vc == vc1)
+ continue;
+
+ if (vc->fd_readv)
+ len = vc->fd_readv(vc->opaque, iov, iovcnt);
+ else if (vc->fd_read)
+ len = vc_sendv_compat(vc, iov, iovcnt);
+
+ max_len = MAX(max_len, len);
+ }
+
+ return max_len;
+}
+
#if defined(CONFIG_SLIRP)
/* slirp network adapter */
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