From 83e942e0c7634121243478fa2f4e3459b33d4a67 Mon Sep 17 00:00:00 2001
From: Dor Laor <[EMAIL PROTECTED]>
Date: Wed, 19 Dec 2007 23:43:24 +0200
Subject: [PATCH] virtio network device
This patch implements the backend support for the virtio network
device. The
device is optimized for virtualized environments by limiting the number of
guest=>host transitions per-packet. In the best case, the number of
transitions per-packet is < 1.
With some further optimizations, I have been able to obtain 1.5gbit/sec
host=>guest with this driver (compared to the 90mbit/sec from the rtl8139
card). This requires additional patches not present in this series.
Signed-off-by: Anthony Liguori <[EMAIL PROTECTED]>
Cc: Rusty Russell <[EMAIL PROTECTED]>
Cc: Avi Kivity <[EMAIL PROTECTED]>
Cc: Dor Laor <[EMAIL PROTECTED]>
---
qemu/Makefile.target | 2 +-
qemu/hw/pc.h | 5 ++
qemu/hw/pci.c | 5 +-
qemu/hw/virtio-net.c | 178
++++++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 188 insertions(+), 2 deletions(-)
create mode 100644 qemu/hw/virtio-net.c
diff --git a/qemu/Makefile.target b/qemu/Makefile.target
index 8b5853b..17ff6f2 100644
--- a/qemu/Makefile.target
+++ b/qemu/Makefile.target
@@ -464,7 +464,7 @@ VL_OBJS += rtl8139.o
VL_OBJS+= hypercall.o
# virtio devices
-VL_OBJS += virtio.o
+VL_OBJS += virtio.o virtio-net.o
ifeq ($(TARGET_BASE_ARCH), i386)
# Hardware support
diff --git a/qemu/hw/pc.h b/qemu/hw/pc.h
index beb711c..ce1a1f3 100644
--- a/qemu/hw/pc.h
+++ b/qemu/hw/pc.h
@@ -142,4 +142,9 @@ void pci_piix4_ide_init(PCIBus *bus,
BlockDriverState **hd_table, int devfn,
void isa_ne2000_init(int base, qemu_irq irq, NICInfo *nd);
+/* virtio-net.c */
+
+void *virtio_net_init(PCIBus *bus, NICInfo *nd, int devfn);
+
+
#endif
diff --git a/qemu/hw/pci.c b/qemu/hw/pci.c
index f8cbf1a..545901c 100644
--- a/qemu/hw/pci.c
+++ b/qemu/hw/pci.c
@@ -25,6 +25,7 @@
#include "pci.h"
#include "console.h"
#include "net.h"
+#include "pc.h"
//#define DEBUG_PCI
@@ -638,9 +639,11 @@ void pci_nic_init(PCIBus *bus, NICInfo *nd, int devfn)
pci_rtl8139_init(bus, nd, devfn);
} else if (strcmp(nd->model, "pcnet") == 0) {
pci_pcnet_init(bus, nd, devfn);
+ } else if (strcmp(nd->model, "virtio") == 0) {
+ virtio_net_init(bus, nd, devfn);
} else if (strcmp(nd->model, "?") == 0) {
fprintf(stderr, "qemu: Supported PCI NICs: i82551 i82557b i82559er"
- " ne2k_pci pcnet rtl8139\n");
+ " ne2k_pci pcnet rtl8139 virtio\n");
exit (1);
} else {
fprintf(stderr, "qemu: Unsupported NIC: %s\n", nd->model);
diff --git a/qemu/hw/virtio-net.c b/qemu/hw/virtio-net.c
new file mode 100644
index 0000000..3320dd8
--- /dev/null
+++ b/qemu/hw/virtio-net.c
@@ -0,0 +1,178 @@
+/*
+ * Virtio Network Device
+ *
+ * Copyright IBM, Corp. 2007
+ *
+ * Authors:
+ * Anthony Liguori <[EMAIL PROTECTED]>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include "virtio.h"
+#include "net.h"
+#include "pc.h"
+
+/* from Linux's virtio_net.h */
+
+/* The ID for virtio_net */
+#define VIRTIO_ID_NET 1
+
+/* The feature bitmap for virtio net */
+#define VIRTIO_NET_F_NO_CSUM 0
+#define VIRTIO_NET_F_TSO4 1
+#define VIRTIO_NET_F_UFO 2
+#define VIRTIO_NET_F_TSO4_ECN 3
+#define VIRTIO_NET_F_TSO6 4
+#define VIRTIO_NET_F_MAC 5
+
+/* The config defining mac address (6 bytes) */
+struct virtio_net_config
+{
+ uint8_t mac[6];
+} __attribute__((packed));
+
+/* This is the first element of the scatter-gather list. If you don't
+ * specify GSO or CSUM features, you can simply ignore the header. */
+struct virtio_net_hdr
+{
+#define VIRTIO_NET_HDR_F_NEEDS_CSUM 1 // Use csum_start, csum_offset
+ uint8_t flags;
+#define VIRTIO_NET_HDR_GSO_NONE 0 // Not a GSO frame
+#define VIRTIO_NET_HDR_GSO_TCPV4 1 // GSO frame, IPv4 TCP (TSO)
+/* FIXME: Do we need this? If they said they can handle ECN, do they
care? */
+#define VIRTIO_NET_HDR_GSO_TCPV4_ECN 2 // GSO frame, IPv4 TCP w/ ECN
+#define VIRTIO_NET_HDR_GSO_UDP 3 // GSO frame, IPv4 UDP (UFO)
+#define VIRTIO_NET_HDR_GSO_TCPV6 4 // GSO frame, IPv6 TCP
+ uint8_t gso_type;
+ uint16_t gso_size;
+ uint16_t csum_start;
+ uint16_t csum_offset;
+};
+
+typedef struct VirtIONet
+{
+ VirtIODevice vdev;
+ uint8_t mac[6];
+ VirtQueue *rx_vq;
+ VirtQueue *tx_vq;
+ VLANClientState *vc;
+ int can_receive;
+} VirtIONet;
+
+static VirtIONet *to_virtio_net(VirtIODevice *vdev)
+{
+ return (VirtIONet *)vdev;
+}
+
+static void virtio_net_update_config(VirtIODevice *vdev, uint8_t *config)
+{
+ VirtIONet *n = to_virtio_net(vdev);
+ struct virtio_net_config netcfg;
+
+ memcpy(netcfg.mac, n->mac, 6);
+ memcpy(config, &netcfg, sizeof(netcfg));
+}
+
+static uint32_t virtio_net_get_features(VirtIODevice *vdev)
+{
+ return (1 << VIRTIO_NET_F_MAC);
+}
+
+/* RX */
+
+static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
+{
+ VirtIONet *n = to_virtio_net(vdev);
+ n->can_receive = 1;
+}
+
+static int virtio_net_can_receive(void *opaque)
+{
+ VirtIONet *n = opaque;
+
+ return (n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK) && n->can_receive;
+}
+
+static void virtio_net_receive(void *opaque, const uint8_t *buf, int size)
+{
+ VirtIONet *n = opaque;
+ VirtQueueElement elem;
+ struct virtio_net_hdr *hdr;
+ int offset, i;
+
+ /* FIXME: the drivers really need to set their status better */
+ if (n->rx_vq->vring.avail == NULL) {
+ n->can_receive = 0;
+ return;
+ }
+
+ if (virtqueue_pop(n->rx_vq, &elem) == 0) {
+ /* wait until the guest adds some rx bufs */
+ n->can_receive = 0;
+ return;
+ }
+
+ hdr = (void *)elem.in_sg[0].iov_base;
+ hdr->flags = 0;
+ hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
+
+ /* copy in packet. ugh */
+ offset = 0;
+ i = 1;
+ while (offset < size && i < elem.in_num) {
+ int len = MIN(elem.in_sg[i].iov_len, size - offset);
+ memcpy(elem.in_sg[i].iov_base, buf + offset, len);
+ offset += len;
+ i++;
+ }
+
+ /* signal other side */
+ virtqueue_push(n->rx_vq, &elem, sizeof(*hdr) + offset);
+ virtio_notify(&n->vdev, n->rx_vq);
+}
+
+/* TX */
+static void virtio_net_handle_tx(VirtIODevice *vdev, VirtQueue *vq)
+{
+ VirtIONet *n = to_virtio_net(vdev);
+ VirtQueueElement elem;
+
+ while (virtqueue_pop(vq, &elem)) {
+ int i;
+ size_t len = 0;
+
+ /* ignore the header for now */
+ for (i = 1; i < elem.out_num; i++) {
+ qemu_send_packet(n->vc, elem.out_sg[i].iov_base,
+ elem.out_sg[i].iov_len);
+ len += elem.out_sg[i].iov_len;
+ }
+
+ virtqueue_push(vq, &elem, sizeof(struct virtio_net_hdr) + len);
+ virtio_notify(&n->vdev, vq);
+ }
+}
+
+void *virtio_net_init(PCIBus *bus, NICInfo *nd, int devfn)
+{
+ VirtIONet *n;
+
+ n = (VirtIONet *)virtio_init_pci(bus, "virtio-net", 6900, 0x1000,
+ 0, VIRTIO_ID_NET,
+ 0x02, 0x00, 0x00,
+ 6, sizeof(VirtIONet));
+
+ n->vdev.update_config = virtio_net_update_config;
+ n->vdev.get_features = virtio_net_get_features;
+ n->rx_vq = virtio_add_queue(&n->vdev, 512, virtio_net_handle_rx);
+ n->tx_vq = virtio_add_queue(&n->vdev, 128, virtio_net_handle_tx);
+ n->can_receive = 0;
+ memcpy(n->mac, nd->macaddr, 6);
+ n->vc = qemu_new_vlan_client(nd->vlan, virtio_net_receive,
+ virtio_net_can_receive, n);
+
+ return &n->vdev;
+}
--
1.5.3.3
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