virtio-net: Make tx_timer timeout configurable

Add an option to make the TX mitigation timer adjustable as a device
option.  The 150us hard coded default used currently is reasonable,
but may not be suitable for all workloads, this gives us a way to
adjust it using a single binary.  We can't support any random option
though, so use the "x-" prefix to indicate this is a developer
option.  Usage:

-device virtio-net-pci,x-txtimer=500000,... # .5ms timeout

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Alex Williamson 2010-09-02 09:00:50 -06:00 committed by Michael S. Tsirkin
parent ca736c8e74
commit f0c07c7c7b
7 changed files with 27 additions and 7 deletions

View File

@ -27,6 +27,7 @@
#include "elf.h"
#include "hw/virtio.h"
#include "hw/virtio-serial.h"
#include "hw/virtio-net.h"
#include "hw/sysbus.h"
#include "kvm.h"
@ -110,7 +111,7 @@ static int s390_virtio_net_init(VirtIOS390Device *dev)
{
VirtIODevice *vdev;
vdev = virtio_net_init((DeviceState *)dev, &dev->nic);
vdev = virtio_net_init((DeviceState *)dev, &dev->nic, &dev->net);
if (!vdev) {
return -1;
}
@ -327,6 +328,8 @@ static VirtIOS390DeviceInfo s390_virtio_net = {
.qdev.size = sizeof(VirtIOS390Device),
.qdev.props = (Property[]) {
DEFINE_NIC_PROPERTIES(VirtIOS390Device, nic),
DEFINE_PROP_UINT32("x-txtimer", VirtIOS390Device,
net.txtimer, TX_TIMER_INTERVAL),
DEFINE_PROP_END_OF_LIST(),
},
};

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@ -43,6 +43,7 @@ typedef struct VirtIOS390Device {
uint32_t host_features;
/* Max. number of ports we can have for a the virtio-serial device */
uint32_t max_virtserial_ports;
virtio_net_conf net;
} VirtIOS390Device;
typedef struct VirtIOS390Bus {

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@ -68,6 +68,7 @@ typedef struct {
uint32_t id;
NICConf nic;
uint32_t host_features;
virtio_net_conf net;
} SyborgVirtIOProxy;
static uint32_t syborg_virtio_readl(void *opaque, target_phys_addr_t offset)
@ -284,7 +285,7 @@ static int syborg_virtio_net_init(SysBusDevice *dev)
VirtIODevice *vdev;
SyborgVirtIOProxy *proxy = FROM_SYSBUS(SyborgVirtIOProxy, dev);
vdev = virtio_net_init(&dev->qdev, &proxy->nic);
vdev = virtio_net_init(&dev->qdev, &proxy->nic, &proxy->net);
return syborg_virtio_init(proxy, vdev);
}
@ -295,6 +296,8 @@ static SysBusDeviceInfo syborg_virtio_net_info = {
.qdev.props = (Property[]) {
DEFINE_NIC_PROPERTIES(SyborgVirtIOProxy, nic),
DEFINE_VIRTIO_NET_FEATURES(SyborgVirtIOProxy, host_features),
DEFINE_PROP_UINT32("x-txtimer", SyborgVirtIOProxy,
net.txtimer, TX_TIMER_INTERVAL),
DEFINE_PROP_END_OF_LIST(),
}
};

View File

@ -36,6 +36,7 @@ typedef struct VirtIONet
VirtQueue *ctrl_vq;
NICState *nic;
QEMUTimer *tx_timer;
uint32_t tx_timeout;
int tx_timer_active;
uint32_t has_vnet_hdr;
uint8_t has_ufo;
@ -702,7 +703,7 @@ static void virtio_net_handle_tx(VirtIODevice *vdev, VirtQueue *vq)
virtio_net_flush_tx(n, vq);
} else {
qemu_mod_timer(n->tx_timer,
qemu_get_clock(vm_clock) + TX_TIMER_INTERVAL);
qemu_get_clock(vm_clock) + n->tx_timeout);
n->tx_timer_active = 1;
virtio_queue_set_notification(vq, 0);
}
@ -842,7 +843,7 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
if (n->tx_timer_active) {
qemu_mod_timer(n->tx_timer,
qemu_get_clock(vm_clock) + TX_TIMER_INTERVAL);
qemu_get_clock(vm_clock) + n->tx_timeout);
}
return 0;
}
@ -903,7 +904,8 @@ static void virtio_net_vmstate_change(void *opaque, int running, int reason)
virtio_net_set_status(&n->vdev, n->vdev.status & status);
}
VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf)
VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
virtio_net_conf *net)
{
VirtIONet *n;
@ -931,6 +933,7 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf)
n->tx_timer = qemu_new_timer(vm_clock, virtio_net_tx_timer, n);
n->tx_timer_active = 0;
n->tx_timeout = net->txtimer;
n->mergeable_rx_bufs = 0;
n->promisc = 1; /* for compatibility */

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@ -49,6 +49,11 @@
#define TX_TIMER_INTERVAL 150000 /* 150 us */
typedef struct virtio_net_conf
{
uint32_t txtimer;
} virtio_net_conf;
/* Maximum packet size we can receive from tap device: header + 64k */
#define VIRTIO_NET_MAX_BUFSIZE (sizeof(struct virtio_net_hdr) + (64 << 10))

View File

@ -107,6 +107,7 @@ typedef struct {
#endif
/* Max. number of ports we can have for a the virtio-serial device */
uint32_t max_virtserial_ports;
virtio_net_conf net;
} VirtIOPCIProxy;
/* virtio device */
@ -613,7 +614,7 @@ static int virtio_net_init_pci(PCIDevice *pci_dev)
VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
VirtIODevice *vdev;
vdev = virtio_net_init(&pci_dev->qdev, &proxy->nic);
vdev = virtio_net_init(&pci_dev->qdev, &proxy->nic, &proxy->net);
vdev->nvectors = proxy->nvectors;
virtio_init_pci(proxy, vdev,
@ -690,6 +691,8 @@ static PCIDeviceInfo virtio_info[] = {
DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, 3),
DEFINE_VIRTIO_NET_FEATURES(VirtIOPCIProxy, host_features),
DEFINE_NIC_PROPERTIES(VirtIOPCIProxy, nic),
DEFINE_PROP_UINT32("x-txtimer", VirtIOPCIProxy,
net.txtimer, TX_TIMER_INTERVAL),
DEFINE_PROP_END_OF_LIST(),
},
.qdev.reset = virtio_pci_reset,

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@ -185,7 +185,9 @@ void virtio_bind_device(VirtIODevice *vdev, const VirtIOBindings *binding,
/* Base devices. */
VirtIODevice *virtio_blk_init(DeviceState *dev, BlockConf *conf);
VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf);
struct virtio_net_conf;
VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
struct virtio_net_conf *net);
VirtIODevice *virtio_serial_init(DeviceState *dev, uint32_t max_nr_ports);
VirtIODevice *virtio_balloon_init(DeviceState *dev);
#ifdef CONFIG_LINUX