qemu/net: flag to control the number of vectors a nic has

Add an option to specify the number of MSI-X vectors for PCI NIC cards. This
can also be used to disable MSI-X, for compatibility with old qemu. This
option currently only affects virtio cards.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Michael S. Tsirkin 2009-06-21 19:51:18 +03:00 committed by Anthony Liguori
parent 566e2d3e88
commit ffe6370c9f
4 changed files with 33 additions and 8 deletions

View File

@ -745,7 +745,10 @@ VirtIODevice *virtio_net_init(DeviceState *dev)
n->mac_table.macs = qemu_mallocz(MAC_TABLE_ENTRIES * ETH_ALEN);
n->vlans = qemu_mallocz(MAX_VLAN >> 3);
if (dev->nd->nvectors == NIC_NVECTORS_UNSPECIFIED)
n->vdev.nvectors = 3;
else
n->vdev.nvectors = dev->nd->nvectors;
register_savevm("virtio-net", virtio_net_id++, VIRTIO_NET_VM_VERSION,
virtio_net_save, virtio_net_load, n);

18
net.c
View File

@ -2169,7 +2169,7 @@ int net_client_init(Monitor *mon, const char *device, const char *p)
}
if (!strcmp(device, "nic")) {
static const char * const nic_params[] = {
"vlan", "name", "macaddr", "model", "addr", NULL
"vlan", "name", "macaddr", "model", "addr", "vectors", NULL
};
NICInfo *nd;
uint8_t *macaddr;
@ -2207,6 +2207,22 @@ int net_client_init(Monitor *mon, const char *device, const char *p)
if (get_param_value(buf, sizeof(buf), "addr", p)) {
nd->devaddr = strdup(buf);
}
nd->nvectors = NIC_NVECTORS_UNSPECIFIED;
if (get_param_value(buf, sizeof(buf), "vectors", p)) {
char *endptr;
long vectors = strtol(buf, &endptr, 0);
if (*endptr) {
config_error(mon, "invalid syntax for # of vectors\n");
ret = -1;
goto out;
}
if (vectors < 0 || vectors > 0x7ffffff) {
config_error(mon, "invalid # of vectors\n");
ret = -1;
goto out;
}
nd->nvectors = vectors;
}
nd->vlan = vlan;
nd->name = name;
nd->used = 1;

4
net.h
View File

@ -84,6 +84,9 @@ int do_set_link(Monitor *mon, const char *name, const char *up_or_down);
/* NIC info */
#define MAX_NICS 8
enum {
NIC_NVECTORS_UNSPECIFIED = -1
};
struct NICInfo {
uint8_t macaddr[6];
@ -94,6 +97,7 @@ struct NICInfo {
void *private;
int used;
int bootable;
int nvectors;
};
extern int nb_nics;

View File

@ -736,7 +736,7 @@ STEXI
ETEXI
DEF("net", HAS_ARG, QEMU_OPTION_net,
"-net nic[,vlan=n][,macaddr=mac][,model=type][,name=str][,addr=str]\n"
"-net nic[,vlan=n][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
" create a new Network Interface Card and connect it to VLAN 'n'\n"
#ifdef CONFIG_SLIRP
"-net user[,vlan=n][,name=str][,hostname=host]\n"
@ -777,16 +777,18 @@ DEF("net", HAS_ARG, QEMU_OPTION_net,
"-net none use it alone to have zero network devices; if no -net option\n"
" is provided, the default is '-net nic -net user'\n")
STEXI
@item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}][,name=@var{name}][,addr=@var{addr}]
@item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}][,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
= 0 is the default). The NIC is an ne2k_pci by default on the PC
target. Optionally, the MAC address can be changed to @var{mac}, the
device address set to @var{addr} (PCI cards only),
and a @var{name} can be assigned for use in monitor commands. If no
@option{-net} option is specified, a single NIC is created.
Qemu can emulate several different models of network card.
and a @var{name} can be assigned for use in monitor commands.
Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
that the card should have; this option currently only affects virtio cards; set
@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
NIC is created. Qemu can emulate several different models of network card.
Valid values for @var{type} are
@code{i82551}, @code{i82557b}, @code{i82559er},
@code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
@code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
@code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
Not all devices are supported on all targets. Use -net nic,model=?