In virtio-net guest driver, currently we write MAC address to pci config space byte by byte, this means that we have an intermediate step where mac is wrong. This patch introduced a new control command to set MAC address, it's atomic.
VIRTIO_NET_F_CTRL_MAC_ADDR is a new feature bit for compatibility. "mac" field will be set to read-only when VIRTIO_NET_F_CTRL_MAC_ADDR is acked. Signed-off-by: Amos Kong <ak...@redhat.com> --- hw/pc_piix.c | 4 ++++ hw/virtio-net.c | 13 ++++++++++++- hw/virtio-net.h | 12 ++++++++++-- 3 files changed, 26 insertions(+), 3 deletions(-) diff --git a/hw/pc_piix.c b/hw/pc_piix.c index 0a6923d..6218350 100644 --- a/hw/pc_piix.c +++ b/hw/pc_piix.c @@ -297,6 +297,10 @@ static QEMUMachine pc_i440fx_machine_v1_4 = { .driver = "usb-tablet",\ .property = "usb_version",\ .value = stringify(1),\ + },{\ + .driver = "virtio-net-pci",\ + .property = "ctrl_mac_addr",\ + .value = "off", \ } static QEMUMachine pc_machine_v1_3 = { diff --git a/hw/virtio-net.c b/hw/virtio-net.c index af1f3a1..acef5a5 100644 --- a/hw/virtio-net.c +++ b/hw/virtio-net.c @@ -93,7 +93,8 @@ static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config) memcpy(&netcfg, config, sizeof(netcfg)); - if (memcmp(netcfg.mac, n->mac, ETH_ALEN)) { + if (!(n->vdev.guest_features >> VIRTIO_NET_F_CTRL_MAC_ADDR & 1) && + memcmp(netcfg.mac, n->mac, ETH_ALEN)) { memcpy(n->mac, netcfg.mac, ETH_ALEN); qemu_format_nic_info_str(&n->nic->nc, n->mac); } @@ -350,6 +351,16 @@ static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd, struct virtio_net_ctrl_mac mac_data; size_t s; + if (cmd == VIRTIO_NET_CTRL_MAC_ADDR_SET) { + if (iov_size(iov, iov_cnt) != sizeof(n->mac)) { + return VIRTIO_NET_ERR; + } + s = iov_to_buf(iov, iov_cnt, 0, &n->mac, sizeof(n->mac)); + assert(s == sizeof(n->mac)); + qemu_format_nic_info_str(&n->nic->nc, n->mac); + return VIRTIO_NET_OK; + } + if (cmd != VIRTIO_NET_CTRL_MAC_TABLE_SET) { return VIRTIO_NET_ERR; } diff --git a/hw/virtio-net.h b/hw/virtio-net.h index d46fb98..1ec632f 100644 --- a/hw/virtio-net.h +++ b/hw/virtio-net.h @@ -44,6 +44,8 @@ #define VIRTIO_NET_F_CTRL_VLAN 19 /* Control channel VLAN filtering */ #define VIRTIO_NET_F_CTRL_RX_EXTRA 20 /* Extra RX mode control support */ +#define VIRTIO_NET_F_CTRL_MAC_ADDR 23 /* Set MAC address */ + #define VIRTIO_NET_S_LINK_UP 1 /* Link is up */ #define TX_TIMER_INTERVAL 150000 /* 150 us */ @@ -106,7 +108,7 @@ typedef uint8_t virtio_net_ctrl_ack; #define VIRTIO_NET_CTRL_RX_MODE_NOBCAST 5 /* - * Control the MAC filter table. + * Control the MAC * * The MAC filter table is managed by the hypervisor, the guest should * assume the size is infinite. Filtering should be considered @@ -119,6 +121,10 @@ typedef uint8_t virtio_net_ctrl_ack; * first sg list contains unicast addresses, the second is for multicast. * This functionality is present if the VIRTIO_NET_F_CTRL_RX feature * is available. + * + * The ADDR_SET command requests one out scatterlist, it contains a + * 6 bytes MAC address. This functionality is present if the + * VIRTIO_NET_F_CTRL_MAC_ADDR feature is available. */ struct virtio_net_ctrl_mac { uint32_t entries; @@ -126,6 +132,7 @@ struct virtio_net_ctrl_mac { }; #define VIRTIO_NET_CTRL_MAC 1 #define VIRTIO_NET_CTRL_MAC_TABLE_SET 0 + #define VIRTIO_NET_CTRL_MAC_ADDR_SET 1 /* * Control VLAN filtering @@ -158,5 +165,6 @@ struct virtio_net_ctrl_mac { DEFINE_PROP_BIT("ctrl_vq", _state, _field, VIRTIO_NET_F_CTRL_VQ, true), \ DEFINE_PROP_BIT("ctrl_rx", _state, _field, VIRTIO_NET_F_CTRL_RX, true), \ DEFINE_PROP_BIT("ctrl_vlan", _state, _field, VIRTIO_NET_F_CTRL_VLAN, true), \ - DEFINE_PROP_BIT("ctrl_rx_extra", _state, _field, VIRTIO_NET_F_CTRL_RX_EXTRA, true) + DEFINE_PROP_BIT("ctrl_rx_extra", _state, _field, VIRTIO_NET_F_CTRL_RX_EXTRA, true), \ + DEFINE_PROP_BIT("ctrl_mac_addr", _state, _field, VIRTIO_NET_F_CTRL_MAC_ADDR, true) #endif -- 1.7.1