On 07/14/2015 03:53 PM, Fam Zheng wrote: > Since a90a742 "tap: Drop tap_can_send", all nics that returns false from > .can_receive() are required to explicitly flush the incoming queue when the > status of it is changing back to true, otherwise the backend will sop > processing more rx packets. > > The purpose of this callback is to tell the peer backend (tap, socket, etc) > "hold on until guest consumes old data because my buffer is not ready". More > often than not NICs also do this when driver deactivated the card or disabled > rx, causing the packets being unnessarily queued, where they should actualy be > dropped. > > This series adds such missing qemu_flush_queued_packets calls for all NICs, > and > drops such unnecessary conditions in .can_receive(), so that NICs now: > > - returns false from .can_receive when guest buffers are busy. > - calls qemu_flush_queued_packets when buffers are available again. > - returns -1 from .receive when rx is not enabled. > > e1000, ne2000, rocker and vmxnet3 are not included because they're fixed by > other patches on the list and applied to Stefan's tree. > > virtio-net is covered by another thread: > > https://lists.gnu.org/archive/html/qemu-devel/2015-06/msg07377.html
When will the virtio-net patch be accepted? Without this patch, virtio-net + tap can not work. Thanks Wen Congyang > > All other NICs are okay, as they already do the flush on the state transition > points. > > Please review. > > Fam Zheng (12): > xgmac: Drop packets with eth_can_rx is false. > pcnet: Drop pcnet_can_receive > eepro100: Drop nic_can_receive > usbnet: Drop usbnet_can_receive > etsec: Move etsec_can_receive into etsec_receive > etsec: Flush queue when rx buffer is consumed > mcf_fec: Drop mcf_fec_can_receive > milkymist-minimac2: Flush queued packets when link comes up > mipsnet: Flush queued packets when receiving is enabled > stellaris_enet: Flush queued packets when read done > dp8393x: Flush packets when link comes up > axienet: Flush queued packets when rx is done > > hw/net/dp8393x.c | 8 ++++++++ > hw/net/eepro100.c | 11 ----------- > hw/net/fsl_etsec/etsec.c | 20 ++++++++++---------- > hw/net/fsl_etsec/etsec.h | 4 +++- > hw/net/fsl_etsec/rings.c | 15 +++++++++------ > hw/net/lance.c | 1 - > hw/net/mcf_fec.c | 9 +-------- > hw/net/milkymist-minimac2.c | 12 ++++++------ > hw/net/mipsnet.c | 9 +++++++-- > hw/net/pcnet-pci.c | 1 - > hw/net/pcnet.c | 9 --------- > hw/net/pcnet.h | 1 - > hw/net/stellaris_enet.c | 14 +++++--------- > hw/net/xgmac.c | 8 ++++---- > hw/net/xilinx_axienet.c | 22 ++++++++++++++++++++++ > hw/usb/dev-network.c | 20 ++++---------------- > 16 files changed, 79 insertions(+), 85 deletions(-) >
