diff options
authorBo Yang <>2012-08-29 19:26:11 +0800
committerDoug Goldstein <>2012-10-24 02:05:04 -0500
commitff7aef9e665a0417a66e5c92cc5bf1ba7f4c22d3 (patch)
parentcpu_physical_memory_write_rom() needs to do TB invalidates (diff)
eepro100: Fix network hang when rx buffers run out
This is reported by QA. When installing os with pxe, after the initial kernel and initrd are loaded, the procedure tries to copy files from install server to local harddisk, the network becomes stall because of running out of receive descriptor. [Whitespace fixes and removed qemu_notify_event() because Paolo's earlier net patches have moved it into qemu_flush_queued_packets(). Additional info: I can reproduce the network hang with a tap device doing a iPXE HTTP boot as follows: $ qemu -enable-kvm -m 1024 \ -netdev tap,id=netdev0,script=no,downscript=no \ -device i82559er,netdev=netdev0,romfile=80861209.rom \ -drive if=virtio,cache=none,file=test.img iPXE> ifopen net0 iPXE> config # set static network configuration iPXE> kernel I needed a vanilla iPXE ROM to get to the iPXE prompt. I think the boot prompt has been disabled in the ROMs that ship with QEMU to reduce boot time. During the vmlinuz HTTP download there is a network hang. hw/eepro100.c has reached the end of the rx descriptor list. When the iPXE driver replenishes the rx descriptor list we don't kick the QEMU net subsystem and event loop, thereby leaving the tap netdev without its file descriptor in select(2). Stefan Hajnoczi <>] Signed-off-by: Bo Yang <> Signed-off-by: Stefan Hajnoczi <> (cherry picked from commit 1069985fb132cd4324fc02d371f1e61492a1823f)
1 files changed, 3 insertions, 1 deletions
diff --git a/hw/eepro100.c b/hw/eepro100.c
index 6279ae36e..5b621967c 100644
--- a/hw/eepro100.c
+++ b/hw/eepro100.c
@@ -1036,6 +1036,7 @@ static void eepro100_ru_command(EEPRO100State * s, uint8_t val)
set_ru_state(s, ru_ready);
s->ru_offset = e100_read_reg4(s, SCBPointer);
+ qemu_flush_queued_packets(&s->nic->nc);
TRACE(OTHER, logout("val=0x%02x (rx start)\n", val));
@@ -1763,7 +1764,8 @@ static ssize_t nic_receive(VLANClientState *nc, const uint8_t * buf, size_t size
if (rfd_command & COMMAND_EL) {
/* EL bit is set, so this was the last frame. */
logout("receive: Running out of frames\n");
- set_ru_state(s, ru_suspended);
+ set_ru_state(s, ru_no_resources);
+ eepro100_rnr_interrupt(s);
if (rfd_command & COMMAND_S) {
/* S bit is set. */