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[Qemu-devel] [PULL for 2.5 1/9] e1000: fix hang of win2k12 shutdown with
From: |
Jason Wang |
Subject: |
[Qemu-devel] [PULL for 2.5 1/9] e1000: fix hang of win2k12 shutdown with flood ping |
Date: |
Mon, 7 Dec 2015 11:26:05 +0800 |
From: "Denis V. Lunev" <address@hidden>
e1000 driver in Win2k12 is really well rotten. It 100% hangs on shutdown
of UP VM under flood ping. The guest checks card state and reinjects
itself interrupt in a loop. This is fatal for UP machine.
There is no good way to fix this misbehavior but to kludge it. The
emulation has interrupt throttling register aka ITR which limits
interrupt rate and allows the guest to proceed this phase.
There is no problem with this kludge for Linux guests - it adjust the
value of it itself.
On the other hand according to the initial research in
commit e9845f0985f088dd01790f4821026df0afba5795
Author: Vincenzo Maffione <address@hidden>
Date: Fri Aug 2 18:30:52 2013 +0200
e1000: add interrupt mitigation support
...
Interrupt mitigation boosts performance when the guest suffers from
an high interrupt rate (i.e. receiving short UDP packets at high packet
rate). For some numerical results see the following link
http://info.iet.unipi.it/~luigi/papers/20130520-rizzo-vm.pdf
this should also boost performance a bit.
See https://bugzilla.redhat.com/show_bug.cgi?id=874406 for additional
details.
Signed-off-by: Denis V. Lunev <address@hidden>
CC: Vincenzo Maffione <address@hidden>
CC: Stefan Hajnoczi <address@hidden>
Signed-off-by: Jason Wang <address@hidden>
---
hw/net/e1000.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/hw/net/e1000.c b/hw/net/e1000.c
index c877e06..bec06e9 100644
--- a/hw/net/e1000.c
+++ b/hw/net/e1000.c
@@ -447,6 +447,11 @@ static void e1000_reset(void *opaque)
e1000_link_down(d);
}
+ /* Throttle interrupts to prevent guest (e.g Win 2012) from
+ * reinjecting interrupts endlessly. TODO: fix non ITR case.
+ */
+ d->mac_reg[ITR] = 250;
+
/* Some guests expect pre-initialized RAH/RAL (AddrValid flag + MACaddr) */
d->mac_reg[RA] = 0;
d->mac_reg[RA + 1] = E1000_RAH_AV;
--
2.5.0
- [Qemu-devel] [PULL for 2.5 0/9] Net patches, Jason Wang, 2015/12/06
- [Qemu-devel] [PULL for 2.5 1/9] e1000: fix hang of win2k12 shutdown with flood ping,
Jason Wang <=
- [Qemu-devel] [PULL for 2.5 2/9] net: pcnet: add check to validate receive data size(CVE-2015-7504), Jason Wang, 2015/12/06
- [Qemu-devel] [PULL for 2.5 3/9] pcnet: fix rx buffer overflow(CVE-2015-7512), Jason Wang, 2015/12/06
- [Qemu-devel] [PULL for 2.5 4/9] vmxnet3: silence warning, Jason Wang, 2015/12/06
- [Qemu-devel] [PULL for 2.5 5/9] net/vmxnet3.c: fix a build error when enabling debug output, Jason Wang, 2015/12/06
- [Qemu-devel] [PULL for 2.5 6/9] lan9118: fix emulation of MAC address loaded bit in E2P_CMD register, Jason Wang, 2015/12/06
- [Qemu-devel] [PULL for 2.5 7/9] lan9118: log and ignore access to invalid registers, rather than aborting, Jason Wang, 2015/12/06
- [Qemu-devel] [PULL for 2.5 8/9] net/vmxnet3: fix debug macro pattern for vmxnet3, Jason Wang, 2015/12/06
- [Qemu-devel] [PULL for 2.5 9/9] net/vmxnet3: remove redundant VMW_SHPRN(...) definition, Jason Wang, 2015/12/06
- Re: [Qemu-devel] [PULL for 2.5 0/9] Net patches, Peter Maydell, 2015/12/07