[Qemu-devel] [Bug 1661386] Re: Assertion `ret == cpu->kvm_msr_buf->nmsrs' failed

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
To: qemu-devel@nongnu.org
Subject: [Qemu-devel] [Bug 1661386] Re: Assertion `ret == cpu->kvm_msr_buf->nmsrs' failed
Date: Fri, 03 Feb 2017 19:51:41 -0000	[thread overview]
Message-ID: <20170203195141.18202.35112.malone@wampee.canonical.com> (raw)
In-Reply-To: 20170202204510.26617.69309.malonedeb@wampee.canonical.com

Ah well that is a bit better; you see now it's failing in kvm_**get**_msrs rather
than put; so the question is which of the two changes made it survive kvm_put_msrs

I'd hoped that the flags in (2) would have turned off the CPU flag and
thus made it go in both of them.

kvm_msr_entry_add: @103 index=20f value=0
qemu-system-x86_64: /home/matwey/lab/qemu/target/i386/kvm.c:2218:
kvm_get_msrs: Assertion `ret == cpu->kvm_msr_buf->nmsrs' failed.

1) Was it the steal time or the pmu change that made it flip over to the get_msrs?
2) Can you get it to flip over to the get_msrs with the flag rather than the code change?

Dave

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1661386

Title:
  Assertion `ret == cpu->kvm_msr_buf->nmsrs' failed

Status in QEMU:
  New

Bug description:
  Hello,

  I see the following when try to run qemu from master as the following:

  # ./x86_64-softmmu/qemu-system-x86_64 --version
  QEMU emulator version 2.8.50 (v2.8.0-1006-g4e9f524)
  Copyright (c) 2003-2016 Fabrice Bellard and the QEMU Project developers
  # ./x86_64-softmmu/qemu-system-x86_64 -machine accel=kvm -nodefaults
  -no-reboot -nographic -cpu host -vga none  -kernel .build.kernel.kvm
  -initrd .build.initrd.kvm -append 'panic=1 no-kvmclock console=ttyS0
  loglevel=7' -m 1024 -serial stdio
  qemu-system-x86_64: /home/matwey/lab/qemu/target/i386/kvm.c:1849:
  kvm_put_msrs: Assertion `ret == cpu->kvm_msr_buf->nmsrs' failed.

  First broken commit has been bisected:

  commit 48e1a45c3166d659f781171a47dabf4a187ed7a5
  Author: Paolo Bonzini <pbonzini@redhat.com>
  Date:   Wed Mar 30 22:55:29 2016 +0200

      target-i386: assert that KVM_GET/SET_MSRS can set all requested MSRs

      This would have caught the bug in the previous patch.

      Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

  My cpuinfo is the following:

  processor       : 0
  vendor_id       : GenuineIntel
  cpu family      : 6
  model           : 44
  model name      : Intel(R) Xeon(R) CPU           X5675  @ 3.07GHz
  stepping        : 2
  microcode       : 0x14
  cpu MHz         : 3066.775
  cache size      : 12288 KB
  physical id     : 0
  siblings        : 2
  core id         : 0
  cpu cores       : 2
  apicid          : 0
  initial apicid  : 0
  fpu             : yes
  fpu_exception   : yes
  cpuid level     : 11
  wp              : yes
  flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts mmx fxsr sse sse2 ss ht syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts nopl xtopology tsc_reliable nonstop_tsc aperfmperf pni pclmulqdq vmx ssse3 cx16 sse4_1 sse4_2 popcnt aes hypervisor lahf_lm ida arat epb dtherm tpr_shadow vnmi ept vpid
  bugs            :
  bogomips        : 6133.55
  clflush size    : 64
  cache_alignment : 64
  address sizes   : 40 bits physical, 48 bits virtual
  power management:

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1661386/+subscriptions