Re: [Qemu-devel] [Bug 1037675] Re: Guest Kernel Panic if using "-cpu host" in qemu-kvm 1.1.1

[Gleb Natapov]

On Mon, Sep 10, 2012 at 10:23:26AM -0000, Till Schäfer wrote:
> [    0.027998] Process swapper/0 (pid: 1, threadinfo ffff88000f8b8000, task 
> ffff88000f8b0000)
> [    0.027998] Stack:
> [    0.027998]  0000000000000000 ffffffff81b1b550 ffff88000f8b9ef0 
> ffffffff81aa4989
> [    0.027998]  0000000000000040 ffffffff81a800d8 ffff88000f8b9f20 
> ffffffff81b1b550
> [    0.027998]  ffffffff81aa4955 0000000000000000 ffff88000f8b9f20 
> ffffffff810002ea
> [    0.027998] Call Trace:
> [    0.027998]  [<ffffffff81aa4989>] init_hw_perf_events+0x34/0x3ef
> [    0.027998]  [<ffffffff81aa4955>] ? check_bugs+0x2d/0x2d
> [    0.027998]  [<ffffffff810002ea>] do_one_initcall+0x7a/0x12c
> [    0.027998]  [<ffffffff81a9eb45>] kernel_init+0x7a/0x141
> [    0.027998]  [<ffffffff814963b4>] kernel_thread_helper+0x4/0x10
> [    0.027998]  [<ffffffff81a9eacb>] ? start_kernel+0x339/0x339
> [    0.027998]  [<ffffffff814963b0>] ? gs_change+0xb/0xb
> [    0.027998] Code: 48 d3 e0 48 ff c8 41 ff ca 48 89 05 b4 99 fd ff 7e 2b 83 
> e2 1f b8 03 00 00 00 83 fa 02 b9 45 03 00 00 0f 4f c2 89 05 91 99 fd ff <0f> 
> 32 48 c1 e2 20 89 c0 48 09 c2 48 89 15 ef 99 fd ff e8 cf be 
> [    0.027998] RIP  [<ffffffff81aa553f>] intel_pmu_init+0x283/0x85e
> [    0.027998]  RSP <ffff88000f8b9ea0>
> [    0.029015] ---[ end trace 4eaa2a86a8e2da22 ]---
> [    0.030006] swapper/0 used greatest stack depth: 5576 bytes left
> [    0.031005] Kernel panic - not syncing: Attempted to kill init!
> [    0.032006] Pid: 1, comm: swapper/0 Tainted: G      D      3.2.12-gentoo #1
> [    0.033000] Call Trace:
> [    0.034003]  [<ffffffff8148d64e>] panic+0x8c/0x198
> [    0.035005]  [<ffffffff8103e1f0>] do_exit+0x98/0x7d8
> [    0.036005]  [<ffffffff8103c564>] ? kmsg_dump+0x46/0xd2
> [    0.037007]  [<ffffffff81490078>] oops_end+0xb1/0xb9
> [    0.038001]  [<ffffffff81004bd9>] die+0x55/0x60
> [    0.039005]  [<ffffffff8148fd30>] do_general_protection+0x12e/0x136
> [    0.040001]  [<ffffffff81aa4955>] ? check_bugs+0x2d/0x2d
> [    0.041005]  [<ffffffff8148f83f>] general_protection+0x1f/0x30
Guest tries to use PMU MSR and gets #GP. I wonder which MSR it uses that
KVM does not emulate. Can you trace it like that: 
http://www.linux-kvm.org/page/Tracing

You can run qemu with -cpu host,level=9 to disable PMU emulation.

> [    0.042001]  [<ffffffff81aa4955>] ? check_bugs+0x2d/0x2d
> [    0.043004]  [<ffffffff81aa553f>] ? intel_pmu_init+0x283/0x85e
> [    0.044001]  [<ffffffff81aa4989>] init_hw_perf_events+0x34/0x3ef
> [    0.045005]  [<ffffffff81aa4955>] ? check_bugs+0x2d/0x2d
> [    0.046003]  [<ffffffff810002ea>] do_one_initcall+0x7a/0x12c
> [    0.047003]  [<ffffffff81a9eb45>] kernel_init+0x7a/0x141
> [    0.048000]  [<ffffffff814963b4>] kernel_thread_helper+0x4/0x10
> [    0.049000]  [<ffffffff81a9eacb>] ? start_kernel+0x339/0x339
> [    0.050008]  [<ffffffff814963b0>] ? gs_change+0xb/0xb
> 

--
                        Gleb.