Re: kvm_buf_set_msrs: Assertion `ret == cpu->kvm_msr_buf->nmsrs' failed.

[Paolo Bonzini]

On 20/05/20 10:22, Li Feng wrote:
>> - bit 2, vmx-exit-nosave-debugctl
>> - bit 9, host address space size, is handled automatically by QEMU
>> - bit 15, vmx-exit-ack-intr
>> - bit 17, vmx-exit-save-pat
>> - bit 18, vmx-exit-load-pat
>> - bit 19, vmx-exit-save-efer
>> - bit 20, vmx-exit-load-efer
>> - bit 21, vmx-exit-save-preemption-timer
>>
>> Try removing all of these and see if QEMU starts:
>>
>> qemu-kvm ... -cpu
>> host,-vmx-exit-nosave-debugctl,-vmx-exit-ack-intr,-vmx-exit-save-pat,-vmx-exit-load-pat,-vmx-exit-save-efer,-vmx-exit-load-efer,-vmx-exit-save-preemption-timer
>>
>> And then add them back one at a time.
> Hi, Paolo.
> Thanks, the crash is still here when removing the above features:
> qemu-system-x86_64: error: failed to set MSR 0x48f to 0x36fff00036dff
> 
> After computing xor, the result is 0b1000000000.
> The bit 9 is set.

Are you running KVM with a 32-bit kernel.

Paolo