Re: qemu-4.2: failed to set MSR 0x48b to 0x1582e00000000: Assertion `ret

> 1) running "vmxcap" on the Azure VM

You need to run "modprobe msr" before.

Paolo

$ sudo ./vmxcap

Basic VMX Information

Traceback (most recent call last):

File "./vmxcap", line 280, in <module>

c.show()

File "./vmxcap", line 82, in show

value = msr().read(self.msr, 0)

File "./vmxcap", line 33, in __init__

self.f = open('/dev/msr0', 'rb', 0)

IOError: [Errno 2] No such file or directory: '/dev/msr0'

> 2) adding "-vmx-xsaves,-vmx-shadow-vmcs" to the "-cpu" option and, if it
> works, add only one of the two.

nop, this didn't work

> 3) if it doesn't work, adding "-vmx" to the "-cpu" option. Either way,
> run "x86info -a" in the resulting VM.

yes, -vmx works

x86info -a -> https://paste.centos.org/view/f88f02f4

thanks

-

Julio

From: Paolo Bonzini <address@hidden>
Sent: Saturday, December 14, 2019 1:30 AM
To: Philippe Mathieu-Daudé <address@hidden>; Montes, Julio <address@hidden>; qemu-devel <address@hidden>
Cc: Eduardo Habkost <address@hidden>
Subject: Re: qemu-4.2: failed to set MSR 0x48b to 0x1582e00000000: Assertion `ret == cpu->kvm_msr_buf->nmsrs' failed.

On 14/12/19 02:31, Philippe Mathieu-Daudé wrote:
>
> failed to launch qemu: exit status 1, error messages from qemu log:
> qemu-system-x86_64: error: failed to set MSR 0x48b to 0x1582e00000000
> qemu-system-x86_64: /root/qemu/target/i386/kvm.c:2947: kvm_put_msrs:
> Assertion `ret == cpu->kvm_msr_buf->nmsrs' failed.

It could be a KVM bug too. The following features are being enabled:

#define VMX_SECONDARY_EXEC_XSAVES                   0x00100000
#define VMX_SECONDARY_EXEC_SHADOW_VMCS              0x00004000
#define VMX_SECONDARY_EXEC_ENABLE_INVPCID           0x00001000
#define VMX_SECONDARY_EXEC_RDRAND_EXITING           0x00000800
#define VMX_SECONDARY_EXEC_ENABLE_VPID              0x00000020
#define VMX_SECONDARY_EXEC_ENABLE_EPT               0x00000002
#define VMX_SECONDARY_EXEC_DESC                     0x00000004
#define VMX_SECONDARY_EXEC_RDTSCP                   0x00000008

Can you try:

1) running "vmxcap" on the Azure VM

2) adding "-vmx-xsaves,-vmx-shadow-vmcs" to the "-cpu" option and, if it
works, add only one of the two.

3) if it doesn't work, adding "-vmx" to the "-cpu" option. Either way,
run "x86info -a" in the resulting VM.

Thanks,

Paolo

From:	Montes, Julio
Subject:	Re: qemu-4.2: failed to set MSR 0x48b to 0x1582e00000000: Assertion `ret == cpu->kvm_msr_buf->nmsrs' failed.
Date:	Mon, 16 Dec 2019 19:27:25 +0000