Re: [PATCH] target/i386: relax assert when old host kernels don't include msrs

[Paolo Bonzini]

On 04/12/19 09:50, Catherine Ho wrote:
> Commit 20a78b02d315 ("target/i386: add VMX features") unconditionally
> add vmx msr entry although older host kernels don't include them.
> 
> But old host kernel + newest qemu will cause a qemu crash as follows:
> qemu-system-x86_64: error: failed to set MSR 0x480 to 0x0
> target/i386/kvm.c:2932: kvm_put_msrs: Assertion `ret ==
> cpu->kvm_msr_buf->nmsrs' failed.
> 
> This fixes it by relaxing the condition.

This is intentional.  The VMX MSR entries should not have been added.
What combination of host kernel/QEMU are you using, and what QEMU
command line?

Paolo