[MODERATED] Re: ***UNCHECKED*** Re: [PATCH v7 3/5] NX 3

[Joerg Roedel <jroedel@suse.de>]

On Fri, Oct 25, 2019 at 10:48:04AM +0200, speck for Paolo Bonzini wrote:
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index e7970a2e8eae..1f923dee99e5 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -992,6 +992,9 @@ static bool update_transition_efer(struct vcpu_vmx *vmx, int efer_offset)
>  		ignore_bits &= ~(u64)EFER_SCE;
>  #endif
>  
> +	guest_efer &= ~ignore_bits;
> +	guest_efer |= host_efer & ignore_bits;
> +
>  	/*
>  	 * On EPT, we can't emulate NX, so we must switch EFER atomically.
>  	 * On CPUs that support "load IA32_EFER", always switch EFER
> @@ -1010,9 +1013,6 @@ static bool update_transition_efer(struct vcpu_vmx *vmx, int efer_offset)
>  	} else {
>  		clear_atomic_switch_msr(vmx, MSR_EFER);
>  
> -		guest_efer &= ~ignore_bits;
> -		guest_efer |= host_efer & ignore_bits;
> -
>  		vmx->guest_msrs[efer_offset].data = guest_efer;
>  		vmx->guest_msrs[efer_offset].mask = ~ignore_bits;
>  
> 
> 

This works on my machine with ept=0 but breaks with ept=1:

	KVM: entry failed, hardware error 0x80000021

Regards,

	Joerg