Re: [PATCH 11/11] kvm: vmx: workaround FEATURE_CONTROL[17] is not set by BIOS

From: "Huang, Kai" <kai.huang@linux.intel.com>
To: Kai Huang <kaih.linux@gmail.com>,
	pbonzini@redhat.com, rkrcmar@redhat.com, kvm@vger.kernel.org
Subject: Re: [PATCH 11/11] kvm: vmx: workaround FEATURE_CONTROL[17] is not set by BIOS
Date: Mon, 8 May 2017 17:29:33 +1200	[thread overview]
Message-ID: <1594dbed-6ac8-63ac-5e28-cec90a983b8e@linux.intel.com> (raw)
In-Reply-To: <20170508052434.3627-12-kai.huang@linux.intel.com>

Oops.. Please ignore this patch :)

Thanks,
-Kai

On 5/8/2017 5:24 PM, Kai Huang wrote:
> even this bit is not set by BIOS, current ucode patch allows write to
> IA32_SGXLEPUBKEYHASHn.
> ---
>  arch/x86/kvm/vmx.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 1022295ba925..9e687ce45b48 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -2254,12 +2254,20 @@ static void decache_tsc_multiplier(struct vcpu_vmx *vmx)
>  	vmcs_write64(TSC_MULTIPLIER, vmx->current_tsc_ratio);
>  }
>
> +#define	UCODE_PATCH
>  static bool cpu_sgx_lepubkeyhash_writable(void)
>  {
>  	u64 val, sgx_lc_enabled_mask = (FEATURE_CONTROL_LOCKED |
>  			FEATURE_CONTROL_SGX_LAUNCH_CONTROL_ENABLE);
>
>  	rdmsrl(MSR_IA32_FEATURE_CONTROL, val);
> +#ifdef UCODE_PATCH
> +	/*
> +	 * current ucode patch can support write to IA32_SGXLEPUBKEYHASHn
> +	 * even if FEATURE_CONTROL[17] is not set.
> +	 */
> +	val |=  FEATURE_CONTROL_SGX_LAUNCH_CONTROL_ENABLE;
> +#endif
>
>  	return ((val & sgx_lc_enabled_mask) == sgx_lc_enabled_mask);
>  }
>