linux-kernel - Re: [PATCH v1 07/11] KVM: VMX: optimize APIC ID read with APICv

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <37522ab8-1af8-b7a1-320d-66622e89197b@redhat.com>
Date:	Fri, 1 Jul 2016 10:42:54 +0200
From:	Paolo Bonzini <pbonzini@...hat.com>
To:	Radim Krčmář <rkrcmar@...hat.com>,
	linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:	"Lan, Tianyu" <tianyu.lan@...el.com>,
	Igor Mammedov <imammedo@...hat.com>,
	Jan Kiszka <jan.kiszka@....de>, Peter Xu <peterx@...hat.com>
Subject: Re: [PATCH v1 07/11] KVM: VMX: optimize APIC ID read with APICv



On 30/06/2016 22:54, Radim Krčmář wrote:
> The register is in hardware-compatible format now, so there is not need
> to intercept.
> 
> Signed-off-by: Radim Krčmář <rkrcmar@...hat.com>
> ---
>  v1: new, split from the previous patch
> 
>  arch/x86/kvm/vmx.c | 3 ---
>  1 file changed, 3 deletions(-)
> 
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 85e2f0a882ca..a10038258b80 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -6447,9 +6447,6 @@ static __init int hardware_setup(void)
>  	for (msr = 0x800; msr <= 0x8ff; msr++)
>  		vmx_disable_intercept_msr_read_x2apic(msr);
>  
> -	/* According SDM, in x2apic mode, the whole id reg is used.  But in
> -	 * KVM, it only use the highest eight bits. Need to intercept it */
> -	vmx_enable_intercept_msr_read_x2apic(0x802);
>  	/* TMCCT */
>  	vmx_enable_intercept_msr_read_x2apic(0x839);
>  	/* TPR */
> 

Reviewed-by: Paolo Bonzini <pbonzini@...hat.com>