linux-kernel - Re: [PATCH] KVM: nVMX: Disable unrestricted mode if ept=0

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: <54842A61.5080006@web.de>
Date:	Sun, 07 Dec 2014 11:22:25 +0100
From:	Jan Kiszka <jan.kiszka@....de>
To:	Bandan Das <bsd@...hat.com>, kvm@...r.kernel.org
CC:	pbonzini@...hat.com, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] KVM: nVMX: Disable unrestricted mode if ept=0

On 2014-12-06 16:02, Bandan Das wrote:
> 
> If L0 has disabled EPT, don't advertise unrestricted
> mode at all since it depends on EPT to run real mode code.
> 
> Signed-off-by: Bandan Das <bsd@...hat.com>
> ---
>  arch/x86/kvm/vmx.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 3e556c6..ed70394 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -2377,12 +2377,12 @@ static __init void nested_vmx_setup_ctls_msrs(void)
>  	nested_vmx_secondary_ctls_low = 0;
>  	nested_vmx_secondary_ctls_high &=
>  		SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
> -		SECONDARY_EXEC_UNRESTRICTED_GUEST |
>  		SECONDARY_EXEC_WBINVD_EXITING;
>  
>  	if (enable_ept) {
>  		/* nested EPT: emulate EPT also to L1 */
> -		nested_vmx_secondary_ctls_high |= SECONDARY_EXEC_ENABLE_EPT;
> +		nested_vmx_secondary_ctls_high |= SECONDARY_EXEC_ENABLE_EPT |
> +			SECONDARY_EXEC_UNRESTRICTED_GUEST;
>  		nested_vmx_ept_caps = VMX_EPT_PAGE_WALK_4_BIT |
>  			 VMX_EPTP_WB_BIT | VMX_EPT_2MB_PAGE_BIT |
>  			 VMX_EPT_INVEPT_BIT;
> 

Reviewed-by: Jan Kiszka <jan.kiszka@...mens.com>

Jan



Download attachment "signature.asc" of type "application/pgp-signature" (199 bytes)