Message-ID: <479A56B2.7010306@codemonkey.ws>
Date: Fri, 25 Jan 2008 15:37:54 -0600
From: Anthony Liguori <anthony@codemonkey.ws>
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To: Joerg Roedel <joerg.roedel@amd.com>
CC: Avi Kivity <avi@qumranet.com>, kvm-devel@lists.sourceforge.net,
       linux-kernel@vger.kernel.org
Subject: Re: [kvm-devel] [PATCH 4/8] X86: export information about NPT to
 generic x86 code
References: <1201294393-22613-1-git-send-email-joerg.roedel@amd.com> <1201294393-22613-5-git-send-email-joerg.roedel@amd.com>
In-Reply-To: <1201294393-22613-5-git-send-email-joerg.roedel@amd.com>
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Joerg Roedel wrote:
> The generic x86 code has to know if the specific implementation uses Nested
> Paging. In the generic code Nested Paging is called Hardware Assisted Paging
> (HAP) to avoid confusion with (future) HAP implementations of other vendors.
> This patch exports the availability of HAP to the generic x86 code.
>
> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
> ---
>  arch/x86/kvm/svm.c         |    7 +++++++
>  arch/x86/kvm/vmx.c         |    7 +++++++
>  include/asm-x86/kvm_host.h |    2 ++
>  3 files changed, 16 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 2e718ff..d0bfdd8 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -1678,6 +1678,11 @@ static bool svm_cpu_has_accelerated_tpr(void)
>  	return false;
>  }
>  
> +static bool svm_hap_enabled(void)
> +{
> +	return npt_enabled;
> +}
> +
>   

To help with bisecting, you should probably return false here until the 
patch that actually implements NPT support.  Otherwise, the 7th patch in 
this series breaks KVM for SVM.

Regards,

Anthony Liguori

>  static struct kvm_x86_ops svm_x86_ops = {
>  	.cpu_has_kvm_support = has_svm,
>  	.disabled_by_bios = is_disabled,
> @@ -1734,6 +1739,8 @@ static struct kvm_x86_ops svm_x86_ops = {
>  	.inject_pending_vectors = do_interrupt_requests,
>  
>  	.set_tss_addr = svm_set_tss_addr,
> +
> +	.hap_enabled = svm_hap_enabled,
>  };
>  
>  static int __init svm_init(void)
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 00a00e4..8feb775 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -2631,6 +2631,11 @@ static void __init vmx_check_processor_compat(void *rtn)
>  	}
>  }
>  
> +static bool vmx_hap_enabled(void)
> +{
> +	return false;
> +}
> +
>  static struct kvm_x86_ops vmx_x86_ops = {
>  	.cpu_has_kvm_support = cpu_has_kvm_support,
>  	.disabled_by_bios = vmx_disabled_by_bios,
> @@ -2688,6 +2693,8 @@ static struct kvm_x86_ops vmx_x86_ops = {
>  	.inject_pending_vectors = do_interrupt_requests,
>  
>  	.set_tss_addr = vmx_set_tss_addr,
> +
> +	.hap_enabled = vmx_hap_enabled,
>  };
>  
>  static int __init vmx_init(void)
> diff --git a/include/asm-x86/kvm_host.h b/include/asm-x86/kvm_host.h
> index 67ae307..45a9d05 100644
> --- a/include/asm-x86/kvm_host.h
> +++ b/include/asm-x86/kvm_host.h
> @@ -392,6 +392,8 @@ struct kvm_x86_ops {
>  				       struct kvm_run *run);
>  
>  	int (*set_tss_addr)(struct kvm *kvm, unsigned int addr);
> +
> +	bool (*hap_enabled)(void);
>  };
>  
>  extern struct kvm_x86_ops *kvm_x86_ops;
>   

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