Re: [PATCH 5/6] Nested SVM: Implement INVLPGA

[Joerg Roedel <joerg.roedel@amd.com>]

On Fri, May 15, 2009 at 10:22:19AM +0200, Alexander Graf wrote:
> SVM adds another way to do INVLPG by ASID which Hyper-V makes use of,
> so let's implement it!
> 
> For now we just do the same thing invlpg does, as asid switching
> means we flush the mmu anyways. That might change one day though.
> 
> Signed-off-by: Alexander Graf <agraf@suse.de>
> ---
>  arch/x86/kvm/svm.c |   14 +++++++++++++-
>  1 files changed, 13 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 30e6b43..b2c6cf3 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -1785,6 +1785,18 @@ static int clgi_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
>  	return 1;
>  }
>  
> +static int invlpga_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
> +{
> +	struct kvm_vcpu *vcpu = &svm->vcpu;
> +	nsvm_printk("INVLPGA\n");
> +	svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
> +	skip_emulated_instruction(&svm->vcpu);
> +
> +	kvm_mmu_reset_context(vcpu);
> +	kvm_mmu_load(vcpu);
> +	return 1;
> +}
> +

Hmm, since we flush the TLB on every nested-guest entry I think we can
make this function a nop.

>  static int invalid_op_interception(struct vcpu_svm *svm,
>  				   struct kvm_run *kvm_run)
>  {
> @@ -2130,7 +2142,7 @@ static int (*svm_exit_handlers[])(struct vcpu_svm *svm,
>  	[SVM_EXIT_INVD]                         = emulate_on_interception,
>  	[SVM_EXIT_HLT]				= halt_interception,
>  	[SVM_EXIT_INVLPG]			= invlpg_interception,
> -	[SVM_EXIT_INVLPGA]			= invalid_op_interception,
> +	[SVM_EXIT_INVLPGA]			= invlpga_interception,
>  	[SVM_EXIT_IOIO] 		  	= io_interception,
>  	[SVM_EXIT_MSR]				= msr_interception,
>  	[SVM_EXIT_TASK_SWITCH]			= task_switch_interception,
> -- 
> 1.6.0.2
> 
> 

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