Re: [PATCH 2/2] KVM: MMU: Use base_role.nxe for mmu.nx

Marcelo Tosatti
2010-09-14T22:56:48Z

On Tue, Sep 14, 2010 at 05:46:13PM +0200, Joerg Roedel wrote:
> This patch removes the mmu.nx field and uses the equivalent
> field mmu.base_role.nxe instead.
>
> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
> ---
> arch/x86/include/asm/kvm_host.h | 2 --
> arch/x86/kvm/mmu.c | 27 +++++++++++++--------------
> arch/x86/kvm/paging_tmpl.h | 4 ++--
> arch/x86/kvm/x86.c | 3 ---
> 4 files changed, 15 insertions(+), 21 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 8a83177..50506be 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -259,8 +259,6 @@ struct kvm_mmu {
> u64 *lm_root;
> u64 rsvd_bits_mask[2][4];
>
> - bool nx;
> -
> u64 pdptrs[4]; /* pae */
> };
>
> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
> index 3ce56bf..21d2983 100644
> --- a/arch/x86/kvm/mmu.c
> +++ b/arch/x86/kvm/mmu.c
> @@ -238,7 +238,7 @@ static int is_cpuid_PSE36(void)
>
> static int is_nx(struct kvm_vcpu *vcpu)
> {
> - return vcpu->arch.efer & EFER_NX;
> + return !!(vcpu->arch.efer & EFER_NX);
> }
>
> static int is_shadow_present_pte(u64 pte)
> @@ -2634,7 +2634,7 @@ static int nonpaging_init_context(struct kvm_vcpu *vcpu,
> context->shadow_root_level = PT32E_ROOT_LEVEL;
> context->root_hpa = INVALID_PAGE;
> context->direct_map = true;
> - context->nx = false;
> + context->base_role.nxe = 0;
> return 0;
> }
>
> @@ -2688,7 +2688,7 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu,
> int maxphyaddr = cpuid_maxphyaddr(vcpu);
> u64 exb_bit_rsvd = 0;
>
> - if (!context->nx)
> + if (!context->base_role.nxe)
> exb_bit_rsvd = rsvd_bits(63, 63);
> switch (level) {
> case PT32_ROOT_LEVEL:
> @@ -2747,7 +2747,7 @@ static int paging64_init_context_common(struct kvm_vcpu *vcpu,
> struct kvm_mmu *context,
> int level)
> {
> - context->nx = is_nx(vcpu);
> + context->base_role.nxe = is_nx(vcpu);
>
> reset_rsvds_bits_mask(vcpu, context, level);
>
> @@ -2775,7 +2775,7 @@ static int paging64_init_context(struct kvm_vcpu *vcpu,
> static int paging32_init_context(struct kvm_vcpu *vcpu,
> struct kvm_mmu *context)
> {
> - context->nx = false;
> + context->base_role.nxe = 0;
>
> reset_rsvds_bits_mask(vcpu, context, PT32_ROOT_LEVEL);
>
> @@ -2815,24 +2815,23 @@ static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
> context->set_cr3 = kvm_x86_ops->set_tdp_cr3;
> context->get_cr3 = get_cr3;
> context->inject_page_fault = kvm_inject_page_fault;
> - context->nx = is_nx(vcpu);
>
> if (!is_paging(vcpu)) {
> - context->nx = false;
> + context->base_role.nxe = 0;
> context->gva_to_gpa = nonpaging_gva_to_gpa;
> context->root_level = 0;
> } else if (is_long_mode(vcpu)) {
> - context->nx = is_nx(vcpu);
> + context->base_role.nxe = is_nx(vcpu);
> reset_rsvds_bits_mask(vcpu, context, PT64_ROOT_LEVEL);
> context->gva_to_gpa = paging64_gva_to_gpa;
> context->root_level = PT64_ROOT_LEVEL;
> } else if (is_pae(vcpu)) {
> - context->nx = is_nx(vcpu);
> + context->base_role.nxe = is_nx(vcpu);
> reset_rsvds_bits_mask(vcpu, context, PT32E_ROOT_LEVEL);
> context->gva_to_gpa = paging64_gva_to_gpa;
> context->root_level = PT32E_ROOT_LEVEL;
> } else {
> - context->nx = false;
> + context->base_role.nxe = 0;
> reset_rsvds_bits_mask(vcpu, context, PT32_ROOT_LEVEL);
> context->gva_to_gpa = paging32_gva_to_gpa;
> context->root_level = PT32_ROOT_LEVEL;

For tdp better set base_role.nxe to zero, otherwise duplicate tdp
pagetables can be created if the guest switches between nx/non-nx.