KVM: x86/mmu: Capture TDP level when updating CPUID

Snapshot the TDP level now that it's invariant (SVM) or dependent only
on host capabilities and guest CPUID (VMX).  This avoids having to call
kvm_x86_ops.get_tdp_level() when initializing a TDP MMU and/or
calculating the page role, and thus avoids the associated retpoline.

Drop the WARN in vmx_get_tdp_level() as updating CPUID while L2 is
active is legal, if dodgy.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200502043234.12481-11-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Sean Christopherson
2020-05-01 21:32:34 -07:00
committed by Paolo Bonzini
parent 0047fcade4
commit e93fd3b3e8
5 changed files with 7 additions and 7 deletions

View File

@@ -4894,7 +4894,7 @@ kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu, bool base_only)
union kvm_mmu_role role = kvm_calc_mmu_role_common(vcpu, base_only);
role.base.ad_disabled = (shadow_accessed_mask == 0);
role.base.level = kvm_x86_ops.get_tdp_level(vcpu);
role.base.level = vcpu->arch.tdp_level;
role.base.direct = true;
role.base.gpte_is_8_bytes = true;
@@ -4915,7 +4915,7 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
context->sync_page = nonpaging_sync_page;
context->invlpg = NULL;
context->update_pte = nonpaging_update_pte;
context->shadow_root_level = kvm_x86_ops.get_tdp_level(vcpu);
context->shadow_root_level = vcpu->arch.tdp_level;
context->direct_map = true;
context->get_guest_pgd = get_cr3;
context->get_pdptr = kvm_pdptr_read;
@@ -5680,7 +5680,7 @@ static int alloc_mmu_pages(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu)
* SVM's 32-bit NPT support, TDP paging doesn't use PAE paging and can
* skip allocating the PDP table.
*/
if (tdp_enabled && kvm_x86_ops.get_tdp_level(vcpu) > PT32E_ROOT_LEVEL)
if (tdp_enabled && vcpu->arch.tdp_level > PT32E_ROOT_LEVEL)
return 0;
page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_DMA32);