diff options
| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2020-04-15 13:34:50 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-04-21 09:13:06 -0400 |
| commit | 9932b49e5abef0218254d15b8278e3dbee5ceea3 (patch) | |
| tree | 1fd2a3cae927158f857660b31856e3a9cbaab90f /arch/x86 | |
| parent | 4dcefa312a6c1cc2aa2dd8a9ba76d97d63b3bd17 (diff) | |
KVM: nVMX: Invoke ept_save_pdptrs() if and only if PAE paging is enabled
Invoke ept_save_pdptrs() when restoring L1's host state on a "late"
VM-Fail if and only if PAE paging is enabled. This saves a CALL in the
common case where L1 is a 64-bit host, and avoids incorrectly marking
the PDPTRs as dirty.
WARN if ept_save_pdptrs() is called with PAE disabled now that the
nested usage pre-checks is_pae_paging(). Barring a bug in KVM's MMU,
attempting to read the PDPTRs with PAE disabled is now impossible.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200415203454.8296-2-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/vmx/nested.c | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 13 |
2 files changed, 8 insertions, 7 deletions
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 6f303ccd478d..5a214cbf243c 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -4250,7 +4250,7 @@ static void nested_vmx_restore_host_state(struct kvm_vcpu *vcpu) * VMFail, like everything else we just need to ensure our * software model is up-to-date. */ - if (enable_ept) + if (enable_ept && is_pae_paging(vcpu)) ept_save_pdptrs(vcpu); kvm_mmu_reset_context(vcpu); diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 19a82f846e8e..f9bee922f1e6 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -2937,12 +2937,13 @@ void ept_save_pdptrs(struct kvm_vcpu *vcpu) { struct kvm_mmu *mmu = vcpu->arch.walk_mmu; - if (is_pae_paging(vcpu)) { - mmu->pdptrs[0] = vmcs_read64(GUEST_PDPTR0); - mmu->pdptrs[1] = vmcs_read64(GUEST_PDPTR1); - mmu->pdptrs[2] = vmcs_read64(GUEST_PDPTR2); - mmu->pdptrs[3] = vmcs_read64(GUEST_PDPTR3); - } + if (WARN_ON_ONCE(!is_pae_paging(vcpu))) + return; + + mmu->pdptrs[0] = vmcs_read64(GUEST_PDPTR0); + mmu->pdptrs[1] = vmcs_read64(GUEST_PDPTR1); + mmu->pdptrs[2] = vmcs_read64(GUEST_PDPTR2); + mmu->pdptrs[3] = vmcs_read64(GUEST_PDPTR3); kvm_register_mark_dirty(vcpu, VCPU_EXREG_PDPTR); } |