From bf627a9288372d065f157ea445d11b900575193e Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Mon, 8 Oct 2018 21:28:13 +0200 Subject: x86/kvm/mmu: check if MMU reconfiguration is needed in init_kvm_nested_mmu() We don't use root page role for nested_mmu, however, optimizing out re-initialization in case nothing changed is still valuable as this is done for every nested vmentry. Signed-off-by: Vitaly Kuznetsov Reviewed-by: Sean Christopherson Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch/x86/kvm') diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 9ed046fbab5e..c73d9f650de7 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -4936,8 +4936,14 @@ static void init_kvm_softmmu(struct kvm_vcpu *vcpu) static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu) { + union kvm_mmu_role new_role = kvm_calc_mmu_role_common(vcpu, false); struct kvm_mmu *g_context = &vcpu->arch.nested_mmu; + new_role.base.word &= mmu_base_role_mask.word; + if (new_role.as_u64 == g_context->mmu_role.as_u64) + return; + + g_context->mmu_role.as_u64 = new_role.as_u64; g_context->get_cr3 = get_cr3; g_context->get_pdptr = kvm_pdptr_read; g_context->inject_page_fault = kvm_inject_page_fault; -- cgit v1.2.3-59-g8ed1b