From bcb72d0627e8a3e531021c9bd2a14fae8da63ef3 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Mon, 7 Jun 2021 12:01:56 +0300 Subject: [PATCH] KVM: nVMX: Drop obsolete (and pointless) pdptrs_changed() check Remove the pdptrs_changed() check when loading L2's CR3. The set of available registers is always reset when switching VMCSes (see commit e5d03de5937e, "KVM: nVMX: Reset register cache (available and dirty masks) on VMCS switch"), thus the "are PDPTRs available" check will always fail. And even if it didn't fail, reading guest memory to check the PDPTRs is just as expensive as reading guest memory to load 'em. Signed-off-by: Sean Christopherson Message-Id: <20210607090203.133058-2-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx/nested.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index e77b8ee28df8..47f4aa609778 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -1118,11 +1118,9 @@ static int nested_vmx_load_cr3(struct kvm_vcpu *vcpu, unsigned long cr3, bool ne * must not be dereferenced. */ if (!nested_ept && is_pae_paging(vcpu) && - (cr3 != kvm_read_cr3(vcpu) || pdptrs_changed(vcpu))) { - if (CC(!load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3))) { - *entry_failure_code = ENTRY_FAIL_PDPTE; - return -EINVAL; - } + CC(!load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3))) { + *entry_failure_code = ENTRY_FAIL_PDPTE; + return -EINVAL; } /* -- 2.39.5