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Date: Wed, 8 Jul 2020 11:36:11 +0200 From: Vitaly Kuznetsov <vkuznets@...hat.com> To: kvm@...r.kernel.org, Paolo Bonzini <pbonzini@...hat.com> Cc: Sean Christopherson <sean.j.christopherson@...el.com>, Wanpeng Li <wanpengli@...cent.com>, Jim Mattson <jmattson@...gle.com>, Junaid Shahid <junaids@...gle.com>, linux-kernel@...r.kernel.org Subject: [PATCH v2 3/3] KVM: x86: drop superfluous mmu_check_root() from fast_pgd_switch() The mmu_check_root() check in fast_pgd_switch() seems to be superfluous: when GPA is outside of the visible range cached_root_available() will fail for non-direct roots (as we can't have a matching one on the list) and we don't seem to care for direct ones. Also, raising #TF immediately when a non-existent GFN is written to CR3 doesn't seem to mach architectural behavior. Drop the check. Signed-off-by: Vitaly Kuznetsov <vkuznets@...hat.com> --- arch/x86/kvm/mmu/mmu.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index ebf0cb3f1ce0..16c7701f1741 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -4277,8 +4277,7 @@ static bool fast_pgd_switch(struct kvm_vcpu *vcpu, gpa_t new_pgd, */ if (mmu->shadow_root_level >= PT64_ROOT_4LEVEL && mmu->root_level >= PT64_ROOT_4LEVEL) - return !mmu_check_root(vcpu, new_pgd >> PAGE_SHIFT) && - cached_root_available(vcpu, new_pgd, new_role); + return cached_root_available(vcpu, new_pgd, new_role); return false; } -- 2.25.4
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