linux-kernel - [PATCH v3 2/9] KVM: nSVM: stop dereferencing vcpu->arch.mmu to get the context in kvm_init_shadow{,_npt}

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu,  9 Jul 2020 16:53:51 +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 v3 2/9] KVM: nSVM: stop dereferencing vcpu->arch.mmu to get the context in kvm_init_shadow{,_npt}_mmu()

Now as kvm_init_shadow_npt_mmu() is separated from kvm_init_shadow_mmu()
we always know the MMU context we need to use so there is no need to
dereference vcpu->arch.mmu pointer.

Suggested-by: Paolo Bonzini <pbonzini@...hat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@...hat.com>
---
 arch/x86/kvm/mmu/mmu.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 93f18e5fa8b5..69fa51af8cbf 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4952,11 +4952,10 @@ kvm_calc_shadow_mmu_root_page_role(struct kvm_vcpu *vcpu, bool base_only)
 	return role;
 }
 
-static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, u32 cr0, u32 cr4,
-				    u32 efer, union kvm_mmu_role new_role)
+static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *context,
+				    u32 cr0, u32 cr4, u32 efer,
+				    union kvm_mmu_role new_role)
 {
-	struct kvm_mmu *context = vcpu->arch.mmu;
-
 	if (!(cr0 & X86_CR0_PG))
 		nonpaging_init_context(vcpu, context);
 	else if (efer & EFER_LMA)
@@ -4972,23 +4971,23 @@ static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, u32 cr0, u32 cr4,
 
 static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, u32 cr0, u32 cr4, u32 efer)
 {
-	struct kvm_mmu *context = vcpu->arch.mmu;
+	struct kvm_mmu *context = &vcpu->arch.root_mmu;
 	union kvm_mmu_role new_role =
 		kvm_calc_shadow_mmu_root_page_role(vcpu, false);
 
 	if (new_role.as_u64 != context->mmu_role.as_u64)
-		shadow_mmu_init_context(vcpu, cr0, cr4, efer, new_role);
+		shadow_mmu_init_context(vcpu, context, cr0, cr4, efer, new_role);
 }
 
 void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, u32 cr0, u32 cr4, u32 efer,
 			     gpa_t nested_cr3)
 {
-	struct kvm_mmu *context = vcpu->arch.mmu;
+	struct kvm_mmu *context = &vcpu->arch.guest_mmu;
 	union kvm_mmu_role new_role =
 		kvm_calc_shadow_mmu_root_page_role(vcpu, false);
 
 	if (new_role.as_u64 != context->mmu_role.as_u64)
-		shadow_mmu_init_context(vcpu, cr0, cr4, efer, new_role);
+		shadow_mmu_init_context(vcpu, context, cr0, cr4, efer, new_role);
 }
 EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu);
 
-- 
2.25.4