linux-kernel - [PATCH 18/54] KVM: x86/mmu: Move nested NPT reserved bit calculation into MMU proper

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 for Android: free password hash cracker in your pocket

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

Message-Id: <20210622175739.3610207-19-seanjc@google.com>
Date:   Tue, 22 Jun 2021 10:57:03 -0700
From:   Sean Christopherson <seanjc@...gle.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Yu Zhang <yu.c.zhang@...ux.intel.com>,
        Maxim Levitsky <mlevitsk@...hat.com>
Subject: [PATCH 18/54] KVM: x86/mmu: Move nested NPT reserved bit calculation
 into MMU proper

Move nested NPT's invocation of reset_shadow_zero_bits_mask() into the
MMU proper and unexport said function.  Aside from dropping an export,
this is a baby step toward eliminating the call entirely by fixing the
shadow_root_level confusion.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/mmu.h        |  3 ---
 arch/x86/kvm/mmu/mmu.c    | 11 ++++++++---
 arch/x86/kvm/svm/nested.c |  1 -
 3 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 4e926f4935b0..62844bacd13f 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -68,9 +68,6 @@ static __always_inline u64 rsvd_bits(int s, int e)
 void kvm_mmu_set_mmio_spte_mask(u64 mmio_value, u64 mmio_mask, u64 access_mask);
 void kvm_mmu_set_ept_masks(bool has_ad_bits, bool has_exec_only);
 
-void
-reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, struct kvm_mmu *context);
-
 void kvm_init_mmu(struct kvm_vcpu *vcpu);
 void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0,
 			     unsigned long cr4, u64 efer, gpa_t nested_cr3);
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 02c54426e7a2..5a46a87b23b0 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4212,8 +4212,8 @@ static inline u64 reserved_hpa_bits(void)
  * table in guest or amd nested guest, its mmu features completely
  * follow the features in guest.
  */
-void
-reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, struct kvm_mmu *context)
+static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu,
+					struct kvm_mmu *context)
 {
 	/*
 	 * KVM uses NX when TDP is disabled to handle a variety of scenarios,
@@ -4247,7 +4247,6 @@ reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, struct kvm_mmu *context)
 	}
 
 }
-EXPORT_SYMBOL_GPL(reset_shadow_zero_bits_mask);
 
 static inline bool boot_cpu_is_amd(void)
 {
@@ -4714,6 +4713,12 @@ void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0,
 		 */
 		context->shadow_root_level = new_role.base.level;
 	}
+
+	/*
+	 * Redo the shadow bits, the reset done by shadow_mmu_init_context()
+	 * (above) may use the wrong shadow_root_level.
+	 */
+	reset_shadow_zero_bits_mask(vcpu, context);
 }
 EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu);
 
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 33b2f9337e26..927e545591c3 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -110,7 +110,6 @@ static void nested_svm_init_mmu_context(struct kvm_vcpu *vcpu)
 	vcpu->arch.mmu->get_guest_pgd     = nested_svm_get_tdp_cr3;
 	vcpu->arch.mmu->get_pdptr         = nested_svm_get_tdp_pdptr;
 	vcpu->arch.mmu->inject_page_fault = nested_svm_inject_npf_exit;
-	reset_shadow_zero_bits_mask(vcpu, vcpu->arch.mmu);
 	vcpu->arch.walk_mmu              = &vcpu->arch.nested_mmu;
 }
 
-- 
2.32.0.288.g62a8d224e6-goog