From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Ben Gardon <bgardon@google.com>,
Brijesh Singh <brijesh.singh@amd.com>,
Tom Lendacky <thomas.lendacky@amd.com>
Subject: [PATCH 05/15] KVM: x86/mmu: Check PDPTRs before allocating PAE roots
Date: Tue, 2 Mar 2021 10:45:30 -0800 [thread overview]
Message-ID: <20210302184540.2829328-6-seanjc@google.com> (raw)
In-Reply-To: <20210302184540.2829328-1-seanjc@google.com>
Check the validity of the PDPTRs before allocating any of the PAE roots,
otherwise a bad PDPTR will cause KVM to leak any previously allocated
roots.
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/mmu/mmu.c | 20 ++++++++++++++------
1 file changed, 14 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index e5c3701112f8..aa20e8d32197 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3262,7 +3262,7 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu)
static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
{
- u64 pdptr, pm_mask;
+ u64 pdptrs[4], pm_mask;
gfn_t root_gfn, root_pgd;
hpa_t root;
int i;
@@ -3273,6 +3273,17 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
if (mmu_check_root(vcpu, root_gfn))
return 1;
+ if (vcpu->arch.mmu->root_level == PT32E_ROOT_LEVEL) {
+ for (i = 0; i < 4; ++i) {
+ pdptrs[i] = vcpu->arch.mmu->get_pdptr(vcpu, i);
+ if (!(pdptrs[i] & PT_PRESENT_MASK))
+ continue;
+
+ if (mmu_check_root(vcpu, pdptrs[i] >> PAGE_SHIFT))
+ return 1;
+ }
+ }
+
/*
* Do we shadow a long mode page table? If so we need to
* write-protect the guests page table root.
@@ -3331,14 +3342,11 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
MMU_WARN_ON(VALID_PAGE(vcpu->arch.mmu->pae_root[i]));
if (vcpu->arch.mmu->root_level == PT32E_ROOT_LEVEL) {
- pdptr = vcpu->arch.mmu->get_pdptr(vcpu, i);
- if (!(pdptr & PT_PRESENT_MASK)) {
+ if (!(pdptrs[i] & PT_PRESENT_MASK)) {
vcpu->arch.mmu->pae_root[i] = 0;
continue;
}
- root_gfn = pdptr >> PAGE_SHIFT;
- if (mmu_check_root(vcpu, root_gfn))
- return 1;
+ root_gfn = pdptrs[i] >> PAGE_SHIFT;
}
root = mmu_alloc_root(vcpu, root_gfn, i << 30,
--
2.30.1.766.gb4fecdf3b7-goog
next prev parent reply other threads:[~2021-03-02 22:08 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-02 18:45 [PATCH 00/15] KVM: x86/mmu: Lots of bug fixes Sean Christopherson
2021-03-02 18:45 ` [PATCH 01/15] KVM: nSVM: Set the shadow root level to the TDP level for nested NPT Sean Christopherson
2021-03-02 18:45 ` [PATCH 02/15] KVM: x86/mmu: Alloc page for PDPTEs when shadowing 32-bit NPT with 64-bit Sean Christopherson
2021-03-03 17:28 ` Ben Gardon
2021-03-02 18:45 ` [PATCH 03/15] KVM: x86/mmu: Ensure MMU pages are available when allocating roots Sean Christopherson
2021-03-03 0:21 ` Ben Gardon
2021-03-03 16:46 ` Sean Christopherson
2021-03-02 18:45 ` [PATCH 04/15] KVM: x86/mmu: Allocate the lm_root before allocating PAE roots Sean Christopherson
2021-03-02 18:45 ` Sean Christopherson [this message]
2021-03-02 18:45 ` [PATCH 06/15] KVM: x86/mmu: Fix and unconditionally enable WARNs to detect PAE leaks Sean Christopherson
2021-03-02 18:45 ` [PATCH 07/15] KVM: x86/mmu: Use '0' as the one and only value for an invalid PAE root Sean Christopherson
2021-03-02 18:45 ` [PATCH 08/15] KVM: x86/mmu: Set the C-bit in the PDPTRs and LM pseudo-PDPTRs Sean Christopherson
2021-03-02 18:45 ` [PATCH 09/15] KVM: x86/mmu: Mark the PAE roots as decrypted for shadow paging Sean Christopherson
2021-03-02 18:45 ` [PATCH 10/15] KVM: SVM: Don't strip the C-bit from CR2 on #PF interception Sean Christopherson
2021-03-02 18:45 ` [PATCH 11/15] KVM: nVMX: Defer the MMU reload to the normal path on an EPTP switch Sean Christopherson
2021-03-02 18:45 ` [PATCH 12/15] KVM: x86: Defer the MMU unload to the normal path on an global INVPCID Sean Christopherson
2021-03-02 18:45 ` [PATCH 13/15] KVM: x86/mmu: Unexport MMU load/unload functions Sean Christopherson
2021-03-02 18:45 ` [PATCH 14/15] KVM: x86/mmu: Sync roots after MMU load iff load as successful Sean Christopherson
2021-03-02 18:45 ` [PATCH 15/15] KVM: x86/mmu: WARN on NULL pae_root and bad shadow root level Sean Christopherson
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