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| author | Tom Lendacky <thomas.lendacky@amd.com> | 2020-12-10 11:09:43 -0600 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-12-15 05:20:46 -0500 |
| commit | 8d4846b9b15045598d760470789716fb08b9b317 (patch) | |
| tree | 13e227a9cbb6cd9b3f677462cef8c24ee7f61567 /arch/x86/kvm/svm | |
| parent | f1c6366e304328de301be362eca905a3503ff33b (diff) | |
| download | linux-8d4846b9b15045598d760470789716fb08b9b317.tar.bz2 | |
KVM: SVM: Prevent debugging under SEV-ES
Since the guest register state of an SEV-ES guest is encrypted, debugging
is not supported. Update the code to prevent guest debugging when the
guest has protected state.
Additionally, an SEV-ES guest must only and always intercept DR7 reads and
writes. Update set_dr_intercepts() and clr_dr_intercepts() to account for
this.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <8db966fa2f9803d6454ce773863025d0e2e7f3cc.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/svm')
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 9 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/svm.h | 37 |
2 files changed, 32 insertions, 14 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index db81fb131033..bec427acab20 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1805,6 +1805,9 @@ static void svm_set_dr6(struct vcpu_svm *svm, unsigned long value) { struct vmcb *vmcb = svm->vmcb; + if (svm->vcpu.arch.guest_state_protected) + return; + if (unlikely(value != vmcb->save.dr6)) { vmcb->save.dr6 = value; vmcb_mark_dirty(vmcb, VMCB_DR); @@ -1815,6 +1818,9 @@ static void svm_sync_dirty_debug_regs(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); + if (vcpu->arch.guest_state_protected) + return; + get_debugreg(vcpu->arch.db[0], 0); get_debugreg(vcpu->arch.db[1], 1); get_debugreg(vcpu->arch.db[2], 2); @@ -1833,6 +1839,9 @@ static void svm_set_dr7(struct kvm_vcpu *vcpu, unsigned long value) { struct vcpu_svm *svm = to_svm(vcpu); + if (vcpu->arch.guest_state_protected) + return; + svm->vmcb->save.dr7 = value; vmcb_mark_dirty(svm->vmcb, VMCB_DR); } diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index f96a0a66ca35..abfe53d6b3dc 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -272,21 +272,24 @@ static inline void set_dr_intercepts(struct vcpu_svm *svm) { struct vmcb *vmcb = get_host_vmcb(svm); - vmcb_set_intercept(&vmcb->control, INTERCEPT_DR0_READ); - vmcb_set_intercept(&vmcb->control, INTERCEPT_DR1_READ); - vmcb_set_intercept(&vmcb->control, INTERCEPT_DR2_READ); - vmcb_set_intercept(&vmcb->control, INTERCEPT_DR3_READ); - vmcb_set_intercept(&vmcb->control, INTERCEPT_DR4_READ); - vmcb_set_intercept(&vmcb->control, INTERCEPT_DR5_READ); - vmcb_set_intercept(&vmcb->control, INTERCEPT_DR6_READ); + if (!sev_es_guest(svm->vcpu.kvm)) { + vmcb_set_intercept(&vmcb->control, INTERCEPT_DR0_READ); + vmcb_set_intercept(&vmcb->control, INTERCEPT_DR1_READ); + vmcb_set_intercept(&vmcb->control, INTERCEPT_DR2_READ); + vmcb_set_intercept(&vmcb->control, INTERCEPT_DR3_READ); + vmcb_set_intercept(&vmcb->control, INTERCEPT_DR4_READ); + vmcb_set_intercept(&vmcb->control, INTERCEPT_DR5_READ); + vmcb_set_intercept(&vmcb->control, INTERCEPT_DR6_READ); + vmcb_set_intercept(&vmcb->control, INTERCEPT_DR0_WRITE); + vmcb_set_intercept(&vmcb->control, INTERCEPT_DR1_WRITE); + vmcb_set_intercept(&vmcb->control, INTERCEPT_DR2_WRITE); + vmcb_set_intercept(&vmcb->control, INTERCEPT_DR3_WRITE); + vmcb_set_intercept(&vmcb->control, INTERCEPT_DR4_WRITE); + vmcb_set_intercept(&vmcb->control, INTERCEPT_DR5_WRITE); + vmcb_set_intercept(&vmcb->control, INTERCEPT_DR6_WRITE); + } + vmcb_set_intercept(&vmcb->control, INTERCEPT_DR7_READ); - vmcb_set_intercept(&vmcb->control, INTERCEPT_DR0_WRITE); - vmcb_set_intercept(&vmcb->control, INTERCEPT_DR1_WRITE); - vmcb_set_intercept(&vmcb->control, INTERCEPT_DR2_WRITE); - vmcb_set_intercept(&vmcb->control, INTERCEPT_DR3_WRITE); - vmcb_set_intercept(&vmcb->control, INTERCEPT_DR4_WRITE); - vmcb_set_intercept(&vmcb->control, INTERCEPT_DR5_WRITE); - vmcb_set_intercept(&vmcb->control, INTERCEPT_DR6_WRITE); vmcb_set_intercept(&vmcb->control, INTERCEPT_DR7_WRITE); recalc_intercepts(svm); @@ -298,6 +301,12 @@ static inline void clr_dr_intercepts(struct vcpu_svm *svm) vmcb->control.intercepts[INTERCEPT_DR] = 0; + /* DR7 access must remain intercepted for an SEV-ES guest */ + if (sev_es_guest(svm->vcpu.kvm)) { + vmcb_set_intercept(&vmcb->control, INTERCEPT_DR7_READ); + vmcb_set_intercept(&vmcb->control, INTERCEPT_DR7_WRITE); + } + recalc_intercepts(svm); } |