From: Oliver Upton <oupton@google.com>
To: kvm@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Jim Mattson <jmattson@google.com>,
Peter Shier <pshier@google.com>,
Sean Christopherson <sean.j.christopherson@intel.com>,
Oliver Upton <oupton@google.com>
Subject: [PATCH v2 2/5] KVM: nVMX: Handle pending #DB when injecting INIT VM-exit
Date: Tue, 28 Jan 2020 01:27:12 -0800 [thread overview]
Message-ID: <20200128092715.69429-3-oupton@google.com> (raw)
In-Reply-To: <20200128092715.69429-1-oupton@google.com>
SDM 27.3.4 states that the 'pending debug exceptions' VMCS field will
be populated if a VM-exit caused by an INIT signal takes priority over a
debug-trap. Emulate this behavior when synthesizing an INIT signal
VM-exit into L1.
Fixes: 558b8d50dbff ("KVM: x86: Fix INIT signal handling in various CPU states")
Signed-off-by: Oliver Upton <oupton@google.com>
---
arch/x86/kvm/vmx/nested.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 95b3f4306ac2..aba16599ca69 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -3572,6 +3572,27 @@ static void nested_vmx_inject_exception_vmexit(struct kvm_vcpu *vcpu,
nested_vmx_vmexit(vcpu, EXIT_REASON_EXCEPTION_NMI, intr_info, exit_qual);
}
+static inline bool nested_vmx_check_pending_dbg(struct kvm_vcpu *vcpu)
+{
+ return vcpu->arch.exception.nr == DB_VECTOR &&
+ vcpu->arch.exception.pending &&
+ vcpu->arch.exception.has_payload;
+}
+
+/*
+ * If a higher priority VM-exit is delivered before a debug-trap, hardware will
+ * set the 'pending debug exceptions' field appropriately for reinjection on the
+ * next VM-entry.
+ */
+static void nested_vmx_set_pending_dbg(struct kvm_vcpu *vcpu)
+{
+ vmcs_writel(GUEST_PENDING_DBG_EXCEPTIONS, vcpu->arch.exception.payload);
+ vcpu->arch.exception.has_payload = false;
+ vcpu->arch.exception.payload = 0;
+ vcpu->arch.exception.pending = false;
+ vcpu->arch.exception.injected = true;
+}
+
static int vmx_check_nested_events(struct kvm_vcpu *vcpu, bool external_intr)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
@@ -3584,6 +3605,8 @@ static int vmx_check_nested_events(struct kvm_vcpu *vcpu, bool external_intr)
test_bit(KVM_APIC_INIT, &apic->pending_events)) {
if (block_nested_events)
return -EBUSY;
+ if (nested_vmx_check_pending_dbg(vcpu))
+ nested_vmx_set_pending_dbg(vcpu);
clear_bit(KVM_APIC_INIT, &apic->pending_events);
nested_vmx_vmexit(vcpu, EXIT_REASON_INIT_SIGNAL, 0, 0);
return 0;
--
2.25.0.341.g760bfbb309-goog
next prev parent reply other threads:[~2020-01-28 9:27 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-28 9:27 [PATCH v2 0/5] Handle monitor trap flag during instruction emulation Oliver Upton
2020-01-28 9:27 ` [PATCH v2 1/5] KVM: x86: Mask off reserved bit from #DB exception payload Oliver Upton
2020-01-28 9:27 ` Oliver Upton [this message]
2020-02-03 19:13 ` [PATCH v2 2/5] KVM: nVMX: Handle pending #DB when injecting INIT VM-exit Sean Christopherson
2020-02-03 23:00 ` Sean Christopherson
2020-01-28 9:27 ` [PATCH v2 3/5] KVM: x86: Deliver exception payload on KVM_GET_VCPU_EVENTS Oliver Upton
2020-02-03 19:48 ` Sean Christopherson
2020-01-28 9:27 ` [PATCH v2 4/5] KVM: nVMX: Emulate MTF when performing instruction emulation Oliver Upton
2020-02-03 22:58 ` Sean Christopherson
2020-02-06 10:42 ` Oliver Upton
2021-08-13 0:23 ` Jim Mattson
2021-08-13 16:35 ` Sean Christopherson
2021-08-13 17:03 ` Jim Mattson
2020-01-28 9:27 ` [kvm-unit-tests PATCH v2 5/5] x86: VMX: Add tests for monitor trap flag Oliver Upton
2020-01-28 9:39 ` [PATCH v2 0/5] Handle monitor trap flag during instruction emulation Oliver Upton
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