From: Melody Wang <[email protected]>

When Restricted Injection is active, only #HV exceptions can be injected
into the SEV-SNP guest.

Detect that, and then follow the #HV doorbell communication from the GHCB
specification to inject NMIs.

Co-developed-by: Thomas Lendacky <[email protected]>
Signed-off-by: Thomas Lendacky <[email protected]>
Signed-off-by: Melody Wang <[email protected]>
Signed-off-by: Joerg Roedel <[email protected]>
---
 arch/x86/kvm/svm/sev.c | 19 ++++++++++++++++---
 arch/x86/kvm/svm/svm.c |  8 ++++++++
 arch/x86/kvm/svm/svm.h |  1 +
 3 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index f2f40f81ba86..b48745fad8c5 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -5428,7 +5428,10 @@ static void __sev_snp_inject(enum inject_type type, 
struct kvm_vcpu *vcpu)
                return;
        }
 
-       hvdb->events.vector = vcpu->arch.interrupt.nr;
+       if (type == INJECT_NMI)
+               hvdb->events.nmi = 1;
+       else
+               hvdb->events.vector = vcpu->arch.interrupt.nr;
 
        prepare_hv_injection(svm, hvdb);
 
@@ -5508,10 +5511,17 @@ void sev_snp_cancel_injection(struct kvm_vcpu *vcpu)
        /* Copy info back into event_inj field (replaces #HV) */
        svm->vmcb->control.event_inj = SVM_EVTINJ_VALID;
 
+       /*
+        * KVM only injects a single event each time (prepare_hv_injection),
+        * so when events.nmi is true, the vector will be zero
+        */
        if (hvdb->events.vector)
                svm->vmcb->control.event_inj |= hvdb->events.vector |
                                                SVM_EVTINJ_TYPE_INTR;
 
+       if (hvdb->events.nmi)
+               svm->vmcb->control.event_inj |= SVM_EVTINJ_TYPE_NMI;
+
        hvdb->events.pending_events = 0;
 
 out:
@@ -5537,8 +5547,11 @@ bool sev_snp_blocked(enum inject_type type, struct 
kvm_vcpu *vcpu)
        if (!hvdb)
                return true;
 
-       /* Indicate interrupts blocked based on guest acknowledgment */
-       blocked = !!hvdb->events.vector;
+       /* Indicate NMIs and interrupts blocked based on guest acknowledgment */
+       if (type == INJECT_NMI)
+               blocked = hvdb->events.nmi;
+       else
+               blocked = !!hvdb->events.vector;
 
        unmap_hvdb(vcpu, &hvdb_map);
 
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 7253936c460c..5255393986cc 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3738,6 +3738,9 @@ static void svm_inject_nmi(struct kvm_vcpu *vcpu)
 {
        struct vcpu_svm *svm = to_svm(vcpu);
 
+       if (sev_snp_inject(INJECT_NMI, vcpu))
+               goto status;
+
        svm->vmcb->control.event_inj = SVM_EVTINJ_VALID | SVM_EVTINJ_TYPE_NMI;
 
        if (svm->nmi_l1_to_l2)
@@ -3752,6 +3755,8 @@ static void svm_inject_nmi(struct kvm_vcpu *vcpu)
                svm->nmi_masked = true;
                svm_set_iret_intercept(svm);
        }
+
+status:
        ++vcpu->stat.nmi_injections;
 }
 
@@ -3968,6 +3973,9 @@ bool svm_nmi_blocked(struct kvm_vcpu *vcpu)
        if (!gif_set(svm))
                return true;
 
+       if (sev_snp_is_rinj_active(vcpu))
+               return sev_snp_blocked(INJECT_NMI, vcpu);
+
        if (is_guest_mode(vcpu) && nested_exit_on_nmi(svm))
                return false;
 
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index a22ad5de03ea..bb0e5bfdb9a6 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -57,6 +57,7 @@ extern struct kvm_x86_ops svm_x86_ops __initdata;
 
 enum inject_type {
        INJECT_IRQ,
+       INJECT_NMI,
 };
 
 /*
-- 
2.53.0


Reply via email to