From: Paolo Bonzini <pbonzini@redhat.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: seanjc@google.com, stable@vger.kernel.org
Subject: [PATCH 2/4] KVM: VMX: prepare sync_pir_to_irr for running with APICv disabled
Date: Mon, 22 Nov 2021 19:43:09 -0500 [thread overview]
Message-ID: <20211123004311.2954158-3-pbonzini@redhat.com> (raw)
In-Reply-To: <20211123004311.2954158-1-pbonzini@redhat.com>
If APICv is disabled for this vCPU, assigned devices may
still attempt to post interrupts. In that case, we need
to cancel the vmentry and deliver the interrupt with
KVM_REQ_EVENT. Extend the existing code that handles
injection of L1 interrupts into L2 to cover this case
as well.
vmx_hwapic_irr_update is only called when APICv is active
so it would be confusing to add a check for
vcpu->arch.apicv_active in there. Instead, just use
vmx_set_rvi directly in vmx_sync_pir_to_irr.
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/vmx/vmx.c | 35 +++++++++++++++++++++++------------
1 file changed, 23 insertions(+), 12 deletions(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index ba66c171d951..cccf1eab58ac 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6264,7 +6264,7 @@ static int vmx_sync_pir_to_irr(struct kvm_vcpu *vcpu)
int max_irr;
bool max_irr_updated;
- if (KVM_BUG_ON(!vcpu->arch.apicv_active, vcpu->kvm))
+ if (KVM_BUG_ON(!enable_apicv, vcpu->kvm))
return -EIO;
if (pi_test_on(&vmx->pi_desc)) {
@@ -6276,20 +6276,31 @@ static int vmx_sync_pir_to_irr(struct kvm_vcpu *vcpu)
smp_mb__after_atomic();
max_irr_updated =
kvm_apic_update_irr(vcpu, vmx->pi_desc.pir, &max_irr);
-
- /*
- * If we are running L2 and L1 has a new pending interrupt
- * which can be injected, this may cause a vmexit or it may
- * be injected into L2. Either way, this interrupt will be
- * processed via KVM_REQ_EVENT, not RVI, because we do not use
- * virtual interrupt delivery to inject L1 interrupts into L2.
- */
- if (is_guest_mode(vcpu) && max_irr_updated)
- kvm_make_request(KVM_REQ_EVENT, vcpu);
} else {
max_irr = kvm_lapic_find_highest_irr(vcpu);
+ max_irr_updated = false;
}
- vmx_hwapic_irr_update(vcpu, max_irr);
+
+ /*
+ * If virtual interrupt delivery is not in use, the interrupt
+ * will be processed via KVM_REQ_EVENT, not RVI. This can happen
+ * in two cases:
+ *
+ * 1) If we are running L2 and L1 has a new pending interrupt
+ * which can be injected, this may cause a vmexit or it may
+ * be injected into L2. We do not use virtual interrupt
+ * delivery to inject L1 interrupts into L2.
+ *
+ * 2) If APICv is disabled for this vCPU, assigned devices may
+ * still attempt to post interrupts. The posted interrupt
+ * vector will cause a vmexit and the subsequent entry will
+ * call sync_pir_to_irr.
+ */
+ if (!is_guest_mode(vcpu) && vcpu->arch.apicv_active)
+ vmx_set_rvi(max_irr);
+ else if (max_irr_updated)
+ kvm_make_request(KVM_REQ_EVENT, vcpu);
+
return max_irr;
}
--
2.27.0
next prev parent reply other threads:[~2021-11-23 0:43 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-23 0:43 [PATCH 0/4] KVM: VMX: process posted interrupts on APICv-disable vCPUs Paolo Bonzini
2021-11-23 0:43 ` [PATCH 1/4] KVM: x86: ignore APICv if LAPIC is not enabled Paolo Bonzini
2021-11-25 1:36 ` Sean Christopherson
2021-11-29 23:32 ` David Matlack
2021-11-30 7:50 ` Maxim Levitsky
2021-11-23 0:43 ` Paolo Bonzini [this message]
2021-11-29 22:14 ` [PATCH 2/4] KVM: VMX: prepare sync_pir_to_irr for running with APICv disabled Sean Christopherson
2021-11-30 8:31 ` Paolo Bonzini
2021-11-29 23:34 ` David Matlack
2021-11-30 7:57 ` Maxim Levitsky
2021-11-23 0:43 ` [PATCH 3/4] KVM: x86: check PIR even for vCPUs with disabled APICv Paolo Bonzini
2021-11-29 23:39 ` David Matlack
2021-11-30 7:58 ` Maxim Levitsky
2021-11-23 0:43 ` [PATCH 4/4] KVM: x86: Use a stable condition around all VT-d PI paths Paolo Bonzini
2021-11-29 23:41 ` David Matlack
2021-11-30 8:05 ` Maxim Levitsky
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