[RFC PATCH 5/5] x86/kvm: Add target VMPL to IRQs and send to APIC for VMPL

[Roy Hopkins <roy.hopkins@xxxxxxxx>]

Systems that support VMPLs need to decide which VMPL each
IRQ is destined for; each VMPL can support its own set of hardware
devices that generate interrupts.

This commit extends kvm_lapic_irq to include a target_vmpl field the
sends the IRQ to the APIC instance at the target VMPL.

Signed-off-by: Roy Hopkins <roy.hopkins@xxxxxxxx>
---
 arch/x86/include/asm/kvm_host.h | 1 +
 arch/x86/kvm/ioapic.c           | 3 +++
 arch/x86/kvm/irq_comm.c         | 1 +
 arch/x86/kvm/lapic.c            | 6 +++++-
 4 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 3dd3a5ff0cec..d0febb67dabf 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1624,6 +1624,7 @@ struct kvm_lapic_irq {
 	u32 shorthand;
 	u32 dest_id;
 	bool msi_redir_hint;
+	unsigned int target_vmpl;
 };
 
 static inline u16 kvm_lapic_irq_dest_mode(bool dest_mode_logical)
diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c
index 995eb5054360..7b835a192561 100644
--- a/arch/x86/kvm/ioapic.c
+++ b/arch/x86/kvm/ioapic.c
@@ -413,6 +413,8 @@ static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val)
 			irq.shorthand = APIC_DEST_NOSHORT;
 			irq.dest_id = e->fields.dest_id;
 			irq.msi_redir_hint = false;
+			irq.target_vmpl = ioapic->kvm->arch.default_irq_vmpl;
+
 			bitmap_zero(vcpu_bitmap, KVM_MAX_VCPUS);
 			kvm_bitmap_or_dest_vcpus(ioapic->kvm, &irq,
 						 vcpu_bitmap);
@@ -458,6 +460,7 @@ static int ioapic_service(struct kvm_ioapic *ioapic, int irq, bool line_status)
 	irqe.level = 1;
 	irqe.shorthand = APIC_DEST_NOSHORT;
 	irqe.msi_redir_hint = false;
+	irqe.target_vmpl = ioapic->kvm->arch.default_irq_vmpl;
 
 	if (irqe.trig_mode == IOAPIC_EDGE_TRIG)
 		ioapic->irr_delivered |= 1 << irq;
diff --git a/arch/x86/kvm/irq_comm.c b/arch/x86/kvm/irq_comm.c
index 8136695f7b96..6bd4a78dddba 100644
--- a/arch/x86/kvm/irq_comm.c
+++ b/arch/x86/kvm/irq_comm.c
@@ -119,6 +119,7 @@ void kvm_set_msi_irq(struct kvm *kvm, struct kvm_kernel_irq_routing_entry *e,
 	irq->msi_redir_hint = msg.arch_addr_lo.redirect_hint;
 	irq->level = 1;
 	irq->shorthand = APIC_DEST_NOSHORT;
+	irq->target_vmpl = kvm->arch.default_irq_vmpl;
 }
 EXPORT_SYMBOL_GPL(kvm_set_msi_irq);
 
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index e2dd573e4f2d..20b433a78457 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -836,7 +836,9 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
 int kvm_apic_set_irq(struct kvm_vcpu *vcpu, struct kvm_lapic_irq *irq,
 		     struct dest_map *dest_map)
 {
-	struct kvm_lapic *apic = vcpu->arch.apic;
+	struct kvm_lapic *apic = vcpu->vcpu_parent->vcpu_vmpl[irq->target_vmpl]->arch.apic;
+	if (!apic)
+		return -EINVAL;
 
 	return __apic_accept_irq(apic, irq->delivery_mode, irq->vector,
 			irq->level, irq->trig_mode, dest_map);
@@ -1528,6 +1530,8 @@ void kvm_apic_send_ipi(struct kvm_lapic *apic, u32 icr_low, u32 icr_high)
 	irq.trig_mode = icr_low & APIC_INT_LEVELTRIG;
 	irq.shorthand = icr_low & APIC_SHORT_MASK;
 	irq.msi_redir_hint = false;
+	/* IPIs always target the same VMPL as the source */
+	irq.target_vmpl = apic->vcpu->vmpl;
 	if (apic_x2apic_mode(apic))
 		irq.dest_id = icr_high;
 	else
-- 
2.43.0