From d0e9f244ed5bebb5b2103bec16e4490ecd0e78fa Mon Sep 17 00:00:00 2001
From: Sainath Grandhi <sainath.grandhi@intel.com>
Date: Thu, 9 Aug 2018 12:31:47 -0700
Subject: [PATCH] hv: Interrupt handling in ACRN partition mode

ACRN in partition mode does not have vector and APIC ID remapping for
device interrupts. Only MSIs are supported. No IOAPIC and legacy interrupts
for the VMs in ACRN partition mode.

Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
---
 hypervisor/arch/x86/idt.S         |  4 ++++
 hypervisor/arch/x86/irq.c         | 22 ++++++++++++++++++++++
 hypervisor/arch/x86/virq.c        |  4 ++++
 hypervisor/include/arch/x86/irq.h |  3 +++
 4 files changed, 33 insertions(+)

diff --git a/hypervisor/arch/x86/idt.S b/hypervisor/arch/x86/idt.S
index 251d2eb3a..0cec1542e 100644
--- a/hypervisor/arch/x86/idt.S
+++ b/hypervisor/arch/x86/idt.S
@@ -389,7 +389,11 @@ external_interrupt_save_frame:
     /* Put current stack pointer into 1st param register (rdi) */
     movq    %rsp, %rdi
 
+#ifdef CONFIG_PARTITION_MODE
+    call   partition_mode_dispatch_interrupt
+#else
     call   dispatch_interrupt
+#endif
 
     /*
      * We disable softirq path from interrupt IRET, since right now all IRQ
diff --git a/hypervisor/arch/x86/irq.c b/hypervisor/arch/x86/irq.c
index d48e15e79..1585097d5 100644
--- a/hypervisor/arch/x86/irq.c
+++ b/hypervisor/arch/x86/irq.c
@@ -431,6 +431,28 @@ ERR:
 	return;
 }
 
+#ifdef CONFIG_PARTITION_MODE
+void partition_mode_dispatch_interrupt(struct intr_excp_ctx *ctx)
+{
+	uint8_t vr = ctx->vector;
+	struct vcpu *vcpu;
+
+	/*
+	 * There is no vector and APIC ID remapping for VMs in
+	 * ACRN partition mode. Device interrupts are injected with the same
+	 * vector into vLAPIC of vCPU running on the pCPU. Vectors used for
+	 * HV services are handled by HV using dispatch_interrupt.
+	 */
+	vcpu = per_cpu(vcpu, get_cpu_id());
+	if (vr < VECTOR_FOR_PRI_START) {
+		send_lapic_eoi();
+		vlapic_intr_edge(vcpu, vr);
+	} else {
+		dispatch_interrupt(ctx);
+	}
+}
+#endif
+
 int handle_level_interrupt_common(struct irq_desc *desc,
 			__unused void *handler_data)
 {
diff --git a/hypervisor/arch/x86/virq.c b/hypervisor/arch/x86/virq.c
index e800b7838..e9c46f775 100644
--- a/hypervisor/arch/x86/virq.c
+++ b/hypervisor/arch/x86/virq.c
@@ -373,7 +373,11 @@ int external_interrupt_vmexit_handler(struct vcpu *vcpu)
 
 	ctx.vector = intr_info & 0xFFU;
 
+#ifdef CONFIG_PARTITION_MODE
+	partition_mode_dispatch_interrupt(&ctx);
+#else
 	dispatch_interrupt(&ctx);
+#endif
 
 	vcpu_retain_rip(vcpu);
 
diff --git a/hypervisor/include/arch/x86/irq.h b/hypervisor/include/arch/x86/irq.h
index ac5ee6184..a83df530e 100644
--- a/hypervisor/include/arch/x86/irq.h
+++ b/hypervisor/include/arch/x86/irq.h
@@ -55,6 +55,9 @@ void init_default_irqs(uint16_t cpu_id);
 
 void dispatch_exception(struct intr_excp_ctx *ctx);
 void dispatch_interrupt(struct intr_excp_ctx *ctx);
+#ifdef CONFIG_PARTITION_MODE
+void partition_mode_dispatch_interrupt(struct intr_excp_ctx *ctx);
+#endif
 
 void setup_notification(void);