[PATCH v7 12/17] KVM: Implement IRQ bypass consumer callbacks for x86

[Feng Wu <feng.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>]

Implement the following callbacks for x86:

- kvm_arch_irq_bypass_add_producer
- kvm_arch_irq_bypass_del_producer
- kvm_arch_irq_bypass_stop: dummy callback
- kvm_arch_irq_bypass_resume: dummy callback

and set CONFIG_HAVE_KVM_IRQ_BYPASS for x86.

Signed-off-by: Feng Wu <feng.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 arch/x86/include/asm/kvm_host.h |  1 +
 arch/x86/kvm/Kconfig            |  1 +
 arch/x86/kvm/x86.c              | 34 ++++++++++++++++++++++++++++++++++
 3 files changed, 36 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 82d0709..3038c1b 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -24,6 +24,7 @@
 #include <linux/perf_event.h>
 #include <linux/pvclock_gtod.h>
 #include <linux/clocksource.h>
+#include <linux/irqbypass.h>
 
 #include <asm/pvclock-abi.h>
 #include <asm/desc.h>
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index c951d44..b90776f 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -30,6 +30,7 @@ config KVM
 	select HAVE_KVM_IRQCHIP
 	select HAVE_KVM_IRQFD
 	select IRQ_BYPASS_MANAGER
+	select HAVE_KVM_IRQ_BYPASS
 	select HAVE_KVM_IRQ_ROUTING
 	select HAVE_KVM_EVENTFD
 	select KVM_APIC_ARCHITECTURE
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 8f09a76..be4b561 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -50,6 +50,8 @@
 #include <linux/pci.h>
 #include <linux/timekeeper_internal.h>
 #include <linux/pvclock_gtod.h>
+#include <linux/kvm_irqfd.h>
+#include <linux/irqbypass.h>
 #include <trace/events/kvm.h>
 
 #define CREATE_TRACE_POINTS
@@ -8321,6 +8323,38 @@ out:
 	return ret;
 }
 
+int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
+				      struct irq_bypass_producer *prod)
+{
+	struct kvm_kernel_irqfd *irqfd =
+		container_of(cons, struct kvm_kernel_irqfd, consumer);
+
+	irqfd->producer = prod;
+
+	return kvm_arch_update_pi_irte(irqfd->kvm, prod->irq, irqfd->gsi, 1);
+}
+
+void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
+				      struct irq_bypass_producer *prod)
+{
+	int ret;
+	struct kvm_kernel_irqfd *irqfd =
+		container_of(cons, struct kvm_kernel_irqfd, consumer);
+
+	irqfd->producer = NULL;
+
+	/*
+	 * When producer of consumer is unregistered, we change back to
+	 * remapped mode, so we can re-use the current implementation
+	 * when the irq is masked/disabed or the consumer side (KVM
+	 * int this case doesn't want to receive the interrupts.
+	*/
+	ret = kvm_arch_update_pi_irte(irqfd->kvm, prod->irq, irqfd->gsi, 0);
+	if (ret)
+		printk(KERN_INFO "irq bypass consumer (token %p) unregistration"
+		       " fails: %d\n", irqfd->consumer.token, ret);
+}
+
 EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_exit);
 EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_inj_virq);
 EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_page_fault);
-- 
2.1.0