[PATCH v9 14/18] KVM: Implement IRQ bypass consumer callbacks for x86

From: Feng Wu
Date: Fri Sep 18 2015 - 10:47:31 EST


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@xxxxxxxxx>
---
v8:
- Move the weak irq bypas stop and irq bypass start to this patch.
- Call kvm_x86_ops->update_pi_irte() instead of kvm_arch_update_pi_irte().

arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/Kconfig | 1 +
arch/x86/kvm/x86.c | 44 +++++++++++++++++++++++++++++++++++++++++
virt/kvm/eventfd.c | 12 +++++++++++
4 files changed, 58 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 8c44286..0ddd353 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 9dcd501..79dac02 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
@@ -8249,6 +8251,48 @@ bool kvm_arch_has_noncoherent_dma(struct kvm *kvm)
}
EXPORT_SYMBOL_GPL(kvm_arch_has_noncoherent_dma);

+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);
+
+ if (kvm_x86_ops->update_pi_irte) {
+ irqfd->producer = prod;
+ return kvm_x86_ops->update_pi_irte(irqfd->kvm,
+ prod->irq, irqfd->gsi, 1);
+ }
+
+ return -EINVAL;
+}
+
+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);
+
+ if (!kvm_x86_ops->update_pi_irte) {
+ WARN_ON(irqfd->producer != NULL);
+ return;
+ }
+
+ WARN_ON(irqfd->producer != prod);
+ 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_x86_ops->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);
diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index d7a230f..c0a56a1 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -256,6 +256,18 @@ static void irqfd_update(struct kvm *kvm, struct kvm_kernel_irqfd *irqfd)
write_seqcount_end(&irqfd->irq_entry_sc);
}

+#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS
+void __attribute__((weak)) kvm_arch_irq_bypass_stop(
+ struct irq_bypass_consumer *cons)
+{
+}
+
+void __attribute__((weak)) kvm_arch_irq_bypass_start(
+ struct irq_bypass_consumer *cons)
+{
+}
+#endif
+
static int
kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args)
{
--
2.1.0

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