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[V5,2/6] kvm: detect assigned device via irqbypass manager

Message ID 20200731065533.4144-3-lingshan.zhu@intel.com
State Not Applicable
Delegated to: David Miller
Headers show
Series IRQ offloading for vDPA | expand

Commit Message

Zhu Lingshan July 31, 2020, 6:55 a.m. UTC
vDPA devices has dedicated backed hardware like
passthrough-ed devices. Then it is possible to setup irq
offloading to vCPU for vDPA devices. Thus this patch tries to
manipulated assigned device counters by
kvm_arch_start/end_assignment() in irqbypass manager, so that
assigned devices could be detected in update_pi_irte()

We will increase/decrease the assigned device counter in kvm/x86.
Both vDPA and VFIO would go through this code path.

Only X86 uses these counters and kvm_arch_start/end_assignment(),
so this code path only affect x86 for now.

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Suggested-by: Jason Wang <jasowang@redhat.com>
 arch/x86/kvm/x86.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)
diff mbox series


diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 88c593f83b28..76a2e7fd18c7 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -10630,11 +10630,17 @@  int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
 	struct kvm_kernel_irqfd *irqfd =
 		container_of(cons, struct kvm_kernel_irqfd, consumer);
+	int ret;
 	irqfd->producer = prod;
+	kvm_arch_start_assignment(irqfd->kvm);
+	ret = kvm_x86_ops.update_pi_irte(irqfd->kvm,
+					 prod->irq, irqfd->gsi, 1);
+	if (ret)
+		kvm_arch_end_assignment(irqfd->kvm);
-	return kvm_x86_ops.update_pi_irte(irqfd->kvm,
-					   prod->irq, irqfd->gsi, 1);
+	return ret;
 void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
@@ -10657,6 +10663,8 @@  void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
 	if (ret)
 		printk(KERN_INFO "irq bypass consumer (token %p) unregistration"
 		       " fails: %d\n", irqfd->consumer.token, ret);
+	kvm_arch_end_assignment(irqfd->kvm);
 int kvm_arch_update_irqfd_routing(struct kvm *kvm, unsigned int host_irq,