Commit 2edd9cb7 authored Jul 31, 2020 by Zhu Lingshan Committed by Michael S. Tsirkin Aug 05, 2020

kvm: detect assigned device via irqbypass manager



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>
Link: https://lore.kernel.org/r/20200731065533.4144-3-lingshan.zhu@intel.com


Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

parent 265a0ad8

arch/x86/kvm/x86.c

+10 −2

Original line number	Diff line number	Diff line
		@@ -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;

		return kvm_x86_ops.update_pi_irte(irqfd->kvm,
		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 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,

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