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From: Zhu Lingshan <lingshan.zhu@intel.com>
To: jasowang@redhat.com, alex.williamson@redhat.com, mst@redhat.com,
	pbonzini@redhat.com, sean.j.christopherson@intel.com,
	wanpengli@tencent.com
Cc: virtualization@lists.linux-foundation.org,
	netdev@vger.kernel.org, kvm@vger.kernel.org, eli@mellanox.com,
	shahafs@mellanox.com, parav@mellanox.com,
	Zhu Lingshan <lingshan.zhu@intel.com>
Subject: [PATCH V4 2/6] kvm: detect assigned device via irqbypass manager
Date: Tue, 28 Jul 2020 12:24:01 +0800
Message-ID: <20200728042405.17579-3-lingshan.zhu@intel.com> (raw)
In-Reply-To: <20200728042405.17579-1-lingshan.zhu@intel.com>

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 --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,
-- 
2.18.4


  parent reply index

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-28  4:23 [PATCH V4 0/6] IRQ offloading for vDPA Zhu Lingshan
2020-07-28  4:24 ` [PATCH V4 1/6] vhost: introduce vhost_vring_call Zhu Lingshan
2020-07-28  4:24 ` Zhu Lingshan [this message]
2020-07-28  4:24 ` [PATCH V4 3/6] vDPA: add get_vq_irq() in vdpa_config_ops Zhu Lingshan
2020-07-28  7:42   ` Jason Wang
2020-07-28  4:24 ` [PATCH V4 4/6] vhost_vdpa: implement IRQ offloading in vhost_vdpa Zhu Lingshan
2020-07-28  7:53   ` Jason Wang
     [not found]     ` <f3e375da-3aa8-7a0c-237c-25943667a535@intel.com>
2020-07-28 10:29       ` Jason Wang
2020-07-28  9:04   ` Eli Cohen
2020-07-29  9:21     ` Jason Wang
2020-07-29  9:55       ` Eli Cohen
2020-07-29 10:19         ` Jason Wang
2020-07-29 11:13           ` Eli Cohen
2020-07-29 14:15           ` Eli Cohen
2020-07-31  3:11             ` Jason Wang
2020-07-28  4:24 ` [PATCH V4 5/6] ifcvf: implement vdpa_config_ops.get_vq_irq() Zhu Lingshan
2020-07-28  4:24 ` [PATCH V4 6/6] irqbypass: do not start cons/prod when failed connect Zhu Lingshan
2020-07-31  3:18 ` [PATCH V4 0/6] IRQ offloading for vDPA Jason Wang

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