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From: Jason Wang <jasowang@redhat.com>
To: Zhu Lingshan <lingshan.zhu@intel.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
Subject: Re: [PATCH V4 0/6] IRQ offloading for vDPA
Date: Fri, 31 Jul 2020 11:18:40 +0800
Message-ID: <d3a12faa-44b5-1c1b-2047-7b39863d82a7@redhat.com> (raw)
In-Reply-To: <20200728042405.17579-1-lingshan.zhu@intel.com>


On 2020/7/28 下午12:23, Zhu Lingshan wrote:
> This series intends to implement IRQ offloading for
> vhost_vdpa.
>
> By the feat of irq forwarding facilities like posted
> interrupt on X86, irq bypass can  help deliver
> interrupts to vCPU directly.
>
> vDPA devices have dedicated hardware backends like VFIO
> pass-throughed devices. So it would be possible to setup
> irq offloading(irq bypass) for vDPA devices and gain
> performance improvements.
>
> In my testing, with this feature, we can save 0.1ms
> in a ping between two VFs on average.
> changes from V3:
> (1)removed vDPA irq allocate/free helpers in vDPA core.
> (2)add a new function get_vq_irq() in struct vdpa_config_ops,
> upper layer driver can use this function to: A. query the
> irq numbner of a vq. B. detect whether a vq is enabled.
> (3)implement get_vq_irq() in ifcvf driver.
> (4)in vhost_vdpa, set_status() will setup irq offloading when
> setting DRIVER_OK, and unsetup when receive !DRIVER_OK.
> (5)minor improvements.


Ok, I think you can go ahead to post a V5. It's not bad to start with 
get_vq_irq() and we can do any changes afterwards if it can work for 
some cases.

Thanks


      parent reply index

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-28  4:23 Zhu Lingshan
2020-07-28  4:24 ` [PATCH V4 1/6] vhost: introduce vhost_vring_call Zhu Lingshan
2020-07-28  4:24 ` [PATCH V4 2/6] kvm: detect assigned device via irqbypass manager Zhu Lingshan
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 ` Jason Wang [this message]

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