| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <f352a1d1-6732-3237-c85e-ffca085195ff@redhat.com>
Date: Wed, 15 Jul 2020 16:51:46 +0800
From: Jason Wang <jasowang@...hat.com>
To: "Zhu, Lingshan" <lingshan.zhu@...el.com>, mst@...hat.com,
alex.williamson@...hat.com, pbonzini@...hat.com,
sean.j.christopherson@...el.com, wanpengli@...cent.com
Cc: virtualization@...ts.linux-foundation.org, kvm@...r.kernel.org,
netdev@...r.kernel.org, dan.daly@...el.com
Subject: Re: [PATCH 3/7] vhost_vdpa: implement IRQ offloading functions in
vhost_vdpa
On 2020/7/13 下午5:47, Zhu, Lingshan wrote:
>
>
> On 7/13/2020 4:22 PM, Jason Wang wrote:
>>
>> On 2020/7/12 下午10:49, Zhu Lingshan wrote:
>>> This patch introduce a set of functions for setup/unsetup
>>> and update irq offloading respectively by register/unregister
>>> and re-register the irq_bypass_producer.
>>>
>>> Signed-off-by: Zhu Lingshan <lingshan.zhu@...el.com>
>>> ---
>>> drivers/vhost/vdpa.c | 69
>>> ++++++++++++++++++++++++++++++++++++++++++++++++++++
>>> 1 file changed, 69 insertions(+)
>>>
>>> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
>>> index 2fcc422..92683e4 100644
>>> --- a/drivers/vhost/vdpa.c
>>> +++ b/drivers/vhost/vdpa.c
>>> @@ -115,6 +115,63 @@ static irqreturn_t vhost_vdpa_config_cb(void
>>> *private)
>>> return IRQ_HANDLED;
>>> }
>>> +static void vhost_vdpa_setup_vq_irq(struct vdpa_device *dev, int
>>> qid, int irq)
>>> +{
>>> + struct vhost_vdpa *v = vdpa_get_drvdata(dev);
>>> + struct vhost_virtqueue *vq = &v->vqs[qid];
>>> + int ret;
>>> +
>>> + vq_err(vq, "setup irq bypass for vq %d with irq = %d\n", qid,
>>> irq);
>>> + spin_lock(&vq->call_ctx.ctx_lock);
>>> + if (!vq->call_ctx.ctx)
>>> + return;
>>> +
>>> + vq->call_ctx.producer.token = vq->call_ctx.ctx;
>>> + vq->call_ctx.producer.irq = irq;
>>> + ret = irq_bypass_register_producer(&vq->call_ctx.producer);
>>> + spin_unlock(&vq->call_ctx.ctx_lock);
>>> +
>>> + if (unlikely(ret))
>>> + vq_err(vq,
>>> + "irq bypass producer (token %p registration fails: %d\n",
>>> + vq->call_ctx.producer.token, ret);
>>
>>
>> Not sure this deserves a vq_err(), irq will be relayed through
>> eventfd if irq bypass manager can't work.
> OK, I see vq_err() will eventfd_signal err_ctx than just print a
> message, will remove all vq_err().
>>
>>
>>> +}
>>> +
>>> +static void vhost_vdpa_unsetup_vq_irq(struct vdpa_device *dev, int
>>> qid)
>>> +{
>>> + struct vhost_vdpa *v = vdpa_get_drvdata(dev);
>>> + struct vhost_virtqueue *vq = &v->vqs[qid];
>>> +
>>> + spin_lock(&vq->call_ctx.ctx_lock);
>>> + irq_bypass_unregister_producer(&vq->call_ctx.producer);
>>> + spin_unlock(&vq->call_ctx.ctx_lock);
>>> +
>>> + vq_err(vq, "unsetup irq bypass for vq %d\n", qid);
>>
>>
>> Why call vq_err() here?
>>
>>
>>> +}
>>> +
>>> +static void vhost_vdpa_update_vq_irq(struct vhost_virtqueue *vq)
>>> +{
>>> + struct eventfd_ctx *ctx;
>>> + void *token;
>>> +
>>> + spin_lock(&vq->call_ctx.ctx_lock);
>>> + ctx = vq->call_ctx.ctx;
>>> + token = vq->call_ctx.producer.token;
>>> + if (ctx == token)
>>> + return;
>>
>>
>> Need do unlock here.
> sure!
>>
>>
>>> +
>>> + if (!ctx && token)
>>> + irq_bypass_unregister_producer(&vq->call_ctx.producer);
>>> +
>>> + if (ctx && ctx != token) {
>>> + irq_bypass_unregister_producer(&vq->call_ctx.producer);
>>> + vq->call_ctx.producer.token = ctx;
>>> + irq_bypass_register_producer(&vq->call_ctx.producer);
>>> + }
>>> +
>>> + spin_unlock(&vq->call_ctx.ctx_lock);
>>
>>
>> This should be rare so I'd use simple codes just do unregister and
>> register.
>
> do you mean remove "if (ctx && ctx != token)"? I think this could be
> useful, we should only update it when ctx!=NULL and ctx!= existing token.
>
I meant something like:
unregister();
vq->call_ctx.producer.token = ctx;
register();
>>
>>
>>> +}
>>> +
>>> static void vhost_vdpa_reset(struct vhost_vdpa *v)
>>> {
>>> struct vdpa_device *vdpa = v->vdpa;
>>> @@ -332,6 +389,7 @@ static long vhost_vdpa_set_config_call(struct
>>> vhost_vdpa *v, u32 __user *argp)
>>> return 0;
>>> }
>>> +
>>
>>
>> Unnecessary change.
> this new blank line is added because there is no blank line between
> functions, I will double check
The point is not mixing coding style fix with other fixes or enhancement.
Thanks
> THanks, BR Zhu Lingshan
>>
>>
>>> static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned
>>> int cmd,
>>> void __user *argp)
>>> {
>>> @@ -390,6 +448,16 @@ static long vhost_vdpa_vring_ioctl(struct
>>> vhost_vdpa *v, unsigned int cmd,
>>> cb.private = NULL;
>>> }
>>> ops->set_vq_cb(vdpa, idx, &cb);
>>> +#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS
>>> + /*
>>> + * if it has a non-zero irq, means there is a
>>> + * previsouly registered irq_bypass_producer,
>>> + * we should update it when ctx (its token)
>>> + * changes.
>>> + */
>>> + if (vq->call_ctx.producer.irq)
>>> + vhost_vdpa_update_vq_irq(vq);
>>> +#endif
>>> break;
>>> case VHOST_SET_VRING_NUM:
>>> @@ -741,6 +809,7 @@ static int vhost_vdpa_open(struct inode *inode,
>>> struct file *filep)
>>> vqs[i] = &v->vqs[i];
>>> vqs[i]->handle_kick = handle_vq_kick;
>>> }
>>> +
>>
>>
>> Unnecessary change.
>>
>> Thanks
>>
>>
>>> vhost_dev_init(dev, vqs, nvqs, 0, 0, 0, false,
>>> vhost_vdpa_process_iotlb_msg);
>>
Powered by blists - more mailing lists