Message-ID: <4A40A721.3020901@redhat.com>
Date: Tue, 23 Jun 2009 12:57:53 +0300
From: Avi Kivity <avi@redhat.com>
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To: "Michael S. Tsirkin" <mst@redhat.com>
CC: Gregory Haskins <ghaskins@novell.com>, kvm@vger.kernel.org,
       linux-kernel@vger.kernel.org, mtosatti@redhat.com,
       paulmck@linux.vnet.ibm.com, markmc@redhat.com
Subject: Re: [KVM PATCH v8 3/3] KVM: add iosignalfd support
References: <20090619002224.15859.97977.stgit@dev.haskins.net> <20090619003045.15859.73197.stgit@dev.haskins.net> <20090623085633.GA16294@redhat.com>
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On 06/23/2009 11:56 AM, Michael S. Tsirkin wrote:
> On Thu, Jun 18, 2009 at 08:30:46PM -0400, Gregory Haskins wrote:
>    
>> +static int
>> +iosignalfd_group_in_range(struct kvm_io_device *this, gpa_t addr, int len,
>> +			  int is_write)
>> +{
>> +	struct _iosignalfd_group *p = to_group(this);
>> +
>> +	return ((addr>= p->addr&&  (addr<  p->addr + p->length)));
>> +}
>>      
>
> I think I see a problem here. For virtio, we do not necessarily want all
> virtqueues for a device to live in kernel: there might be control
> virtqueues that we want to leave in userspace. Since this claims all
> writes to a specific address, the signal never makes it to userspace.
>    

Userspace could create an eventfd for this control queue and wait for it 
to fire.

-- 
error compiling committee.c: too many arguments to function

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