Re: [PATCH v4] kvm: Use a bitmap for tracking used GSIs

From: Avi Kivity <avi@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Alex Williamson <alex.williamson@hp.com>,
	kvm@vger.kernel.org, sheng.yang@intel.com
Subject: Re: [PATCH v4] kvm: Use a bitmap for tracking used GSIs
Date: Mon, 18 May 2009 17:46:09 +0300	[thread overview]
Message-ID: <4A1174B1.9080201@redhat.com> (raw)
In-Reply-To: <20090518144020.GB23940@redhat.com>

Michael S. Tsirkin wrote:
>> If it generates the interrupt after masking it in the msi-x entry, we'll  
>> see it.  If it generates the interrupt before masking it, it may or may  
>> not receive the interrupt, even on real hardware.
>>     
>
> Yes but in the later case, real hardware must re-send the pending
> interrupt after it is unmasked (that's the spec). We would just lose it.
>   

That's a different matter.  We need to buffer the interrupt pending bit, 
and a way for userspace to either query that buffer or have a 
conditional injection (inject_if_pending).

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