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From: Avi Kivity <avi@redhat.com>
To: "Kumar, Venkat" <Venkat.Kumar@lsi.com>
Cc: "kvm@vger.kernel.org" <kvm@vger.kernel.org>
Subject: Re: Virtio Queries
Date: Mon, 13 Apr 2009 14:07:27 +0300	[thread overview]
Message-ID: <49E31CEF.30904@redhat.com> (raw)
In-Reply-To: <3D9CB4061D1EB3408D4A0B910433453C030298EEC8@inbmail01.lsi.com>

Kumar, Venkat wrote:
> Hi, I am a few questions on Virtio, Hope somebody clarifies them
>
> 1. What is the address type that is put inside the vring descriptor in the virt queue while placing a request? Is it the guest virtual address or guest physical address?
>   

Guest physical address.  Guest virtual addresses change meanings from 
time to time.

> 2. If it is Guest physical address, how qemu converts it to its virtual address before processing the buffer?
>   

See the logic in cpu_physical_memory_rw() and cpu_physical_memory_map().

> 3. How does qemu interact with guest once it receives the buffers from the virt queue for doing the IO?
>   

qemu advanced the ring indexes, and notifies the guest by sending an 
interrupt when the requests are completed.

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


  reply	other threads:[~2009-04-13 11:07 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-09 15:43 Virtio Queries Kumar, Venkat
2009-04-13 11:07 ` Avi Kivity [this message]
2009-04-13 13:11   ` Kumar, Venkat
2009-04-13 13:26     ` Avi Kivity

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