From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alkesh Shah Subject: Disk IO using QEMU Date: Thu, 19 Apr 2007 00:18:14 -0400 Message-ID: <4626ED86.5040803@cc.gatech.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org Hi, I am trying to understand how Disk I/O actually works in HVM. From what I understand, whenever a disk i/o takes place in a guest OS, a VMEXIT occurs. The hypervisor than executes some handler, which sets up an event pending bit for the event channel communicating with the QEMU-DM in the Domain 0. QEMU-DM than emulates these I/O instructions. Specifically, I wanted to know - 1. The functions that are called in this process.... or the files that I need to look at in order to understand the exact flow. 2. Since, QEMU-DM handles both the display as well as the disk I/O, is the same event channel port used for communication between hypervisor and qemu-dm for both display and disk i/o? Thank you for you help. Regards, Alkesh Shah