Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754878Ab0AEQAv (ORCPT ); Tue, 5 Jan 2010 11:00:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754855Ab0AEQAr (ORCPT ); Tue, 5 Jan 2010 11:00:47 -0500 Received: from mx1.redhat.com ([209.132.183.28]:57638 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754844Ab0AEQAp (ORCPT ); Tue, 5 Jan 2010 11:00:45 -0500 Message-ID: <4B4361EE.2030201@redhat.com> Date: Tue, 05 Jan 2010 10:59:42 -0500 From: Rik van Riel Organization: Red Hat, Inc User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091209 Fedora/3.0-4.fc12 Lightning/1.0pre Thunderbird/3.0 MIME-Version: 1.0 To: Jun Koi CC: Gleb Natapov , kvm@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, avi@redhat.com, mingo@elte.hu, a.p.zijlstra@chello.nl, tglx@linutronix.de, hpa@zytor.com, cl@linux-foundation.org Subject: Re: [PATCH v3 00/12] KVM: Add host swap event notifications for PV guest References: <1262700774-1808-1-git-send-email-gleb@redhat.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1785 Lines: 35 On 01/05/2010 10:05 AM, Jun Koi wrote: > On Tue, Jan 5, 2010 at 11:12 PM, Gleb Natapov wrote: >> KVM virtualizes guest memory by means of shadow pages or HW assistance >> like NPT/EPT. Not all memory used by a guest is mapped into the guest >> address space or even present in a host memory at any given time. >> When vcpu tries to access memory page that is not mapped into the guest >> address space KVM is notified about it. KVM maps the page into the guest >> address space and resumes vcpu execution. If the page is swapped out >> from host memory vcpu execution is suspended till the page is not swapped >> into the memory again. This is inefficient since vcpu can do other work >> (run other task or serve interrupts) while page gets swapped in. >> >> To overcome this inefficiency this patch series implements "asynchronous >> page fault" for paravirtualized KVM guests. If a page that vcpu is >> trying to access is swapped out KVM sends an async PF to the vcpu >> and continues vcpu execution. Requested page is swapped in by another >> thread in parallel. When vcpu gets async PF it puts faulted task to >> sleep until "wake up" interrupt is delivered. When the page is brought >> to the host memory KVM sends "wake up" interrupt and the guest's task >> resumes execution. >> > > Is it true that to make this work, we will need a (PV) kernel driver > for each guest OS (Windows, Linux, ...)? This patch series contains the guest kernel code for Linux, as well as the host side code. -- All rights reversed. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/