From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id 9D5F96B004A for ; Thu, 7 Oct 2010 09:37:20 -0400 (EDT) Message-ID: <4CADCCF8.5000408@redhat.com> Date: Thu, 07 Oct 2010 15:36:56 +0200 From: Avi Kivity MIME-Version: 1.0 Subject: Re: [PATCH v6 11/12] Let host know whether the guest can handle async PF in non-userspace context. References: <1286207794-16120-1-git-send-email-gleb@redhat.com> <1286207794-16120-12-git-send-email-gleb@redhat.com> In-Reply-To: <1286207794-16120-12-git-send-email-gleb@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Gleb Natapov Cc: kvm@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, mingo@elte.hu, a.p.zijlstra@chello.nl, tglx@linutronix.de, hpa@zytor.com, riel@redhat.com, cl@linux-foundation.org, mtosatti@redhat.com List-ID: On 10/04/2010 05:56 PM, Gleb Natapov wrote: > If guest can detect that it runs in non-preemptable context it can > handle async PFs at any time, so let host know that it can send async > PF even if guest cpu is not in userspace. > > > > MSR_KVM_ASYNC_PF_EN: 0x4b564d02 > data: Bits 63-6 hold 64-byte aligned physical address of a 32bit memory > - area which must be in guest RAM. Bits 5-1 are reserved and should be > + area which must be in guest RAM. Bits 5-2 are reserved and should be > zero. Bit 0 is 1 when asynchronous page faults are enabled on the vcpu > - 0 when disabled. > + 0 when disabled. Bit 2 is 1 if asynchronous page faults can be injected > + when vcpu is in kernel mode. Please use cpl instead of user mode and kernel mode. The original terms are ambiguous for cpl ==1 || cpl == 2. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org