From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Jackson Subject: RE: [PATCH] Fix hvm vcpu hotplug bug Date: Tue, 24 Aug 2010 15:19:23 +0100 Message-ID: <19571.54507.780108.421366@mariner.uk.xensource.com> References: <19554.43920.11785.97567@mariner.uk.xensource.com> <19563.58860.249044.209893@mariner.uk.xensource.com> <19565.17092.616097.195948@mariner.uk.xensource.com> <19566.33227.5055.515834@mariner.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: "Liu, Jinsong" Cc: Keir Fraser , "Jiang, Yunhong" , Ian Jackson , "xen-devel@lists.xensource.com" , "Li, Xin" List-Id: xen-devel@lists.xenproject.org Liu, Jinsong writes ("RE: [Xen-devel] [PATCH] Fix hvm vcpu hotplug bug"): > Ian Jackson wrote: > > Liu, Jinsong writes ("RE: [Xen-devel] [PATCH] Fix hvm vcpu hotplug bug"): > >> [linux/drivers/acpi/acpica/ will:] > >> 1). clear pge_en x by writing '0' to the bit; > >> 2). asynchronic call control method; > >> 3). clear gpe_sts x by writing '1' to the bit; > >> 4). re-enable gpe_en x by writing '1' to the bit; > > > > So the code in qemu should never clear gpe_sts itself. > > No, that's just what qemu should do, to simulate hardware behavior. Obviously I still haven't understood. If the guest kernel driver is supposed to clear this bit as you seem to say above, then it should not be cleared automatically by qemu-dm as part of the hotplug notification. Obviously the register ought to be emulated by qemu and the bit ought to be cleared in qemu when the kernel driver writes an inactive value to it. None of this seems to be implemented in qemu right now AFAICT ? Ian.