From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wen Congyang Subject: Re: [Qemu-devel] [PATCH 0/2 v3] kvm: notify host when guest panicked Date: Thu, 22 Mar 2012 16:34:11 +0800 Message-ID: <4F6AE403.8070500@cn.fujitsu.com> References: <4F60726E.3090807@cn.fujitsu.com> <4F607325.6050607@redhat.com> <20120314104608.GU2304@redhat.com> <4F607789.4010109@redhat.com> <4F607CE4.2060809@cn.fujitsu.com> <4F609822.7050502@redhat.com> <20120314131415.GB2304@redhat.com> <4F609A15.5020902@redhat.com> <20120314132552.GC2304@redhat.com> <20120315103923.GL2304@redhat.com> <4F61D1AF.4040603@siemens.com> <4F61D688.5040406@redhat.com> <4F6A2832.9080306@codemonkey.ws> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Avi Kivity , Jan Kiszka , Gleb Natapov , qemu-devel , "linux-kernel@vger.kernel.org" , Eric Northup , kvm list , Amit Shah , KAMEZAWA Hiroyuki To: Anthony Liguori Return-path: In-Reply-To: <4F6A2832.9080306@codemonkey.ws> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org At 03/22/2012 03:12 AM, Anthony Liguori Wrote: > On 03/15/2012 06:46 AM, Avi Kivity wrote: >> On 03/15/2012 01:25 PM, Jan Kiszka wrote: >>>>> >>>> There was such vm exit (KVM_EXIT_HYPERCALL), but it was deemed to be a >>>> bad idea. >>> >>> BTW, this would help a lot in emulating hypercalls of other hypervisors >>> (or of KVM's VAPIC in the absence of in-kernel irqchip - I had to jump >>> through hoops therefore) in user space. Not all those hypercall handlers >>> actually have to reside in the KVM module. >>> >> >> That is true. On the other hand the hypercall ABI might go to pieces if >> there was no central implementation. > > Just declare that outl 0x505 is a megaultracall and s/vmcall/outb/g and > call it a day. Why use 0x505? Is it a reserved port, and it will not be used by any device? How can I get all reserved port? Thanks Wen Congyang > > The performance difference between vmcall and outl is so tiny compared > to the cost of dropping to userspace that it really doesn't matter which > instruction is used. > > Regards, > > Anthony Liguori > >> > > -- > 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/ > From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:37214) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SAdRT-000290-MZ for qemu-devel@nongnu.org; Thu, 22 Mar 2012 04:32:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SAdRN-0002Wn-CR for qemu-devel@nongnu.org; Thu, 22 Mar 2012 04:32:19 -0400 Received: from [222.73.24.84] (port=14476 helo=song.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SAdRN-0002WH-1m for qemu-devel@nongnu.org; Thu, 22 Mar 2012 04:32:13 -0400 Message-ID: <4F6AE403.8070500@cn.fujitsu.com> Date: Thu, 22 Mar 2012 16:34:11 +0800 From: Wen Congyang MIME-Version: 1.0 References: <4F60726E.3090807@cn.fujitsu.com> <4F607325.6050607@redhat.com> <20120314104608.GU2304@redhat.com> <4F607789.4010109@redhat.com> <4F607CE4.2060809@cn.fujitsu.com> <4F609822.7050502@redhat.com> <20120314131415.GB2304@redhat.com> <4F609A15.5020902@redhat.com> <20120314132552.GC2304@redhat.com> <20120315103923.GL2304@redhat.com> <4F61D1AF.4040603@siemens.com> <4F61D688.5040406@redhat.com> <4F6A2832.9080306@codemonkey.ws> In-Reply-To: <4F6A2832.9080306@codemonkey.ws> Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1 Subject: Re: [Qemu-devel] [PATCH 0/2 v3] kvm: notify host when guest panicked List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: kvm list , Gleb Natapov , Jan Kiszka , "linux-kernel@vger.kernel.org" , qemu-devel , Eric Northup , Amit Shah , KAMEZAWA Hiroyuki , Avi Kivity At 03/22/2012 03:12 AM, Anthony Liguori Wrote: > On 03/15/2012 06:46 AM, Avi Kivity wrote: >> On 03/15/2012 01:25 PM, Jan Kiszka wrote: >>>>> >>>> There was such vm exit (KVM_EXIT_HYPERCALL), but it was deemed to be a >>>> bad idea. >>> >>> BTW, this would help a lot in emulating hypercalls of other hypervisors >>> (or of KVM's VAPIC in the absence of in-kernel irqchip - I had to jump >>> through hoops therefore) in user space. Not all those hypercall handlers >>> actually have to reside in the KVM module. >>> >> >> That is true. On the other hand the hypercall ABI might go to pieces if >> there was no central implementation. > > Just declare that outl 0x505 is a megaultracall and s/vmcall/outb/g and > call it a day. Why use 0x505? Is it a reserved port, and it will not be used by any device? How can I get all reserved port? Thanks Wen Congyang > > The performance difference between vmcall and outl is so tiny compared > to the cost of dropping to userspace that it really doesn't matter which > instruction is used. > > Regards, > > Anthony Liguori > >> > > -- > 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/ >