From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Guo Date: Thu, 03 May 2018 08:37:37 +0000 Subject: Re: [PATCH 05/11] KVM: PPC: add GPR RA update skeleton for MMIO emulation Message-Id: <20180503083737.GE6755@simonLocalRHEL7.x64> List-Id: References: <1524657284-16706-1-git-send-email-wei.guo.simon@gmail.com> <1524657284-16706-6-git-send-email-wei.guo.simon@gmail.com> <20180503055814.GF6795@fergus.ozlabs.ibm.com> In-Reply-To: <20180503055814.GF6795@fergus.ozlabs.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Paul Mackerras Cc: linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org On Thu, May 03, 2018 at 03:58:14PM +1000, Paul Mackerras wrote: > On Wed, Apr 25, 2018 at 07:54:38PM +0800, wei.guo.simon@gmail.com wrote: > > From: Simon Guo > > > > To optimize kvm emulation code with analyse_instr, adds new > > mmio_update_ra flag to aid with GPR RA update. > > > > This patch arms RA update at load/store emulation path for both > > qemu mmio emulation or coalesced mmio emulation. > > It's not clear to me why you need to do this. The existing code > writes RA at the point where the instruction is decoded. In later > patches, you change that so the RA update occurs after the MMIO > operation is performed. Is there a particular reason why you made > that change? > > Paul. I wanted to avoid the case that GPR RA was updated even when EMULATE_FAIL. But if it is not mandatory, I can update RA in kvmppc_emulate_loadstore() instead.. Thanks, - Simon From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-x244.google.com (mail-pg0-x244.google.com [IPv6:2607:f8b0:400e:c05::244]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 40c7ww70KTzF2T1 for ; Thu, 3 May 2018 18:44:16 +1000 (AEST) Received: by mail-pg0-x244.google.com with SMTP id g20-v6so5949192pgv.1 for ; Thu, 03 May 2018 01:44:16 -0700 (PDT) Date: Thu, 3 May 2018 16:37:37 +0800 From: Simon Guo To: Paul Mackerras Cc: kvm-ppc@vger.kernel.org, kvm@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH 05/11] KVM: PPC: add GPR RA update skeleton for MMIO emulation Message-ID: <20180503083737.GE6755@simonLocalRHEL7.x64> References: <1524657284-16706-1-git-send-email-wei.guo.simon@gmail.com> <1524657284-16706-6-git-send-email-wei.guo.simon@gmail.com> <20180503055814.GF6795@fergus.ozlabs.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20180503055814.GF6795@fergus.ozlabs.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, May 03, 2018 at 03:58:14PM +1000, Paul Mackerras wrote: > On Wed, Apr 25, 2018 at 07:54:38PM +0800, wei.guo.simon@gmail.com wrote: > > From: Simon Guo > > > > To optimize kvm emulation code with analyse_instr, adds new > > mmio_update_ra flag to aid with GPR RA update. > > > > This patch arms RA update at load/store emulation path for both > > qemu mmio emulation or coalesced mmio emulation. > > It's not clear to me why you need to do this. The existing code > writes RA at the point where the instruction is decoded. In later > patches, you change that so the RA update occurs after the MMIO > operation is performed. Is there a particular reason why you made > that change? > > Paul. I wanted to avoid the case that GPR RA was updated even when EMULATE_FAIL. But if it is not mandatory, I can update RA in kvmppc_emulate_loadstore() instead.. Thanks, - Simon From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Guo Subject: Re: [PATCH 05/11] KVM: PPC: add GPR RA update skeleton for MMIO emulation Date: Thu, 3 May 2018 16:37:37 +0800 Message-ID: <20180503083737.GE6755@simonLocalRHEL7.x64> References: <1524657284-16706-1-git-send-email-wei.guo.simon@gmail.com> <1524657284-16706-6-git-send-email-wei.guo.simon@gmail.com> <20180503055814.GF6795@fergus.ozlabs.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org To: Paul Mackerras Return-path: Content-Disposition: inline In-Reply-To: <20180503055814.GF6795@fergus.ozlabs.ibm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+glppe-linuxppc-embedded-2=m.gmane.org@lists.ozlabs.org Sender: "Linuxppc-dev" List-Id: kvm.vger.kernel.org On Thu, May 03, 2018 at 03:58:14PM +1000, Paul Mackerras wrote: > On Wed, Apr 25, 2018 at 07:54:38PM +0800, wei.guo.simon@gmail.com wrote: > > From: Simon Guo > > > > To optimize kvm emulation code with analyse_instr, adds new > > mmio_update_ra flag to aid with GPR RA update. > > > > This patch arms RA update at load/store emulation path for both > > qemu mmio emulation or coalesced mmio emulation. > > It's not clear to me why you need to do this. The existing code > writes RA at the point where the instruction is decoded. In later > patches, you change that so the RA update occurs after the MMIO > operation is performed. Is there a particular reason why you made > that change? > > Paul. I wanted to avoid the case that GPR RA was updated even when EMULATE_FAIL. But if it is not mandatory, I can update RA in kvmppc_emulate_loadstore() instead.. Thanks, - Simon