From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: RFC: New API for PPC for vcpu mmu access Date: Mon, 07 Feb 2011 19:13:46 +0200 Message-ID: <4D50284A.4020606@redhat.com> References: <9F6FE96B71CF29479FF1CDC8046E15030BCD40@039-SN1MPN1-002.039d.mgd.msft.net> <20110202160821.5a223366@udp111988uds> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Scott Wood , Yoder Stuart-B08248 , "kvm-ppc@vger.kernel.org" , "kvm@vger.kernel.org" , "qemu-devel@nongnu.org" To: Alexander Graf Return-path: In-Reply-To: Sender: kvm-ppc-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 02/03/2011 11:19 AM, Alexander Graf wrote: > > > > I have no idea what things will look like 10 years down the road, but > > currently e500mc has 576 entries (512 TLB0, 64 TLB1). > > That sums up to 64 * 576 bytes, which is 36kb. Ouch. Certainly nothing we want to transfer every time qemu feels like resolving an EA. You could have an ioctl to translate addresses (x86 had KVM_TRANSLATE or similar), or have the TLB stored in user memory, so there is no need to transfer it (on the other hand, you have to re-validate it every time you peek at it). -- error compiling committee.c: too many arguments to function From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=46756 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PmUfr-0004U7-K6 for qemu-devel@nongnu.org; Mon, 07 Feb 2011 12:14:53 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PmUfm-0003TL-Gh for qemu-devel@nongnu.org; Mon, 07 Feb 2011 12:14:47 -0500 Received: from mx1.redhat.com ([209.132.183.28]:47441) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PmUfm-0003TB-9b for qemu-devel@nongnu.org; Mon, 07 Feb 2011 12:14:46 -0500 Message-ID: <4D50284A.4020606@redhat.com> Date: Mon, 07 Feb 2011 19:13:46 +0200 From: Avi Kivity MIME-Version: 1.0 References: <9F6FE96B71CF29479FF1CDC8046E15030BCD40@039-SN1MPN1-002.039d.mgd.msft.net> <20110202160821.5a223366@udp111988uds> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] Re: RFC: New API for PPC for vcpu mmu access List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: Scott Wood , Yoder Stuart-B08248 , "kvm@vger.kernel.org" , "kvm-ppc@vger.kernel.org" , "qemu-devel@nongnu.org" On 02/03/2011 11:19 AM, Alexander Graf wrote: > > > > I have no idea what things will look like 10 years down the road, but > > currently e500mc has 576 entries (512 TLB0, 64 TLB1). > > That sums up to 64 * 576 bytes, which is 36kb. Ouch. Certainly nothing we want to transfer every time qemu feels like resolving an EA. You could have an ioctl to translate addresses (x86 had KVM_TRANSLATE or similar), or have the TLB stored in user memory, so there is no need to transfer it (on the other hand, you have to re-validate it every time you peek at it). -- error compiling committee.c: too many arguments to function From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Date: Mon, 07 Feb 2011 17:13:46 +0000 Subject: Re: RFC: New API for PPC for vcpu mmu access Message-Id: <4D50284A.4020606@redhat.com> List-Id: References: <9F6FE96B71CF29479FF1CDC8046E15030BCD40@039-SN1MPN1-002.039d.mgd.msft.net> <20110202160821.5a223366@udp111988uds> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Alexander Graf Cc: Scott Wood , Yoder Stuart-B08248 , "kvm-ppc@vger.kernel.org" , "kvm@vger.kernel.org" , "qemu-devel@nongnu.org" On 02/03/2011 11:19 AM, Alexander Graf wrote: > > > > I have no idea what things will look like 10 years down the road, but > > currently e500mc has 576 entries (512 TLB0, 64 TLB1). > > That sums up to 64 * 576 bytes, which is 36kb. Ouch. Certainly nothing we want to transfer every time qemu feels like resolving an EA. You could have an ioctl to translate addresses (x86 had KVM_TRANSLATE or similar), or have the TLB stored in user memory, so there is no need to transfer it (on the other hand, you have to re-validate it every time you peek at it). -- error compiling committee.c: too many arguments to function