From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Wed, 25 Jun 2014 11:24:47 +0200 (CEST) Received: from mailapp01.imgtec.com ([195.59.15.196]:41921 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S6816503AbaFYJYnhcEqk (ORCPT ); Wed, 25 Jun 2014 11:24:43 +0200 Received: from KLMAIL01.kl.imgtec.org (unknown [192.168.5.35]) by Websense Email Security Gateway with ESMTPS id 650B13E3FDF03; Wed, 25 Jun 2014 10:24:34 +0100 (IST) Received: from LEMAIL01.le.imgtec.org (192.168.152.62) by KLMAIL01.kl.imgtec.org (192.168.5.35) with Microsoft SMTP Server (TLS) id 14.3.181.6; Wed, 25 Jun 2014 10:24:36 +0100 Received: from [192.168.154.101] (192.168.154.101) by LEMAIL01.le.imgtec.org (192.168.152.62) with Microsoft SMTP Server (TLS) id 14.3.174.1; Wed, 25 Jun 2014 10:24:36 +0100 Message-ID: <53AA9554.1050908@imgtec.com> Date: Wed, 25 Jun 2014 10:24:36 +0100 From: James Hogan User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Deng-Cheng Zhu , CC: , , , , Subject: Re: [PATCH v3 6/9] MIPS: KVM: Restore correct value for WIRED at TLB uninit References: <1403631071-6012-1-git-send-email-dengcheng.zhu@imgtec.com> <1403631071-6012-7-git-send-email-dengcheng.zhu@imgtec.com> In-Reply-To: <1403631071-6012-7-git-send-email-dengcheng.zhu@imgtec.com> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.154.101] Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 40799 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: james.hogan@imgtec.com Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips On 24/06/14 18:31, Deng-Cheng Zhu wrote: > From: Deng-Cheng Zhu > > At TLB initialization, the commpage TLB entry is reserved on top of the > existing WIRED entries (the number not necessarily be 0). > > Signed-off-by: Deng-Cheng Zhu > --- > arch/mips/kvm/mips.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c > index 27250ee..3d53d34 100644 > --- a/arch/mips/kvm/mips.c > +++ b/arch/mips/kvm/mips.c > @@ -170,7 +170,7 @@ void kvm_arch_sync_events(struct kvm *kvm) > static void kvm_mips_uninit_tlbs(void *arg) > { > /* Restore wired count */ > - write_c0_wired(0); > + write_c0_wired(read_c0_wired() - 1); > mtc0_tlbw_hazard(); > /* Clear out all the TLBs */ > kvm_local_flush_tlb_all(); kvm_local_flush_tlb_all blasts all the entries away regardless of wired, so I don't think this is an improvement. I suspect to really be safe/correct in the presence of other dynamic users of wired it would have to either manage arbitrary allocation/deallocation of per-cpu tlb entries correctly from a single place, or abandon the use of wired altogether. Cheers James From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailapp01.imgtec.com ([195.59.15.196]:41921 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S6816503AbaFYJYnhcEqk (ORCPT ); Wed, 25 Jun 2014 11:24:43 +0200 Message-ID: <53AA9554.1050908@imgtec.com> Date: Wed, 25 Jun 2014 10:24:36 +0100 From: James Hogan MIME-Version: 1.0 Subject: Re: [PATCH v3 6/9] MIPS: KVM: Restore correct value for WIRED at TLB uninit References: <1403631071-6012-1-git-send-email-dengcheng.zhu@imgtec.com> <1403631071-6012-7-git-send-email-dengcheng.zhu@imgtec.com> In-Reply-To: <1403631071-6012-7-git-send-email-dengcheng.zhu@imgtec.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-Path: Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-subscribe: List-owner: List-post: List-archive: To: Deng-Cheng Zhu , pbonzini@redhat.com Cc: gleb@kernel.org, kvm@vger.kernel.org, sanjayl@kymasys.com, ralf@linux-mips.org, linux-mips@linux-mips.org Message-ID: <20140625092436.1UjiC0D_tCdPAHYbZc39Ldf2CIYCLta4tCbKVFdd0W0@z> On 24/06/14 18:31, Deng-Cheng Zhu wrote: > From: Deng-Cheng Zhu > > At TLB initialization, the commpage TLB entry is reserved on top of the > existing WIRED entries (the number not necessarily be 0). > > Signed-off-by: Deng-Cheng Zhu > --- > arch/mips/kvm/mips.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c > index 27250ee..3d53d34 100644 > --- a/arch/mips/kvm/mips.c > +++ b/arch/mips/kvm/mips.c > @@ -170,7 +170,7 @@ void kvm_arch_sync_events(struct kvm *kvm) > static void kvm_mips_uninit_tlbs(void *arg) > { > /* Restore wired count */ > - write_c0_wired(0); > + write_c0_wired(read_c0_wired() - 1); > mtc0_tlbw_hazard(); > /* Clear out all the TLBs */ > kvm_local_flush_tlb_all(); kvm_local_flush_tlb_all blasts all the entries away regardless of wired, so I don't think this is an improvement. I suspect to really be safe/correct in the presence of other dynamic users of wired it would have to either manage arbitrary allocation/deallocation of per-cpu tlb entries correctly from a single place, or abandon the use of wired altogether. Cheers James