From patchwork Thu Feb 2 12:04:31 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: James Hogan X-Patchwork-Id: 9551695 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 33D6360236 for ; Thu, 2 Feb 2017 12:05:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 23CE726861 for ; Thu, 2 Feb 2017 12:05:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 18A9328425; Thu, 2 Feb 2017 12:05:50 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C072226861 for ; Thu, 2 Feb 2017 12:05:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751516AbdBBMFJ (ORCPT ); Thu, 2 Feb 2017 07:05:09 -0500 Received: from mailapp01.imgtec.com ([195.59.15.196]:30299 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751473AbdBBMFI (ORCPT ); Thu, 2 Feb 2017 07:05:08 -0500 Received: from hhmail02.hh.imgtec.org (unknown [10.100.10.20]) by Forcepoint Email with ESMTPS id BCC1F922D92B4; Thu, 2 Feb 2017 12:05:03 +0000 (GMT) Received: from jhogan-linux.le.imgtec.org (192.168.154.110) by hhmail02.hh.imgtec.org (10.100.10.21) with Microsoft SMTP Server (TLS) id 14.3.294.0; Thu, 2 Feb 2017 12:05:06 +0000 From: James Hogan To: CC: James Hogan , Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Ralf Baechle , Subject: [PATCH v2 18/30] KVM: MIPS/TLB: Fix off-by-one in TLB invalidate Date: Thu, 2 Feb 2017 12:04:31 +0000 Message-ID: <45c9a17158efd486f17ced44d54000b5420fe4eb.1486036366.git-series.james.hogan@imgtec.com> X-Mailer: git-send-email 2.11.0 MIME-Version: 1.0 In-Reply-To: References: X-Originating-IP: [192.168.154.110] Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP kvm_mips_host_tlb_inv() uses the TLBP instruction to probe the host TLB for an entry matching the given guest virtual address, and determines whether a match was found based on whether CP0_Index > 0. This is technically incorrect as an index of 0 (with the high bit clear) is a perfectly valid TLB index. This is harmless at the moment due to the use of at least 1 wired TLB entry for the KVM commpage, however we will soon be ridding ourselves of that particular wired entry so lets fix the condition in case the entry needing invalidation does land at TLB index 0. Signed-off-by: James Hogan Cc: Paolo Bonzini Cc: "Radim Krčmář" Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org --- arch/mips/kvm/tlb.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/mips/kvm/tlb.c b/arch/mips/kvm/tlb.c index 6c1f894b8754..4bf82613d440 100644 --- a/arch/mips/kvm/tlb.c +++ b/arch/mips/kvm/tlb.c @@ -282,7 +282,7 @@ int kvm_mips_host_tlb_inv(struct kvm_vcpu *vcpu, unsigned long va) if (idx >= current_cpu_data.tlbsize) BUG(); - if (idx > 0) { + if (idx >= 0) { write_c0_entryhi(UNIQUE_ENTRYHI(idx)); write_c0_entrylo0(0); write_c0_entrylo1(0); @@ -297,7 +297,7 @@ int kvm_mips_host_tlb_inv(struct kvm_vcpu *vcpu, unsigned long va) local_irq_restore(flags); - if (idx > 0) + if (idx >= 0) kvm_debug("%s: Invalidated entryhi %#lx @ idx %d\n", __func__, (va & VPN2_MASK) | kvm_mips_get_user_asid(vcpu), idx);