From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailapp01.imgtec.com ([195.59.15.196]:24520 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S23993032AbdAFBdnseY8u (ORCPT ); Fri, 6 Jan 2017 02:33:43 +0100 From: James Hogan Subject: [PATCH 18/30] KVM: MIPS/TLB: Fix off-by-one in TLB invalidate Date: Fri, 6 Jan 2017 01:32:50 +0000 Message-ID: <8e0a619f180adcd98d6ba977a696a74ac0b7ed41.1483665879.git-series.james.hogan@imgtec.com> MIME-Version: 1.0 In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit 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: linux-mips@linux-mips.org Cc: James Hogan , Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Ralf Baechle , kvm@vger.kernel.org Message-ID: <20170106013250.m8L97Qrn-YFJzzsKc5iRFmsXptunazyyvxoUEHY9Ers@z> 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 ba490130b5e7..0bd380968627 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); -- git-series 0.8.10