From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Mackerras Subject: [PATCH 3/5] KVM: PPC: Book3S PR: Don't keep scanning HPTEG after we find a match Date: Sat, 22 Jun 2013 17:14:48 +1000 Message-ID: <20130622071448.GD2791@iris.ozlabs.ibm.com> References: <20130622071244.GA2791@iris.ozlabs.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org To: Alexander Graf , kvm-ppc@vger.kernel.org Return-path: Received: from ozlabs.org ([203.10.76.45]:59735 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751037Ab3FVHQh (ORCPT ); Sat, 22 Jun 2013 03:16:37 -0400 Content-Disposition: inline In-Reply-To: <20130622071244.GA2791@iris.ozlabs.ibm.com> Sender: kvm-owner@vger.kernel.org List-ID: The loop in kvmppc_mmu_book3s_64_xlate() that looks up a translation in the guest hashed page table (HPT) keeps going if it finds an HPTE that matches but doesn't allow access. This is incorrect; it is different from what the hardware does, and there should never be more than one matching HPTE anyway. This fixes it to stop when any matching HPTE is found. Signed-off-by: Paul Mackerras --- arch/powerpc/kvm/book3s_64_mmu.c | 14 ++------------ 1 file changed, 2 insertions(+), 12 deletions(-) diff --git a/arch/powerpc/kvm/book3s_64_mmu.c b/arch/powerpc/kvm/book3s_64_mmu.c index b871721..2e93bb5 100644 --- a/arch/powerpc/kvm/book3s_64_mmu.c +++ b/arch/powerpc/kvm/book3s_64_mmu.c @@ -167,7 +167,6 @@ static int kvmppc_mmu_book3s_64_xlate(struct kvm_vcpu *vcpu, gva_t eaddr, int i; u8 key = 0; bool found = false; - bool perm_err = false; int second = 0; ulong mp_ea = vcpu->arch.magic_page_ea; @@ -248,11 +247,6 @@ do_second: break; } - if (!gpte->may_read) { - perm_err = true; - continue; - } - dprintk("KVM MMU: Translated 0x%lx [0x%llx] -> 0x%llx " "-> 0x%lx\n", eaddr, avpn, gpte->vpage, gpte->raddr); @@ -281,6 +275,8 @@ do_second: if (pteg[i+1] != oldr) copy_to_user((void __user *)ptegp, pteg, sizeof(pteg)); + if (!gpte->may_read) + return -EPERM; return 0; } else { dprintk("KVM MMU: No PTE found (ea=0x%lx sdr1=0x%llx " @@ -296,13 +292,7 @@ do_second: } } - no_page_found: - - - if (perm_err) - return -EPERM; - return -ENOENT; no_seg_found: -- 1.8.3.1