Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759307Ab0GAV2O (ORCPT ); Thu, 1 Jul 2010 17:28:14 -0400 Received: from kroah.org ([198.145.64.141]:33275 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933179Ab0GAVPg (ORCPT ); Thu, 1 Jul 2010 17:15:36 -0400 X-Mailbox-Line: From gregkh@clark.site Thu Jul 1 10:43:02 2010 Message-Id: <20100701174302.814231455@clark.site> User-Agent: quilt/0.48-10.1 Date: Thu, 01 Jul 2010 10:44:43 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Avi Kivity Subject: [193/200] KVM: MMU: Dont read pdptrs with mmu spinlock held in mmu_alloc_roots In-Reply-To: <20100701175201.GA2149@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2098 Lines: 68 2.6.34-stable review patch. If anyone has any objections, please let me know. ------------------ From: Avi Kivity On svm, kvm_read_pdptr() may require reading guest memory, which can sleep. Push the spinlock into mmu_alloc_roots(), and only take it after we've read the pdptr. Tested-by: Joerg Roedel Signed-off-by: Avi Kivity Signed-off-by: Greg Kroah-Hartman (Cherry-picked from commit 8facbbff071ff2b19268d3732e31badc60471e21) --- arch/x86/kvm/mmu.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2085,11 +2085,13 @@ static int mmu_alloc_roots(struct kvm_vc direct = 1; if (mmu_check_root(vcpu, root_gfn)) return 1; + spin_lock(&vcpu->kvm->mmu_lock); sp = kvm_mmu_get_page(vcpu, root_gfn, 0, PT64_ROOT_LEVEL, direct, ACC_ALL, NULL); root = __pa(sp->spt); ++sp->root_count; + spin_unlock(&vcpu->kvm->mmu_lock); vcpu->arch.mmu.root_hpa = root; return 0; } @@ -2111,11 +2113,14 @@ static int mmu_alloc_roots(struct kvm_vc root_gfn = 0; if (mmu_check_root(vcpu, root_gfn)) return 1; + spin_lock(&vcpu->kvm->mmu_lock); sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30, PT32_ROOT_LEVEL, direct, ACC_ALL, NULL); root = __pa(sp->spt); ++sp->root_count; + spin_unlock(&vcpu->kvm->mmu_lock); + vcpu->arch.mmu.pae_root[i] = root | PT_PRESENT_MASK; } vcpu->arch.mmu.root_hpa = __pa(vcpu->arch.mmu.pae_root); @@ -2479,7 +2484,9 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu) goto out; spin_lock(&vcpu->kvm->mmu_lock); kvm_mmu_free_some_pages(vcpu); + spin_unlock(&vcpu->kvm->mmu_lock); r = mmu_alloc_roots(vcpu); + spin_lock(&vcpu->kvm->mmu_lock); mmu_sync_roots(vcpu); spin_unlock(&vcpu->kvm->mmu_lock); if (r) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/