Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754302Ab0GCIGp (ORCPT ); Sat, 3 Jul 2010 04:06:45 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:55980 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754175Ab0GCIGd (ORCPT ); Sat, 3 Jul 2010 04:06:33 -0400 Message-ID: <4C2EEEA2.5090305@cn.fujitsu.com> Date: Sat, 03 Jul 2010 16:02:42 +0800 From: Xiao Guangrong User-Agent: Thunderbird 2.0.0.24 (Windows/20100228) MIME-Version: 1.0 To: Avi Kivity CC: Marcelo Tosatti , LKML , KVM list Subject: [PATCH] KVM: VMX: fix tlb flush with invalid root Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2623 Lines: 77 Commit 341d9b535b6c simplify reload logic while entry guest mode, it can avoid unnecessary sync-root if KVM_REQ_MMU_RELOAD and KVM_REQ_MMU_SYNC both set. But, it cause a issue that when we handle 'KVM_REQ_TLB_FLUSH', the root is invalid, it is triggered during my test: Kernel BUG at ffffffffa00212b8 [verbose debug info unavailable] ...... [] ? fget_light+0x111/0x28e [] sys_ioctl+0x47/0x6a [] system_call_fastpath+0x16/0x1b Code: f0 eb 21 f7 c2 00 00 00 04 74 22 48 8d 45 f0 48 c7 45 f0 00 00 00 00 48 c7 45 f8 00 00 00 00 b9 02 00 00 00 66 0f 38 80 08 77 02 <0f> 0b c9 c3 55 48 89 e5 0f 1f 44 00 00 ba 00 68 00 00 48 8b 8f RIP [] vmx_flush_tlb+0xdf/0xe3 [kvm_intel] RSP Fixed by directly return if the root is not ready. Signed-off-by: Xiao Guangrong --- arch/x86/include/asm/kvm_host.h | 2 ++ arch/x86/kvm/mmu.c | 2 -- arch/x86/kvm/vmx.c | 5 ++++- 3 files changed, 6 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 2bda624..8f522ec 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -40,6 +40,8 @@ 0xFFFFFF0000000000ULL) #define INVALID_PAGE (~(hpa_t)0) +#define VALID_PAGE(x) ((x) != INVALID_PAGE) + #define UNMAPPED_GVA (~(gpa_t)0) /* KVM Hugepage definitions for x86 */ diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index a0c5c31..399ddb0 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -92,8 +92,6 @@ module_param(oos_shadow, bool, 0644); #define PT_FIRST_AVAIL_BITS_SHIFT 9 #define PT64_SECOND_AVAIL_BITS_SHIFT 52 -#define VALID_PAGE(x) ((x) != INVALID_PAGE) - #define PT64_LEVEL_BITS 9 #define PT64_LEVEL_SHIFT(level) \ diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 806ab12..ebaaeaf 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1831,8 +1831,11 @@ static void exit_lmode(struct kvm_vcpu *vcpu) static void vmx_flush_tlb(struct kvm_vcpu *vcpu) { vpid_sync_context(to_vmx(vcpu)); - if (enable_ept) + if (enable_ept) { + if (!VALID_PAGE(vcpu->arch.mmu.root_hpa)) + return; ept_sync_context(construct_eptp(vcpu->arch.mmu.root_hpa)); + } } static void vmx_decache_cr0_guest_bits(struct kvm_vcpu *vcpu) -- 1.6.1.2 -- 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/