Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752624Ab3FZCvM (ORCPT ); Tue, 25 Jun 2013 22:51:12 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:54140 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752064Ab3FZCpW (ORCPT ); Tue, 25 Jun 2013 22:45:22 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Zhanghaoyu (A)" , "Paolo Bonzini" Date: Wed, 26 Jun 2013 03:35:58 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [05/26] KVM: x86: remove vcpu's CPL check in host-invoked XCR set In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.101 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1773 Lines: 58 3.2.48-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: "Zhanghaoyu (A)" commit 764bcbc5a6d7a2f3e75c9f0e4caa984e2926e346 upstream. __kvm_set_xcr function does the CPL check when set xcr. __kvm_set_xcr is called in two flows, one is invoked by guest, call stack shown as below, handle_xsetbv(or xsetbv_interception) kvm_set_xcr __kvm_set_xcr the other one is invoked by host, for example during system reset: kvm_arch_vcpu_ioctl kvm_vcpu_ioctl_x86_set_xcrs __kvm_set_xcr The former does need the CPL check, but the latter does not. Signed-off-by: Zhang Haoyu [Tweaks to commit message. - Paolo] Signed-off-by: Paolo Bonzini Signed-off-by: Ben Hutchings --- arch/x86/kvm/x86.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -551,8 +551,6 @@ int __kvm_set_xcr(struct kvm_vcpu *vcpu, if (index != XCR_XFEATURE_ENABLED_MASK) return 1; xcr0 = xcr; - if (kvm_x86_ops->get_cpl(vcpu) != 0) - return 1; if (!(xcr0 & XSTATE_FP)) return 1; if ((xcr0 & XSTATE_YMM) && !(xcr0 & XSTATE_SSE)) @@ -566,7 +564,8 @@ int __kvm_set_xcr(struct kvm_vcpu *vcpu, int kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr) { - if (__kvm_set_xcr(vcpu, index, xcr)) { + if (kvm_x86_ops->get_cpl(vcpu) != 0 || + __kvm_set_xcr(vcpu, index, xcr)) { kvm_inject_gp(vcpu, 0); return 1; } -- 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/