From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Zhang Haoyu , Paolo Bonzini Subject: [ 05/27] KVM: x86: remove vcpus CPL check in host-invoked XCR set Date: Tue, 25 Jun 2013 11:35:24 -0700 Message-Id: <20130625183518.296893797@linuxfoundation.org> In-Reply-To: <20130625183517.651770593@linuxfoundation.org> References: <20130625183517.651770593@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.4-stable 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: Greg Kroah-Hartman --- 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 @@ -555,8 +555,6 @@ 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)) @@ -570,7 +568,8 @@ 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; }