KVM: x86: remove vcpu's CPL check in host-invoked XCR set (764bcbc5) · Commits · 戴 / test

__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. Cc: stable@vger.kernel.org Signed-off-by:

Zhang Haoyu <haoyu.zhang@huawei.com> [Tweaks to commit message. - Paolo] Signed-off-by:

Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/x86.c

+2 −3

Original line number	Original line	Diff line number	Diff line
	@@ -582,8 +582,6 @@ int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
	if (index != XCR_XFEATURE_ENABLED_MASK)		if (index != XCR_XFEATURE_ENABLED_MASK)
	return 1;		return 1;
	xcr0 = xcr;		xcr0 = xcr;
	if (kvm_x86_ops->get_cpl(vcpu) != 0)
	return 1;
	if (!(xcr0 & XSTATE_FP))		if (!(xcr0 & XSTATE_FP))
	return 1;		return 1;
	if ((xcr0 & XSTATE_YMM) && !(xcr0 & XSTATE_SSE))		if ((xcr0 & XSTATE_YMM) && !(xcr0 & XSTATE_SSE))
	@@ -597,7 +595,8 @@ int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)

	int kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)		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);		kvm_inject_gp(vcpu, 0);
	return 1;		return 1;
	}		}

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