linux-kernel - [PATCH 4.9 002/128] KVM: x86: fix return value for reserved EFER

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Date:   Wed, 29 May 2019 20:05:34 -0700
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Pavel Machek <pavel@...x.de>,
        Sean Christopherson <sean.j.christopherson@...el.com>,
        Paolo Bonzini <pbonzini@...hat.com>
Subject: [PATCH 4.9 002/128] KVM: x86: fix return value for reserved EFER

From: Paolo Bonzini <pbonzini@...hat.com>

commit 66f61c92889ff3ca365161fb29dd36d6354682ba upstream.

Commit 11988499e62b ("KVM: x86: Skip EFER vs. guest CPUID checks for
host-initiated writes", 2019-04-02) introduced a "return false" in a
function returning int, and anyway set_efer has a "nonzero on error"
conventon so it should be returning 1.

Reported-by: Pavel Machek <pavel@...x.de>
Fixes: 11988499e62b ("KVM: x86: Skip EFER vs. guest CPUID checks for host-initiated writes")
Cc: Sean Christopherson <sean.j.christopherson@...el.com>
Cc: stable@...r.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 arch/x86/kvm/x86.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1109,7 +1109,7 @@ static int set_efer(struct kvm_vcpu *vcp
 	u64 efer = msr_info->data;

 	if (efer & efer_reserved_bits)
-		return false;
+		return 1;

 	if (!msr_info->host_initiated) {
 		if (!__kvm_valid_efer(vcpu, efer))