kvm: vmx: Fix entry number check for add_atomic_switch_msr()

commit 98ae70cc476e833332a2c6bb72f941a25f0de226 upstream.

Commit ca83b4a7f2d068da79a0 ("x86/KVM/VMX: Add find_msr() helper function")
introduces the helper function find_msr(), which returns -ENOENT when
not find the msr in vmx->msr_autoload.guest/host. Correct checking contion
of no more available entry in vmx->msr_autoload.

Fixes: ca83b4a7f2d0 ("x86/KVM/VMX: Add find_msr() helper function")
Cc: stable@vger.kernel.org
Signed-off-by: Xiaoyao Li <xiaoyao.li@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 91db841101ca4aed239ac0aea80409016a28b971..1870fa7387b75e1b9892ee6b4598e85494cba537 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2178,7 +2178,8 @@ static void add_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr,
        if (!entry_only)
                j = find_msr(&m->host, msr);
 
-       if (i == NR_AUTOLOAD_MSRS || j == NR_AUTOLOAD_MSRS) {
+       if ((i < 0 && m->guest.nr == NR_AUTOLOAD_MSRS) ||
+               (j < 0 &&  m->host.nr == NR_AUTOLOAD_MSRS)) {
                printk_once(KERN_WARNING "Not enough msr switch entries. "
                                "Can't add msr %x\n", msr);
                return;