x86/kvm/nVMX: read from MSR_IA32_VMX_PROCBASED_CTLS2 only when it is available

commit 6b1971c694975e49af302229202c0043568b1791 upstream.

SDM says MSR_IA32_VMX_PROCBASED_CTLS2 is only available "If
(CPUID.01H:ECX.[5] && IA32_VMX_PROCBASED_CTLS[63])". It was found that
some old cpus (namely "Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz (family: 0x6,
model: 0xf, stepping: 0x6") don't have it. Add the missing check.

Reported-by: Zdenek Kaspar <zkaspar82@gmail.com>
Tested-by: Zdenek Kaspar <zkaspar82@gmail.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Cc: stable@vger.kernel.org
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 4ce6595e454cb2f506045ce2db002edfcc08a3cb..96740c6b4924435048860934750a06d4c5c2a5e3 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3620,9 +3620,11 @@ static void nested_vmx_setup_ctls_msrs(struct nested_vmx_msrs *msrs, bool apicv)
         * secondary cpu-based controls.  Do not include those that
         * depend on CPUID bits, they are added later by vmx_cpuid_update.
         */
-       rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2,
-               msrs->secondary_ctls_low,
-               msrs->secondary_ctls_high);
+       if (msrs->procbased_ctls_high & CPU_BASED_ACTIVATE_SECONDARY_CONTROLS)
+               rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2,
+                     msrs->secondary_ctls_low,
+                     msrs->secondary_ctls_high);
+
        msrs->secondary_ctls_low = 0;
        msrs->secondary_ctls_high &=
                SECONDARY_EXEC_DESC |