[PATCH 4.4 05/67] kvm: x86: Fix vmwrite to SECONDARY_VM_EXEC_CONTROL

From: Greg Kroah-Hartman
Date: Wed Jan 27 2016 - 17:14:23 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Huaitong Han <huaitong.han@xxxxxxxxx>

commit 45bdbcfdf241149642fb6c25ab0c209d59c371b7 upstream.

vmx_cpuid_tries to update SECONDARY_VM_EXEC_CONTROL in the VMCS, but
it will cause a vmwrite error on older CPUs because the code does not
check for the presence of CPU_BASED_ACTIVATE_SECONDARY_CONTROLS.

This will get rid of the following trace on e.g. Core2 6600:

vmwrite error: reg 401e value 10 (err 12)
Call Trace:
[<ffffffff8116e2b9>] dump_stack+0x40/0x57
[<ffffffffa020b88d>] vmx_cpuid_update+0x5d/0x150 [kvm_intel]
[<ffffffffa01d8fdc>] kvm_vcpu_ioctl_set_cpuid2+0x4c/0x70 [kvm]
[<ffffffffa01b8363>] kvm_arch_vcpu_ioctl+0x903/0xfa0 [kvm]

Fixes: feda805fe7c4ed9cf78158e73b1218752e3b4314
Reported-by: Zdenek Kaspar <zkaspar82@xxxxxxxxx>
Signed-off-by: Huaitong Han <huaitong.han@xxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/x86/kvm/vmx.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -8932,7 +8932,8 @@ static void vmx_cpuid_update(struct kvm_
best->ebx &= ~bit(X86_FEATURE_INVPCID);
}

- vmcs_set_secondary_exec_control(secondary_exec_ctl);
+ if (cpu_has_secondary_exec_ctrls())
+ vmcs_set_secondary_exec_control(secondary_exec_ctl);

if (static_cpu_has(X86_FEATURE_PCOMMIT) && nested) {
if (guest_cpuid_has_pcommit(vcpu))