[PATCH 1/2] KVM: VMX: Don't expose unrestricted_guest is enabled if ept is disabled

From: Wanpeng Li
Date: Sat Oct 07 2017 - 22:35:19 EST


From: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>

SDM mentioned:

"If either the âunrestricted guestâ VM-execution control or the âmode-based
execute control for EPTâ VM- execution control is 1, the âenable EPTâ
VM-execution control must also be 1."

However, we can still observe unrestricted_guest is Y after inserting the kvm-intel.ko
w/ ept=N. It depends on later starts a guest in order that the function
vmx_compute_secondary_exec_control() can be executed, then both the module parameter
and exec control fields will be amended.

This patch fixes it by amending module parameter immediately during vmcs data setup.

Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Radim KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 244e366..3e664ca 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6737,7 +6737,7 @@ static __init int hardware_setup(void)
if (!cpu_has_vmx_ept_ad_bits() || !enable_ept)
enable_ept_ad_bits = 0;

- if (!cpu_has_vmx_unrestricted_guest())
+ if (!cpu_has_vmx_unrestricted_guest() || !enable_ept)
enable_unrestricted_guest = 0;

if (!cpu_has_vmx_flexpriority())
--
2.7.4