On Mon, 2021-01-25 at 10:41 +0100, Vitaly Kuznetsov wrote:
> Robert Hoo <robert.hu@xxxxxxxxxxxxxxx> writes:
> We'll have to do something about Enlightened VMCS I believe. In
> theory,
> when eVMCS is in use, 'CPU_BASED_ACTIVATE_TERTIARY_CONTROLS' should
> not
> be exposed, e.g. when KVM hosts a EVMCS enabled guest the control
> should
> be filtered out. Something like (completely untested):
>
> diff --git a/arch/x86/kvm/vmx/evmcs.c b/arch/x86/kvm/vmx/evmcs.c
> index 41f24661af04..c44ff05f3235 100644
> --- a/arch/x86/kvm/vmx/evmcs.c
> +++ b/arch/x86/kvm/vmx/evmcs.c
> @@ -299,6 +299,7 @@ const unsigned int nr_evmcs_1_fields =
> ARRAY_SIZE(vmcs_field_to_evmcs_1);
>
> __init void evmcs_sanitize_exec_ctrls(struct vmcs_config *vmcs_conf)
> {
> + vmcs_conf->cpu_based_exec_ctrl &=
> ~EVMCS1_UNSUPPORTED_EXEC_CTRL;
> vmcs_conf->pin_based_exec_ctrl &=
> ~EVMCS1_UNSUPPORTED_PINCTRL;
> vmcs_conf->cpu_based_2nd_exec_ctrl &=
> ~EVMCS1_UNSUPPORTED_2NDEXEC;
>
> diff --git a/arch/x86/kvm/vmx/evmcs.h b/arch/x86/kvm/vmx/evmcs.h
> index bd41d9462355..bf2c5e7a4a8f 100644
> --- a/arch/x86/kvm/vmx/evmcs.h
> +++ b/arch/x86/kvm/vmx/evmcs.h
> @@ -50,6 +50,7 @@ DECLARE_STATIC_KEY_FALSE(enable_evmcs);
> */
> #define EVMCS1_UNSUPPORTED_PINCTRL (PIN_BASED_POSTED_INTR | \
> PIN_BASED_VMX_PREEMPTION_TIMER)
> +#define EVMCS1_UNSUPPORTED_EXEC_CTRL
> (CPU_BASED_ACTIVATE_TERTIARY_CONTROLS)
> #define
> EVMCS1_UNSUPPORTED_2NDEXEC \
> (SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY
> | \
> SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES
> | \
>
> should do the job I think.
>
Hi Vitaly,
I'm going to incorporate above patch in my next version. Shall I have
it your signed-off-by?
[setup_vmcs_config: filter out tertiary control when using eVMCS]
signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
