David Hildenbrand <david@xxxxxxxxxx> writes:
> We already always set that type but don't check if it is supported. Also
> for nVMX, we only support WB for now. Let's just require it.
Out of curiosity, is there old hardware that supports ept but not WB ?
Bandan
> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
> ---
> arch/x86/kvm/vmx.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index f6638ed..023c6dc 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -1200,6 +1200,11 @@ static inline bool cpu_has_vmx_ept_4levels(void)
> return vmx_capability.ept & VMX_EPT_PAGE_WALK_4_BIT;
> }
>
> +static inline bool cpu_has_vmx_ept_mt_wb(void)
> +{
> + return vmx_capability.ept & VMX_EPTP_WB_BIT;
> +}
> +
> static inline bool cpu_has_vmx_ept_ad_bits(void)
> {
> return vmx_capability.ept & VMX_EPT_AD_BIT;
> @@ -4302,7 +4307,6 @@ static u64 construct_eptp(struct kvm_vcpu *vcpu, unsigned long root_hpa)
> {
> u64 eptp = VMX_EPTP_MT_WB | VMX_EPTP_PWL_4;
>
> - /* TODO write the value reading from MSR */
> if (enable_ept_ad_bits &&
> (!is_guest_mode(vcpu) || nested_ept_ad_enabled(vcpu)))
> eptp |= VMX_EPTP_AD_ENABLE_BIT;
> @@ -6638,7 +6642,8 @@ static __init int hardware_setup(void)
> init_vmcs_shadow_fields();
>
> if (!cpu_has_vmx_ept() ||
> - !cpu_has_vmx_ept_4levels()) {
> + !cpu_has_vmx_ept_4levels() ||
> + !cpu_has_vmx_ept_mt_wb()) {
> enable_ept = 0;
> enable_unrestricted_guest = 0;
> enable_ept_ad_bits = 0;
