Re: [PATCH 09/16] x86/vmx: Introduce VMX_FEATURES_*

From: Paolo Bonzini
Date: Mon Oct 07 2019 - 13:08:30 EST


On 04/10/19 23:56, Sean Christopherson wrote:
> +#define VMX_FEATURE_RDSEED_EXITING ( 2*32+ 16) /* "" VM-Exit on RDSEED */
> +#define VMX_FEATURE_PAGE_MOD_LOGGING ( 2*32+ 17) /* "pml" Log dirty pages into buffer */
> +#define VMX_FEATURE_EPT_VIOLATION_VE ( 2*32+ 18) /* "" Conditionally reflect EPT violations as #VE exceptions */
> +#define VMX_FEATURE_PT_CONCEAL_VMX ( 2*32+ 19) /* "" Suppress VMX indicators in Processor Trace */
> +#define VMX_FEATURE_XSAVES ( 2*32+ 20) /* "" Enable XSAVES and XRSTORS in guest */
> +#define VMX_FEATURE_RESERVED_PIN_21 ( 2*32+ 21) /* "" Reserved */
> +#define VMX_FEATURE_MODE_BASED_EPT_EXEC ( 2*32+ 22) /* Enable separate EPT EXEC bits for supervisor vs. user */
> +#define VMX_FEATURE_RESERVED_PIN_23 ( 2*32+ 23) /* "" Reserved */
> +#define VMX_FEATURE_PT_USE_GPA ( 2*32+ 24) /* "" Processor Trace logs GPAs */
> +#define VMX_FEATURE_TSC_SCALING ( 2*32+ 25) /* Scale hardware TSC when read in guest */
> +#define VMX_FEATURE_RESERVED_PIN_26 ( 2*32+ 26) /* "" Reserved */
> +#define VMX_FEATURE_RESERVED_PIN_27 ( 2*32+ 27) /* "" Reserved */
> +#define VMX_FEATURE_ENCLV_EXITING ( 2*32+ 28) /* "" VM-Exit on ENCLV (leaf dependent) */
> +#define VMX_FEATURE_RESERVED_PIN_29 ( 2*32+ 29) /* "" Reserved */
> +#define VMX_FEATURE_RESERVED_PIN_30 ( 2*32+ 30) /* "" Reserved */
> +#define VMX_FEATURE_RESERVED_PIN_31 ( 2*32+ 31) /* "" Reserved */

Pasto on the reserved bit names, but in general why is it useful to
define them?

Paolo