Re: [PATCH v6 2/9] KVM: VMX: Extend BUILD_CONTROLS_SHADOW macro to support 64-bit variation

From: Maxim Levitsky
Date: Fri Feb 25 2022 - 09:24:45 EST


On Fri, 2022-02-25 at 16:22 +0800, Zeng Guang wrote:
> From: Robert Hoo <robert.hu@xxxxxxxxxxxxxxx>
>
> The Tertiary VM-Exec Control, different from previous control fields, is 64
> bit. So extend BUILD_CONTROLS_SHADOW() by adding a 'bit' parameter, to
> support both 32 bit and 64 bit fields' auxiliary functions building.
>
> Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> Signed-off-by: Robert Hoo <robert.hu@xxxxxxxxxxxxxxx>
> Signed-off-by: Zeng Guang <guang.zeng@xxxxxxxxx>
> ---
> arch/x86/kvm/vmx/vmx.h | 59 ++++++++++++++++++++++--------------------
> 1 file changed, 31 insertions(+), 28 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
> index 7f2c82e7f38f..e07c76974fb0 100644
> --- a/arch/x86/kvm/vmx/vmx.h
> +++ b/arch/x86/kvm/vmx/vmx.h
> @@ -456,35 +456,38 @@ static inline u8 vmx_get_rvi(void)
> return vmcs_read16(GUEST_INTR_STATUS) & 0xff;
> }
>
> -#define BUILD_CONTROLS_SHADOW(lname, uname) \
> -static inline void lname##_controls_set(struct vcpu_vmx *vmx, u32 val) \
> -{ \
> - if (vmx->loaded_vmcs->controls_shadow.lname != val) { \
> - vmcs_write32(uname, val); \
> - vmx->loaded_vmcs->controls_shadow.lname = val; \
> - } \
> -} \
> -static inline u32 __##lname##_controls_get(struct loaded_vmcs *vmcs) \
> -{ \
> - return vmcs->controls_shadow.lname; \
> -} \
> -static inline u32 lname##_controls_get(struct vcpu_vmx *vmx) \
> -{ \
> - return __##lname##_controls_get(vmx->loaded_vmcs); \
> -} \
> -static inline void lname##_controls_setbit(struct vcpu_vmx *vmx, u32 val) \
> -{ \
> - lname##_controls_set(vmx, lname##_controls_get(vmx) | val); \
> -} \
> -static inline void lname##_controls_clearbit(struct vcpu_vmx *vmx, u32 val) \
> -{ \
> - lname##_controls_set(vmx, lname##_controls_get(vmx) & ~val); \
> +#define BUILD_CONTROLS_SHADOW(lname, uname, bits) \
> +static inline \
> +void lname##_controls_set(struct vcpu_vmx *vmx, u##bits val) \
> +{ \
> + if (vmx->loaded_vmcs->controls_shadow.lname != val) { \
> + vmcs_write##bits(uname, val); \
> + vmx->loaded_vmcs->controls_shadow.lname = val; \
> + } \
> +} \
> +static inline u##bits __##lname##_controls_get(struct loaded_vmcs *vmcs)\
> +{ \
> + return vmcs->controls_shadow.lname; \
> +} \
> +static inline u##bits lname##_controls_get(struct vcpu_vmx *vmx) \
> +{ \
> + return __##lname##_controls_get(vmx->loaded_vmcs); \
> +} \
> +static inline \
> +void lname##_controls_setbit(struct vcpu_vmx *vmx, u##bits val) \
> +{ \
> + lname##_controls_set(vmx, lname##_controls_get(vmx) | val); \
> +} \
> +static inline \
> +void lname##_controls_clearbit(struct vcpu_vmx *vmx, u##bits val) \
> +{ \
> + lname##_controls_set(vmx, lname##_controls_get(vmx) & ~val); \
> }
> -BUILD_CONTROLS_SHADOW(vm_entry, VM_ENTRY_CONTROLS)
> -BUILD_CONTROLS_SHADOW(vm_exit, VM_EXIT_CONTROLS)
> -BUILD_CONTROLS_SHADOW(pin, PIN_BASED_VM_EXEC_CONTROL)
> -BUILD_CONTROLS_SHADOW(exec, CPU_BASED_VM_EXEC_CONTROL)
> -BUILD_CONTROLS_SHADOW(secondary_exec, SECONDARY_VM_EXEC_CONTROL)
> +BUILD_CONTROLS_SHADOW(vm_entry, VM_ENTRY_CONTROLS, 32)
> +BUILD_CONTROLS_SHADOW(vm_exit, VM_EXIT_CONTROLS, 32)
> +BUILD_CONTROLS_SHADOW(pin, PIN_BASED_VM_EXEC_CONTROL, 32)
> +BUILD_CONTROLS_SHADOW(exec, CPU_BASED_VM_EXEC_CONTROL, 32)
> +BUILD_CONTROLS_SHADOW(secondary_exec, SECONDARY_VM_EXEC_CONTROL, 32)
>
> /*
> * VMX_REGS_LAZY_LOAD_SET - The set of registers that will be updated in the

I must admit that this will make it a bit harder to find references in the code.
I personally would just use pair of 32 bit capabilities, but I don't have strong opinion
on this.

Thus:

Reviewed-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>

Best regards,
Maxim Levitsky