Re: [PATCH v3 3/4] KVM: SVM: Add GHCB Accessor functions

[Sean Christopherson <sean.j.christopherson@intel.com>]

On Mon, Aug 03, 2020 at 02:27:07PM +0200, Joerg Roedel wrote:
> From: Joerg Roedel <jroedel@suse.de>
> 
> Building a correct GHCB for the hypervisor requires setting valid bits
> in the GHCB. Simplify that process by providing accessor functions to
> set values and to update the valid bitmap and to check the valid bitmap
> in KVM.
> 
> Signed-off-by: Joerg Roedel <jroedel@suse.de>
> ---
>  arch/x86/include/asm/svm.h | 43 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 43 insertions(+)
> 
> diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
> index 9a3e0b802716..71a308f1fbc8 100644
> --- a/arch/x86/include/asm/svm.h
> +++ b/arch/x86/include/asm/svm.h
> @@ -341,4 +341,47 @@ struct __attribute__ ((__packed__)) vmcb {
>  
>  #define SVM_CR0_SELECTIVE_MASK (X86_CR0_TS | X86_CR0_MP)
>  
> +/* GHCB Accessor functions */
> +
> +#define GHCB_BITMAP_IDX(field)							\
> +        (offsetof(struct vmcb_save_area, field) / sizeof(u64))
> +
> +#define DEFINE_GHCB_ACCESSORS(field)						\
> +	static inline bool ghcb_##field##_is_valid(const struct ghcb *ghcb)	\
> +	{									\
> +		return test_bit(GHCB_BITMAP_IDX(field),				\
> +				(unsigned long *)&(ghcb)->save.valid_bitmap);	\

'ghcb' doesn't need to be wrapped in (), it's a parameter to a function.

> +	}									\
> +										\
> +	static inline void ghcb_set_##field(struct ghcb *ghcb, u64 value)	\
> +	{									\
> +		__set_bit(GHCB_BITMAP_IDX(field),				\
> +			  (unsigned long *)&(ghcb)->save.valid_bitmap);		\

Same comment here.

> +		ghcb->save.field = value;					\
> +	}
> +
> +DEFINE_GHCB_ACCESSORS(cpl)
> +DEFINE_GHCB_ACCESSORS(rip)
> +DEFINE_GHCB_ACCESSORS(rsp)
> +DEFINE_GHCB_ACCESSORS(rax)
> +DEFINE_GHCB_ACCESSORS(rcx)
> +DEFINE_GHCB_ACCESSORS(rdx)
> +DEFINE_GHCB_ACCESSORS(rbx)
> +DEFINE_GHCB_ACCESSORS(rbp)
> +DEFINE_GHCB_ACCESSORS(rsi)
> +DEFINE_GHCB_ACCESSORS(rdi)
> +DEFINE_GHCB_ACCESSORS(r8)
> +DEFINE_GHCB_ACCESSORS(r9)
> +DEFINE_GHCB_ACCESSORS(r10)
> +DEFINE_GHCB_ACCESSORS(r11)
> +DEFINE_GHCB_ACCESSORS(r12)
> +DEFINE_GHCB_ACCESSORS(r13)
> +DEFINE_GHCB_ACCESSORS(r14)
> +DEFINE_GHCB_ACCESSORS(r15)
> +DEFINE_GHCB_ACCESSORS(sw_exit_code)
> +DEFINE_GHCB_ACCESSORS(sw_exit_info_1)
> +DEFINE_GHCB_ACCESSORS(sw_exit_info_2)
> +DEFINE_GHCB_ACCESSORS(sw_scratch)
> +DEFINE_GHCB_ACCESSORS(xcr0)
> +
>  #endif
> -- 
> 2.17.1
>