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

Sean Christopherson
2020-08-03T18:45:49Z

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
>