Re: [RFC v1 5/7] x86/hvm: Move INSTR_* constants to hvm.h

[Teddy Astie <teddy.astie@xxxxxxxxxx>]

Hello,

Le 18/05/2026 à 15:14, Ross Lagerwall a écrit :
> These aren't specific to SVM and will be used for emulator fast path so
> move them to hvm.h.
>
> Signed-off-by: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
> ---
>   xen/arch/x86/hvm/svm/svm.h         | 29 -----------------------------
>   xen/arch/x86/include/asm/hvm/hvm.h | 29 +++++++++++++++++++++++++++++
>   2 files changed, 29 insertions(+), 29 deletions(-)
>
> diff --git a/xen/arch/x86/hvm/svm/svm.h b/xen/arch/x86/hvm/svm/svm.h
> index cfa411ad5ae1..f75bca7c5f66 100644
> --- a/xen/arch/x86/hvm/svm/svm.h
> +++ b/xen/arch/x86/hvm/svm/svm.h
> @@ -36,35 +36,6 @@ static inline void svm_invlpga(unsigned long linear, 
> uint32_t asid)
>       asm volatile ( "invlpga" :: "a" (linear), "c" (asid) );
>   }
>   
> -/*
> - * Encoding for svm_get_insn_len().  We take X86EMUL_OPC() for the main
> - * opcode, shifted left to make room for the ModRM byte.
> - *
> - * The Grp7 instructions have their ModRM byte expressed in octal for easier
> - * cross referencing with the opcode extension table.
> - */
> -#define INSTR_ENC(opc, modrm) (((opc) << 8) | (modrm))
> -
> -#define INSTR_PAUSE      INSTR_ENC(X86EMUL_OPC_F3(0, 0x90), 0)
> -#define INSTR_INT3       INSTR_ENC(X86EMUL_OPC(   0, 0xcc), 0)
> -#define INSTR_ICEBP      INSTR_ENC(X86EMUL_OPC(   0, 0xf1), 0)
> -#define INSTR_HLT        INSTR_ENC(X86EMUL_OPC(   0, 0xf4), 0)
> -#define INSTR_XSETBV     INSTR_ENC(X86EMUL_OPC(0x0f, 0x01), 0321) /* octal-ok 
> */
> -#define INSTR_VMRUN      INSTR_ENC(X86EMUL_OPC(0x0f, 0x01), 0330) /* octal-ok 
> */
> -#define INSTR_VMCALL     INSTR_ENC(X86EMUL_OPC(0x0f, 0x01), 0331) /* octal-ok 
> */
> -#define INSTR_VMLOAD     INSTR_ENC(X86EMUL_OPC(0x0f, 0x01), 0332) /* octal-ok 
> */
> -#define INSTR_VMSAVE     INSTR_ENC(X86EMUL_OPC(0x0f, 0x01), 0333) /* octal-ok 
> */
> -#define INSTR_STGI       INSTR_ENC(X86EMUL_OPC(0x0f, 0x01), 0334) /* octal-ok 
> */
> -#define INSTR_CLGI       INSTR_ENC(X86EMUL_OPC(0x0f, 0x01), 0335) /* octal-ok 
> */
> -#define INSTR_INVLPGA    INSTR_ENC(X86EMUL_OPC(0x0f, 0x01), 0337) /* octal-ok 
> */
> -#define INSTR_RDTSCP     INSTR_ENC(X86EMUL_OPC(0x0f, 0x01), 0371) /* octal-ok 
> */
> -#define INSTR_INVD       INSTR_ENC(X86EMUL_OPC(0x0f, 0x08), 0)
> -#define INSTR_WBINVD     INSTR_ENC(X86EMUL_OPC(0x0f, 0x09), 0)
> -#define INSTR_WRMSR      INSTR_ENC(X86EMUL_OPC(0x0f, 0x30), 0)
> -#define INSTR_RDTSC      INSTR_ENC(X86EMUL_OPC(0x0f, 0x31), 0)
> -#define INSTR_RDMSR      INSTR_ENC(X86EMUL_OPC(0x0f, 0x32), 0)
> -#define INSTR_CPUID      INSTR_ENC(X86EMUL_OPC(0x0f, 0xa2), 0)
> -
>   unsigned int svm_get_insn_len(struct vcpu *v, unsigned int instr_enc);
>   unsigned int svm_get_task_switch_insn_len(void);
>   
> diff --git a/xen/arch/x86/include/asm/hvm/hvm.h b/xen/arch/x86/include/asm/hvm/hvm.h
> index e7c1364802f8..a9b64814ca71 100644
> --- a/xen/arch/x86/include/asm/hvm/hvm.h
> +++ b/xen/arch/x86/include/asm/hvm/hvm.h
> @@ -851,6 +851,35 @@ static inline void hvm_sync_pir_to_irr(struct vcpu *v)
>           alternative_vcall(hvm_funcs.sync_pir_to_irr, v);
>   }
>   
> +/*
> + * Encoding for svm_get_insn_len().  We take X86EMUL_OPC() for the main
> + * opcode, shifted left to make room for the ModRM byte.
> + *
> + * The Grp7 instructions have their ModRM byte expressed in octal for easier
> + * cross referencing with the opcode extension table.
> + */
> +#define INSTR_ENC(opc, modrm) (((opc) << 8) | (modrm))
> +
> +#define INSTR_PAUSE      INSTR_ENC(X86EMUL_OPC_F3(0, 0x90), 0)
> +#define INSTR_INT3       INSTR_ENC(X86EMUL_OPC(   0, 0xcc), 0)
> +#define INSTR_ICEBP      INSTR_ENC(X86EMUL_OPC(   0, 0xf1), 0)
> +#define INSTR_HLT        INSTR_ENC(X86EMUL_OPC(   0, 0xf4), 0)
> +#define INSTR_XSETBV     INSTR_ENC(X86EMUL_OPC(0x0f, 0x01), 0321) /* octal-ok 
> */
> +#define INSTR_VMRUN      INSTR_ENC(X86EMUL_OPC(0x0f, 0x01), 0330) /* octal-ok 
> */
> +#define INSTR_VMCALL     INSTR_ENC(X86EMUL_OPC(0x0f, 0x01), 0331) /* octal-ok 
> */
I assume a part of the plan is to use these constants for VMX as well.
Hence, you very likely want to split VMCALL (VMX) and VMMCALL (SVM) 
encodings (which is oddly named INSTR_VMCALL despite actually being 
actually vmmcall encoding).
> +#define INSTR_VMLOAD     INSTR_ENC(X86EMUL_OPC(0x0f, 0x01), 0332) /* octal-ok 
> */
> +#define INSTR_VMSAVE     INSTR_ENC(X86EMUL_OPC(0x0f, 0x01), 0333) /* octal-ok 
> */
> +#define INSTR_STGI       INSTR_ENC(X86EMUL_OPC(0x0f, 0x01), 0334) /* octal-ok 
> */
> +#define INSTR_CLGI       INSTR_ENC(X86EMUL_OPC(0x0f, 0x01), 0335) /* octal-ok 
> */
> +#define INSTR_INVLPGA    INSTR_ENC(X86EMUL_OPC(0x0f, 0x01), 0337) /* octal-ok 
> */
> +#define INSTR_RDTSCP     INSTR_ENC(X86EMUL_OPC(0x0f, 0x01), 0371) /* octal-ok 
> */
> +#define INSTR_INVD       INSTR_ENC(X86EMUL_OPC(0x0f, 0x08), 0)
> +#define INSTR_WBINVD     INSTR_ENC(X86EMUL_OPC(0x0f, 0x09), 0)
> +#define INSTR_WRMSR      INSTR_ENC(X86EMUL_OPC(0x0f, 0x30), 0)
> +#define INSTR_RDTSC      INSTR_ENC(X86EMUL_OPC(0x0f, 0x31), 0)
> +#define INSTR_RDMSR      INSTR_ENC(X86EMUL_OPC(0x0f, 0x32), 0)
> +#define INSTR_CPUID      INSTR_ENC(X86EMUL_OPC(0x0f, 0xa2), 0)
> +
>   #else  /* CONFIG_HVM */
>   
>   #define hvm_enabled false
Teddy

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