From: Roman Kisel <romank@xxxxxxxxxxxxxxxxxxx> Sent: Tuesday, February 11, 2025 5:43 PM
>
> To run in the VTL mode, Hyper-V drivers have to know what
> VTL the system boots in, and the arm64/hyperv code does not
> have the means to compute that.
>
> Refactor the code to hoist the function that detects VTL,
> make it arch-neutral to be able to employ it to get the VTL
> on arm64.
>
> Signed-off-by: Roman Kisel <romank@xxxxxxxxxxxxxxxxxxx>
> ---
> arch/x86/hyperv/hv_init.c | 34 ----------------------------------
> drivers/hv/hv_common.c | 32 ++++++++++++++++++++++++++++++++
> include/asm-generic/mshyperv.h | 6 ++++++
> include/hyperv/hvgdk_mini.h | 2 +-
> 4 files changed, 39 insertions(+), 35 deletions(-)
>
> diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
> index 173005e6a95d..383bca1a3ae2 100644
> --- a/arch/x86/hyperv/hv_init.c
> +++ b/arch/x86/hyperv/hv_init.c
> @@ -411,40 +411,6 @@ static void __init hv_get_partition_id(void)
> local_irq_restore(flags);
> }
>
> -#if IS_ENABLED(CONFIG_HYPERV_VTL_MODE)
> -static u8 __init get_vtl(void)
> -{
> - u64 control = HV_HYPERCALL_REP_COMP_1 | HVCALL_GET_VP_REGISTERS;
> - struct hv_input_get_vp_registers *input;
> - struct hv_output_get_vp_registers *output;
> - unsigned long flags;
> - u64 ret;
> -
> - local_irq_save(flags);
> - input = *this_cpu_ptr(hyperv_pcpu_input_arg);
> - output = *this_cpu_ptr(hyperv_pcpu_output_arg);
> -
> - memset(input, 0, struct_size(input, names, 1));
> - input->partition_id = HV_PARTITION_ID_SELF;
> - input->vp_index = HV_VP_INDEX_SELF;
> - input->input_vtl.as_uint8 = 0;
> - input->names[0] = HV_REGISTER_VSM_VP_STATUS;
> -
> - ret = hv_do_hypercall(control, input, output);
> - if (hv_result_success(ret)) {
> - ret = output->values[0].reg8 & HV_X64_VTL_MASK;
> - } else {
> - pr_err("Failed to get VTL(error: %lld) exiting...\n", ret);
> - BUG();
> - }
> -
> - local_irq_restore(flags);
> - return ret;
> -}
> -#else
> -static inline u8 get_vtl(void) { return 0; }
> -#endif
> -
> /*
> * This function is to be invoked early in the boot sequence after the
> * hypervisor has been detected.
> diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
> index af5d1dc451f6..70f754710170 100644
> --- a/drivers/hv/hv_common.c
> +++ b/drivers/hv/hv_common.c
> @@ -283,6 +283,38 @@ static inline bool hv_output_page_exists(void)
> return hv_root_partition || IS_ENABLED(CONFIG_HYPERV_VTL_MODE);
> }
>
> +#if IS_ENABLED(CONFIG_HYPERV_VTL_MODE)
> +u8 __init get_vtl(void)
> +{
> + u64 control = HV_HYPERCALL_REP_COMP_1 | HVCALL_GET_VP_REGISTERS;
> + struct hv_input_get_vp_registers *input;
> + struct hv_output_get_vp_registers *output;
> + unsigned long flags;
> + u64 ret;
> +
> + local_irq_save(flags);
> + input = *this_cpu_ptr(hyperv_pcpu_input_arg);
> + output = *this_cpu_ptr(hyperv_pcpu_output_arg);
> +
> + memset(input, 0, struct_size(input, names, 1));
> + input->partition_id = HV_PARTITION_ID_SELF;
> + input->vp_index = HV_VP_INDEX_SELF;
> + input->input_vtl.as_uint8 = 0;
> + input->names[0] = HV_REGISTER_VSM_VP_STATUS;
> +
> + ret = hv_do_hypercall(control, input, output);
> + if (hv_result_success(ret)) {
> + ret = output->values[0].reg8 & HV_VTL_MASK;
> + } else {
> + pr_err("Failed to get VTL(error: %lld) exiting...\n", ret);
> + BUG();
> + }
> +
> + local_irq_restore(flags);
> + return ret;
> +}
> +#endif
> +
> int __init hv_common_init(void)
> {
> int i;
> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
> index a7bbe504e4f3..bb36856c3467 100644
> --- a/include/asm-generic/mshyperv.h
> +++ b/include/asm-generic/mshyperv.h
> @@ -314,4 +314,10 @@ static inline enum hv_isolation_type
> hv_get_isolation_type(void)
> }
> #endif /* CONFIG_HYPERV */
>
> +#if IS_ENABLED(CONFIG_HYPERV_VTL_MODE)
> +u8 __init get_vtl(void);
> +#else
> +static inline u8 get_vtl(void) { return 0; }
> +#endif
> +
> #endif
> diff --git a/include/hyperv/hvgdk_mini.h b/include/hyperv/hvgdk_mini.h
> index 155615175965..0f8443595732 100644
> --- a/include/hyperv/hvgdk_mini.h
> +++ b/include/hyperv/hvgdk_mini.h
> @@ -1202,7 +1202,7 @@ struct hv_send_ipi { /*
> HV_INPUT_SEND_SYNTHETIC_CLUSTER_IPI */
> u64 cpu_mask;
> } __packed;
>
> -#define HV_X64_VTL_MASK GENMASK(3, 0)
> +#define HV_VTL_MASK GENMASK(3, 0)
>
> /* Hyper-V memory host visibility */
> enum hv_mem_host_visibility {
> --
> 2.43.0
>
Reviewed-by: Michael Kelley <mhklinux@xxxxxxxxxxx>
