RE: [PATCH v5 04/10] hyperv: Introduce hv_recommend_using_aeoi()

Michael Kelley
2025-03-06T19:12:47Z

From: Nuno Das Neves <nunodasneves@linux.microsoft.com>
>
> Factor out the check for enabling auto eoi, to be reused in root
> partition code.

Reviewed-by: Michael Kelley <mhklinux@outlook.com>

>
> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
> ---
> drivers/hv/hv.c | 12 +-----------
> include/asm-generic/mshyperv.h | 13 +++++++++++++
> 2 files changed, 14 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
> index a38f84548bc2..308c8f279df8 100644
> --- a/drivers/hv/hv.c
> +++ b/drivers/hv/hv.c
> @@ -313,17 +313,7 @@ void hv_synic_enable_regs(unsigned int cpu)
>
> shared_sint.vector = vmbus_interrupt;
> shared_sint.masked = false;
> -
> - /*
> - * On architectures where Hyper-V doesn't support AEOI (e.g., ARM64),
> - * it doesn't provide a recommendation flag and AEOI must be disabled.
> - */
> -#ifdef HV_DEPRECATING_AEOI_RECOMMENDED
> - shared_sint.auto_eoi =
> - !(ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED);
> -#else
> - shared_sint.auto_eoi = 0;
> -#endif
> + shared_sint.auto_eoi = hv_recommend_using_aeoi();
> hv_set_msr(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
>
> /* Enable the global synic bit */
> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
> index 258034dfd829..1f46d19a16aa 100644
> --- a/include/asm-generic/mshyperv.h
> +++ b/include/asm-generic/mshyperv.h
> @@ -77,6 +77,19 @@ extern u64 hv_do_fast_hypercall16(u16 control, u64 input1, u64
> input2);
> bool hv_isolation_type_snp(void);
> bool hv_isolation_type_tdx(void);
>
> +/*
> + * On architectures where Hyper-V doesn't support AEOI (e.g., ARM64),
> + * it doesn't provide a recommendation flag and AEOI must be disabled.
> + */
> +static inline bool hv_recommend_using_aeoi(void)
> +{
> +#ifdef HV_DEPRECATING_AEOI_RECOMMENDED
> + return !(ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED);
> +#else
> + return false;
> +#endif
> +}
> +
> static inline struct hv_proximity_domain_info hv_numa_node_to_pxm_info(int node)
> {
> struct hv_proximity_domain_info pxm_info = {};
> --
> 2.34.1