Re: [RFC PATCH 01/18] x86/hyperv: convert hyperv statuses to linux error codes

[Vitaly Kuznetsov]

Nuno Das Neves <nunodasneves@xxxxxxxxxxxxxxxxxxx> writes:

> Return linux-friendly error codes from hypercall wrapper functions.
> This will be needed in the mshv module.
>
> Signed-off-by: Nuno Das Neves <nunodasneves@xxxxxxxxxxxxxxxxxxx>
> ---
>  arch/x86/hyperv/hv_proc.c         | 30 ++++++++++++++++++++++++++---
>  arch/x86/include/asm/mshyperv.h   |  1 +
>  include/asm-generic/hyperv-tlfs.h | 32 +++++++++++++++++++++----------
>  3 files changed, 50 insertions(+), 13 deletions(-)
>
> diff --git a/arch/x86/hyperv/hv_proc.c b/arch/x86/hyperv/hv_proc.c
> index 0fd972c9129a..8f86f8e86748 100644
> --- a/arch/x86/hyperv/hv_proc.c
> +++ b/arch/x86/hyperv/hv_proc.c
> @@ -18,6 +18,30 @@
>  #define HV_DEPOSIT_MAX_ORDER (8)
>  #define HV_DEPOSIT_MAX (1 << HV_DEPOSIT_MAX_ORDER)
>  
> +int hv_status_to_errno(int hv_status)
> +{
> +	switch (hv_status) {
> +	case HV_STATUS_SUCCESS:
> +		return 0;
> +	case HV_STATUS_INVALID_PARAMETER:
> +	case HV_STATUS_UNKNOWN_PROPERTY:
> +	case HV_STATUS_PROPERTY_VALUE_OUT_OF_RANGE:
> +	case HV_STATUS_INVALID_VP_INDEX:
> +	case HV_STATUS_INVALID_REGISTER_VALUE:
> +	case HV_STATUS_INVALID_LP_INDEX:
> +		return EINVAL;
> +	case HV_STATUS_ACCESS_DENIED:
> +	case HV_STATUS_OPERATION_DENIED:
> +		return EACCES;
> +	case HV_STATUS_NOT_ACKNOWLEDGED:
> +	case HV_STATUS_INVALID_VP_STATE:
> +	case HV_STATUS_INVALID_PARTITION_STATE:
> +		return EBADFD;
> +	}
> +	return ENOTRECOVERABLE;
> +}
> +EXPORT_SYMBOL_GPL(hv_status_to_errno);
> +
>  /*
>   * Deposits exact number of pages
>   * Must be called with interrupts enabled
> @@ -99,7 +123,7 @@ int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages)
>  
>  	if (status != HV_STATUS_SUCCESS) {
>  		pr_err("Failed to deposit pages: %d\n", status);
> -		ret = status;
> +		ret = -hv_status_to_errno(status);

"-hv_status_to_errno" looks weird, could we just return
'-EINVAL'/'-EACCES'/... from hv_status_to_errno() instead?

>  		goto err_free_allocations;
>  	}
>  
> @@ -155,7 +179,7 @@ int hv_call_add_logical_proc(int node, u32 lp_index, u32 apic_id)
>  			if (status != HV_STATUS_SUCCESS) {
>  				pr_err("%s: cpu %u apic ID %u, %d\n", __func__,
>  				       lp_index, apic_id, status);
> -				ret = status;
> +				ret = -hv_status_to_errno(status);
>  			}
>  			break;
>  		}
> @@ -203,7 +227,7 @@ int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u32 flags)
>  			if (status != HV_STATUS_SUCCESS) {
>  				pr_err("%s: vcpu %u, lp %u, %d\n", __func__,
>  				       vp_index, flags, status);
> -				ret = status;
> +				ret = -hv_status_to_errno(status);
>  			}
>  			break;
>  		}
> diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
> index cbee72550a12..eb75faa4d4c5 100644
> --- a/arch/x86/include/asm/mshyperv.h
> +++ b/arch/x86/include/asm/mshyperv.h
> @@ -243,6 +243,7 @@ int hyperv_flush_guest_mapping_range(u64 as,
>  int hyperv_fill_flush_guest_mapping_list(
>  		struct hv_guest_mapping_flush_list *flush,
>  		u64 start_gfn, u64 end_gfn);
> +int hv_status_to_errno(int hv_status);
>  
>  extern bool hv_root_partition;
>  
> diff --git a/include/asm-generic/hyperv-tlfs.h b/include/asm-generic/hyperv-tlfs.h
> index dd385c6a71b5..445244192fa4 100644
> --- a/include/asm-generic/hyperv-tlfs.h
> +++ b/include/asm-generic/hyperv-tlfs.h
> @@ -181,16 +181,28 @@ enum HV_GENERIC_SET_FORMAT {
>  #define HV_HYPERCALL_REP_START_MASK	GENMASK_ULL(59, 48)
>  
>  /* hypercall status code */
> -#define HV_STATUS_SUCCESS			0
> -#define HV_STATUS_INVALID_HYPERCALL_CODE	2
> -#define HV_STATUS_INVALID_HYPERCALL_INPUT	3
> -#define HV_STATUS_INVALID_ALIGNMENT		4
> -#define HV_STATUS_INVALID_PARAMETER		5
> -#define HV_STATUS_OPERATION_DENIED		8
> -#define HV_STATUS_INSUFFICIENT_MEMORY		11
> -#define HV_STATUS_INVALID_PORT_ID		17
> -#define HV_STATUS_INVALID_CONNECTION_ID		18
> -#define HV_STATUS_INSUFFICIENT_BUFFERS		19
> +#define HV_STATUS_SUCCESS			0x0
> +#define HV_STATUS_INVALID_HYPERCALL_CODE	0x2
> +#define HV_STATUS_INVALID_HYPERCALL_INPUT	0x3
> +#define HV_STATUS_INVALID_ALIGNMENT		0x4
> +#define HV_STATUS_INVALID_PARAMETER		0x5
> +#define HV_STATUS_ACCESS_DENIED			0x6
> +#define HV_STATUS_INVALID_PARTITION_STATE	0x7
> +#define HV_STATUS_OPERATION_DENIED		0x8
> +#define HV_STATUS_UNKNOWN_PROPERTY		0x9
> +#define HV_STATUS_PROPERTY_VALUE_OUT_OF_RANGE	0xA
> +#define HV_STATUS_INSUFFICIENT_MEMORY		0xB
> +#define HV_STATUS_INVALID_PARTITION_ID		0xD
> +#define HV_STATUS_INVALID_VP_INDEX		0xE
> +#define HV_STATUS_NOT_FOUND			0x10
> +#define HV_STATUS_INVALID_PORT_ID		0x11
> +#define HV_STATUS_INVALID_CONNECTION_ID		0x12
> +#define HV_STATUS_INSUFFICIENT_BUFFERS		0x13
> +#define HV_STATUS_NOT_ACKNOWLEDGED		0x14
> +#define HV_STATUS_INVALID_VP_STATE		0x15
> +#define HV_STATUS_NO_RESOURCES			0x1D
> +#define HV_STATUS_INVALID_LP_INDEX		0x41
> +#define HV_STATUS_INVALID_REGISTER_VALUE	0x50
>  
>  /*
>   * The Hyper-V TimeRefCount register and the TSC

-- 
Vitaly