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

[Nuno Das Neves <nunodasneves@linux.microsoft.com>]

On 2/9/2021 5:04 AM, Vitaly Kuznetsov wrote:
> Nuno Das Neves <nunodasneves@linux.microsoft.com> 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@linux.microsoft.com>
>> ---
>>  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?
> 

Yes, good idea.

>>  		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
>