RE: [PATCH 02/19] asm-generic/hyperv: convert hyperv statuses to strings

[Sunil Muthuswamy <sunilmut@microsoft.com>]

> -----Original Message-----
> From: Nuno Das Neves <nunodasneves@linux.microsoft.com>
> Sent: Friday, May 28, 2021 3:43 PM
> To: linux-hyperv@vger.kernel.org; linux-kernel@vger.kernel.org
> Cc: virtualization@lists.linux-foundation.org; Michael Kelley <mikelley@microsoft.com>; viremana@linux.microsoft.com; Sunil
> Muthuswamy <sunilmut@microsoft.com>; wei.liu@kernel.org; vkuznets <vkuznets@redhat.com>; Lillian Grassin-Drake
> <Lillian.GrassinDrake@microsoft.com>; KY Srinivasan <kys@microsoft.com>
> Subject: [PATCH 02/19] asm-generic/hyperv: convert hyperv statuses to strings
> 
> Allow hyperv hypercall failures to be debugged more easily with dmesg.
> This will be used in the mshv module.
> 
> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
> ---
>  arch/x86/hyperv/hv_init.c         |  2 +-
>  arch/x86/hyperv/hv_proc.c         | 10 +++---
>  include/asm-generic/hyperv-tlfs.h | 52 ++++++++++++++++++-------------
>  include/asm-generic/mshyperv.h    |  8 +++++
>  4 files changed, 44 insertions(+), 28 deletions(-)
> 
> diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
> index bb0ae4b5c00f..722bafdb2225 100644
> --- a/arch/x86/hyperv/hv_init.c
> +++ b/arch/x86/hyperv/hv_init.c
> @@ -349,7 +349,7 @@ static void __init hv_get_partition_id(void)
>  	status = hv_do_hypercall(HVCALL_GET_PARTITION_ID, NULL, output_page);
>  	if (!hv_result_success(status)) {
>  		/* No point in proceeding if this failed */
> -		pr_err("Failed to get partition ID: %lld\n", status);
> +		pr_err("Failed to get partition ID: %s\n", hv_status_to_string(status));
>  		BUG();
>  	}
>  	hv_current_partition_id = output_page->partition_id;
> diff --git a/arch/x86/hyperv/hv_proc.c b/arch/x86/hyperv/hv_proc.c
> index 59cf9a9e0975..30951e778577 100644
> --- a/arch/x86/hyperv/hv_proc.c
> +++ b/arch/x86/hyperv/hv_proc.c
> @@ -117,7 +117,7 @@ int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages)
>  				     page_count, 0, input_page, NULL);
>  	local_irq_restore(flags);
>  	if (!hv_result_success(status)) {
> -		pr_err("Failed to deposit pages: %lld\n", status);
> +		pr_err("Failed to deposit pages: %s\n", hv_status_to_string(status));
>  		ret = hv_status_to_errno(status);
>  		goto err_free_allocations;
>  	}
> @@ -172,8 +172,8 @@ int hv_call_add_logical_proc(int node, u32 lp_index, u32 apic_id)
> 
>  		if (hv_result(status) != HV_STATUS_INSUFFICIENT_MEMORY) {
>  			if (!hv_result_success(status)) {
> -				pr_err("%s: cpu %u apic ID %u, %lld\n", __func__,
> -				       lp_index, apic_id, status);
> +				pr_err("%s: cpu %u apic ID %u, %s\n", __func__,
> +				       lp_index, apic_id, hv_status_to_string(status));
>  				ret = hv_status_to_errno(status);
>  			}
>  			break;
> @@ -222,8 +222,8 @@ int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u32 flags)
> 
>  		if (hv_result(status) != HV_STATUS_INSUFFICIENT_MEMORY) {
>  			if (!hv_result_success(status)) {
> -				pr_err("%s: vcpu %u, lp %u, %lld\n", __func__,
> -				       vp_index, flags, status);
> +				pr_err("%s: vcpu %u, lp %u, %s\n", __func__,
> +				       vp_index, flags, hv_status_to_string(status));
>  				ret = hv_status_to_errno(status);
>  			}
>  			break;
> diff --git a/include/asm-generic/hyperv-tlfs.h b/include/asm-generic/hyperv-tlfs.h
> index fe6d41d0b114..40ff7cdd4a2b 100644
> --- a/include/asm-generic/hyperv-tlfs.h
> +++ b/include/asm-generic/hyperv-tlfs.h
> @@ -189,28 +189,36 @@ enum HV_GENERIC_SET_FORMAT {
>  #define HV_HYPERCALL_REP_START_MASK	GENMASK_ULL(59, 48)
> 
>  /* hypercall status code */
> -#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
> +#define __HV_STATUS_DEF(OP) \
> +	OP(HV_STATUS_SUCCESS,				0x0) \
> +	OP(HV_STATUS_INVALID_HYPERCALL_CODE,		0x2) \
> +	OP(HV_STATUS_INVALID_HYPERCALL_INPUT,		0x3) \
> +	OP(HV_STATUS_INVALID_ALIGNMENT,			0x4) \
> +	OP(HV_STATUS_INVALID_PARAMETER,			0x5) \
> +	OP(HV_STATUS_ACCESS_DENIED,			0x6) \
> +	OP(HV_STATUS_INVALID_PARTITION_STATE,		0x7) \
> +	OP(HV_STATUS_OPERATION_DENIED,			0x8) \
> +	OP(HV_STATUS_UNKNOWN_PROPERTY,			0x9) \
> +	OP(HV_STATUS_PROPERTY_VALUE_OUT_OF_RANGE,	0xA) \
> +	OP(HV_STATUS_INSUFFICIENT_MEMORY,		0xB) \
> +	OP(HV_STATUS_INVALID_PARTITION_ID,		0xD) \
> +	OP(HV_STATUS_INVALID_VP_INDEX,			0xE) \
> +	OP(HV_STATUS_NOT_FOUND,				0x10) \
> +	OP(HV_STATUS_INVALID_PORT_ID,			0x11) \
> +	OP(HV_STATUS_INVALID_CONNECTION_ID,		0x12) \
> +	OP(HV_STATUS_INSUFFICIENT_BUFFERS,		0x13) \
> +	OP(HV_STATUS_NOT_ACKNOWLEDGED,			0x14) \
> +	OP(HV_STATUS_INVALID_VP_STATE,			0x15) \
> +	OP(HV_STATUS_NO_RESOURCES,			0x1D) \
> +	OP(HV_STATUS_INVALID_LP_INDEX,			0x41) \
> +	OP(HV_STATUS_INVALID_REGISTER_VALUE,		0x50)
> +
> +#define __HV_MAKE_HV_STATUS_ENUM(NAME, VAL) NAME = (VAL),
> +#define __HV_MAKE_HV_STATUS_CASE(NAME, VAL) case (NAME): return (#NAME);
> +
> +enum hv_status {
> +	__HV_STATUS_DEF(__HV_MAKE_HV_STATUS_ENUM)
> +};
> 
>  /*
>   * The Hyper-V TimeRefCount register and the TSC
> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
> index 9a000ba2bb75..21fb71ca1ba9 100644
> --- a/include/asm-generic/mshyperv.h
> +++ b/include/asm-generic/mshyperv.h
> @@ -59,6 +59,14 @@ static inline unsigned int hv_repcomp(u64 status)
>  			 HV_HYPERCALL_REP_COMP_OFFSET;
>  }
> 
> +static inline const char *hv_status_to_string(u64 hv_status)
> +{
> +	switch (hv_result(hv_status)) {
> +	__HV_STATUS_DEF(__HV_MAKE_HV_STATUS_CASE)
> +	default : return "Unknown";
> +	}
> +}
Wouldn't this be a big switch statement that will get duplicated all over the place
in the code because of the inline (and also the strings within)?

- Sunil