Commit e7e6902f authored by Roman Kisel's avatar Roman Kisel Committed by Wei Liu
Browse files

Drivers: hv: Provide arch-neutral implementation of get_vtl() 



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: default avatarRoman Kisel <romank@linux.microsoft.com>
Reviewed-by: default avatarMichael Kelley <mhklinux@outlook.com>
Reviewed-by: default avatarTianyu Lan <tiala@microsoft.com>
Link: https://lore.kernel.org/r/20250428210742.435282-5-romank@linux.microsoft.com


Signed-off-by: default avatarWei Liu <wei.liu@kernel.org>
Message-ID: <20250428210742.435282-5-romank@linux.microsoft.com>
parent f41ceff1

arch/x86/hyperv/hv_init.c

+0 −34
Original line number Diff line number Diff line
@@ -390,40 +390,6 @@ static void __init hv_stimer_setup_percpu_clockev(void) 
		old_setup_percpu_clockev();

}



#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.

drivers/hv/hv_common.c

+31 −0
Original line number Diff line number Diff line
@@ -317,6 +317,37 @@ void __init hv_get_partition_id(void) 
		pr_err("Hyper-V: failed to get partition ID: %#x\n",

		       hv_result(status));

}

#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)

{

include/asm-generic/mshyperv.h

+6 −0
Original line number Diff line number Diff line
@@ -378,4 +378,10 @@ static inline int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u3 
}

#endif /* CONFIG_MSHV_ROOT */



#if IS_ENABLED(CONFIG_HYPERV_VTL_MODE)

u8 __init get_vtl(void);

#else

static inline u8 get_vtl(void) { return 0; }

#endif



#endif

include/hyperv/hvgdk_mini.h

+1 −1
Original line number Diff line number Diff line
@@ -1228,7 +1228,7 @@ 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 {