include/asm-generic/mshyperv.h - linux - Git at Google

 /* SPDX-License-Identifier: GPL-2.0 */

 /*
  * Linux-specific definitions for managing interactions with Microsoft's
  * Hyper-V hypervisor. The definitions in this file are architecture
  * independent. See arch/<arch>/include/asm/mshyperv.h for definitions
  * that are specific to architecture <arch>.
  *
  * Definitions that are specified in the Hyper-V Top Level Functional
  * Spec (TLFS) should not go in this file, but should instead go in
  * hyperv-tlfs.h.
  *
  * Copyright (C) 2019, Microsoft, Inc.
  *
  * Author : Michael Kelley <mikelley@microsoft.com>
  */

 #ifndef _ASM_GENERIC_MSHYPERV_H
 #define _ASM_GENERIC_MSHYPERV_H

 #include <linux/types.h>
 #include <linux/atomic.h>
 #include <linux/bitops.h>
 #include <linux/cpumask.h>
 #include <linux/nmi.h>
 #include <asm/ptrace.h>
 #include <asm/hyperv-tlfs.h>

 struct ms_hyperv_info {
 	u32 features;
 	u32 priv_high;
 	u32 misc_features;
 	u32 hints;
 	u32 nested_features;
 	u32 max_vp_index;
 	u32 max_lp_index;
 	u32 isolation_config_a;
 	u32 isolation_config_b;
 };
 extern struct ms_hyperv_info ms_hyperv;

 extern void  __percpu  **hyperv_pcpu_input_arg;
 extern void  __percpu  **hyperv_pcpu_output_arg;

 extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr);
 extern u64 hv_do_fast_hypercall8(u16 control, u64 input8);

 /* Helper functions that provide a consistent pattern for checking Hyper-V hypercall status. */
 static inline int hv_result(u64 status)
 {
 	return status & HV_HYPERCALL_RESULT_MASK;
 }

 static inline bool hv_result_success(u64 status)
 {
 	return hv_result(status) == HV_STATUS_SUCCESS;
 }

 static inline unsigned int hv_repcomp(u64 status)
 {
 	/* Bits [43:32] of status have 'Reps completed' data. */
 	return (status & HV_HYPERCALL_REP_COMP_MASK) >>
 			 HV_HYPERCALL_REP_COMP_OFFSET;
 }

 /*
  * Rep hypercalls. Callers of this functions are supposed to ensure that
  * rep_count and varhead_size comply with Hyper-V hypercall definition.
  */
 static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
 				      void *input, void *output)
 {
 	u64 control = code;
 	u64 status;
 	u16 rep_comp;

 	control |= (u64)varhead_size << HV_HYPERCALL_VARHEAD_OFFSET;
 	control |= (u64)rep_count << HV_HYPERCALL_REP_COMP_OFFSET;

 	do {
 		status = hv_do_hypercall(control, input, output);
 		if (!hv_result_success(status))
 			return status;

 		rep_comp = hv_repcomp(status);

 		control &= ~HV_HYPERCALL_REP_START_MASK;
 		control |= (u64)rep_comp << HV_HYPERCALL_REP_START_OFFSET;

 		touch_nmi_watchdog();
 	} while (rep_comp < rep_count);

 	return status;
 }

 /* Generate the guest OS identifier as described in the Hyper-V TLFS */
 static inline  __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version,
 				       __u64 d_info2)
 {
 	__u64 guest_id = 0;

 	guest_id = (((__u64)HV_LINUX_VENDOR_ID) << 48);
 	guest_id |= (d_info1 << 48);
 	guest_id |= (kernel_version << 16);
 	guest_id |= d_info2;

 	return guest_id;
 }

 /* Free the message slot and signal end-of-message if required */
 static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
 {
 	/*
 	 * On crash we're reading some other CPU's message page and we need
 	 * to be careful: this other CPU may already had cleared the header
 	 * and the host may already had delivered some other message there.
 	 * In case we blindly write msg->header.message_type we're going
 	 * to lose it. We can still lose a message of the same type but
 	 * we count on the fact that there can only be one
 	 * CHANNELMSG_UNLOAD_RESPONSE and we don't care about other messages
 	 * on crash.
 	 */
 	if (cmpxchg(&msg->header.message_type, old_msg_type,
 		    HVMSG_NONE) != old_msg_type)
 		return;

 	/*
 	 * The cmxchg() above does an implicit memory barrier to
 	 * ensure the write to MessageType (ie set to
 	 * HVMSG_NONE) happens before we read the
 	 * MessagePending and EOMing. Otherwise, the EOMing
 	 * will not deliver any more messages since there is
 	 * no empty slot
 	 */
 	if (msg->header.message_flags.msg_pending) {
 		/*
 		 * This will cause message queue rescan to
 		 * possibly deliver another msg from the
 		 * hypervisor
 		 */
 		hv_set_register(HV_REGISTER_EOM, 0);
 	}
 }

 void hv_setup_vmbus_handler(void (*handler)(void));
 void hv_remove_vmbus_handler(void);
 void hv_setup_stimer0_handler(void (*handler)(void));
 void hv_remove_stimer0_handler(void);

 void hv_setup_kexec_handler(void (*handler)(void));
 void hv_remove_kexec_handler(void);
 void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs));
 void hv_remove_crash_handler(void);

 extern int vmbus_interrupt;
 extern int vmbus_irq;

 extern bool hv_root_partition;

 #if IS_ENABLED(CONFIG_HYPERV)
 /*
  * Hypervisor's notion of virtual processor ID is different from
  * Linux' notion of CPU ID. This information can only be retrieved
  * in the context of the calling CPU. Setup a map for easy access
  * to this information.
  */
 extern u32 *hv_vp_index;
 extern u32 hv_max_vp_index;

 extern u64 (*hv_read_reference_counter)(void);

 /* Sentinel value for an uninitialized entry in hv_vp_index array */
 #define VP_INVAL	U32_MAX

 int __init hv_common_init(void);
 void __init hv_common_free(void);
 int hv_common_cpu_init(unsigned int cpu);
 int hv_common_cpu_die(unsigned int cpu);

 void *hv_alloc_hyperv_page(void);
 void *hv_alloc_hyperv_zeroed_page(void);
 void hv_free_hyperv_page(unsigned long addr);

 /**
  * hv_cpu_number_to_vp_number() - Map CPU to VP.
  * @cpu_number: CPU number in Linux terms
  *
  * This function returns the mapping between the Linux processor
  * number and the hypervisor's virtual processor number, useful
  * in making hypercalls and such that talk about specific
  * processors.
  *
  * Return: Virtual processor number in Hyper-V terms
  */
 static inline int hv_cpu_number_to_vp_number(int cpu_number)
 {
 	return hv_vp_index[cpu_number];
 }

 static inline int __cpumask_to_vpset(struct hv_vpset *vpset,
 				    const struct cpumask *cpus,
 				    bool exclude_self)
 {
 	int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1;
 	int this_cpu = smp_processor_id();

 	/* valid_bank_mask can represent up to 64 banks */
 	if (hv_max_vp_index / 64 >= 64)
 		return 0;

 	/*
 	 * Clear all banks up to the maximum possible bank as hv_tlb_flush_ex
 	 * structs are not cleared between calls, we risk flushing unneeded
 	 * vCPUs otherwise.
 	 */
 	for (vcpu_bank = 0; vcpu_bank <= hv_max_vp_index / 64; vcpu_bank++)
 		vpset->bank_contents[vcpu_bank] = 0;

 	/*
 	 * Some banks may end up being empty but this is acceptable.
 	 */
 	for_each_cpu(cpu, cpus) {
 		if (exclude_self && cpu == this_cpu)
 			continue;
 		vcpu = hv_cpu_number_to_vp_number(cpu);
 		if (vcpu == VP_INVAL)
 			return -1;
 		vcpu_bank = vcpu / 64;
 		vcpu_offset = vcpu % 64;
 		__set_bit(vcpu_offset, (unsigned long *)
 			  &vpset->bank_contents[vcpu_bank]);
 		if (vcpu_bank >= nr_bank)
 			nr_bank = vcpu_bank + 1;
 	}
 	vpset->valid_bank_mask = GENMASK_ULL(nr_bank - 1, 0);
 	return nr_bank;
 }

 static inline int cpumask_to_vpset(struct hv_vpset *vpset,
 				    const struct cpumask *cpus)
 {
 	return __cpumask_to_vpset(vpset, cpus, false);
 }

 static inline int cpumask_to_vpset_noself(struct hv_vpset *vpset,
 				    const struct cpumask *cpus)
 {
 	WARN_ON_ONCE(preemptible());
 	return __cpumask_to_vpset(vpset, cpus, true);
 }

 void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die);
 bool hv_is_hyperv_initialized(void);
 bool hv_is_hibernation_supported(void);
 enum hv_isolation_type hv_get_isolation_type(void);
 bool hv_is_isolation_supported(void);
 void hyperv_cleanup(void);
 bool hv_query_ext_cap(u64 cap_query);
 #else /* CONFIG_HYPERV */
 static inline bool hv_is_hyperv_initialized(void) { return false; }
 static inline bool hv_is_hibernation_supported(void) { return false; }
 static inline void hyperv_cleanup(void) {}
 #endif /* CONFIG_HYPERV */

 #endif
	/* SPDX-License-Identifier: GPL-2.0 */

	/*
	* Linux-specific definitions for managing interactions with Microsoft's
	* Hyper-V hypervisor. The definitions in this file are architecture
	* independent. See arch/<arch>/include/asm/mshyperv.h for definitions
	* that are specific to architecture <arch>.
	*
	* Definitions that are specified in the Hyper-V Top Level Functional
	* Spec (TLFS) should not go in this file, but should instead go in
	* hyperv-tlfs.h.
	*
	* Copyright (C) 2019, Microsoft, Inc.
	*
	* Author : Michael Kelley <mikelley@microsoft.com>
	*/

	#ifndef _ASM_GENERIC_MSHYPERV_H
	#define _ASM_GENERIC_MSHYPERV_H

	#include <linux/types.h>
	#include <linux/atomic.h>
	#include <linux/bitops.h>
	#include <linux/cpumask.h>
	#include <linux/nmi.h>
	#include <asm/ptrace.h>
	#include <asm/hyperv-tlfs.h>

	struct ms_hyperv_info {
	u32 features;
	u32 priv_high;
	u32 misc_features;
	u32 hints;
	u32 nested_features;
	u32 max_vp_index;
	u32 max_lp_index;
	u32 isolation_config_a;
	u32 isolation_config_b;
	};
	extern struct ms_hyperv_info ms_hyperv;

	extern void __percpu **hyperv_pcpu_input_arg;
	extern void __percpu **hyperv_pcpu_output_arg;

	extern u64 hv_do_hypercall(u64 control, void inputaddr, void outputaddr);
	extern u64 hv_do_fast_hypercall8(u16 control, u64 input8);

	/* Helper functions that provide a consistent pattern for checking Hyper-V hypercall status. */
	static inline int hv_result(u64 status)
	{
	return status & HV_HYPERCALL_RESULT_MASK;
	}

	static inline bool hv_result_success(u64 status)
	{
	return hv_result(status) == HV_STATUS_SUCCESS;
	}

	static inline unsigned int hv_repcomp(u64 status)
	{
	/* Bits [43:32] of status have 'Reps completed' data. */
	return (status & HV_HYPERCALL_REP_COMP_MASK) >>
	HV_HYPERCALL_REP_COMP_OFFSET;
	}

	/*
	* Rep hypercalls. Callers of this functions are supposed to ensure that
	* rep_count and varhead_size comply with Hyper-V hypercall definition.
	*/
	static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
	void input, void output)
	{
	u64 control = code;
	u64 status;
	u16 rep_comp;

	control \|= (u64)varhead_size << HV_HYPERCALL_VARHEAD_OFFSET;
	control \|= (u64)rep_count << HV_HYPERCALL_REP_COMP_OFFSET;

	do {
	status = hv_do_hypercall(control, input, output);
	if (!hv_result_success(status))
	return status;

	rep_comp = hv_repcomp(status);

	control &= ~HV_HYPERCALL_REP_START_MASK;
	control \|= (u64)rep_comp << HV_HYPERCALL_REP_START_OFFSET;

	touch_nmi_watchdog();
	} while (rep_comp < rep_count);

	return status;
	}

	/* Generate the guest OS identifier as described in the Hyper-V TLFS */
	static inline __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version,
	__u64 d_info2)
	{
	__u64 guest_id = 0;

	guest_id = (((__u64)HV_LINUX_VENDOR_ID) << 48);
	guest_id \|= (d_info1 << 48);
	guest_id \|= (kernel_version << 16);
	guest_id \|= d_info2;

	return guest_id;
	}

	/* Free the message slot and signal end-of-message if required */
	static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
	{
	/*
	* On crash we're reading some other CPU's message page and we need
	* to be careful: this other CPU may already had cleared the header
	* and the host may already had delivered some other message there.
	* In case we blindly write msg->header.message_type we're going
	* to lose it. We can still lose a message of the same type but
	* we count on the fact that there can only be one
	* CHANNELMSG_UNLOAD_RESPONSE and we don't care about other messages
	* on crash.
	*/
	if (cmpxchg(&msg->header.message_type, old_msg_type,
	HVMSG_NONE) != old_msg_type)
	return;

	/*
	* The cmxchg() above does an implicit memory barrier to
	* ensure the write to MessageType (ie set to
	* HVMSG_NONE) happens before we read the
	* MessagePending and EOMing. Otherwise, the EOMing
	* will not deliver any more messages since there is
	* no empty slot
	*/
	if (msg->header.message_flags.msg_pending) {
	/*
	* This will cause message queue rescan to
	* possibly deliver another msg from the
	* hypervisor
	*/
	hv_set_register(HV_REGISTER_EOM, 0);
	}
	}

	void hv_setup_vmbus_handler(void (*handler)(void));
	void hv_remove_vmbus_handler(void);
	void hv_setup_stimer0_handler(void (*handler)(void));
	void hv_remove_stimer0_handler(void);

	void hv_setup_kexec_handler(void (*handler)(void));
	void hv_remove_kexec_handler(void);
	void hv_setup_crash_handler(void (handler)(struct pt_regs regs));
	void hv_remove_crash_handler(void);

	extern int vmbus_interrupt;
	extern int vmbus_irq;

	extern bool hv_root_partition;

	#if IS_ENABLED(CONFIG_HYPERV)
	/*
	* Hypervisor's notion of virtual processor ID is different from
	* Linux' notion of CPU ID. This information can only be retrieved
	* in the context of the calling CPU. Setup a map for easy access
	* to this information.
	*/
	extern u32 *hv_vp_index;
	extern u32 hv_max_vp_index;

	extern u64 (*hv_read_reference_counter)(void);

	/* Sentinel value for an uninitialized entry in hv_vp_index array */
	#define VP_INVAL U32_MAX

	int __init hv_common_init(void);
	void __init hv_common_free(void);
	int hv_common_cpu_init(unsigned int cpu);
	int hv_common_cpu_die(unsigned int cpu);

	void *hv_alloc_hyperv_page(void);
	void *hv_alloc_hyperv_zeroed_page(void);
	void hv_free_hyperv_page(unsigned long addr);

	/**
	* hv_cpu_number_to_vp_number() - Map CPU to VP.
	* @cpu_number: CPU number in Linux terms
	*
	* This function returns the mapping between the Linux processor
	* number and the hypervisor's virtual processor number, useful
	* in making hypercalls and such that talk about specific
	* processors.
	*
	* Return: Virtual processor number in Hyper-V terms
	*/
	static inline int hv_cpu_number_to_vp_number(int cpu_number)
	{
	return hv_vp_index[cpu_number];
	}

	static inline int __cpumask_to_vpset(struct hv_vpset *vpset,
	const struct cpumask *cpus,
	bool exclude_self)
	{
	int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1;
	int this_cpu = smp_processor_id();

	/* valid_bank_mask can represent up to 64 banks */
	if (hv_max_vp_index / 64 >= 64)
	return 0;

	/*
	* Clear all banks up to the maximum possible bank as hv_tlb_flush_ex
	* structs are not cleared between calls, we risk flushing unneeded
	* vCPUs otherwise.
	*/
	for (vcpu_bank = 0; vcpu_bank <= hv_max_vp_index / 64; vcpu_bank++)
	vpset->bank_contents[vcpu_bank] = 0;

	/*
	* Some banks may end up being empty but this is acceptable.
	*/
	for_each_cpu(cpu, cpus) {
	if (exclude_self && cpu == this_cpu)
	continue;
	vcpu = hv_cpu_number_to_vp_number(cpu);
	if (vcpu == VP_INVAL)
	return -1;
	vcpu_bank = vcpu / 64;
	vcpu_offset = vcpu % 64;
	__set_bit(vcpu_offset, (unsigned long *)
	&vpset->bank_contents[vcpu_bank]);
	if (vcpu_bank >= nr_bank)
	nr_bank = vcpu_bank + 1;
	}
	vpset->valid_bank_mask = GENMASK_ULL(nr_bank - 1, 0);
	return nr_bank;
	}

	static inline int cpumask_to_vpset(struct hv_vpset *vpset,
	const struct cpumask *cpus)
	{
	return __cpumask_to_vpset(vpset, cpus, false);
	}

	static inline int cpumask_to_vpset_noself(struct hv_vpset *vpset,
	const struct cpumask *cpus)
	{
	WARN_ON_ONCE(preemptible());
	return __cpumask_to_vpset(vpset, cpus, true);
	}

	void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die);
	bool hv_is_hyperv_initialized(void);
	bool hv_is_hibernation_supported(void);
	enum hv_isolation_type hv_get_isolation_type(void);
	bool hv_is_isolation_supported(void);
	void hyperv_cleanup(void);
	bool hv_query_ext_cap(u64 cap_query);
	#else /* CONFIG_HYPERV */
	static inline bool hv_is_hyperv_initialized(void) { return false; }
	static inline bool hv_is_hibernation_supported(void) { return false; }
	static inline void hyperv_cleanup(void) {}
	#endif /* CONFIG_HYPERV */

	#endif