- Add a module description to the Hyper-V vmbus module.

- Rework some vmbus code to separate architecture specifics out to
 arch/x86/. This is part of the work of adding arm64 support to Hyper-V.
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Merge tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyper-v updates from Sasha Levin:

 - Add a module description to the Hyper-V vmbus module.

 - Rework some vmbus code to separate architecture specifics out to
   arch/x86/. This is part of the work of adding arm64 support to
   Hyper-V.

* tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  Drivers: hv: vmbus: Break out ISA independent parts of mshyperv.h
  drivers: hv: Add a module description line to the hv_vmbus driver

MAINTAINERS

@@ -7422,6 +7422,7 @@ F:	net/vmw_vsock/hyperv_transport.c
 F:	include/clocksource/hyperv_timer.h
 F:	include/linux/hyperv.h
 F:	include/uapi/linux/hyperv.h
+F:	include/asm-generic/mshyperv.h
 F:	tools/hv/
 F:	Documentation/ABI/stable/sysfs-bus-vmbus
 

arch/x86/include/asm/mshyperv.h

@@ -3,84 +3,15 @@
 #define _ASM_X86_MSHYPER_H
 
 #include <linux/types.h>
-#include <linux/atomic.h>
 #include <linux/nmi.h>
 #include <asm/io.h>
 #include <asm/hyperv-tlfs.h>
 #include <asm/nospec-branch.h>
 
-#define VP_INVAL	U32_MAX
-
-struct ms_hyperv_info {
-	u32 features;
-	u32 misc_features;
-	u32 hints;
-	u32 nested_features;
-	u32 max_vp_index;
-	u32 max_lp_index;
-};
-
-extern struct ms_hyperv_info ms_hyperv;
-
-
 typedef int (*hyperv_fill_flush_list_func)(
 		struct hv_guest_mapping_flush_list *flush,
 		void *data);
 
-/*
- * Generate the guest ID.
- */
-
-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;
-
-	/*
-	 * Make sure 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
-	 */
-	mb();
-
-	if (msg->header.message_flags.msg_pending) {
-		/*
-		 * This will cause message queue rescan to
-		 * possibly deliver another msg from the
-		 * hypervisor
-		 */
-		wrmsrl(HV_X64_MSR_EOM, 0);
-	}
-}
-
 #define hv_init_timer(timer, tick) \
 	wrmsrl(HV_X64_MSR_STIMER0_COUNT + (2*timer), tick)
 #define hv_init_timer_config(timer, val) \
@@ -97,6 +28,8 @@ static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
 
 #define hv_get_vp_index(index) rdmsrl(HV_X64_MSR_VP_INDEX, index)
 
+#define hv_signal_eom() wrmsrl(HV_X64_MSR_EOM, 0)
+
 #define hv_get_synint_state(int_num, val) \
 	rdmsrl(HV_X64_MSR_SINT0 + int_num, val)
 #define hv_set_synint_state(int_num, val) \
@@ -122,13 +55,6 @@ void hyperv_reenlightenment_vector(void);
 #define trace_hyperv_callback_vector hyperv_callback_vector
 #endif
 void hyperv_vector_handler(struct pt_regs *regs);
-void hv_setup_vmbus_irq(void (*handler)(void));
-void hv_remove_vmbus_irq(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);
 
 /*
  * Routines for stimer0 Direct Mode handling.
@@ -136,8 +62,6 @@ void hv_remove_crash_handler(void);
  */
 void hv_stimer0_vector_handler(struct pt_regs *regs);
 void hv_stimer0_callback_vector(void);
-int hv_setup_stimer0_irq(int *irq, int *vector, void (*handler)(void));
-void hv_remove_stimer0_irq(int irq);
 
 static inline void hv_enable_stimer0_percpu_irq(int irq) {}
 static inline void hv_disable_stimer0_percpu_irq(int irq) {}
@@ -282,14 +206,6 @@ static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
 	return status;
 }
 
-/*
- * 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 struct hv_vp_assist_page **hv_vp_assist_page;
 
 static inline struct hv_vp_assist_page *hv_get_vp_assist_page(unsigned int cpu)
@@ -300,63 +216,8 @@ static inline struct hv_vp_assist_page *hv_get_vp_assist_page(unsigned int cpu)
 	return hv_vp_assist_page[cpu];
 }
 
-/**
- * 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)
-{
-	int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1;
-
-	/* 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) {
-		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;
-}
-
 void __init hyperv_init(void);
 void hyperv_setup_mmu_ops(void);
-void hyperv_report_panic(struct pt_regs *regs, long err);
-void hyperv_report_panic_msg(phys_addr_t pa, size_t size);
-bool hv_is_hyperv_initialized(void);
-void hyperv_cleanup(void);
 
 void hyperv_reenlightenment_intr(struct pt_regs *regs);
 void set_hv_tscchange_cb(void (*cb)(void));
@@ -379,8 +240,6 @@ static inline void hv_apic_init(void) {}
 
 #else /* CONFIG_HYPERV */
 static inline void hyperv_init(void) {}
-static inline bool hv_is_hyperv_initialized(void) { return false; }
-static inline void hyperv_cleanup(void) {}
 static inline void hyperv_setup_mmu_ops(void) {}
 static inline void set_hv_tscchange_cb(void (*cb)(void)) {}
 static inline void clear_hv_tscchange_cb(void) {}
@@ -397,4 +256,7 @@ static inline int hyperv_flush_guest_mapping_range(u64 as,
 }
 #endif /* CONFIG_HYPERV */
 
+
+#include <asm-generic/mshyperv.h>
+
 #endif

drivers/hv/vmbus_drv.c

@@ -2163,6 +2163,7 @@ static void __exit vmbus_exit(void)
 
 
 MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Microsoft Hyper-V VMBus Driver");
 
 subsys_initcall(hv_acpi_init);
 module_exit(vmbus_exit);

include/asm-generic/mshyperv.h

@@ -0,0 +1,180 @@
+/* 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 <asm/ptrace.h>
+#include <asm/hyperv-tlfs.h>
+
+struct ms_hyperv_info {
+	u32 features;
+	u32 misc_features;
+	u32 hints;
+	u32 nested_features;
+	u32 max_vp_index;
+	u32 max_lp_index;
+};
+extern struct ms_hyperv_info ms_hyperv;
+
+extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr);
+extern u64 hv_do_fast_hypercall8(u16 control, u64 input8);
+
+
+/* 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_signal_eom();
+	}
+}
+
+void hv_setup_vmbus_irq(void (*handler)(void));
+void hv_remove_vmbus_irq(void);
+void hv_enable_vmbus_irq(void);
+void hv_disable_vmbus_irq(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);
+
+#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;
+
+/* Sentinel value for an uninitialized entry in hv_vp_index array */
+#define VP_INVAL	U32_MAX
+
+/**
+ * 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)
+{
+	int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1;
+
+	/* 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) {
+		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;
+}
+
+void hyperv_report_panic(struct pt_regs *regs, long err);
+void hyperv_report_panic_msg(phys_addr_t pa, size_t size);
+bool hv_is_hyperv_initialized(void);
+void hyperv_cleanup(void);
+#else /* CONFIG_HYPERV */
+static inline bool hv_is_hyperv_initialized(void) { return false; }
+static inline void hyperv_cleanup(void) {}
+#endif /* CONFIG_HYPERV */
+
+#if IS_ENABLED(CONFIG_HYPERV)
+extern int hv_setup_stimer0_irq(int *irq, int *vector, void (*handler)(void));
+extern void hv_remove_stimer0_irq(int irq);
+#endif
+
+#endif