2 files changed, 159 insertions, 0 deletions

diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index aaf59b7da98a..7c9c895432a9 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -3,8 +3,28 @@
 
 #include <linux/types.h>
 #include <linux/interrupt.h>
+#include <linux/clocksource.h>
 #include <asm/hyperv.h>
 
+/*
+ * The below CPUID leaves are present if VersionAndFeatures.HypervisorPresent
+ * is set by CPUID(HVCPUID_VERSION_FEATURES).
+ */
+enum hv_cpuid_function {
+        HVCPUID_VERSION_FEATURES                = 0x00000001,
+        HVCPUID_VENDOR_MAXFUNCTION              = 0x40000000,
+        HVCPUID_INTERFACE                       = 0x40000001,
+
+        /*
+         * The remaining functions depend on the value of
+         * HVCPUID_INTERFACE
+         */
+        HVCPUID_VERSION                         = 0x40000002,
+        HVCPUID_FEATURES                        = 0x40000003,
+        HVCPUID_ENLIGHTENMENT_INFO              = 0x40000004,
+        HVCPUID_IMPLEMENTATION_LIMITS           = 0x40000005,
+};
+
 struct ms_hyperv_info {
         u32 features;
         u32 misc_features;
@@ -13,6 +33,128 @@ struct ms_hyperv_info {
 
 extern struct ms_hyperv_info ms_hyperv;
 
+/*
+ * Declare the MSR used to setup pages used to communicate with the hypervisor.
+ */
+union hv_x64_msr_hypercall_contents {
+        u64 as_uint64;
+        struct {
+                u64 enable:1;
+                u64 reserved:11;
+                u64 guest_physical_address:52;
+        };
+};
+
+/*
+ * TSC page layout.
+ */
+
+struct ms_hyperv_tsc_page {
+        volatile u32 tsc_sequence;
+        u32 reserved1;
+        volatile u64 tsc_scale;
+        volatile s64 tsc_offset;
+        u64 reserved2[509];
+};
+
+/*
+ * The guest OS needs to register the guest ID with the hypervisor.
+ * The guest ID is a 64 bit entity and the structure of this ID is
+ * specified in the Hyper-V specification:
+ *
+ * msdn.microsoft.com/en-us/library/windows/hardware/ff542653%28v=vs.85%29.aspx
+ *
+ * While the current guideline does not specify how Linux guest ID(s)
+ * need to be generated, our plan is to publish the guidelines for
+ * Linux and other guest operating systems that currently are hosted
+ * on Hyper-V. The implementation here conforms to this yet
+ * unpublished guidelines.
+ *
+ *
+ * Bit(s)
+ * 63 - Indicates if the OS is Open Source or not; 1 is Open Source
+ * 62:56 - Os Type; Linux is 0x100
+ * 55:48 - Distro specific identification
+ * 47:16 - Linux kernel version number
+ * 15:0  - Distro specific identification
+ *
+ *
+ */
+
+#define HV_LINUX_VENDOR_ID              0x8100
+
+/*
+ * Generate the guest ID based on the guideline described above.
+ */
+
+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_get_current_tick(tick) rdmsrl(HV_X64_MSR_TIME_REF_COUNT, tick)
+#define hv_init_timer(timer, tick) wrmsrl(timer, tick)
+#define hv_init_timer_config(config, val) wrmsrl(config, val)
+
+#define hv_get_simp(val) rdmsrl(HV_X64_MSR_SIMP, val)
+#define hv_set_simp(val) wrmsrl(HV_X64_MSR_SIMP, val)
+
+#define hv_get_siefp(val) rdmsrl(HV_X64_MSR_SIEFP, val)
+#define hv_set_siefp(val) wrmsrl(HV_X64_MSR_SIEFP, val)
+
+#define hv_get_synic_state(val) rdmsrl(HV_X64_MSR_SCONTROL, val)
+#define hv_set_synic_state(val) wrmsrl(HV_X64_MSR_SCONTROL, val)
+
+#define hv_get_vp_index(index) rdmsrl(HV_X64_MSR_VP_INDEX, index)
+
+#define hv_get_synint_state(int_num, val) rdmsrl(int_num, val)
+#define hv_set_synint_state(int_num, val) wrmsrl(int_num, val)
+
 void hyperv_callback_vector(void);
 #ifdef CONFIG_TRACING
 #define trace_hyperv_callback_vector hyperv_callback_vector
@@ -25,4 +167,13 @@ 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)
+extern struct clocksource *hyperv_cs;
+
+void hyperv_init(void);
+void hyperv_report_panic(struct pt_regs *regs);
+bool hv_is_hypercall_page_setup(void);
+void hyperv_cleanup(void);
+#endif
 #endif
diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h
index 9b1a91834ac8..3a20ccf787b8 100644
--- a/arch/x86/include/uapi/asm/hyperv.h
+++ b/arch/x86/include/uapi/asm/hyperv.h
@@ -73,6 +73,9 @@
   */
 #define HV_X64_MSR_STAT_PAGES_AVAILABLE         (1 << 8)
 
+/* Crash MSR available */
+#define HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE (1 << 10)
+
 /*
  * Feature identification: EBX indicates which flags were specified at
  * partition creation. The format is the same as the partition creation
@@ -144,6 +147,11 @@
  */
 #define HV_X64_RELAXED_TIMING_RECOMMENDED       (1 << 5)
 
+/*
+ * Crash notification flag.
+ */
+#define HV_CRASH_CTL_CRASH_NOTIFY (1ULL << 63)
+
 /* MSR used to identify the guest OS. */
 #define HV_X64_MSR_GUEST_OS_ID                  0x40000000