FreeBSD/Linux Kernel Cross Reference
sys/dev/hyperv/vmbus/x86/hyperv_x86.c

     /*- SPDX-License-Identifier: BSD-2-Clause-FreeBSD
      * Copyright (c) 2009-2012,2016-2017, 2022 Microsoft Corp.
      * Copyright (c) 2012 NetApp Inc.
      * Copyright (c) 2012 Citrix Inc.
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice unmodified, this list of conditions, and the following
     *    disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     */
    
    /**
     * Implements low-level interactions with Hyper-V/Azure
     */
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/kernel.h>
    #include <sys/malloc.h>
    #include <sys/timetc.h>
    
    #include <vm/vm.h>
    #include <vm/pmap.h>
    #include <vm/vm_extern.h>
    #include <vm/vm_kern.h>
    
    #include <dev/hyperv/include/hyperv.h>
    #include <dev/hyperv/include/hyperv_busdma.h>
    #include <dev/hyperv/vmbus/hyperv_var.h>
    #include <dev/hyperv/vmbus/x86/hyperv_machdep.h>
    #include <dev/hyperv/vmbus/x86/hyperv_reg.h>
    #include <dev/hyperv/vmbus/hyperv_common_reg.h>
    
    #define HYPERV_FREEBSD_BUILD 0ULL
    #define HYPERV_FREEBSD_VERSION ((uint64_t)__FreeBSD_version)
    #define HYPERV_FREEBSD_OSID 0ULL
    
    void hyperv_init_tc(void);
    int hypercall_page_setup(vm_paddr_t);
    void hypercall_disable(void);
    bool hyperv_identify_features(void);
    
    u_int hyperv_ver_major;
    u_int hyperv_features;
    u_int hyperv_recommends;
    
    hyperv_tc64_t hyperv_tc64;
    
    static u_int hyperv_pm_features;
    static u_int hyperv_features3;
    static u_int hyperv_get_timecount(struct timecounter *);
    
    static struct timecounter hyperv_timecounter = {
            .tc_get_timecount = hyperv_get_timecount,
            .tc_poll_pps = NULL,
            .tc_counter_mask = 0xffffffff,
            .tc_frequency = HYPERV_TIMER_FREQ,
            .tc_name = "Hyper-V",
            .tc_quality = 2000,
            .tc_flags = 0,
            .tc_priv = NULL
    };
    
    static u_int
    hyperv_get_timecount(struct timecounter *tc __unused)
    {
            return rdmsr(MSR_HV_TIME_REF_COUNT);
    }
    
    static uint64_t
    hyperv_tc64_rdmsr(void)
    {
    
            return (rdmsr(MSR_HV_TIME_REF_COUNT));
    }
    
    void
    hyperv_init_tc(void)
    {
            if (hyperv_features & CPUID_HV_MSR_TIME_REFCNT) {
                   /*
                    * Register Hyper-V timecounter.  This should be done as early
                    * as possible to let DELAY() work, since the 8254 PIT is not
                    * reliably emulated or even available.
                    */
                   tc_init(&hyperv_timecounter);
   
                   /*
                    * Install 64 bits timecounter method for other modules
                    * to use.
                    */
                   hyperv_tc64 = hyperv_tc64_rdmsr;
           }
   }
   
   int
   hypercall_page_setup(vm_paddr_t paddr)
   {
           uint64_t hc, hc_orig;
           hc_orig = rdmsr(MSR_HV_HYPERCALL);
   
           /*
            * Setup the Hypercall page.
            *
            * NOTE: 'reserved' bits MUST be preserved.
            */
           hc = ((paddr >> PAGE_SHIFT) << MSR_HV_HYPERCALL_PGSHIFT) |
               (hc_orig & MSR_HV_HYPERCALL_RSVD_MASK) | MSR_HV_HYPERCALL_ENABLE;
           wrmsr(MSR_HV_HYPERCALL, hc);
   
           /*
            * Confirm that Hypercall page did get setup.
            */
           hc = rdmsr(MSR_HV_HYPERCALL);
           if ((hc & MSR_HV_HYPERCALL_ENABLE) == 0) {
                   printf("hyperv: Hypercall setup failed\n");
                   /* Can't perform any Hyper-V specific actions */
                   vm_guest = VM_GUEST_VM;
                   return (-1);
           }
           return (0);
   }
   
   void
   hypercall_disable(void)
   {
           uint64_t hc;
           /* Disable Hypercall */
           hc = rdmsr(MSR_HV_HYPERCALL);
           wrmsr(MSR_HV_HYPERCALL, (hc & MSR_HV_HYPERCALL_RSVD_MASK));
   }
   
   bool
   hyperv_identify_features(void)
   {
           u_int regs[4];
           unsigned int maxleaf;
   
           if (vm_guest != VM_GUEST_HV)
                   return (false);
   
           do_cpuid(CPUID_LEAF_HV_MAXLEAF, regs);
           maxleaf = regs[0];
           if (maxleaf < CPUID_LEAF_HV_LIMITS)
                   return (false);
   
           do_cpuid(CPUID_LEAF_HV_INTERFACE, regs);
           if (regs[0] != CPUID_HV_IFACE_HYPERV)
                   return (false);
   
           do_cpuid(CPUID_LEAF_HV_FEATURES, regs);
           if ((regs[0] & CPUID_HV_MSR_HYPERCALL) == 0) {
                   /*
                    * Hyper-V w/o Hypercall is impossible; someone
                    * is faking Hyper-V.
                    */
                   return (false);
           }
           hyperv_features = regs[0];
           hyperv_pm_features = regs[2];
           hyperv_features3 = regs[3];
           do_cpuid(CPUID_LEAF_HV_IDENTITY, regs);
           hyperv_ver_major = regs[1] >> 16;
           printf("Hyper-V Version: %d.%d.%d [SP%d]\n", hyperv_ver_major,
               regs[1] & 0xffff, regs[0], regs[2]);
   
           printf("  Features=0x%b\n", hyperv_features,
               "\020"
               "\001VPRUNTIME" /* MSR_HV_VP_RUNTIME */
               "\002TMREFCNT"  /* MSR_HV_TIME_REF_COUNT */
               "\003SYNIC"     /* MSRs for SynIC */
               "\004SYNTM"     /* MSRs for SynTimer */
               "\005APIC"      /* MSR_HV_{EOI,ICR,TPR} */
               "\006HYPERCALL" /* MSR_HV_{GUEST_OS_ID,HYPERCALL} */
               "\007VPINDEX"   /* MSR_HV_VP_INDEX */
               "\010RESET"     /* MSR_HV_RESET */
               "\011STATS"     /* MSR_HV_STATS_ */
               "\012REFTSC"    /* MSR_HV_REFERENCE_TSC */
               "\013IDLE"      /* MSR_HV_GUEST_IDLE */
               "\014TMFREQ"    /* MSR_HV_{TSC,APIC}_FREQUENCY */
               "\015DEBUG");   /* MSR_HV_SYNTH_DEBUG_ */
           printf("  PM Features=0x%b [C%u]\n",
               (hyperv_pm_features & ~CPUPM_HV_CSTATE_MASK),
               "\020"
               "\005C3HPET", /* HPET is required for C3 state */
               CPUPM_HV_CSTATE(hyperv_pm_features));
           printf("  Features3=0x%b\n", hyperv_features3,
               "\020"
               "\001MWAIT"    /* MWAIT */
               "\002DEBUG"    /* guest debug support */
               "\003PERFMON"  /* performance monitor */
               "\004PCPUDPE"  /* physical CPU dynamic partition event */
               "\005XMMHC"    /* hypercall input through XMM regs */
               "\006IDLE"     /* guest idle support */
               "\007SLEEP"    /* hypervisor sleep support */
               "\010NUMA"     /* NUMA distance query support */
               "\011TMFREQ"   /* timer frequency query (TSC, LAPIC) */
               "\012SYNCMC"   /* inject synthetic machine checks */
               "\013CRASH"    /* MSRs for guest crash */
               "\014DEBUGMSR" /* MSRs for guest debug */
               "\015NPIEP"    /* NPIEP */
               "\016HVDIS");  /* disabling hypervisor */
   
           do_cpuid(CPUID_LEAF_HV_RECOMMENDS, regs);
           hyperv_recommends = regs[0];
           if (bootverbose)
                   printf("  Recommends: %08x %08x\n", regs[0], regs[1]);
   
           do_cpuid(CPUID_LEAF_HV_LIMITS, regs);
           if (bootverbose) {
                   printf("  Limits: Vcpu:%d Lcpu:%d Int:%d\n", regs[0], regs[1],
                       regs[2]);
           }
   
           if (maxleaf >= CPUID_LEAF_HV_HWFEATURES) {
                   do_cpuid(CPUID_LEAF_HV_HWFEATURES, regs);
                   if (bootverbose) {
                           printf("  HW Features: %08x, AMD: %08x\n", regs[0],
                               regs[3]);
                   }
           }
           return (true);
   }

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