258 lines
6.5 KiB
C
258 lines
6.5 KiB
C
/*
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* X86 specific Hyper-V initialization code.
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*
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* Copyright (C) 2016, Microsoft, Inc.
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*
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* Author : K. Y. Srinivasan <kys@microsoft.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published
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* by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for more
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* details.
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*
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*/
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#include <linux/types.h>
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#include <asm/hypervisor.h>
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#include <asm/hyperv.h>
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#include <asm/mshyperv.h>
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#include <linux/version.h>
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#include <linux/vmalloc.h>
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#include <linux/mm.h>
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#include <linux/clockchips.h>
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#include <linux/hyperv.h>
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#ifdef CONFIG_HYPERV_TSCPAGE
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static struct ms_hyperv_tsc_page *tsc_pg;
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struct ms_hyperv_tsc_page *hv_get_tsc_page(void)
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{
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return tsc_pg;
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}
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static u64 read_hv_clock_tsc(struct clocksource *arg)
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{
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u64 current_tick = hv_read_tsc_page(tsc_pg);
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if (current_tick == U64_MAX)
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rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
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return current_tick;
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}
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static struct clocksource hyperv_cs_tsc = {
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.name = "hyperv_clocksource_tsc_page",
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.rating = 400,
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.read = read_hv_clock_tsc,
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.mask = CLOCKSOURCE_MASK(64),
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.flags = CLOCK_SOURCE_IS_CONTINUOUS,
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};
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#endif
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static u64 read_hv_clock_msr(struct clocksource *arg)
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{
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u64 current_tick;
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/*
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* Read the partition counter to get the current tick count. This count
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* is set to 0 when the partition is created and is incremented in
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* 100 nanosecond units.
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*/
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rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
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return current_tick;
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}
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static struct clocksource hyperv_cs_msr = {
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.name = "hyperv_clocksource_msr",
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.rating = 400,
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.read = read_hv_clock_msr,
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.mask = CLOCKSOURCE_MASK(64),
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.flags = CLOCK_SOURCE_IS_CONTINUOUS,
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};
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static void *hypercall_pg;
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struct clocksource *hyperv_cs;
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EXPORT_SYMBOL_GPL(hyperv_cs);
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/*
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* This function is to be invoked early in the boot sequence after the
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* hypervisor has been detected.
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*
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* 1. Setup the hypercall page.
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* 2. Register Hyper-V specific clocksource.
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*/
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void hyperv_init(void)
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{
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u64 guest_id;
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union hv_x64_msr_hypercall_contents hypercall_msr;
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if (x86_hyper != &x86_hyper_ms_hyperv)
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return;
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/*
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* Setup the hypercall page and enable hypercalls.
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* 1. Register the guest ID
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* 2. Enable the hypercall and register the hypercall page
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*/
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guest_id = generate_guest_id(0, LINUX_VERSION_CODE, 0);
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wrmsrl(HV_X64_MSR_GUEST_OS_ID, guest_id);
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hypercall_pg = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_RX);
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if (hypercall_pg == NULL) {
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wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
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return;
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}
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rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
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hypercall_msr.enable = 1;
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hypercall_msr.guest_physical_address = vmalloc_to_pfn(hypercall_pg);
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wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
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/*
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* Register Hyper-V specific clocksource.
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*/
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#ifdef CONFIG_HYPERV_TSCPAGE
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if (ms_hyperv.features & HV_X64_MSR_REFERENCE_TSC_AVAILABLE) {
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union hv_x64_msr_hypercall_contents tsc_msr;
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tsc_pg = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL);
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if (!tsc_pg)
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goto register_msr_cs;
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hyperv_cs = &hyperv_cs_tsc;
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rdmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
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tsc_msr.enable = 1;
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tsc_msr.guest_physical_address = vmalloc_to_pfn(tsc_pg);
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wrmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
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hyperv_cs_tsc.archdata.vclock_mode = VCLOCK_HVCLOCK;
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clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100);
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return;
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}
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register_msr_cs:
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#endif
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/*
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* For 32 bit guests just use the MSR based mechanism for reading
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* the partition counter.
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*/
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hyperv_cs = &hyperv_cs_msr;
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if (ms_hyperv.features & HV_X64_MSR_TIME_REF_COUNT_AVAILABLE)
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clocksource_register_hz(&hyperv_cs_msr, NSEC_PER_SEC/100);
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}
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/*
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* This routine is called before kexec/kdump, it does the required cleanup.
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*/
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void hyperv_cleanup(void)
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{
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union hv_x64_msr_hypercall_contents hypercall_msr;
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/* Reset our OS id */
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wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
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/* Reset the hypercall page */
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hypercall_msr.as_uint64 = 0;
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wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
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/* Reset the TSC page */
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hypercall_msr.as_uint64 = 0;
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wrmsrl(HV_X64_MSR_REFERENCE_TSC, hypercall_msr.as_uint64);
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}
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EXPORT_SYMBOL_GPL(hyperv_cleanup);
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/*
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* hv_do_hypercall- Invoke the specified hypercall
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*/
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u64 hv_do_hypercall(u64 control, void *input, void *output)
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{
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u64 input_address = (input) ? virt_to_phys(input) : 0;
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u64 output_address = (output) ? virt_to_phys(output) : 0;
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#ifdef CONFIG_X86_64
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u64 hv_status = 0;
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if (!hypercall_pg)
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return (u64)ULLONG_MAX;
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__asm__ __volatile__("mov %0, %%r8" : : "r" (output_address) : "r8");
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__asm__ __volatile__("call *%3" : "=a" (hv_status) :
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"c" (control), "d" (input_address),
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"m" (hypercall_pg));
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return hv_status;
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#else
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u32 control_hi = control >> 32;
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u32 control_lo = control & 0xFFFFFFFF;
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u32 hv_status_hi = 1;
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u32 hv_status_lo = 1;
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u32 input_address_hi = input_address >> 32;
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u32 input_address_lo = input_address & 0xFFFFFFFF;
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u32 output_address_hi = output_address >> 32;
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u32 output_address_lo = output_address & 0xFFFFFFFF;
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if (!hypercall_pg)
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return (u64)ULLONG_MAX;
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__asm__ __volatile__ ("call *%8" : "=d"(hv_status_hi),
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"=a"(hv_status_lo) : "d" (control_hi),
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"a" (control_lo), "b" (input_address_hi),
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"c" (input_address_lo), "D"(output_address_hi),
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"S"(output_address_lo), "m" (hypercall_pg));
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return hv_status_lo | ((u64)hv_status_hi << 32);
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#endif /* !x86_64 */
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}
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EXPORT_SYMBOL_GPL(hv_do_hypercall);
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void hyperv_report_panic(struct pt_regs *regs)
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{
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static bool panic_reported;
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/*
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* We prefer to report panic on 'die' chain as we have proper
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* registers to report, but if we miss it (e.g. on BUG()) we need
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* to report it on 'panic'.
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*/
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if (panic_reported)
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return;
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panic_reported = true;
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wrmsrl(HV_X64_MSR_CRASH_P0, regs->ip);
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wrmsrl(HV_X64_MSR_CRASH_P1, regs->ax);
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wrmsrl(HV_X64_MSR_CRASH_P2, regs->bx);
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wrmsrl(HV_X64_MSR_CRASH_P3, regs->cx);
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wrmsrl(HV_X64_MSR_CRASH_P4, regs->dx);
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/*
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* Let Hyper-V know there is crash data available
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*/
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wrmsrl(HV_X64_MSR_CRASH_CTL, HV_CRASH_CTL_CRASH_NOTIFY);
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}
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EXPORT_SYMBOL_GPL(hyperv_report_panic);
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bool hv_is_hypercall_page_setup(void)
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{
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union hv_x64_msr_hypercall_contents hypercall_msr;
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/* Check if the hypercall page is setup */
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hypercall_msr.as_uint64 = 0;
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rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
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if (!hypercall_msr.enable)
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return false;
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return true;
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}
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EXPORT_SYMBOL_GPL(hv_is_hypercall_page_setup);
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