278 lines
6.9 KiB
C
278 lines
6.9 KiB
C
/*
|
|
* X86 specific Hyper-V initialization code.
|
|
*
|
|
* Copyright (C) 2016, Microsoft, Inc.
|
|
*
|
|
* Author : K. Y. Srinivasan <kys@microsoft.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License version 2 as published
|
|
* by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
|
|
* NON INFRINGEMENT. See the GNU General Public License for more
|
|
* details.
|
|
*
|
|
*/
|
|
|
|
#include <linux/types.h>
|
|
#include <asm/hypervisor.h>
|
|
#include <asm/hyperv.h>
|
|
#include <asm/mshyperv.h>
|
|
#include <linux/version.h>
|
|
#include <linux/vmalloc.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/clockchips.h>
|
|
|
|
|
|
#ifdef CONFIG_X86_64
|
|
|
|
static struct ms_hyperv_tsc_page *tsc_pg;
|
|
|
|
static u64 read_hv_clock_tsc(struct clocksource *arg)
|
|
{
|
|
u64 current_tick;
|
|
|
|
if (tsc_pg->tsc_sequence != 0) {
|
|
/*
|
|
* Use the tsc page to compute the value.
|
|
*/
|
|
|
|
while (1) {
|
|
u64 tmp;
|
|
u32 sequence = tsc_pg->tsc_sequence;
|
|
u64 cur_tsc;
|
|
u64 scale = tsc_pg->tsc_scale;
|
|
s64 offset = tsc_pg->tsc_offset;
|
|
|
|
rdtscll(cur_tsc);
|
|
/* current_tick = ((cur_tsc *scale) >> 64) + offset */
|
|
asm("mulq %3"
|
|
: "=d" (current_tick), "=a" (tmp)
|
|
: "a" (cur_tsc), "r" (scale));
|
|
|
|
current_tick += offset;
|
|
if (tsc_pg->tsc_sequence == sequence)
|
|
return current_tick;
|
|
|
|
if (tsc_pg->tsc_sequence != 0)
|
|
continue;
|
|
/*
|
|
* Fallback using MSR method.
|
|
*/
|
|
break;
|
|
}
|
|
}
|
|
rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
|
|
return current_tick;
|
|
}
|
|
|
|
static struct clocksource hyperv_cs_tsc = {
|
|
.name = "hyperv_clocksource_tsc_page",
|
|
.rating = 400,
|
|
.read = read_hv_clock_tsc,
|
|
.mask = CLOCKSOURCE_MASK(64),
|
|
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
|
|
};
|
|
#endif
|
|
|
|
static u64 read_hv_clock_msr(struct clocksource *arg)
|
|
{
|
|
u64 current_tick;
|
|
/*
|
|
* Read the partition counter to get the current tick count. This count
|
|
* is set to 0 when the partition is created and is incremented in
|
|
* 100 nanosecond units.
|
|
*/
|
|
rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
|
|
return current_tick;
|
|
}
|
|
|
|
static struct clocksource hyperv_cs_msr = {
|
|
.name = "hyperv_clocksource_msr",
|
|
.rating = 400,
|
|
.read = read_hv_clock_msr,
|
|
.mask = CLOCKSOURCE_MASK(64),
|
|
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
|
|
};
|
|
|
|
static void *hypercall_pg;
|
|
struct clocksource *hyperv_cs;
|
|
EXPORT_SYMBOL_GPL(hyperv_cs);
|
|
|
|
/*
|
|
* This function is to be invoked early in the boot sequence after the
|
|
* hypervisor has been detected.
|
|
*
|
|
* 1. Setup the hypercall page.
|
|
* 2. Register Hyper-V specific clocksource.
|
|
*/
|
|
void hyperv_init(void)
|
|
{
|
|
u64 guest_id;
|
|
union hv_x64_msr_hypercall_contents hypercall_msr;
|
|
|
|
if (x86_hyper != &x86_hyper_ms_hyperv)
|
|
return;
|
|
|
|
/*
|
|
* Setup the hypercall page and enable hypercalls.
|
|
* 1. Register the guest ID
|
|
* 2. Enable the hypercall and register the hypercall page
|
|
*/
|
|
guest_id = generate_guest_id(0, LINUX_VERSION_CODE, 0);
|
|
wrmsrl(HV_X64_MSR_GUEST_OS_ID, guest_id);
|
|
|
|
hypercall_pg = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_RX);
|
|
if (hypercall_pg == NULL) {
|
|
wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
|
|
return;
|
|
}
|
|
|
|
rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
|
|
hypercall_msr.enable = 1;
|
|
hypercall_msr.guest_physical_address = vmalloc_to_pfn(hypercall_pg);
|
|
wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
|
|
|
|
/*
|
|
* Register Hyper-V specific clocksource.
|
|
*/
|
|
#ifdef CONFIG_X86_64
|
|
if (ms_hyperv.features & HV_X64_MSR_REFERENCE_TSC_AVAILABLE) {
|
|
union hv_x64_msr_hypercall_contents tsc_msr;
|
|
|
|
tsc_pg = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL);
|
|
if (!tsc_pg)
|
|
goto register_msr_cs;
|
|
|
|
hyperv_cs = &hyperv_cs_tsc;
|
|
|
|
rdmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
|
|
|
|
tsc_msr.enable = 1;
|
|
tsc_msr.guest_physical_address = vmalloc_to_pfn(tsc_pg);
|
|
|
|
wrmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
|
|
clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100);
|
|
return;
|
|
}
|
|
register_msr_cs:
|
|
#endif
|
|
/*
|
|
* For 32 bit guests just use the MSR based mechanism for reading
|
|
* the partition counter.
|
|
*/
|
|
|
|
hyperv_cs = &hyperv_cs_msr;
|
|
if (ms_hyperv.features & HV_X64_MSR_TIME_REF_COUNT_AVAILABLE)
|
|
clocksource_register_hz(&hyperv_cs_msr, NSEC_PER_SEC/100);
|
|
}
|
|
|
|
/*
|
|
* This routine is called before kexec/kdump, it does the required cleanup.
|
|
*/
|
|
void hyperv_cleanup(void)
|
|
{
|
|
union hv_x64_msr_hypercall_contents hypercall_msr;
|
|
|
|
/* Reset our OS id */
|
|
wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
|
|
|
|
/* Reset the hypercall page */
|
|
hypercall_msr.as_uint64 = 0;
|
|
wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
|
|
|
|
/* Reset the TSC page */
|
|
hypercall_msr.as_uint64 = 0;
|
|
wrmsrl(HV_X64_MSR_REFERENCE_TSC, hypercall_msr.as_uint64);
|
|
}
|
|
EXPORT_SYMBOL_GPL(hyperv_cleanup);
|
|
|
|
/*
|
|
* hv_do_hypercall- Invoke the specified hypercall
|
|
*/
|
|
u64 hv_do_hypercall(u64 control, void *input, void *output)
|
|
{
|
|
u64 input_address = (input) ? virt_to_phys(input) : 0;
|
|
u64 output_address = (output) ? virt_to_phys(output) : 0;
|
|
#ifdef CONFIG_X86_64
|
|
u64 hv_status = 0;
|
|
|
|
if (!hypercall_pg)
|
|
return (u64)ULLONG_MAX;
|
|
|
|
__asm__ __volatile__("mov %0, %%r8" : : "r" (output_address) : "r8");
|
|
__asm__ __volatile__("call *%3" : "=a" (hv_status) :
|
|
"c" (control), "d" (input_address),
|
|
"m" (hypercall_pg));
|
|
|
|
return hv_status;
|
|
|
|
#else
|
|
|
|
u32 control_hi = control >> 32;
|
|
u32 control_lo = control & 0xFFFFFFFF;
|
|
u32 hv_status_hi = 1;
|
|
u32 hv_status_lo = 1;
|
|
u32 input_address_hi = input_address >> 32;
|
|
u32 input_address_lo = input_address & 0xFFFFFFFF;
|
|
u32 output_address_hi = output_address >> 32;
|
|
u32 output_address_lo = output_address & 0xFFFFFFFF;
|
|
|
|
if (!hypercall_pg)
|
|
return (u64)ULLONG_MAX;
|
|
|
|
__asm__ __volatile__ ("call *%8" : "=d"(hv_status_hi),
|
|
"=a"(hv_status_lo) : "d" (control_hi),
|
|
"a" (control_lo), "b" (input_address_hi),
|
|
"c" (input_address_lo), "D"(output_address_hi),
|
|
"S"(output_address_lo), "m" (hypercall_pg));
|
|
|
|
return hv_status_lo | ((u64)hv_status_hi << 32);
|
|
#endif /* !x86_64 */
|
|
}
|
|
EXPORT_SYMBOL_GPL(hv_do_hypercall);
|
|
|
|
void hyperv_report_panic(struct pt_regs *regs)
|
|
{
|
|
static bool panic_reported;
|
|
|
|
/*
|
|
* We prefer to report panic on 'die' chain as we have proper
|
|
* registers to report, but if we miss it (e.g. on BUG()) we need
|
|
* to report it on 'panic'.
|
|
*/
|
|
if (panic_reported)
|
|
return;
|
|
panic_reported = true;
|
|
|
|
wrmsrl(HV_X64_MSR_CRASH_P0, regs->ip);
|
|
wrmsrl(HV_X64_MSR_CRASH_P1, regs->ax);
|
|
wrmsrl(HV_X64_MSR_CRASH_P2, regs->bx);
|
|
wrmsrl(HV_X64_MSR_CRASH_P3, regs->cx);
|
|
wrmsrl(HV_X64_MSR_CRASH_P4, regs->dx);
|
|
|
|
/*
|
|
* Let Hyper-V know there is crash data available
|
|
*/
|
|
wrmsrl(HV_X64_MSR_CRASH_CTL, HV_CRASH_CTL_CRASH_NOTIFY);
|
|
}
|
|
EXPORT_SYMBOL_GPL(hyperv_report_panic);
|
|
|
|
bool hv_is_hypercall_page_setup(void)
|
|
{
|
|
union hv_x64_msr_hypercall_contents hypercall_msr;
|
|
|
|
/* Check if the hypercall page is setup */
|
|
hypercall_msr.as_uint64 = 0;
|
|
rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
|
|
|
|
if (!hypercall_msr.enable)
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
EXPORT_SYMBOL_GPL(hv_is_hypercall_page_setup);
|