arch/x86/kernel/jailhouse.c

   1 // SPDX-License-Identifier: GPL2.0
   2 /*
   3  * Jailhouse paravirt_ops implementation
   4  *
   5  * Copyright (c) Siemens AG, 2015-2017
   6  *
   7  * Authors:
   8  *  Jan Kiszka <jan.kiszka@siemens.com>
   9  */
  10
  11 #include <linux/acpi_pmtmr.h>
  12 #include <linux/kernel.h>
  13 #include <linux/reboot.h>
  14 #include <asm/apic.h>
  15 #include <asm/cpu.h>
  16 #include <asm/hypervisor.h>
  17 #include <asm/i8259.h>
  18 #include <asm/irqdomain.h>
  19 #include <asm/pci_x86.h>
  20 #include <asm/reboot.h>
  21 #include <asm/setup.h>
  22
  23 static __initdata struct jailhouse_setup_data setup_data;
  24 static unsigned int precalibrated_tsc_khz;
  25
  26 static uint32_t jailhouse_cpuid_base(void)
  27 {
  28         if (boot_cpu_data.cpuid_level < 0 ||
  29             !boot_cpu_has(X86_FEATURE_HYPERVISOR))
  30                 return 0;
  31
  32         return hypervisor_cpuid_base("Jailhouse\0\0\0", 0);
  33 }
  34
  35 static uint32_t __init jailhouse_detect(void)
  36 {
  37         return jailhouse_cpuid_base();
  38 }
  39
  40 static void jailhouse_get_wallclock(struct timespec *now)
  41 {
  42         memset(now, 0, sizeof(*now));
  43 }
  44
  45 static void __init jailhouse_timer_init(void)
  46 {
  47         lapic_timer_frequency = setup_data.apic_khz * (1000 / HZ);
  48 }
  49
  50 static unsigned long jailhouse_get_tsc(void)
  51 {
  52         return precalibrated_tsc_khz;
  53 }
  54
  55 static void __init jailhouse_x2apic_init(void)
  56 {
  57 #ifdef CONFIG_X86_X2APIC
  58         if (!x2apic_enabled())
  59                 return;
  60         /*
  61          * We do not have access to IR inside Jailhouse non-root cells.  So
  62          * we have to run in physical mode.
  63          */
  64         x2apic_phys = 1;
  65         /*
  66          * This will trigger the switch to apic_x2apic_phys.  Empty OEM IDs
  67          * ensure that only this APIC driver picks up the call.
  68          */
  69         default_acpi_madt_oem_check("", "");
  70 #endif
  71 }
  72
  73 static void __init jailhouse_get_smp_config(unsigned int early)
  74 {
  75         struct ioapic_domain_cfg ioapic_cfg = {
  76                 .type = IOAPIC_DOMAIN_STRICT,
  77                 .ops = &mp_ioapic_irqdomain_ops,
  78         };
  79         struct mpc_intsrc mp_irq = {
  80                 .type = MP_INTSRC,
  81                 .irqtype = mp_INT,
  82                 .irqflag = MP_IRQPOL_ACTIVE_HIGH | MP_IRQTRIG_EDGE,
  83         };
  84         unsigned int cpu;
  85
  86         jailhouse_x2apic_init();
  87
  88         register_lapic_address(0xfee00000);
  89
  90         for (cpu = 0; cpu < setup_data.num_cpus; cpu++) {
  91                 generic_processor_info(setup_data.cpu_ids[cpu],
  92                                        boot_cpu_apic_version);
  93         }
  94
  95         smp_found_config = 1;
  96
  97         if (setup_data.standard_ioapic) {
  98                 mp_register_ioapic(0, 0xfec00000, gsi_top, &ioapic_cfg);
  99
 100                 /* Register 1:1 mapping for legacy UART IRQs 3 and 4 */
 101                 mp_irq.srcbusirq = mp_irq.dstirq = 3;
 102                 mp_save_irq(&mp_irq);
 103
 104                 mp_irq.srcbusirq = mp_irq.dstirq = 4;
 105                 mp_save_irq(&mp_irq);
 106         }
 107 }
 108
 109 static void jailhouse_no_restart(void)
 110 {
 111         pr_notice("Jailhouse: Restart not supported, halting\n");
 112         machine_halt();
 113 }
 114
 115 static int __init jailhouse_pci_arch_init(void)
 116 {
 117         pci_direct_init(1);
 118
 119         /*
 120          * There are no bridges on the virtual PCI root bus under Jailhouse,
 121          * thus no other way to discover all devices than a full scan.
 122          * Respect any overrides via the command line, though.
 123          */
 124         if (pcibios_last_bus < 0)
 125                 pcibios_last_bus = 0xff;
 126
 127         return 0;
 128 }
 129
 130 static void __init jailhouse_init_platform(void)
 131 {
 132         u64 pa_data = boot_params.hdr.setup_data;
 133         struct setup_data header;
 134         void *mapping;
 135
 136         x86_init.irqs.pre_vector_init   = x86_init_noop;
 137         x86_init.timers.timer_init      = jailhouse_timer_init;
 138         x86_init.mpparse.get_smp_config = jailhouse_get_smp_config;
 139         x86_init.pci.arch_init          = jailhouse_pci_arch_init;
 140
 141         x86_platform.calibrate_cpu      = jailhouse_get_tsc;
 142         x86_platform.calibrate_tsc      = jailhouse_get_tsc;
 143         x86_platform.get_wallclock      = jailhouse_get_wallclock;
 144         x86_platform.legacy.rtc         = 0;
 145         x86_platform.legacy.warm_reset  = 0;
 146         x86_platform.legacy.i8042       = X86_LEGACY_I8042_PLATFORM_ABSENT;
 147
 148         legacy_pic                      = &null_legacy_pic;
 149
 150         machine_ops.emergency_restart   = jailhouse_no_restart;
 151
 152         while (pa_data) {
 153                 mapping = early_memremap(pa_data, sizeof(header));
 154                 memcpy(&header, mapping, sizeof(header));
 155                 early_memunmap(mapping, sizeof(header));
 156
 157                 if (header.type == SETUP_JAILHOUSE &&
 158                     header.len >= sizeof(setup_data)) {
 159                         pa_data += offsetof(struct setup_data, data);
 160
 161                         mapping = early_memremap(pa_data, sizeof(setup_data));
 162                         memcpy(&setup_data, mapping, sizeof(setup_data));
 163                         early_memunmap(mapping, sizeof(setup_data));
 164
 165                         break;
 166                 }
 167
 168                 pa_data = header.next;
 169         }
 170
 171         if (!pa_data)
 172                 panic("Jailhouse: No valid setup data found");
 173
 174         if (setup_data.compatible_version > JAILHOUSE_SETUP_REQUIRED_VERSION)
 175                 panic("Jailhouse: Unsupported setup data structure");
 176
 177         pmtmr_ioport = setup_data.pm_timer_address;
 178         pr_debug("Jailhouse: PM-Timer IO Port: %#x\n", pmtmr_ioport);
 179
 180         precalibrated_tsc_khz = setup_data.tsc_khz;
 181         setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
 182
 183         pci_probe = 0;
 184
 185         /*
 186          * Avoid that the kernel complains about missing ACPI tables - there
 187          * are none in a non-root cell.
 188          */
 189         disable_acpi();
 190 }
 191
 192 bool jailhouse_paravirt(void)
 193 {
 194         return jailhouse_cpuid_base() != 0;
 195 }
 196
 197 static bool jailhouse_x2apic_available(void)
 198 {
 199         /*
 200          * The x2APIC is only available if the root cell enabled it. Jailhouse
 201          * does not support switching between xAPIC and x2APIC.
 202          */
 203         return x2apic_enabled();
 204 }
 205
 206 const struct hypervisor_x86 x86_hyper_jailhouse __refconst = {
 207         .name                   = "Jailhouse",
 208         .detect                 = jailhouse_detect,
 209         .init.init_platform     = jailhouse_init_platform,
 210         .init.x2apic_available  = jailhouse_x2apic_available,
 211 };