arch/x86/xen/enlighten_hvm.c

   1 #include <linux/acpi.h>
   2 #include <linux/cpu.h>
   3 #include <linux/kexec.h>
   4 #include <linux/memblock.h>
   5
   6 #include <xen/features.h>
   7 #include <xen/events.h>
   8 #include <xen/interface/memory.h>
   9
  10 #include <asm/cpu.h>
  11 #include <asm/smp.h>
  12 #include <asm/reboot.h>
  13 #include <asm/setup.h>
  14 #include <asm/hypervisor.h>
  15 #include <asm/e820/api.h>
  16 #include <asm/early_ioremap.h>
  17
  18 #include <asm/xen/cpuid.h>
  19 #include <asm/xen/hypervisor.h>
  20 #include <asm/xen/page.h>
  21
  22 #include "xen-ops.h"
  23 #include "mmu.h"
  24 #include "smp.h"
  25
  26 static unsigned long shared_info_pfn;
  27
  28 void xen_hvm_init_shared_info(void)
  29 {
  30         struct xen_add_to_physmap xatp;
  31
  32         xatp.domid = DOMID_SELF;
  33         xatp.idx = 0;
  34         xatp.space = XENMAPSPACE_shared_info;
  35         xatp.gpfn = shared_info_pfn;
  36         if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
  37                 BUG();
  38 }
  39
  40 static void __init reserve_shared_info(void)
  41 {
  42         u64 pa;
  43
  44         /*
  45          * Search for a free page starting at 4kB physical address.
  46          * Low memory is preferred to avoid an EPT large page split up
  47          * by the mapping.
  48          * Starting below X86_RESERVE_LOW (usually 64kB) is fine as
  49          * the BIOS used for HVM guests is well behaved and won't
  50          * clobber memory other than the first 4kB.
  51          */
  52         for (pa = PAGE_SIZE;
  53              !e820__mapped_all(pa, pa + PAGE_SIZE, E820_TYPE_RAM) ||
  54              memblock_is_reserved(pa);
  55              pa += PAGE_SIZE)
  56                 ;
  57
  58         shared_info_pfn = PHYS_PFN(pa);
  59
  60         memblock_reserve(pa, PAGE_SIZE);
  61         HYPERVISOR_shared_info = early_memremap(pa, PAGE_SIZE);
  62 }
  63
  64 static void __init xen_hvm_init_mem_mapping(void)
  65 {
  66         early_memunmap(HYPERVISOR_shared_info, PAGE_SIZE);
  67         HYPERVISOR_shared_info = __va(PFN_PHYS(shared_info_pfn));
  68
  69         /*
  70          * The virtual address of the shared_info page has changed, so
  71          * the vcpu_info pointer for VCPU 0 is now stale.
  72          *
  73          * The prepare_boot_cpu callback will re-initialize it via
  74          * xen_vcpu_setup, but we can't rely on that to be called for
  75          * old Xen versions (xen_have_vector_callback == 0).
  76          *
  77          * It is, in any case, bad to have a stale vcpu_info pointer
  78          * so reset it now.
  79          */
  80         xen_vcpu_info_reset(0);
  81 }
  82
  83 static void __init init_hvm_pv_info(void)
  84 {
  85         int major, minor;
  86         uint32_t eax, ebx, ecx, edx, base;
  87
  88         base = xen_cpuid_base();
  89         eax = cpuid_eax(base + 1);
  90
  91         major = eax >> 16;
  92         minor = eax & 0xffff;
  93         printk(KERN_INFO "Xen version %d.%d.\n", major, minor);
  94
  95         xen_domain_type = XEN_HVM_DOMAIN;
  96
  97         /* PVH set up hypercall page in xen_prepare_pvh(). */
  98         if (xen_pvh_domain())
  99                 pv_info.name = "Xen PVH";
 100         else {
 101                 u64 pfn;
 102                 uint32_t msr;
 103
 104                 pv_info.name = "Xen HVM";
 105                 msr = cpuid_ebx(base + 2);
 106                 pfn = __pa(hypercall_page);
 107                 wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
 108         }
 109
 110         xen_setup_features();
 111
 112         cpuid(base + 4, &eax, &ebx, &ecx, &edx);
 113         if (eax & XEN_HVM_CPUID_VCPU_ID_PRESENT)
 114                 this_cpu_write(xen_vcpu_id, ebx);
 115         else
 116                 this_cpu_write(xen_vcpu_id, smp_processor_id());
 117 }
 118
 119 #ifdef CONFIG_KEXEC_CORE
 120 static void xen_hvm_shutdown(void)
 121 {
 122         native_machine_shutdown();
 123         if (kexec_in_progress)
 124                 xen_reboot(SHUTDOWN_soft_reset);
 125 }
 126
 127 static void xen_hvm_crash_shutdown(struct pt_regs *regs)
 128 {
 129         native_machine_crash_shutdown(regs);
 130         xen_reboot(SHUTDOWN_soft_reset);
 131 }
 132 #endif
 133
 134 static int xen_cpu_up_prepare_hvm(unsigned int cpu)
 135 {
 136         int rc = 0;
 137
 138         /*
 139          * This can happen if CPU was offlined earlier and
 140          * offlining timed out in common_cpu_die().
 141          */
 142         if (cpu_report_state(cpu) == CPU_DEAD_FROZEN) {
 143                 xen_smp_intr_free(cpu);
 144                 xen_uninit_lock_cpu(cpu);
 145         }
 146
 147         if (cpu_acpi_id(cpu) != U32_MAX)
 148                 per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu);
 149         else
 150                 per_cpu(xen_vcpu_id, cpu) = cpu;
 151         rc = xen_vcpu_setup(cpu);
 152         if (rc)
 153                 return rc;
 154
 155         if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock))
 156                 xen_setup_timer(cpu);
 157
 158         rc = xen_smp_intr_init(cpu);
 159         if (rc) {
 160                 WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n",
 161                      cpu, rc);
 162         }
 163         return rc;
 164 }
 165
 166 static int xen_cpu_dead_hvm(unsigned int cpu)
 167 {
 168         xen_smp_intr_free(cpu);
 169
 170         if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock))
 171                 xen_teardown_timer(cpu);
 172
 173        return 0;
 174 }
 175
 176 static void __init xen_hvm_guest_init(void)
 177 {
 178         if (xen_pv_domain())
 179                 return;
 180
 181         init_hvm_pv_info();
 182
 183         reserve_shared_info();
 184         xen_hvm_init_shared_info();
 185
 186         /*
 187          * xen_vcpu is a pointer to the vcpu_info struct in the shared_info
 188          * page, we use it in the event channel upcall and in some pvclock
 189          * related functions.
 190          */
 191         xen_vcpu_info_reset(0);
 192
 193         xen_panic_handler_init();
 194
 195         if (xen_feature(XENFEAT_hvm_callback_vector))
 196                 xen_have_vector_callback = 1;
 197
 198         xen_hvm_smp_init();
 199         WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_hvm, xen_cpu_dead_hvm));
 200         xen_unplug_emulated_devices();
 201         x86_init.irqs.intr_init = xen_init_IRQ;
 202         xen_hvm_init_time_ops();
 203         xen_hvm_init_mmu_ops();
 204
 205 #ifdef CONFIG_KEXEC_CORE
 206         machine_ops.shutdown = xen_hvm_shutdown;
 207         machine_ops.crash_shutdown = xen_hvm_crash_shutdown;
 208 #endif
 209 }
 210
 211 static bool xen_nopv;
 212 static __init int xen_parse_nopv(char *arg)
 213 {
 214        xen_nopv = true;
 215        return 0;
 216 }
 217 early_param("xen_nopv", xen_parse_nopv);
 218
 219 bool xen_hvm_need_lapic(void)
 220 {
 221         if (xen_nopv)
 222                 return false;
 223         if (xen_pv_domain())
 224                 return false;
 225         if (!xen_hvm_domain())
 226                 return false;
 227         if (xen_feature(XENFEAT_hvm_pirqs) && xen_have_vector_callback)
 228                 return false;
 229         return true;
 230 }
 231 EXPORT_SYMBOL_GPL(xen_hvm_need_lapic);
 232
 233 static uint32_t __init xen_platform_hvm(void)
 234 {
 235         if (xen_pv_domain() || xen_nopv)
 236                 return 0;
 237
 238         return xen_cpuid_base();
 239 }
 240
 241 static __init void xen_hvm_guest_late_init(void)
 242 {
 243 #ifdef CONFIG_XEN_PVH
 244         /* Test for PVH domain (PVH boot path taken overrides ACPI flags). */
 245         if (!xen_pvh &&
 246             (x86_platform.legacy.rtc || !x86_platform.legacy.no_vga))
 247                 return;
 248
 249         /* PVH detected. */
 250         xen_pvh = true;
 251
 252         /* Make sure we don't fall back to (default) ACPI_IRQ_MODEL_PIC. */
 253         if (!nr_ioapics && acpi_irq_model == ACPI_IRQ_MODEL_PIC)
 254                 acpi_irq_model = ACPI_IRQ_MODEL_PLATFORM;
 255
 256         machine_ops.emergency_restart = xen_emergency_restart;
 257         pv_info.name = "Xen PVH";
 258 #endif
 259 }
 260
 261 const __initconst struct hypervisor_x86 x86_hyper_xen_hvm = {
 262         .name                   = "Xen HVM",
 263         .detect                 = xen_platform_hvm,
 264         .type                   = X86_HYPER_XEN_HVM,
 265         .init.init_platform     = xen_hvm_guest_init,
 266         .init.x2apic_available  = xen_x2apic_para_available,
 267         .init.init_mem_mapping  = xen_hvm_init_mem_mapping,
 268         .init.guest_late_init   = xen_hvm_guest_late_init,
 269         .runtime.pin_vcpu       = xen_pin_vcpu,
 270 };