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 static void __init init_hvm_pv_info(void)
  71 {
  72         int major, minor;
  73         uint32_t eax, ebx, ecx, edx, base;
  74
  75         base = xen_cpuid_base();
  76         eax = cpuid_eax(base + 1);
  77
  78         major = eax >> 16;
  79         minor = eax & 0xffff;
  80         printk(KERN_INFO "Xen version %d.%d.\n", major, minor);
  81
  82         xen_domain_type = XEN_HVM_DOMAIN;
  83
  84         /* PVH set up hypercall page in xen_prepare_pvh(). */
  85         if (xen_pvh_domain())
  86                 pv_info.name = "Xen PVH";
  87         else {
  88                 u64 pfn;
  89                 uint32_t msr;
  90
  91                 pv_info.name = "Xen HVM";
  92                 msr = cpuid_ebx(base + 2);
  93                 pfn = __pa(hypercall_page);
  94                 wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
  95         }
  96
  97         xen_setup_features();
  98
  99         cpuid(base + 4, &eax, &ebx, &ecx, &edx);
 100         if (eax & XEN_HVM_CPUID_VCPU_ID_PRESENT)
 101                 this_cpu_write(xen_vcpu_id, ebx);
 102         else
 103                 this_cpu_write(xen_vcpu_id, smp_processor_id());
 104 }
 105
 106 #ifdef CONFIG_KEXEC_CORE
 107 static void xen_hvm_shutdown(void)
 108 {
 109         native_machine_shutdown();
 110         if (kexec_in_progress)
 111                 xen_reboot(SHUTDOWN_soft_reset);
 112 }
 113
 114 static void xen_hvm_crash_shutdown(struct pt_regs *regs)
 115 {
 116         native_machine_crash_shutdown(regs);
 117         xen_reboot(SHUTDOWN_soft_reset);
 118 }
 119 #endif
 120
 121 static int xen_cpu_up_prepare_hvm(unsigned int cpu)
 122 {
 123         int rc = 0;
 124
 125         /*
 126          * This can happen if CPU was offlined earlier and
 127          * offlining timed out in common_cpu_die().
 128          */
 129         if (cpu_report_state(cpu) == CPU_DEAD_FROZEN) {
 130                 xen_smp_intr_free(cpu);
 131                 xen_uninit_lock_cpu(cpu);
 132         }
 133
 134         if (cpu_acpi_id(cpu) != U32_MAX)
 135                 per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu);
 136         else
 137                 per_cpu(xen_vcpu_id, cpu) = cpu;
 138         rc = xen_vcpu_setup(cpu);
 139         if (rc)
 140                 return rc;
 141
 142         if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock))
 143                 xen_setup_timer(cpu);
 144
 145         rc = xen_smp_intr_init(cpu);
 146         if (rc) {
 147                 WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n",
 148                      cpu, rc);
 149         }
 150         return rc;
 151 }
 152
 153 static int xen_cpu_dead_hvm(unsigned int cpu)
 154 {
 155         xen_smp_intr_free(cpu);
 156
 157         if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock))
 158                 xen_teardown_timer(cpu);
 159
 160        return 0;
 161 }
 162
 163 static void __init xen_hvm_guest_init(void)
 164 {
 165         if (xen_pv_domain())
 166                 return;
 167
 168         init_hvm_pv_info();
 169
 170         reserve_shared_info();
 171         xen_hvm_init_shared_info();
 172
 173         /*
 174          * xen_vcpu is a pointer to the vcpu_info struct in the shared_info
 175          * page, we use it in the event channel upcall and in some pvclock
 176          * related functions.
 177          */
 178         xen_vcpu_info_reset(0);
 179
 180         xen_panic_handler_init();
 181
 182         if (xen_feature(XENFEAT_hvm_callback_vector))
 183                 xen_have_vector_callback = 1;
 184
 185         xen_hvm_smp_init();
 186         WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_hvm, xen_cpu_dead_hvm));
 187         xen_unplug_emulated_devices();
 188         x86_init.irqs.intr_init = xen_init_IRQ;
 189         xen_hvm_init_time_ops();
 190         xen_hvm_init_mmu_ops();
 191
 192 #ifdef CONFIG_KEXEC_CORE
 193         machine_ops.shutdown = xen_hvm_shutdown;
 194         machine_ops.crash_shutdown = xen_hvm_crash_shutdown;
 195 #endif
 196 }
 197
 198 static bool xen_nopv;
 199 static __init int xen_parse_nopv(char *arg)
 200 {
 201        xen_nopv = true;
 202        return 0;
 203 }
 204 early_param("xen_nopv", xen_parse_nopv);
 205
 206 bool xen_hvm_need_lapic(void)
 207 {
 208         if (xen_nopv)
 209                 return false;
 210         if (xen_pv_domain())
 211                 return false;
 212         if (!xen_hvm_domain())
 213                 return false;
 214         if (xen_feature(XENFEAT_hvm_pirqs) && xen_have_vector_callback)
 215                 return false;
 216         return true;
 217 }
 218 EXPORT_SYMBOL_GPL(xen_hvm_need_lapic);
 219
 220 static uint32_t __init xen_platform_hvm(void)
 221 {
 222         if (xen_pv_domain() || xen_nopv)
 223                 return 0;
 224
 225         return xen_cpuid_base();
 226 }
 227
 228 static __init void xen_hvm_guest_late_init(void)
 229 {
 230 #ifdef CONFIG_XEN_PVH
 231         /* Test for PVH domain (PVH boot path taken overrides ACPI flags). */
 232         if (!xen_pvh &&
 233             (x86_platform.legacy.rtc || !x86_platform.legacy.no_vga))
 234                 return;
 235
 236         /* PVH detected. */
 237         xen_pvh = true;
 238
 239         /* Make sure we don't fall back to (default) ACPI_IRQ_MODEL_PIC. */
 240         if (!nr_ioapics && acpi_irq_model == ACPI_IRQ_MODEL_PIC)
 241                 acpi_irq_model = ACPI_IRQ_MODEL_PLATFORM;
 242
 243         machine_ops.emergency_restart = xen_emergency_restart;
 244         pv_info.name = "Xen PVH";
 245 #endif
 246 }
 247
 248 const __initconst struct hypervisor_x86 x86_hyper_xen_hvm = {
 249         .name                   = "Xen HVM",
 250         .detect                 = xen_platform_hvm,
 251         .type                   = X86_HYPER_XEN_HVM,
 252         .init.init_platform     = xen_hvm_guest_init,
 253         .init.x2apic_available  = xen_x2apic_para_available,
 254         .init.init_mem_mapping  = xen_hvm_init_mem_mapping,
 255         .init.guest_late_init   = xen_hvm_guest_late_init,
 256         .runtime.pin_vcpu       = xen_pin_vcpu,
 257 };