arch/x86/xen/enlighten_hvm.c

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