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