1 // SPDX-License-Identifier: GPL-2.0 2 3 #include <linux/acpi.h> 4 #include <linux/cpu.h> 5 #include <linux/kexec.h> 6 #include <linux/memblock.h> 7 8 #include <xen/features.h> 9 #include <xen/events.h> 10 #include <xen/interface/memory.h> 11 12 #include <asm/cpu.h> 13 #include <asm/smp.h> 14 #include <asm/io_apic.h> 15 #include <asm/reboot.h> 16 #include <asm/setup.h> 17 #include <asm/idtentry.h> 18 #include <asm/hypervisor.h> 19 #include <asm/e820/api.h> 20 #include <asm/early_ioremap.h> 21 22 #include <asm/xen/cpuid.h> 23 #include <asm/xen/hypervisor.h> 24 #include <asm/xen/page.h> 25 26 #include "xen-ops.h" 27 #include "mmu.h" 28 #include "smp.h" 29 30 static unsigned long shared_info_pfn; 31 32 void xen_hvm_init_shared_info(void) 33 { 34 struct xen_add_to_physmap xatp; 35 36 xatp.domid = DOMID_SELF; 37 xatp.idx = 0; 38 xatp.space = XENMAPSPACE_shared_info; 39 xatp.gpfn = shared_info_pfn; 40 if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp)) 41 BUG(); 42 } 43 44 static void __init reserve_shared_info(void) 45 { 46 u64 pa; 47 48 /* 49 * Search for a free page starting at 4kB physical address. 50 * Low memory is preferred to avoid an EPT large page split up 51 * by the mapping. 52 * Starting below X86_RESERVE_LOW (usually 64kB) is fine as 53 * the BIOS used for HVM guests is well behaved and won't 54 * clobber memory other than the first 4kB. 55 */ 56 for (pa = PAGE_SIZE; 57 !e820__mapped_all(pa, pa + PAGE_SIZE, E820_TYPE_RAM) || 58 memblock_is_reserved(pa); 59 pa += PAGE_SIZE) 60 ; 61 62 shared_info_pfn = PHYS_PFN(pa); 63 64 memblock_reserve(pa, PAGE_SIZE); 65 HYPERVISOR_shared_info = early_memremap(pa, PAGE_SIZE); 66 } 67 68 static void __init xen_hvm_init_mem_mapping(void) 69 { 70 early_memunmap(HYPERVISOR_shared_info, PAGE_SIZE); 71 HYPERVISOR_shared_info = __va(PFN_PHYS(shared_info_pfn)); 72 73 /* 74 * The virtual address of the shared_info page has changed, so 75 * the vcpu_info pointer for VCPU 0 is now stale. 76 * 77 * The prepare_boot_cpu callback will re-initialize it via 78 * xen_vcpu_setup, but we can't rely on that to be called for 79 * old Xen versions (xen_have_vector_callback == 0). 80 * 81 * It is, in any case, bad to have a stale vcpu_info pointer 82 * so reset it now. 83 */ 84 xen_vcpu_info_reset(0); 85 } 86 87 static void __init init_hvm_pv_info(void) 88 { 89 int major, minor; 90 uint32_t eax, ebx, ecx, edx, base; 91 92 base = xen_cpuid_base(); 93 eax = cpuid_eax(base + 1); 94 95 major = eax >> 16; 96 minor = eax & 0xffff; 97 printk(KERN_INFO "Xen version %d.%d.\n", major, minor); 98 99 xen_domain_type = XEN_HVM_DOMAIN; 100 101 /* PVH set up hypercall page in xen_prepare_pvh(). */ 102 if (xen_pvh_domain()) 103 pv_info.name = "Xen PVH"; 104 else { 105 u64 pfn; 106 uint32_t msr; 107 108 pv_info.name = "Xen HVM"; 109 msr = cpuid_ebx(base + 2); 110 pfn = __pa(hypercall_page); 111 wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32)); 112 } 113 114 xen_setup_features(); 115 116 cpuid(base + 4, &eax, &ebx, &ecx, &edx); 117 if (eax & XEN_HVM_CPUID_VCPU_ID_PRESENT) 118 this_cpu_write(xen_vcpu_id, ebx); 119 else 120 this_cpu_write(xen_vcpu_id, smp_processor_id()); 121 } 122 123 DEFINE_IDTENTRY_SYSVEC(sysvec_xen_hvm_callback) 124 { 125 struct pt_regs *old_regs = set_irq_regs(regs); 126 127 inc_irq_stat(irq_hv_callback_count); 128 129 xen_hvm_evtchn_do_upcall(); 130 131 set_irq_regs(old_regs); 132 } 133 134 #ifdef CONFIG_KEXEC_CORE 135 static void xen_hvm_shutdown(void) 136 { 137 native_machine_shutdown(); 138 if (kexec_in_progress) 139 xen_reboot(SHUTDOWN_soft_reset); 140 } 141 142 static void xen_hvm_crash_shutdown(struct pt_regs *regs) 143 { 144 native_machine_crash_shutdown(regs); 145 xen_reboot(SHUTDOWN_soft_reset); 146 } 147 #endif 148 149 static int xen_cpu_up_prepare_hvm(unsigned int cpu) 150 { 151 int rc = 0; 152 153 /* 154 * This can happen if CPU was offlined earlier and 155 * offlining timed out in common_cpu_die(). 156 */ 157 if (cpu_report_state(cpu) == CPU_DEAD_FROZEN) { 158 xen_smp_intr_free(cpu); 159 xen_uninit_lock_cpu(cpu); 160 } 161 162 if (cpu_acpi_id(cpu) != U32_MAX) 163 per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu); 164 else 165 per_cpu(xen_vcpu_id, cpu) = cpu; 166 rc = xen_vcpu_setup(cpu); 167 if (rc) 168 return rc; 169 170 if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock)) 171 xen_setup_timer(cpu); 172 173 rc = xen_smp_intr_init(cpu); 174 if (rc) { 175 WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n", 176 cpu, rc); 177 } 178 return rc; 179 } 180 181 static int xen_cpu_dead_hvm(unsigned int cpu) 182 { 183 xen_smp_intr_free(cpu); 184 185 if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock)) 186 xen_teardown_timer(cpu); 187 188 return 0; 189 } 190 191 static void __init xen_hvm_guest_init(void) 192 { 193 if (xen_pv_domain()) 194 return; 195 196 init_hvm_pv_info(); 197 198 reserve_shared_info(); 199 xen_hvm_init_shared_info(); 200 201 /* 202 * xen_vcpu is a pointer to the vcpu_info struct in the shared_info 203 * page, we use it in the event channel upcall and in some pvclock 204 * related functions. 205 */ 206 xen_vcpu_info_reset(0); 207 208 xen_panic_handler_init(); 209 210 if (xen_feature(XENFEAT_hvm_callback_vector)) 211 xen_have_vector_callback = 1; 212 213 xen_hvm_smp_init(); 214 WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_hvm, xen_cpu_dead_hvm)); 215 xen_unplug_emulated_devices(); 216 x86_init.irqs.intr_init = xen_init_IRQ; 217 xen_hvm_init_time_ops(); 218 xen_hvm_init_mmu_ops(); 219 220 #ifdef CONFIG_KEXEC_CORE 221 machine_ops.shutdown = xen_hvm_shutdown; 222 machine_ops.crash_shutdown = xen_hvm_crash_shutdown; 223 #endif 224 } 225 226 static __init int xen_parse_nopv(char *arg) 227 { 228 pr_notice("\"xen_nopv\" is deprecated, please use \"nopv\" instead\n"); 229 230 if (xen_cpuid_base()) 231 nopv = true; 232 return 0; 233 } 234 early_param("xen_nopv", xen_parse_nopv); 235 236 bool __init xen_hvm_need_lapic(void) 237 { 238 if (xen_pv_domain()) 239 return false; 240 if (!xen_hvm_domain()) 241 return false; 242 if (xen_feature(XENFEAT_hvm_pirqs) && xen_have_vector_callback) 243 return false; 244 return true; 245 } 246 247 static __init void xen_hvm_guest_late_init(void) 248 { 249 #ifdef CONFIG_XEN_PVH 250 /* Test for PVH domain (PVH boot path taken overrides ACPI flags). */ 251 if (!xen_pvh && 252 (x86_platform.legacy.rtc || !x86_platform.legacy.no_vga)) 253 return; 254 255 /* PVH detected. */ 256 xen_pvh = true; 257 258 if (nopv) 259 panic("\"nopv\" and \"xen_nopv\" parameters are unsupported in PVH guest."); 260 261 /* Make sure we don't fall back to (default) ACPI_IRQ_MODEL_PIC. */ 262 if (!nr_ioapics && acpi_irq_model == ACPI_IRQ_MODEL_PIC) 263 acpi_irq_model = ACPI_IRQ_MODEL_PLATFORM; 264 265 machine_ops.emergency_restart = xen_emergency_restart; 266 pv_info.name = "Xen PVH"; 267 #endif 268 } 269 270 static uint32_t __init xen_platform_hvm(void) 271 { 272 uint32_t xen_domain = xen_cpuid_base(); 273 struct x86_hyper_init *h = &x86_hyper_xen_hvm.init; 274 275 if (xen_pv_domain()) 276 return 0; 277 278 if (xen_pvh_domain() && nopv) { 279 /* Guest booting via the Xen-PVH boot entry goes here */ 280 pr_info("\"nopv\" parameter is ignored in PVH guest\n"); 281 nopv = false; 282 } else if (nopv && xen_domain) { 283 /* 284 * Guest booting via normal boot entry (like via grub2) goes 285 * here. 286 * 287 * Use interface functions for bare hardware if nopv, 288 * xen_hvm_guest_late_init is an exception as we need to 289 * detect PVH and panic there. 290 */ 291 h->init_platform = x86_init_noop; 292 h->x2apic_available = bool_x86_init_noop; 293 h->init_mem_mapping = x86_init_noop; 294 h->init_after_bootmem = x86_init_noop; 295 h->guest_late_init = xen_hvm_guest_late_init; 296 x86_hyper_xen_hvm.runtime.pin_vcpu = x86_op_int_noop; 297 } 298 return xen_domain; 299 } 300 301 struct hypervisor_x86 x86_hyper_xen_hvm __initdata = { 302 .name = "Xen HVM", 303 .detect = xen_platform_hvm, 304 .type = X86_HYPER_XEN_HVM, 305 .init.init_platform = xen_hvm_guest_init, 306 .init.x2apic_available = xen_x2apic_para_available, 307 .init.init_mem_mapping = xen_hvm_init_mem_mapping, 308 .init.guest_late_init = xen_hvm_guest_late_init, 309 .runtime.pin_vcpu = xen_pin_vcpu, 310 .ignore_nopv = true, 311 }; 312