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