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 #include <linux/virtio_anchor.h> 8 9 #include <xen/features.h> 10 #include <xen/events.h> 11 #include <xen/hvm.h> 12 #include <xen/interface/hvm/hvm_op.h> 13 #include <xen/interface/memory.h> 14 15 #include <asm/apic.h> 16 #include <asm/cpu.h> 17 #include <asm/smp.h> 18 #include <asm/io_apic.h> 19 #include <asm/reboot.h> 20 #include <asm/setup.h> 21 #include <asm/idtentry.h> 22 #include <asm/hypervisor.h> 23 #include <asm/e820/api.h> 24 #include <asm/early_ioremap.h> 25 26 #include <asm/xen/cpuid.h> 27 #include <asm/xen/hypervisor.h> 28 #include <asm/xen/page.h> 29 30 #include "xen-ops.h" 31 32 static unsigned long shared_info_pfn; 33 34 __ro_after_init bool xen_percpu_upcall; 35 EXPORT_SYMBOL_GPL(xen_percpu_upcall); 36 37 void xen_hvm_init_shared_info(void) 38 { 39 struct xen_add_to_physmap xatp; 40 41 xatp.domid = DOMID_SELF; 42 xatp.idx = 0; 43 xatp.space = XENMAPSPACE_shared_info; 44 xatp.gpfn = shared_info_pfn; 45 if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp)) 46 BUG(); 47 } 48 49 static void __init reserve_shared_info(void) 50 { 51 u64 pa; 52 53 /* 54 * Search for a free page starting at 4kB physical address. 55 * Low memory is preferred to avoid an EPT large page split up 56 * by the mapping. 57 * Starting below X86_RESERVE_LOW (usually 64kB) is fine as 58 * the BIOS used for HVM guests is well behaved and won't 59 * clobber memory other than the first 4kB. 60 */ 61 for (pa = PAGE_SIZE; 62 !e820__mapped_all(pa, pa + PAGE_SIZE, E820_TYPE_RAM) || 63 memblock_is_reserved(pa); 64 pa += PAGE_SIZE) 65 ; 66 67 shared_info_pfn = PHYS_PFN(pa); 68 69 memblock_reserve(pa, PAGE_SIZE); 70 HYPERVISOR_shared_info = early_memremap(pa, PAGE_SIZE); 71 } 72 73 static void __init xen_hvm_init_mem_mapping(void) 74 { 75 early_memunmap(HYPERVISOR_shared_info, PAGE_SIZE); 76 HYPERVISOR_shared_info = __va(PFN_PHYS(shared_info_pfn)); 77 78 /* 79 * The virtual address of the shared_info page has changed, so 80 * the vcpu_info pointer for VCPU 0 is now stale. 81 * 82 * The prepare_boot_cpu callback will re-initialize it via 83 * xen_vcpu_setup, but we can't rely on that to be called for 84 * old Xen versions (xen_have_vector_callback == 0). 85 * 86 * It is, in any case, bad to have a stale vcpu_info pointer 87 * so reset it now. 88 */ 89 xen_vcpu_info_reset(0); 90 } 91 92 static void __init init_hvm_pv_info(void) 93 { 94 int major, minor; 95 uint32_t eax, ebx, ecx, edx, base; 96 97 base = xen_cpuid_base(); 98 eax = cpuid_eax(base + 1); 99 100 major = eax >> 16; 101 minor = eax & 0xffff; 102 printk(KERN_INFO "Xen version %d.%d.\n", major, minor); 103 104 xen_domain_type = XEN_HVM_DOMAIN; 105 106 /* PVH set up hypercall page in xen_prepare_pvh(). */ 107 if (xen_pvh_domain()) 108 pv_info.name = "Xen PVH"; 109 else 110 pv_info.name = "Xen HVM"; 111 112 xen_setup_features(); 113 114 cpuid(base + 4, &eax, &ebx, &ecx, &edx); 115 if (eax & XEN_HVM_CPUID_VCPU_ID_PRESENT) 116 this_cpu_write(xen_vcpu_id, ebx); 117 else 118 this_cpu_write(xen_vcpu_id, smp_processor_id()); 119 } 120 121 DEFINE_IDTENTRY_SYSVEC(sysvec_xen_hvm_callback) 122 { 123 struct pt_regs *old_regs = set_irq_regs(regs); 124 125 if (xen_percpu_upcall) 126 apic_eoi(); 127 128 inc_irq_stat(irq_hv_callback_count); 129 130 xen_evtchn_do_upcall(); 131 132 set_irq_regs(old_regs); 133 } 134 135 #ifdef CONFIG_KEXEC_CORE 136 static void xen_hvm_shutdown(void) 137 { 138 native_machine_shutdown(); 139 if (kexec_in_progress) 140 xen_reboot(SHUTDOWN_soft_reset); 141 } 142 #endif 143 144 #ifdef CONFIG_CRASH_DUMP 145 static void xen_hvm_crash_shutdown(struct pt_regs *regs) 146 { 147 native_machine_crash_shutdown(regs); 148 xen_reboot(SHUTDOWN_soft_reset); 149 } 150 #endif 151 152 static int xen_cpu_up_prepare_hvm(unsigned int cpu) 153 { 154 int rc = 0; 155 156 /* 157 * If a CPU was offlined earlier and offlining timed out then the 158 * lock mechanism is still initialized. Uninit it unconditionally 159 * as it's safe to call even if already uninited. Interrupts and 160 * timer have already been handled in xen_cpu_dead_hvm(). 161 */ 162 xen_uninit_lock_cpu(cpu); 163 164 if (cpu_acpi_id(cpu) != CPU_ACPIID_INVALID) 165 per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu); 166 else 167 per_cpu(xen_vcpu_id, cpu) = cpu; 168 xen_vcpu_setup(cpu); 169 if (!xen_have_vector_callback) 170 return 0; 171 172 if (xen_percpu_upcall) { 173 rc = xen_set_upcall_vector(cpu); 174 if (rc) { 175 WARN(1, "HVMOP_set_evtchn_upcall_vector" 176 " for CPU %d failed: %d\n", cpu, rc); 177 return rc; 178 } 179 } 180 181 if (xen_feature(XENFEAT_hvm_safe_pvclock)) 182 xen_setup_timer(cpu); 183 184 rc = xen_smp_intr_init(cpu); 185 if (rc) { 186 WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n", 187 cpu, rc); 188 } 189 return rc; 190 } 191 192 static int xen_cpu_dead_hvm(unsigned int cpu) 193 { 194 xen_smp_intr_free(cpu); 195 196 if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock)) 197 xen_teardown_timer(cpu); 198 return 0; 199 } 200 201 static void __init xen_hvm_guest_init(void) 202 { 203 if (xen_pv_domain()) 204 return; 205 206 if (IS_ENABLED(CONFIG_XEN_VIRTIO_FORCE_GRANT)) 207 virtio_set_mem_acc_cb(xen_virtio_restricted_mem_acc); 208 209 init_hvm_pv_info(); 210 211 reserve_shared_info(); 212 xen_hvm_init_shared_info(); 213 214 /* 215 * xen_vcpu is a pointer to the vcpu_info struct in the shared_info 216 * page, we use it in the event channel upcall and in some pvclock 217 * related functions. 218 */ 219 xen_vcpu_info_reset(0); 220 221 xen_panic_handler_init(); 222 223 xen_hvm_smp_init(); 224 WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_hvm, xen_cpu_dead_hvm)); 225 xen_unplug_emulated_devices(); 226 x86_init.irqs.intr_init = xen_init_IRQ; 227 xen_hvm_init_time_ops(); 228 xen_hvm_init_mmu_ops(); 229 230 #ifdef CONFIG_KEXEC_CORE 231 machine_ops.shutdown = xen_hvm_shutdown; 232 #endif 233 #ifdef CONFIG_CRASH_DUMP 234 machine_ops.crash_shutdown = xen_hvm_crash_shutdown; 235 #endif 236 } 237 238 static __init int xen_parse_nopv(char *arg) 239 { 240 pr_notice("\"xen_nopv\" is deprecated, please use \"nopv\" instead\n"); 241 242 if (xen_cpuid_base()) 243 nopv = true; 244 return 0; 245 } 246 early_param("xen_nopv", xen_parse_nopv); 247 248 static __init int xen_parse_no_vector_callback(char *arg) 249 { 250 xen_have_vector_callback = false; 251 return 0; 252 } 253 early_param("xen_no_vector_callback", xen_parse_no_vector_callback); 254 255 static __init bool xen_x2apic_available(void) 256 { 257 return x2apic_supported(); 258 } 259 260 static bool __init msi_ext_dest_id(void) 261 { 262 return cpuid_eax(xen_cpuid_base() + 4) & XEN_HVM_CPUID_EXT_DEST_ID; 263 } 264 265 static __init void xen_hvm_guest_late_init(void) 266 { 267 #ifdef CONFIG_XEN_PVH 268 /* Test for PVH domain (PVH boot path taken overrides ACPI flags). */ 269 if (!xen_pvh && 270 (x86_platform.legacy.rtc || !x86_platform.legacy.no_vga)) 271 return; 272 273 /* PVH detected. */ 274 xen_pvh = true; 275 276 if (nopv) 277 panic("\"nopv\" and \"xen_nopv\" parameters are unsupported in PVH guest."); 278 279 /* Make sure we don't fall back to (default) ACPI_IRQ_MODEL_PIC. */ 280 if (!nr_ioapics && acpi_irq_model == ACPI_IRQ_MODEL_PIC) 281 acpi_irq_model = ACPI_IRQ_MODEL_PLATFORM; 282 283 machine_ops.emergency_restart = xen_emergency_restart; 284 pv_info.name = "Xen PVH"; 285 #endif 286 } 287 288 static uint32_t __init xen_platform_hvm(void) 289 { 290 uint32_t xen_domain = xen_cpuid_base(); 291 struct x86_hyper_init *h = &x86_hyper_xen_hvm.init; 292 293 if (xen_pv_domain()) 294 return 0; 295 296 /* Set correct hypercall function. */ 297 if (xen_domain) 298 xen_hypercall_setfunc(); 299 300 if (xen_pvh_domain() && nopv) { 301 /* Guest booting via the Xen-PVH boot entry goes here */ 302 pr_info("\"nopv\" parameter is ignored in PVH guest\n"); 303 nopv = false; 304 } else if (nopv && xen_domain) { 305 /* 306 * Guest booting via normal boot entry (like via grub2) goes 307 * here. 308 * 309 * Use interface functions for bare hardware if nopv, 310 * xen_hvm_guest_late_init is an exception as we need to 311 * detect PVH and panic there. 312 */ 313 h->init_platform = x86_init_noop; 314 h->x2apic_available = bool_x86_init_noop; 315 h->init_mem_mapping = x86_init_noop; 316 h->init_after_bootmem = x86_init_noop; 317 h->guest_late_init = xen_hvm_guest_late_init; 318 x86_hyper_xen_hvm.runtime.pin_vcpu = x86_op_int_noop; 319 } 320 return xen_domain; 321 } 322 323 struct hypervisor_x86 x86_hyper_xen_hvm __initdata = { 324 .name = "Xen HVM", 325 .detect = xen_platform_hvm, 326 .type = X86_HYPER_XEN_HVM, 327 .init.init_platform = xen_hvm_guest_init, 328 .init.x2apic_available = xen_x2apic_available, 329 .init.init_mem_mapping = xen_hvm_init_mem_mapping, 330 .init.guest_late_init = xen_hvm_guest_late_init, 331 .init.msi_ext_dest_id = msi_ext_dest_id, 332 .runtime.pin_vcpu = xen_pin_vcpu, 333 .ignore_nopv = true, 334 }; 335