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 #include "mmu.h" 32 #include "smp.h" 33 34 static unsigned long shared_info_pfn; 35 36 __ro_after_init bool xen_percpu_upcall; 37 EXPORT_SYMBOL_GPL(xen_percpu_upcall); 38 39 void xen_hvm_init_shared_info(void) 40 { 41 struct xen_add_to_physmap xatp; 42 43 xatp.domid = DOMID_SELF; 44 xatp.idx = 0; 45 xatp.space = XENMAPSPACE_shared_info; 46 xatp.gpfn = shared_info_pfn; 47 if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp)) 48 BUG(); 49 } 50 51 static void __init reserve_shared_info(void) 52 { 53 u64 pa; 54 55 /* 56 * Search for a free page starting at 4kB physical address. 57 * Low memory is preferred to avoid an EPT large page split up 58 * by the mapping. 59 * Starting below X86_RESERVE_LOW (usually 64kB) is fine as 60 * the BIOS used for HVM guests is well behaved and won't 61 * clobber memory other than the first 4kB. 62 */ 63 for (pa = PAGE_SIZE; 64 !e820__mapped_all(pa, pa + PAGE_SIZE, E820_TYPE_RAM) || 65 memblock_is_reserved(pa); 66 pa += PAGE_SIZE) 67 ; 68 69 shared_info_pfn = PHYS_PFN(pa); 70 71 memblock_reserve(pa, PAGE_SIZE); 72 HYPERVISOR_shared_info = early_memremap(pa, PAGE_SIZE); 73 } 74 75 static void __init xen_hvm_init_mem_mapping(void) 76 { 77 early_memunmap(HYPERVISOR_shared_info, PAGE_SIZE); 78 HYPERVISOR_shared_info = __va(PFN_PHYS(shared_info_pfn)); 79 80 /* 81 * The virtual address of the shared_info page has changed, so 82 * the vcpu_info pointer for VCPU 0 is now stale. 83 * 84 * The prepare_boot_cpu callback will re-initialize it via 85 * xen_vcpu_setup, but we can't rely on that to be called for 86 * old Xen versions (xen_have_vector_callback == 0). 87 * 88 * It is, in any case, bad to have a stale vcpu_info pointer 89 * so reset it now. 90 */ 91 xen_vcpu_info_reset(0); 92 } 93 94 static void __init init_hvm_pv_info(void) 95 { 96 int major, minor; 97 uint32_t eax, ebx, ecx, edx, base; 98 99 base = xen_cpuid_base(); 100 eax = cpuid_eax(base + 1); 101 102 major = eax >> 16; 103 minor = eax & 0xffff; 104 printk(KERN_INFO "Xen version %d.%d.\n", major, minor); 105 106 xen_domain_type = XEN_HVM_DOMAIN; 107 108 /* PVH set up hypercall page in xen_prepare_pvh(). */ 109 if (xen_pvh_domain()) 110 pv_info.name = "Xen PVH"; 111 else { 112 u64 pfn; 113 uint32_t msr; 114 115 pv_info.name = "Xen HVM"; 116 msr = cpuid_ebx(base + 2); 117 pfn = __pa(hypercall_page); 118 wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32)); 119 } 120 121 xen_setup_features(); 122 123 cpuid(base + 4, &eax, &ebx, &ecx, &edx); 124 if (eax & XEN_HVM_CPUID_VCPU_ID_PRESENT) 125 this_cpu_write(xen_vcpu_id, ebx); 126 else 127 this_cpu_write(xen_vcpu_id, smp_processor_id()); 128 } 129 130 DEFINE_IDTENTRY_SYSVEC(sysvec_xen_hvm_callback) 131 { 132 struct pt_regs *old_regs = set_irq_regs(regs); 133 134 if (xen_percpu_upcall) 135 ack_APIC_irq(); 136 137 inc_irq_stat(irq_hv_callback_count); 138 139 xen_hvm_evtchn_do_upcall(); 140 141 set_irq_regs(old_regs); 142 } 143 144 #ifdef CONFIG_KEXEC_CORE 145 static void xen_hvm_shutdown(void) 146 { 147 native_machine_shutdown(); 148 if (kexec_in_progress) 149 xen_reboot(SHUTDOWN_soft_reset); 150 } 151 152 static void xen_hvm_crash_shutdown(struct pt_regs *regs) 153 { 154 native_machine_crash_shutdown(regs); 155 xen_reboot(SHUTDOWN_soft_reset); 156 } 157 #endif 158 159 static int xen_cpu_up_prepare_hvm(unsigned int cpu) 160 { 161 int rc = 0; 162 163 /* 164 * This can happen if CPU was offlined earlier and 165 * offlining timed out in common_cpu_die(). 166 */ 167 if (cpu_report_state(cpu) == CPU_DEAD_FROZEN) { 168 xen_smp_intr_free(cpu); 169 xen_uninit_lock_cpu(cpu); 170 } 171 172 if (cpu_acpi_id(cpu) != U32_MAX) 173 per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu); 174 else 175 per_cpu(xen_vcpu_id, cpu) = cpu; 176 xen_vcpu_setup(cpu); 177 if (!xen_have_vector_callback) 178 return 0; 179 180 if (xen_percpu_upcall) { 181 rc = xen_set_upcall_vector(cpu); 182 if (rc) { 183 WARN(1, "HVMOP_set_evtchn_upcall_vector" 184 " for CPU %d failed: %d\n", cpu, rc); 185 return rc; 186 } 187 } 188 189 if (xen_feature(XENFEAT_hvm_safe_pvclock)) 190 xen_setup_timer(cpu); 191 192 rc = xen_smp_intr_init(cpu); 193 if (rc) { 194 WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n", 195 cpu, rc); 196 } 197 return rc; 198 } 199 200 static int xen_cpu_dead_hvm(unsigned int cpu) 201 { 202 xen_smp_intr_free(cpu); 203 204 if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock)) 205 xen_teardown_timer(cpu); 206 return 0; 207 } 208 209 static void __init xen_hvm_guest_init(void) 210 { 211 if (xen_pv_domain()) 212 return; 213 214 if (IS_ENABLED(CONFIG_XEN_VIRTIO_FORCE_GRANT)) 215 virtio_set_mem_acc_cb(virtio_require_restricted_mem_acc); 216 217 init_hvm_pv_info(); 218 219 reserve_shared_info(); 220 xen_hvm_init_shared_info(); 221 222 /* 223 * xen_vcpu is a pointer to the vcpu_info struct in the shared_info 224 * page, we use it in the event channel upcall and in some pvclock 225 * related functions. 226 */ 227 xen_vcpu_info_reset(0); 228 229 xen_panic_handler_init(); 230 231 xen_hvm_smp_init(); 232 WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_hvm, xen_cpu_dead_hvm)); 233 xen_unplug_emulated_devices(); 234 x86_init.irqs.intr_init = xen_init_IRQ; 235 xen_hvm_init_time_ops(); 236 xen_hvm_init_mmu_ops(); 237 238 #ifdef CONFIG_KEXEC_CORE 239 machine_ops.shutdown = xen_hvm_shutdown; 240 machine_ops.crash_shutdown = xen_hvm_crash_shutdown; 241 #endif 242 } 243 244 static __init int xen_parse_nopv(char *arg) 245 { 246 pr_notice("\"xen_nopv\" is deprecated, please use \"nopv\" instead\n"); 247 248 if (xen_cpuid_base()) 249 nopv = true; 250 return 0; 251 } 252 early_param("xen_nopv", xen_parse_nopv); 253 254 static __init int xen_parse_no_vector_callback(char *arg) 255 { 256 xen_have_vector_callback = false; 257 return 0; 258 } 259 early_param("xen_no_vector_callback", xen_parse_no_vector_callback); 260 261 static __init bool xen_x2apic_available(void) 262 { 263 return x2apic_supported(); 264 } 265 266 static bool __init msi_ext_dest_id(void) 267 { 268 return cpuid_eax(xen_cpuid_base() + 4) & XEN_HVM_CPUID_EXT_DEST_ID; 269 } 270 271 static __init void xen_hvm_guest_late_init(void) 272 { 273 #ifdef CONFIG_XEN_PVH 274 /* Test for PVH domain (PVH boot path taken overrides ACPI flags). */ 275 if (!xen_pvh && 276 (x86_platform.legacy.rtc || !x86_platform.legacy.no_vga)) 277 return; 278 279 /* PVH detected. */ 280 xen_pvh = true; 281 282 if (nopv) 283 panic("\"nopv\" and \"xen_nopv\" parameters are unsupported in PVH guest."); 284 285 /* Make sure we don't fall back to (default) ACPI_IRQ_MODEL_PIC. */ 286 if (!nr_ioapics && acpi_irq_model == ACPI_IRQ_MODEL_PIC) 287 acpi_irq_model = ACPI_IRQ_MODEL_PLATFORM; 288 289 machine_ops.emergency_restart = xen_emergency_restart; 290 pv_info.name = "Xen PVH"; 291 #endif 292 } 293 294 static uint32_t __init xen_platform_hvm(void) 295 { 296 uint32_t xen_domain = xen_cpuid_base(); 297 struct x86_hyper_init *h = &x86_hyper_xen_hvm.init; 298 299 if (xen_pv_domain()) 300 return 0; 301 302 if (xen_pvh_domain() && nopv) { 303 /* Guest booting via the Xen-PVH boot entry goes here */ 304 pr_info("\"nopv\" parameter is ignored in PVH guest\n"); 305 nopv = false; 306 } else if (nopv && xen_domain) { 307 /* 308 * Guest booting via normal boot entry (like via grub2) goes 309 * here. 310 * 311 * Use interface functions for bare hardware if nopv, 312 * xen_hvm_guest_late_init is an exception as we need to 313 * detect PVH and panic there. 314 */ 315 h->init_platform = x86_init_noop; 316 h->x2apic_available = bool_x86_init_noop; 317 h->init_mem_mapping = x86_init_noop; 318 h->init_after_bootmem = x86_init_noop; 319 h->guest_late_init = xen_hvm_guest_late_init; 320 x86_hyper_xen_hvm.runtime.pin_vcpu = x86_op_int_noop; 321 } 322 return xen_domain; 323 } 324 325 struct hypervisor_x86 x86_hyper_xen_hvm __initdata = { 326 .name = "Xen HVM", 327 .detect = xen_platform_hvm, 328 .type = X86_HYPER_XEN_HVM, 329 .init.init_platform = xen_hvm_guest_init, 330 .init.x2apic_available = xen_x2apic_available, 331 .init.init_mem_mapping = xen_hvm_init_mem_mapping, 332 .init.guest_late_init = xen_hvm_guest_late_init, 333 .init.msi_ext_dest_id = msi_ext_dest_id, 334 .runtime.pin_vcpu = xen_pin_vcpu, 335 .ignore_nopv = true, 336 }; 337