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/apic.h> 13 #include <asm/cpu.h> 14 #include <asm/smp.h> 15 #include <asm/io_apic.h> 16 #include <asm/reboot.h> 17 #include <asm/setup.h> 18 #include <asm/idtentry.h> 19 #include <asm/hypervisor.h> 20 #include <asm/e820/api.h> 21 #include <asm/early_ioremap.h> 22 23 #include <asm/xen/cpuid.h> 24 #include <asm/xen/hypervisor.h> 25 #include <asm/xen/page.h> 26 27 #include "xen-ops.h" 28 #include "mmu.h" 29 #include "smp.h" 30 31 static unsigned long shared_info_pfn; 32 33 void xen_hvm_init_shared_info(void) 34 { 35 struct xen_add_to_physmap xatp; 36 37 xatp.domid = DOMID_SELF; 38 xatp.idx = 0; 39 xatp.space = XENMAPSPACE_shared_info; 40 xatp.gpfn = shared_info_pfn; 41 if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp)) 42 BUG(); 43 } 44 45 static void __init reserve_shared_info(void) 46 { 47 u64 pa; 48 49 /* 50 * Search for a free page starting at 4kB physical address. 51 * Low memory is preferred to avoid an EPT large page split up 52 * by the mapping. 53 * Starting below X86_RESERVE_LOW (usually 64kB) is fine as 54 * the BIOS used for HVM guests is well behaved and won't 55 * clobber memory other than the first 4kB. 56 */ 57 for (pa = PAGE_SIZE; 58 !e820__mapped_all(pa, pa + PAGE_SIZE, E820_TYPE_RAM) || 59 memblock_is_reserved(pa); 60 pa += PAGE_SIZE) 61 ; 62 63 shared_info_pfn = PHYS_PFN(pa); 64 65 memblock_reserve(pa, PAGE_SIZE); 66 HYPERVISOR_shared_info = early_memremap(pa, PAGE_SIZE); 67 } 68 69 static void __init xen_hvm_init_mem_mapping(void) 70 { 71 early_memunmap(HYPERVISOR_shared_info, PAGE_SIZE); 72 HYPERVISOR_shared_info = __va(PFN_PHYS(shared_info_pfn)); 73 74 /* 75 * The virtual address of the shared_info page has changed, so 76 * the vcpu_info pointer for VCPU 0 is now stale. 77 * 78 * The prepare_boot_cpu callback will re-initialize it via 79 * xen_vcpu_setup, but we can't rely on that to be called for 80 * old Xen versions (xen_have_vector_callback == 0). 81 * 82 * It is, in any case, bad to have a stale vcpu_info pointer 83 * so reset it now. 84 */ 85 xen_vcpu_info_reset(0); 86 } 87 88 static void __init init_hvm_pv_info(void) 89 { 90 int major, minor; 91 uint32_t eax, ebx, ecx, edx, base; 92 93 base = xen_cpuid_base(); 94 eax = cpuid_eax(base + 1); 95 96 major = eax >> 16; 97 minor = eax & 0xffff; 98 printk(KERN_INFO "Xen version %d.%d.\n", major, minor); 99 100 xen_domain_type = XEN_HVM_DOMAIN; 101 102 /* PVH set up hypercall page in xen_prepare_pvh(). */ 103 if (xen_pvh_domain()) 104 pv_info.name = "Xen PVH"; 105 else { 106 u64 pfn; 107 uint32_t msr; 108 109 pv_info.name = "Xen HVM"; 110 msr = cpuid_ebx(base + 2); 111 pfn = __pa(hypercall_page); 112 wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32)); 113 } 114 115 xen_setup_features(); 116 117 cpuid(base + 4, &eax, &ebx, &ecx, &edx); 118 if (eax & XEN_HVM_CPUID_VCPU_ID_PRESENT) 119 this_cpu_write(xen_vcpu_id, ebx); 120 else 121 this_cpu_write(xen_vcpu_id, smp_processor_id()); 122 } 123 124 DEFINE_IDTENTRY_SYSVEC(sysvec_xen_hvm_callback) 125 { 126 struct pt_regs *old_regs = set_irq_regs(regs); 127 128 inc_irq_stat(irq_hv_callback_count); 129 130 xen_hvm_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 } 142 143 static void xen_hvm_crash_shutdown(struct pt_regs *regs) 144 { 145 native_machine_crash_shutdown(regs); 146 xen_reboot(SHUTDOWN_soft_reset); 147 } 148 #endif 149 150 static int xen_cpu_up_prepare_hvm(unsigned int cpu) 151 { 152 int rc = 0; 153 154 /* 155 * This can happen if CPU was offlined earlier and 156 * offlining timed out in common_cpu_die(). 157 */ 158 if (cpu_report_state(cpu) == CPU_DEAD_FROZEN) { 159 xen_smp_intr_free(cpu); 160 xen_uninit_lock_cpu(cpu); 161 } 162 163 if (cpu_acpi_id(cpu) != U32_MAX) 164 per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu); 165 else 166 per_cpu(xen_vcpu_id, cpu) = cpu; 167 xen_vcpu_setup(cpu); 168 if (!xen_have_vector_callback) 169 return 0; 170 171 if (xen_feature(XENFEAT_hvm_safe_pvclock)) 172 xen_setup_timer(cpu); 173 174 rc = xen_smp_intr_init(cpu); 175 if (rc) { 176 WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n", 177 cpu, rc); 178 } 179 return rc; 180 } 181 182 static int xen_cpu_dead_hvm(unsigned int cpu) 183 { 184 xen_smp_intr_free(cpu); 185 186 if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock)) 187 xen_teardown_timer(cpu); 188 return 0; 189 } 190 191 static bool no_vector_callback __initdata; 192 193 static void __init xen_hvm_guest_init(void) 194 { 195 if (xen_pv_domain()) 196 return; 197 198 init_hvm_pv_info(); 199 200 reserve_shared_info(); 201 xen_hvm_init_shared_info(); 202 203 /* 204 * xen_vcpu is a pointer to the vcpu_info struct in the shared_info 205 * page, we use it in the event channel upcall and in some pvclock 206 * related functions. 207 */ 208 xen_vcpu_info_reset(0); 209 210 xen_panic_handler_init(); 211 212 if (!no_vector_callback && xen_feature(XENFEAT_hvm_callback_vector)) 213 xen_have_vector_callback = 1; 214 215 xen_hvm_smp_init(); 216 WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_hvm, xen_cpu_dead_hvm)); 217 xen_unplug_emulated_devices(); 218 x86_init.irqs.intr_init = xen_init_IRQ; 219 xen_hvm_init_time_ops(); 220 xen_hvm_init_mmu_ops(); 221 222 #ifdef CONFIG_KEXEC_CORE 223 machine_ops.shutdown = xen_hvm_shutdown; 224 machine_ops.crash_shutdown = xen_hvm_crash_shutdown; 225 #endif 226 } 227 228 static __init int xen_parse_nopv(char *arg) 229 { 230 pr_notice("\"xen_nopv\" is deprecated, please use \"nopv\" instead\n"); 231 232 if (xen_cpuid_base()) 233 nopv = true; 234 return 0; 235 } 236 early_param("xen_nopv", xen_parse_nopv); 237 238 static __init int xen_parse_no_vector_callback(char *arg) 239 { 240 no_vector_callback = true; 241 return 0; 242 } 243 early_param("xen_no_vector_callback", xen_parse_no_vector_callback); 244 245 static __init bool xen_x2apic_available(void) 246 { 247 return x2apic_supported(); 248 } 249 250 static bool __init msi_ext_dest_id(void) 251 { 252 return cpuid_eax(xen_cpuid_base() + 4) & XEN_HVM_CPUID_EXT_DEST_ID; 253 } 254 255 static __init void xen_hvm_guest_late_init(void) 256 { 257 #ifdef CONFIG_XEN_PVH 258 /* Test for PVH domain (PVH boot path taken overrides ACPI flags). */ 259 if (!xen_pvh && 260 (x86_platform.legacy.rtc || !x86_platform.legacy.no_vga)) 261 return; 262 263 /* PVH detected. */ 264 xen_pvh = true; 265 266 if (nopv) 267 panic("\"nopv\" and \"xen_nopv\" parameters are unsupported in PVH guest."); 268 269 /* Make sure we don't fall back to (default) ACPI_IRQ_MODEL_PIC. */ 270 if (!nr_ioapics && acpi_irq_model == ACPI_IRQ_MODEL_PIC) 271 acpi_irq_model = ACPI_IRQ_MODEL_PLATFORM; 272 273 machine_ops.emergency_restart = xen_emergency_restart; 274 pv_info.name = "Xen PVH"; 275 #endif 276 } 277 278 static uint32_t __init xen_platform_hvm(void) 279 { 280 uint32_t xen_domain = xen_cpuid_base(); 281 struct x86_hyper_init *h = &x86_hyper_xen_hvm.init; 282 283 if (xen_pv_domain()) 284 return 0; 285 286 if (xen_pvh_domain() && nopv) { 287 /* Guest booting via the Xen-PVH boot entry goes here */ 288 pr_info("\"nopv\" parameter is ignored in PVH guest\n"); 289 nopv = false; 290 } else if (nopv && xen_domain) { 291 /* 292 * Guest booting via normal boot entry (like via grub2) goes 293 * here. 294 * 295 * Use interface functions for bare hardware if nopv, 296 * xen_hvm_guest_late_init is an exception as we need to 297 * detect PVH and panic there. 298 */ 299 h->init_platform = x86_init_noop; 300 h->x2apic_available = bool_x86_init_noop; 301 h->init_mem_mapping = x86_init_noop; 302 h->init_after_bootmem = x86_init_noop; 303 h->guest_late_init = xen_hvm_guest_late_init; 304 x86_hyper_xen_hvm.runtime.pin_vcpu = x86_op_int_noop; 305 } 306 return xen_domain; 307 } 308 309 struct hypervisor_x86 x86_hyper_xen_hvm __initdata = { 310 .name = "Xen HVM", 311 .detect = xen_platform_hvm, 312 .type = X86_HYPER_XEN_HVM, 313 .init.init_platform = xen_hvm_guest_init, 314 .init.x2apic_available = xen_x2apic_available, 315 .init.init_mem_mapping = xen_hvm_init_mem_mapping, 316 .init.guest_late_init = xen_hvm_guest_late_init, 317 .init.msi_ext_dest_id = msi_ext_dest_id, 318 .runtime.pin_vcpu = xen_pin_vcpu, 319 .ignore_nopv = true, 320 }; 321