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/interface/memory.h> 12 13 #include <asm/apic.h> 14 #include <asm/cpu.h> 15 #include <asm/smp.h> 16 #include <asm/io_apic.h> 17 #include <asm/reboot.h> 18 #include <asm/setup.h> 19 #include <asm/idtentry.h> 20 #include <asm/hypervisor.h> 21 #include <asm/e820/api.h> 22 #include <asm/early_ioremap.h> 23 24 #include <asm/xen/cpuid.h> 25 #include <asm/xen/hypervisor.h> 26 #include <asm/xen/page.h> 27 28 #include "xen-ops.h" 29 #include "mmu.h" 30 #include "smp.h" 31 32 static unsigned long shared_info_pfn; 33 34 void xen_hvm_init_shared_info(void) 35 { 36 struct xen_add_to_physmap xatp; 37 38 xatp.domid = DOMID_SELF; 39 xatp.idx = 0; 40 xatp.space = XENMAPSPACE_shared_info; 41 xatp.gpfn = shared_info_pfn; 42 if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp)) 43 BUG(); 44 } 45 46 static void __init reserve_shared_info(void) 47 { 48 u64 pa; 49 50 /* 51 * Search for a free page starting at 4kB physical address. 52 * Low memory is preferred to avoid an EPT large page split up 53 * by the mapping. 54 * Starting below X86_RESERVE_LOW (usually 64kB) is fine as 55 * the BIOS used for HVM guests is well behaved and won't 56 * clobber memory other than the first 4kB. 57 */ 58 for (pa = PAGE_SIZE; 59 !e820__mapped_all(pa, pa + PAGE_SIZE, E820_TYPE_RAM) || 60 memblock_is_reserved(pa); 61 pa += PAGE_SIZE) 62 ; 63 64 shared_info_pfn = PHYS_PFN(pa); 65 66 memblock_reserve(pa, PAGE_SIZE); 67 HYPERVISOR_shared_info = early_memremap(pa, PAGE_SIZE); 68 } 69 70 static void __init xen_hvm_init_mem_mapping(void) 71 { 72 early_memunmap(HYPERVISOR_shared_info, PAGE_SIZE); 73 HYPERVISOR_shared_info = __va(PFN_PHYS(shared_info_pfn)); 74 75 /* 76 * The virtual address of the shared_info page has changed, so 77 * the vcpu_info pointer for VCPU 0 is now stale. 78 * 79 * The prepare_boot_cpu callback will re-initialize it via 80 * xen_vcpu_setup, but we can't rely on that to be called for 81 * old Xen versions (xen_have_vector_callback == 0). 82 * 83 * It is, in any case, bad to have a stale vcpu_info pointer 84 * so reset it now. 85 */ 86 xen_vcpu_info_reset(0); 87 } 88 89 static void __init init_hvm_pv_info(void) 90 { 91 int major, minor; 92 uint32_t eax, ebx, ecx, edx, base; 93 94 base = xen_cpuid_base(); 95 eax = cpuid_eax(base + 1); 96 97 major = eax >> 16; 98 minor = eax & 0xffff; 99 printk(KERN_INFO "Xen version %d.%d.\n", major, minor); 100 101 xen_domain_type = XEN_HVM_DOMAIN; 102 103 /* PVH set up hypercall page in xen_prepare_pvh(). */ 104 if (xen_pvh_domain()) 105 pv_info.name = "Xen PVH"; 106 else { 107 u64 pfn; 108 uint32_t msr; 109 110 pv_info.name = "Xen HVM"; 111 msr = cpuid_ebx(base + 2); 112 pfn = __pa(hypercall_page); 113 wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32)); 114 } 115 116 xen_setup_features(); 117 118 cpuid(base + 4, &eax, &ebx, &ecx, &edx); 119 if (eax & XEN_HVM_CPUID_VCPU_ID_PRESENT) 120 this_cpu_write(xen_vcpu_id, ebx); 121 else 122 this_cpu_write(xen_vcpu_id, smp_processor_id()); 123 } 124 125 DEFINE_IDTENTRY_SYSVEC(sysvec_xen_hvm_callback) 126 { 127 struct pt_regs *old_regs = set_irq_regs(regs); 128 129 inc_irq_stat(irq_hv_callback_count); 130 131 xen_hvm_evtchn_do_upcall(); 132 133 set_irq_regs(old_regs); 134 } 135 136 #ifdef CONFIG_KEXEC_CORE 137 static void xen_hvm_shutdown(void) 138 { 139 native_machine_shutdown(); 140 if (kexec_in_progress) 141 xen_reboot(SHUTDOWN_soft_reset); 142 } 143 144 static void xen_hvm_crash_shutdown(struct pt_regs *regs) 145 { 146 native_machine_crash_shutdown(regs); 147 xen_reboot(SHUTDOWN_soft_reset); 148 } 149 #endif 150 151 static int xen_cpu_up_prepare_hvm(unsigned int cpu) 152 { 153 int rc = 0; 154 155 /* 156 * This can happen if CPU was offlined earlier and 157 * offlining timed out in common_cpu_die(). 158 */ 159 if (cpu_report_state(cpu) == CPU_DEAD_FROZEN) { 160 xen_smp_intr_free(cpu); 161 xen_uninit_lock_cpu(cpu); 162 } 163 164 if (cpu_acpi_id(cpu) != U32_MAX) 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_feature(XENFEAT_hvm_safe_pvclock)) 173 xen_setup_timer(cpu); 174 175 rc = xen_smp_intr_init(cpu); 176 if (rc) { 177 WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n", 178 cpu, rc); 179 } 180 return rc; 181 } 182 183 static int xen_cpu_dead_hvm(unsigned int cpu) 184 { 185 xen_smp_intr_free(cpu); 186 187 if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock)) 188 xen_teardown_timer(cpu); 189 return 0; 190 } 191 192 static bool no_vector_callback __initdata; 193 194 static void __init xen_hvm_guest_init(void) 195 { 196 if (xen_pv_domain()) 197 return; 198 199 if (IS_ENABLED(CONFIG_XEN_VIRTIO_FORCE_GRANT)) 200 virtio_set_mem_acc_cb(virtio_require_restricted_mem_acc); 201 202 init_hvm_pv_info(); 203 204 reserve_shared_info(); 205 xen_hvm_init_shared_info(); 206 207 /* 208 * xen_vcpu is a pointer to the vcpu_info struct in the shared_info 209 * page, we use it in the event channel upcall and in some pvclock 210 * related functions. 211 */ 212 xen_vcpu_info_reset(0); 213 214 xen_panic_handler_init(); 215 216 if (!no_vector_callback && xen_feature(XENFEAT_hvm_callback_vector)) 217 xen_have_vector_callback = 1; 218 219 xen_hvm_smp_init(); 220 WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_hvm, xen_cpu_dead_hvm)); 221 xen_unplug_emulated_devices(); 222 x86_init.irqs.intr_init = xen_init_IRQ; 223 xen_hvm_init_time_ops(); 224 xen_hvm_init_mmu_ops(); 225 226 #ifdef CONFIG_KEXEC_CORE 227 machine_ops.shutdown = xen_hvm_shutdown; 228 machine_ops.crash_shutdown = xen_hvm_crash_shutdown; 229 #endif 230 } 231 232 static __init int xen_parse_nopv(char *arg) 233 { 234 pr_notice("\"xen_nopv\" is deprecated, please use \"nopv\" instead\n"); 235 236 if (xen_cpuid_base()) 237 nopv = true; 238 return 0; 239 } 240 early_param("xen_nopv", xen_parse_nopv); 241 242 static __init int xen_parse_no_vector_callback(char *arg) 243 { 244 no_vector_callback = true; 245 return 0; 246 } 247 early_param("xen_no_vector_callback", xen_parse_no_vector_callback); 248 249 static __init bool xen_x2apic_available(void) 250 { 251 return x2apic_supported(); 252 } 253 254 static bool __init msi_ext_dest_id(void) 255 { 256 return cpuid_eax(xen_cpuid_base() + 4) & XEN_HVM_CPUID_EXT_DEST_ID; 257 } 258 259 static __init void xen_hvm_guest_late_init(void) 260 { 261 #ifdef CONFIG_XEN_PVH 262 /* Test for PVH domain (PVH boot path taken overrides ACPI flags). */ 263 if (!xen_pvh && 264 (x86_platform.legacy.rtc || !x86_platform.legacy.no_vga)) 265 return; 266 267 /* PVH detected. */ 268 xen_pvh = true; 269 270 if (nopv) 271 panic("\"nopv\" and \"xen_nopv\" parameters are unsupported in PVH guest."); 272 273 /* Make sure we don't fall back to (default) ACPI_IRQ_MODEL_PIC. */ 274 if (!nr_ioapics && acpi_irq_model == ACPI_IRQ_MODEL_PIC) 275 acpi_irq_model = ACPI_IRQ_MODEL_PLATFORM; 276 277 machine_ops.emergency_restart = xen_emergency_restart; 278 pv_info.name = "Xen PVH"; 279 #endif 280 } 281 282 static uint32_t __init xen_platform_hvm(void) 283 { 284 uint32_t xen_domain = xen_cpuid_base(); 285 struct x86_hyper_init *h = &x86_hyper_xen_hvm.init; 286 287 if (xen_pv_domain()) 288 return 0; 289 290 if (xen_pvh_domain() && nopv) { 291 /* Guest booting via the Xen-PVH boot entry goes here */ 292 pr_info("\"nopv\" parameter is ignored in PVH guest\n"); 293 nopv = false; 294 } else if (nopv && xen_domain) { 295 /* 296 * Guest booting via normal boot entry (like via grub2) goes 297 * here. 298 * 299 * Use interface functions for bare hardware if nopv, 300 * xen_hvm_guest_late_init is an exception as we need to 301 * detect PVH and panic there. 302 */ 303 h->init_platform = x86_init_noop; 304 h->x2apic_available = bool_x86_init_noop; 305 h->init_mem_mapping = x86_init_noop; 306 h->init_after_bootmem = x86_init_noop; 307 h->guest_late_init = xen_hvm_guest_late_init; 308 x86_hyper_xen_hvm.runtime.pin_vcpu = x86_op_int_noop; 309 } 310 return xen_domain; 311 } 312 313 struct hypervisor_x86 x86_hyper_xen_hvm __initdata = { 314 .name = "Xen HVM", 315 .detect = xen_platform_hvm, 316 .type = X86_HYPER_XEN_HVM, 317 .init.init_platform = xen_hvm_guest_init, 318 .init.x2apic_available = xen_x2apic_available, 319 .init.init_mem_mapping = xen_hvm_init_mem_mapping, 320 .init.guest_late_init = xen_hvm_guest_late_init, 321 .init.msi_ext_dest_id = msi_ext_dest_id, 322 .runtime.pin_vcpu = xen_pin_vcpu, 323 .ignore_nopv = true, 324 }; 325