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 * If a CPU was offlined earlier and offlining timed out then the 165 * lock mechanism is still initialized. Uninit it unconditionally 166 * as it's safe to call even if already uninited. Interrupts and 167 * timer have already been handled in xen_cpu_dead_hvm(). 168 */ 169 xen_uninit_lock_cpu(cpu); 170 171 if (cpu_acpi_id(cpu) != U32_MAX) 172 per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu); 173 else 174 per_cpu(xen_vcpu_id, cpu) = cpu; 175 xen_vcpu_setup(cpu); 176 if (!xen_have_vector_callback) 177 return 0; 178 179 if (xen_percpu_upcall) { 180 rc = xen_set_upcall_vector(cpu); 181 if (rc) { 182 WARN(1, "HVMOP_set_evtchn_upcall_vector" 183 " for CPU %d failed: %d\n", cpu, rc); 184 return rc; 185 } 186 } 187 188 if (xen_feature(XENFEAT_hvm_safe_pvclock)) 189 xen_setup_timer(cpu); 190 191 rc = xen_smp_intr_init(cpu); 192 if (rc) { 193 WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n", 194 cpu, rc); 195 } 196 return rc; 197 } 198 199 static int xen_cpu_dead_hvm(unsigned int cpu) 200 { 201 xen_smp_intr_free(cpu); 202 203 if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock)) 204 xen_teardown_timer(cpu); 205 return 0; 206 } 207 208 static void __init xen_hvm_guest_init(void) 209 { 210 if (xen_pv_domain()) 211 return; 212 213 if (IS_ENABLED(CONFIG_XEN_VIRTIO_FORCE_GRANT)) 214 virtio_set_mem_acc_cb(xen_virtio_restricted_mem_acc); 215 216 init_hvm_pv_info(); 217 218 reserve_shared_info(); 219 xen_hvm_init_shared_info(); 220 221 /* 222 * xen_vcpu is a pointer to the vcpu_info struct in the shared_info 223 * page, we use it in the event channel upcall and in some pvclock 224 * related functions. 225 */ 226 xen_vcpu_info_reset(0); 227 228 xen_panic_handler_init(); 229 230 xen_hvm_smp_init(); 231 WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_hvm, xen_cpu_dead_hvm)); 232 xen_unplug_emulated_devices(); 233 x86_init.irqs.intr_init = xen_init_IRQ; 234 xen_hvm_init_time_ops(); 235 xen_hvm_init_mmu_ops(); 236 237 #ifdef CONFIG_KEXEC_CORE 238 machine_ops.shutdown = xen_hvm_shutdown; 239 machine_ops.crash_shutdown = xen_hvm_crash_shutdown; 240 #endif 241 } 242 243 static __init int xen_parse_nopv(char *arg) 244 { 245 pr_notice("\"xen_nopv\" is deprecated, please use \"nopv\" instead\n"); 246 247 if (xen_cpuid_base()) 248 nopv = true; 249 return 0; 250 } 251 early_param("xen_nopv", xen_parse_nopv); 252 253 static __init int xen_parse_no_vector_callback(char *arg) 254 { 255 xen_have_vector_callback = false; 256 return 0; 257 } 258 early_param("xen_no_vector_callback", xen_parse_no_vector_callback); 259 260 static __init bool xen_x2apic_available(void) 261 { 262 return x2apic_supported(); 263 } 264 265 static bool __init msi_ext_dest_id(void) 266 { 267 return cpuid_eax(xen_cpuid_base() + 4) & XEN_HVM_CPUID_EXT_DEST_ID; 268 } 269 270 static __init void xen_hvm_guest_late_init(void) 271 { 272 #ifdef CONFIG_XEN_PVH 273 /* Test for PVH domain (PVH boot path taken overrides ACPI flags). */ 274 if (!xen_pvh && 275 (x86_platform.legacy.rtc || !x86_platform.legacy.no_vga)) 276 return; 277 278 /* PVH detected. */ 279 xen_pvh = true; 280 281 if (nopv) 282 panic("\"nopv\" and \"xen_nopv\" parameters are unsupported in PVH guest."); 283 284 /* Make sure we don't fall back to (default) ACPI_IRQ_MODEL_PIC. */ 285 if (!nr_ioapics && acpi_irq_model == ACPI_IRQ_MODEL_PIC) 286 acpi_irq_model = ACPI_IRQ_MODEL_PLATFORM; 287 288 machine_ops.emergency_restart = xen_emergency_restart; 289 pv_info.name = "Xen PVH"; 290 #endif 291 } 292 293 static uint32_t __init xen_platform_hvm(void) 294 { 295 uint32_t xen_domain = xen_cpuid_base(); 296 struct x86_hyper_init *h = &x86_hyper_xen_hvm.init; 297 298 if (xen_pv_domain()) 299 return 0; 300 301 if (xen_pvh_domain() && nopv) { 302 /* Guest booting via the Xen-PVH boot entry goes here */ 303 pr_info("\"nopv\" parameter is ignored in PVH guest\n"); 304 nopv = false; 305 } else if (nopv && xen_domain) { 306 /* 307 * Guest booting via normal boot entry (like via grub2) goes 308 * here. 309 * 310 * Use interface functions for bare hardware if nopv, 311 * xen_hvm_guest_late_init is an exception as we need to 312 * detect PVH and panic there. 313 */ 314 h->init_platform = x86_init_noop; 315 h->x2apic_available = bool_x86_init_noop; 316 h->init_mem_mapping = x86_init_noop; 317 h->init_after_bootmem = x86_init_noop; 318 h->guest_late_init = xen_hvm_guest_late_init; 319 x86_hyper_xen_hvm.runtime.pin_vcpu = x86_op_int_noop; 320 } 321 return xen_domain; 322 } 323 324 struct hypervisor_x86 x86_hyper_xen_hvm __initdata = { 325 .name = "Xen HVM", 326 .detect = xen_platform_hvm, 327 .type = X86_HYPER_XEN_HVM, 328 .init.init_platform = xen_hvm_guest_init, 329 .init.x2apic_available = xen_x2apic_available, 330 .init.init_mem_mapping = xen_hvm_init_mem_mapping, 331 .init.guest_late_init = xen_hvm_guest_late_init, 332 .init.msi_ext_dest_id = msi_ext_dest_id, 333 .runtime.pin_vcpu = xen_pin_vcpu, 334 .ignore_nopv = true, 335 }; 336