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/cpu.h>
13 #include <asm/smp.h>
14 #include <asm/reboot.h>
15 #include <asm/setup.h>
16 #include <asm/hypervisor.h>
17 #include <asm/e820/api.h>
18 #include <asm/early_ioremap.h>
19
20 #include <asm/xen/cpuid.h>
21 #include <asm/xen/hypervisor.h>
22 #include <asm/xen/page.h>
23
24 #include "xen-ops.h"
25 #include "mmu.h"
26 #include "smp.h"
27
28 static unsigned long shared_info_pfn;
29
xen_hvm_init_shared_info(void)30 void xen_hvm_init_shared_info(void)
31 {
32 struct xen_add_to_physmap xatp;
33
34 xatp.domid = DOMID_SELF;
35 xatp.idx = 0;
36 xatp.space = XENMAPSPACE_shared_info;
37 xatp.gpfn = shared_info_pfn;
38 if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
39 BUG();
40 }
41
reserve_shared_info(void)42 static void __init reserve_shared_info(void)
43 {
44 u64 pa;
45
46 /*
47 * Search for a free page starting at 4kB physical address.
48 * Low memory is preferred to avoid an EPT large page split up
49 * by the mapping.
50 * Starting below X86_RESERVE_LOW (usually 64kB) is fine as
51 * the BIOS used for HVM guests is well behaved and won't
52 * clobber memory other than the first 4kB.
53 */
54 for (pa = PAGE_SIZE;
55 !e820__mapped_all(pa, pa + PAGE_SIZE, E820_TYPE_RAM) ||
56 memblock_is_reserved(pa);
57 pa += PAGE_SIZE)
58 ;
59
60 shared_info_pfn = PHYS_PFN(pa);
61
62 memblock_reserve(pa, PAGE_SIZE);
63 HYPERVISOR_shared_info = early_memremap(pa, PAGE_SIZE);
64 }
65
xen_hvm_init_mem_mapping(void)66 static void __init xen_hvm_init_mem_mapping(void)
67 {
68 early_memunmap(HYPERVISOR_shared_info, PAGE_SIZE);
69 HYPERVISOR_shared_info = __va(PFN_PHYS(shared_info_pfn));
70
71 /*
72 * The virtual address of the shared_info page has changed, so
73 * the vcpu_info pointer for VCPU 0 is now stale.
74 *
75 * The prepare_boot_cpu callback will re-initialize it via
76 * xen_vcpu_setup, but we can't rely on that to be called for
77 * old Xen versions (xen_have_vector_callback == 0).
78 *
79 * It is, in any case, bad to have a stale vcpu_info pointer
80 * so reset it now.
81 */
82 xen_vcpu_info_reset(0);
83 }
84
init_hvm_pv_info(void)85 static void __init init_hvm_pv_info(void)
86 {
87 int major, minor;
88 uint32_t eax, ebx, ecx, edx, base;
89
90 base = xen_cpuid_base();
91 eax = cpuid_eax(base + 1);
92
93 major = eax >> 16;
94 minor = eax & 0xffff;
95 printk(KERN_INFO "Xen version %d.%d.\n", major, minor);
96
97 xen_domain_type = XEN_HVM_DOMAIN;
98
99 /* PVH set up hypercall page in xen_prepare_pvh(). */
100 if (xen_pvh_domain())
101 pv_info.name = "Xen PVH";
102 else {
103 u64 pfn;
104 uint32_t msr;
105
106 pv_info.name = "Xen HVM";
107 msr = cpuid_ebx(base + 2);
108 pfn = __pa(hypercall_page);
109 wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
110 }
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 #ifdef CONFIG_KEXEC_CORE
xen_hvm_shutdown(void)122 static void xen_hvm_shutdown(void)
123 {
124 native_machine_shutdown();
125 if (kexec_in_progress)
126 xen_reboot(SHUTDOWN_soft_reset);
127 }
128
xen_hvm_crash_shutdown(struct pt_regs * regs)129 static void xen_hvm_crash_shutdown(struct pt_regs *regs)
130 {
131 native_machine_crash_shutdown(regs);
132 xen_reboot(SHUTDOWN_soft_reset);
133 }
134 #endif
135
xen_cpu_up_prepare_hvm(unsigned int cpu)136 static int xen_cpu_up_prepare_hvm(unsigned int cpu)
137 {
138 int rc = 0;
139
140 /*
141 * This can happen if CPU was offlined earlier and
142 * offlining timed out in common_cpu_die().
143 */
144 if (cpu_report_state(cpu) == CPU_DEAD_FROZEN) {
145 xen_smp_intr_free(cpu);
146 xen_uninit_lock_cpu(cpu);
147 }
148
149 if (cpu_acpi_id(cpu) != U32_MAX)
150 per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu);
151 else
152 per_cpu(xen_vcpu_id, cpu) = cpu;
153 rc = xen_vcpu_setup(cpu);
154 if (rc)
155 return rc;
156
157 if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock))
158 xen_setup_timer(cpu);
159
160 rc = xen_smp_intr_init(cpu);
161 if (rc) {
162 WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n",
163 cpu, rc);
164 }
165 return rc;
166 }
167
xen_cpu_dead_hvm(unsigned int cpu)168 static int xen_cpu_dead_hvm(unsigned int cpu)
169 {
170 xen_smp_intr_free(cpu);
171
172 if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock))
173 xen_teardown_timer(cpu);
174
175 return 0;
176 }
177
xen_hvm_guest_init(void)178 static void __init xen_hvm_guest_init(void)
179 {
180 if (xen_pv_domain())
181 return;
182
183 init_hvm_pv_info();
184
185 reserve_shared_info();
186 xen_hvm_init_shared_info();
187
188 /*
189 * xen_vcpu is a pointer to the vcpu_info struct in the shared_info
190 * page, we use it in the event channel upcall and in some pvclock
191 * related functions.
192 */
193 xen_vcpu_info_reset(0);
194
195 xen_panic_handler_init();
196
197 if (xen_feature(XENFEAT_hvm_callback_vector))
198 xen_have_vector_callback = 1;
199
200 xen_hvm_smp_init();
201 WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_hvm, xen_cpu_dead_hvm));
202 xen_unplug_emulated_devices();
203 x86_init.irqs.intr_init = xen_init_IRQ;
204 xen_hvm_init_time_ops();
205 xen_hvm_init_mmu_ops();
206
207 #ifdef CONFIG_KEXEC_CORE
208 machine_ops.shutdown = xen_hvm_shutdown;
209 machine_ops.crash_shutdown = xen_hvm_crash_shutdown;
210 #endif
211 }
212
xen_parse_nopv(char * arg)213 static __init int xen_parse_nopv(char *arg)
214 {
215 pr_notice("\"xen_nopv\" is deprecated, please use \"nopv\" instead\n");
216
217 if (xen_cpuid_base())
218 nopv = true;
219 return 0;
220 }
221 early_param("xen_nopv", xen_parse_nopv);
222
xen_hvm_need_lapic(void)223 bool __init xen_hvm_need_lapic(void)
224 {
225 if (xen_pv_domain())
226 return false;
227 if (!xen_hvm_domain())
228 return false;
229 if (xen_feature(XENFEAT_hvm_pirqs) && xen_have_vector_callback)
230 return false;
231 return true;
232 }
233
xen_hvm_guest_late_init(void)234 static __init void xen_hvm_guest_late_init(void)
235 {
236 #ifdef CONFIG_XEN_PVH
237 /* Test for PVH domain (PVH boot path taken overrides ACPI flags). */
238 if (!xen_pvh &&
239 (x86_platform.legacy.rtc || !x86_platform.legacy.no_vga))
240 return;
241
242 /* PVH detected. */
243 xen_pvh = true;
244
245 if (nopv)
246 panic("\"nopv\" and \"xen_nopv\" parameters are unsupported in PVH guest.");
247
248 /* Make sure we don't fall back to (default) ACPI_IRQ_MODEL_PIC. */
249 if (!nr_ioapics && acpi_irq_model == ACPI_IRQ_MODEL_PIC)
250 acpi_irq_model = ACPI_IRQ_MODEL_PLATFORM;
251
252 machine_ops.emergency_restart = xen_emergency_restart;
253 pv_info.name = "Xen PVH";
254 #endif
255 }
256
xen_platform_hvm(void)257 static uint32_t __init xen_platform_hvm(void)
258 {
259 uint32_t xen_domain = xen_cpuid_base();
260 struct x86_hyper_init *h = &x86_hyper_xen_hvm.init;
261
262 if (xen_pv_domain())
263 return 0;
264
265 if (xen_pvh_domain() && nopv) {
266 /* Guest booting via the Xen-PVH boot entry goes here */
267 pr_info("\"nopv\" parameter is ignored in PVH guest\n");
268 nopv = false;
269 } else if (nopv && xen_domain) {
270 /*
271 * Guest booting via normal boot entry (like via grub2) goes
272 * here.
273 *
274 * Use interface functions for bare hardware if nopv,
275 * xen_hvm_guest_late_init is an exception as we need to
276 * detect PVH and panic there.
277 */
278 h->init_platform = x86_init_noop;
279 h->x2apic_available = bool_x86_init_noop;
280 h->init_mem_mapping = x86_init_noop;
281 h->init_after_bootmem = x86_init_noop;
282 h->guest_late_init = xen_hvm_guest_late_init;
283 x86_hyper_xen_hvm.runtime.pin_vcpu = x86_op_int_noop;
284 }
285 return xen_domain;
286 }
287
288 struct hypervisor_x86 x86_hyper_xen_hvm __initdata = {
289 .name = "Xen HVM",
290 .detect = xen_platform_hvm,
291 .type = X86_HYPER_XEN_HVM,
292 .init.init_platform = xen_hvm_guest_init,
293 .init.x2apic_available = xen_x2apic_para_available,
294 .init.init_mem_mapping = xen_hvm_init_mem_mapping,
295 .init.guest_late_init = xen_hvm_guest_late_init,
296 .runtime.pin_vcpu = xen_pin_vcpu,
297 .ignore_nopv = true,
298 };
299