xref: /openbmc/linux/arch/x86/xen/enlighten_hvm.c (revision e3b9f1e8)
1 #include <linux/acpi.h>
2 #include <linux/cpu.h>
3 #include <linux/kexec.h>
4 #include <linux/memblock.h>
5 
6 #include <xen/features.h>
7 #include <xen/events.h>
8 #include <xen/interface/memory.h>
9 
10 #include <asm/cpu.h>
11 #include <asm/smp.h>
12 #include <asm/reboot.h>
13 #include <asm/setup.h>
14 #include <asm/hypervisor.h>
15 #include <asm/e820/api.h>
16 #include <asm/early_ioremap.h>
17 
18 #include <asm/xen/cpuid.h>
19 #include <asm/xen/hypervisor.h>
20 #include <asm/xen/page.h>
21 
22 #include "xen-ops.h"
23 #include "mmu.h"
24 #include "smp.h"
25 
26 static unsigned long shared_info_pfn;
27 
28 void xen_hvm_init_shared_info(void)
29 {
30 	struct xen_add_to_physmap xatp;
31 
32 	xatp.domid = DOMID_SELF;
33 	xatp.idx = 0;
34 	xatp.space = XENMAPSPACE_shared_info;
35 	xatp.gpfn = shared_info_pfn;
36 	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
37 		BUG();
38 }
39 
40 static void __init reserve_shared_info(void)
41 {
42 	u64 pa;
43 
44 	/*
45 	 * Search for a free page starting at 4kB physical address.
46 	 * Low memory is preferred to avoid an EPT large page split up
47 	 * by the mapping.
48 	 * Starting below X86_RESERVE_LOW (usually 64kB) is fine as
49 	 * the BIOS used for HVM guests is well behaved and won't
50 	 * clobber memory other than the first 4kB.
51 	 */
52 	for (pa = PAGE_SIZE;
53 	     !e820__mapped_all(pa, pa + PAGE_SIZE, E820_TYPE_RAM) ||
54 	     memblock_is_reserved(pa);
55 	     pa += PAGE_SIZE)
56 		;
57 
58 	shared_info_pfn = PHYS_PFN(pa);
59 
60 	memblock_reserve(pa, PAGE_SIZE);
61 	HYPERVISOR_shared_info = early_memremap(pa, PAGE_SIZE);
62 }
63 
64 static void __init xen_hvm_init_mem_mapping(void)
65 {
66 	early_memunmap(HYPERVISOR_shared_info, PAGE_SIZE);
67 	HYPERVISOR_shared_info = __va(PFN_PHYS(shared_info_pfn));
68 }
69 
70 static void __init init_hvm_pv_info(void)
71 {
72 	int major, minor;
73 	uint32_t eax, ebx, ecx, edx, base;
74 
75 	base = xen_cpuid_base();
76 	eax = cpuid_eax(base + 1);
77 
78 	major = eax >> 16;
79 	minor = eax & 0xffff;
80 	printk(KERN_INFO "Xen version %d.%d.\n", major, minor);
81 
82 	xen_domain_type = XEN_HVM_DOMAIN;
83 
84 	/* PVH set up hypercall page in xen_prepare_pvh(). */
85 	if (xen_pvh_domain())
86 		pv_info.name = "Xen PVH";
87 	else {
88 		u64 pfn;
89 		uint32_t msr;
90 
91 		pv_info.name = "Xen HVM";
92 		msr = cpuid_ebx(base + 2);
93 		pfn = __pa(hypercall_page);
94 		wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
95 	}
96 
97 	xen_setup_features();
98 
99 	cpuid(base + 4, &eax, &ebx, &ecx, &edx);
100 	if (eax & XEN_HVM_CPUID_VCPU_ID_PRESENT)
101 		this_cpu_write(xen_vcpu_id, ebx);
102 	else
103 		this_cpu_write(xen_vcpu_id, smp_processor_id());
104 }
105 
106 #ifdef CONFIG_KEXEC_CORE
107 static void xen_hvm_shutdown(void)
108 {
109 	native_machine_shutdown();
110 	if (kexec_in_progress)
111 		xen_reboot(SHUTDOWN_soft_reset);
112 }
113 
114 static void xen_hvm_crash_shutdown(struct pt_regs *regs)
115 {
116 	native_machine_crash_shutdown(regs);
117 	xen_reboot(SHUTDOWN_soft_reset);
118 }
119 #endif
120 
121 static int xen_cpu_up_prepare_hvm(unsigned int cpu)
122 {
123 	int rc = 0;
124 
125 	/*
126 	 * This can happen if CPU was offlined earlier and
127 	 * offlining timed out in common_cpu_die().
128 	 */
129 	if (cpu_report_state(cpu) == CPU_DEAD_FROZEN) {
130 		xen_smp_intr_free(cpu);
131 		xen_uninit_lock_cpu(cpu);
132 	}
133 
134 	if (cpu_acpi_id(cpu) != U32_MAX)
135 		per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu);
136 	else
137 		per_cpu(xen_vcpu_id, cpu) = cpu;
138 	rc = xen_vcpu_setup(cpu);
139 	if (rc)
140 		return rc;
141 
142 	if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock))
143 		xen_setup_timer(cpu);
144 
145 	rc = xen_smp_intr_init(cpu);
146 	if (rc) {
147 		WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n",
148 		     cpu, rc);
149 	}
150 	return rc;
151 }
152 
153 static int xen_cpu_dead_hvm(unsigned int cpu)
154 {
155 	xen_smp_intr_free(cpu);
156 
157 	if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock))
158 		xen_teardown_timer(cpu);
159 
160        return 0;
161 }
162 
163 static void __init xen_hvm_guest_init(void)
164 {
165 	if (xen_pv_domain())
166 		return;
167 
168 	init_hvm_pv_info();
169 
170 	reserve_shared_info();
171 	xen_hvm_init_shared_info();
172 
173 	/*
174 	 * xen_vcpu is a pointer to the vcpu_info struct in the shared_info
175 	 * page, we use it in the event channel upcall and in some pvclock
176 	 * related functions.
177 	 */
178 	xen_vcpu_info_reset(0);
179 
180 	xen_panic_handler_init();
181 
182 	if (xen_feature(XENFEAT_hvm_callback_vector))
183 		xen_have_vector_callback = 1;
184 
185 	xen_hvm_smp_init();
186 	WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_hvm, xen_cpu_dead_hvm));
187 	xen_unplug_emulated_devices();
188 	x86_init.irqs.intr_init = xen_init_IRQ;
189 	xen_hvm_init_time_ops();
190 	xen_hvm_init_mmu_ops();
191 
192 #ifdef CONFIG_KEXEC_CORE
193 	machine_ops.shutdown = xen_hvm_shutdown;
194 	machine_ops.crash_shutdown = xen_hvm_crash_shutdown;
195 #endif
196 }
197 
198 static bool xen_nopv;
199 static __init int xen_parse_nopv(char *arg)
200 {
201        xen_nopv = true;
202        return 0;
203 }
204 early_param("xen_nopv", xen_parse_nopv);
205 
206 bool xen_hvm_need_lapic(void)
207 {
208 	if (xen_nopv)
209 		return false;
210 	if (xen_pv_domain())
211 		return false;
212 	if (!xen_hvm_domain())
213 		return false;
214 	if (xen_feature(XENFEAT_hvm_pirqs) && xen_have_vector_callback)
215 		return false;
216 	return true;
217 }
218 EXPORT_SYMBOL_GPL(xen_hvm_need_lapic);
219 
220 static uint32_t __init xen_platform_hvm(void)
221 {
222 	if (xen_pv_domain() || xen_nopv)
223 		return 0;
224 
225 	return xen_cpuid_base();
226 }
227 
228 static __init void xen_hvm_guest_late_init(void)
229 {
230 #ifdef CONFIG_XEN_PVH
231 	/* Test for PVH domain (PVH boot path taken overrides ACPI flags). */
232 	if (!xen_pvh &&
233 	    (x86_platform.legacy.rtc || !x86_platform.legacy.no_vga))
234 		return;
235 
236 	/* PVH detected. */
237 	xen_pvh = true;
238 
239 	/* Make sure we don't fall back to (default) ACPI_IRQ_MODEL_PIC. */
240 	if (!nr_ioapics && acpi_irq_model == ACPI_IRQ_MODEL_PIC)
241 		acpi_irq_model = ACPI_IRQ_MODEL_PLATFORM;
242 
243 	machine_ops.emergency_restart = xen_emergency_restart;
244 	pv_info.name = "Xen PVH";
245 #endif
246 }
247 
248 const __initconst struct hypervisor_x86 x86_hyper_xen_hvm = {
249 	.name                   = "Xen HVM",
250 	.detect                 = xen_platform_hvm,
251 	.type			= X86_HYPER_XEN_HVM,
252 	.init.init_platform     = xen_hvm_guest_init,
253 	.init.x2apic_available  = xen_x2apic_para_available,
254 	.init.init_mem_mapping	= xen_hvm_init_mem_mapping,
255 	.init.guest_late_init	= xen_hvm_guest_late_init,
256 	.runtime.pin_vcpu       = xen_pin_vcpu,
257 };
258