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/io_apic.h>
15#include <asm/reboot.h>
16#include <asm/setup.h>
17#include <asm/idtentry.h>
18#include <asm/hypervisor.h>
19#include <asm/e820/api.h>
20#include <asm/early_ioremap.h>
21
22#include <asm/xen/cpuid.h>
23#include <asm/xen/hypervisor.h>
24#include <asm/xen/page.h>
25
26#include "xen-ops.h"
27#include "mmu.h"
28#include "smp.h"
29
30static unsigned long shared_info_pfn;
31
32void xen_hvm_init_shared_info(void)
33{
34	struct xen_add_to_physmap xatp;
35
36	xatp.domid = DOMID_SELF;
37	xatp.idx = 0;
38	xatp.space = XENMAPSPACE_shared_info;
39	xatp.gpfn = shared_info_pfn;
40	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
41		BUG();
42}
43
44static void __init reserve_shared_info(void)
45{
46	u64 pa;
47
48	/*
49	 * Search for a free page starting at 4kB physical address.
50	 * Low memory is preferred to avoid an EPT large page split up
51	 * by the mapping.
52	 * Starting below X86_RESERVE_LOW (usually 64kB) is fine as
53	 * the BIOS used for HVM guests is well behaved and won't
54	 * clobber memory other than the first 4kB.
55	 */
56	for (pa = PAGE_SIZE;
57	     !e820__mapped_all(pa, pa + PAGE_SIZE, E820_TYPE_RAM) ||
58	     memblock_is_reserved(pa);
59	     pa += PAGE_SIZE)
60		;
61
62	shared_info_pfn = PHYS_PFN(pa);
63
64	memblock_reserve(pa, PAGE_SIZE);
65	HYPERVISOR_shared_info = early_memremap(pa, PAGE_SIZE);
66}
67
68static void __init xen_hvm_init_mem_mapping(void)
69{
70	early_memunmap(HYPERVISOR_shared_info, PAGE_SIZE);
71	HYPERVISOR_shared_info = __va(PFN_PHYS(shared_info_pfn));
72
73	/*
74	 * The virtual address of the shared_info page has changed, so
75	 * the vcpu_info pointer for VCPU 0 is now stale.
76	 *
77	 * The prepare_boot_cpu callback will re-initialize it via
78	 * xen_vcpu_setup, but we can't rely on that to be called for
79	 * old Xen versions (xen_have_vector_callback == 0).
80	 *
81	 * It is, in any case, bad to have a stale vcpu_info pointer
82	 * so reset it now.
83	 */
84	xen_vcpu_info_reset(0);
85}
86
87static void __init init_hvm_pv_info(void)
88{
89	int major, minor;
90	uint32_t eax, ebx, ecx, edx, base;
91
92	base = xen_cpuid_base();
93	eax = cpuid_eax(base + 1);
94
95	major = eax >> 16;
96	minor = eax & 0xffff;
97	printk(KERN_INFO "Xen version %d.%d.\n", major, minor);
98
99	xen_domain_type = XEN_HVM_DOMAIN;
100
101	/* PVH set up hypercall page in xen_prepare_pvh(). */
102	if (xen_pvh_domain())
103		pv_info.name = "Xen PVH";
104	else {
105		u64 pfn;
106		uint32_t msr;
107
108		pv_info.name = "Xen HVM";
109		msr = cpuid_ebx(base + 2);
110		pfn = __pa(hypercall_page);
111		wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
112	}
113
114	xen_setup_features();
115
116	cpuid(base + 4, &eax, &ebx, &ecx, &edx);
117	if (eax & XEN_HVM_CPUID_VCPU_ID_PRESENT)
118		this_cpu_write(xen_vcpu_id, ebx);
119	else
120		this_cpu_write(xen_vcpu_id, smp_processor_id());
121}
122
123DEFINE_IDTENTRY_SYSVEC(sysvec_xen_hvm_callback)
124{
125	struct pt_regs *old_regs = set_irq_regs(regs);
126
127	inc_irq_stat(irq_hv_callback_count);
128
129	xen_hvm_evtchn_do_upcall();
130
131	set_irq_regs(old_regs);
132}
133
134#ifdef CONFIG_KEXEC_CORE
135static void xen_hvm_shutdown(void)
136{
137	native_machine_shutdown();
138	if (kexec_in_progress)
139		xen_reboot(SHUTDOWN_soft_reset);
140}
141
142static void xen_hvm_crash_shutdown(struct pt_regs *regs)
143{
144	native_machine_crash_shutdown(regs);
145	xen_reboot(SHUTDOWN_soft_reset);
146}
147#endif
148
149static int xen_cpu_up_prepare_hvm(unsigned int cpu)
150{
151	int rc = 0;
152
153	/*
154	 * This can happen if CPU was offlined earlier and
155	 * offlining timed out in common_cpu_die().
156	 */
157	if (cpu_report_state(cpu) == CPU_DEAD_FROZEN) {
158		xen_smp_intr_free(cpu);
159		xen_uninit_lock_cpu(cpu);
160	}
161
162	if (cpu_acpi_id(cpu) != U32_MAX)
163		per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu);
164	else
165		per_cpu(xen_vcpu_id, cpu) = cpu;
166	rc = xen_vcpu_setup(cpu);
167	if (rc)
168		return rc;
169
170	if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock))
171		xen_setup_timer(cpu);
172
173	rc = xen_smp_intr_init(cpu);
174	if (rc) {
175		WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n",
176		     cpu, rc);
177	}
178	return rc;
179}
180
181static int xen_cpu_dead_hvm(unsigned int cpu)
182{
183	xen_smp_intr_free(cpu);
184
185	if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock))
186		xen_teardown_timer(cpu);
187
188       return 0;
189}
190
191static bool no_vector_callback __initdata;
192
193static 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
228static __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}
236early_param("xen_nopv", xen_parse_nopv);
237
238static __init int xen_parse_no_vector_callback(char *arg)
239{
240	no_vector_callback = true;
241	return 0;
242}
243early_param("xen_no_vector_callback", xen_parse_no_vector_callback);
244
245bool __init xen_hvm_need_lapic(void)
246{
247	if (xen_pv_domain())
248		return false;
249	if (!xen_hvm_domain())
250		return false;
251	if (xen_feature(XENFEAT_hvm_pirqs) && xen_have_vector_callback)
252		return false;
253	return true;
254}
255
256static __init void xen_hvm_guest_late_init(void)
257{
258#ifdef CONFIG_XEN_PVH
259	/* Test for PVH domain (PVH boot path taken overrides ACPI flags). */
260	if (!xen_pvh &&
261	    (x86_platform.legacy.rtc || !x86_platform.legacy.no_vga))
262		return;
263
264	/* PVH detected. */
265	xen_pvh = true;
266
267	if (nopv)
268		panic("\"nopv\" and \"xen_nopv\" parameters are unsupported in PVH guest.");
269
270	/* Make sure we don't fall back to (default) ACPI_IRQ_MODEL_PIC. */
271	if (!nr_ioapics && acpi_irq_model == ACPI_IRQ_MODEL_PIC)
272		acpi_irq_model = ACPI_IRQ_MODEL_PLATFORM;
273
274	machine_ops.emergency_restart = xen_emergency_restart;
275	pv_info.name = "Xen PVH";
276#endif
277}
278
279static uint32_t __init xen_platform_hvm(void)
280{
281	uint32_t xen_domain = xen_cpuid_base();
282	struct x86_hyper_init *h = &x86_hyper_xen_hvm.init;
283
284	if (xen_pv_domain())
285		return 0;
286
287	if (xen_pvh_domain() && nopv) {
288		/* Guest booting via the Xen-PVH boot entry goes here */
289		pr_info("\"nopv\" parameter is ignored in PVH guest\n");
290		nopv = false;
291	} else if (nopv && xen_domain) {
292		/*
293		 * Guest booting via normal boot entry (like via grub2) goes
294		 * here.
295		 *
296		 * Use interface functions for bare hardware if nopv,
297		 * xen_hvm_guest_late_init is an exception as we need to
298		 * detect PVH and panic there.
299		 */
300		h->init_platform = x86_init_noop;
301		h->x2apic_available = bool_x86_init_noop;
302		h->init_mem_mapping = x86_init_noop;
303		h->init_after_bootmem = x86_init_noop;
304		h->guest_late_init = xen_hvm_guest_late_init;
305		x86_hyper_xen_hvm.runtime.pin_vcpu = x86_op_int_noop;
306	}
307	return xen_domain;
308}
309
310struct hypervisor_x86 x86_hyper_xen_hvm __initdata = {
311	.name                   = "Xen HVM",
312	.detect                 = xen_platform_hvm,
313	.type			= X86_HYPER_XEN_HVM,
314	.init.init_platform     = xen_hvm_guest_init,
315	.init.x2apic_available  = xen_x2apic_para_available,
316	.init.init_mem_mapping	= xen_hvm_init_mem_mapping,
317	.init.guest_late_init	= xen_hvm_guest_late_init,
318	.runtime.pin_vcpu       = xen_pin_vcpu,
319	.ignore_nopv            = true,
320};
321