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
34static unsigned long shared_info_pfn;
35
36__ro_after_init bool xen_percpu_upcall;
37EXPORT_SYMBOL_GPL(xen_percpu_upcall);
38
39void 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
51static 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
75static 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
94static 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
130DEFINE_IDTENTRY_SYSVEC(sysvec_xen_hvm_callback)
131{
132	struct pt_regs *old_regs = set_irq_regs(regs);
133
134	if (xen_percpu_upcall)
135		apic_eoi();
136
137	inc_irq_stat(irq_hv_callback_count);
138
139	xen_evtchn_do_upcall();
140
141	set_irq_regs(old_regs);
142}
143
144#ifdef CONFIG_KEXEC_CORE
145static void xen_hvm_shutdown(void)
146{
147	native_machine_shutdown();
148	if (kexec_in_progress)
149		xen_reboot(SHUTDOWN_soft_reset);
150}
151#endif
152
153#ifdef CONFIG_CRASH_DUMP
154static void xen_hvm_crash_shutdown(struct pt_regs *regs)
155{
156	native_machine_crash_shutdown(regs);
157	xen_reboot(SHUTDOWN_soft_reset);
158}
159#endif
160
161static int xen_cpu_up_prepare_hvm(unsigned int cpu)
162{
163	int rc = 0;
164
165	/*
166	 * If a CPU was offlined earlier and offlining timed out then the
167	 * lock mechanism is still initialized. Uninit it unconditionally
168	 * as it's safe to call even if already uninited. Interrupts and
169	 * timer have already been handled in xen_cpu_dead_hvm().
170	 */
171	xen_uninit_lock_cpu(cpu);
172
173	if (cpu_acpi_id(cpu) != CPU_ACPIID_INVALID)
174		per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu);
175	else
176		per_cpu(xen_vcpu_id, cpu) = cpu;
177	xen_vcpu_setup(cpu);
178	if (!xen_have_vector_callback)
179		return 0;
180
181	if (xen_percpu_upcall) {
182		rc = xen_set_upcall_vector(cpu);
183		if (rc) {
184			WARN(1, "HVMOP_set_evtchn_upcall_vector"
185			     " for CPU %d failed: %d\n", cpu, rc);
186			return rc;
187		}
188	}
189
190	if (xen_feature(XENFEAT_hvm_safe_pvclock))
191		xen_setup_timer(cpu);
192
193	rc = xen_smp_intr_init(cpu);
194	if (rc) {
195		WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n",
196		     cpu, rc);
197	}
198	return rc;
199}
200
201static int xen_cpu_dead_hvm(unsigned int cpu)
202{
203	xen_smp_intr_free(cpu);
204
205	if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock))
206		xen_teardown_timer(cpu);
207	return 0;
208}
209
210static void __init xen_hvm_guest_init(void)
211{
212	if (xen_pv_domain())
213		return;
214
215	if (IS_ENABLED(CONFIG_XEN_VIRTIO_FORCE_GRANT))
216		virtio_set_mem_acc_cb(xen_virtio_restricted_mem_acc);
217
218	init_hvm_pv_info();
219
220	reserve_shared_info();
221	xen_hvm_init_shared_info();
222
223	/*
224	 * xen_vcpu is a pointer to the vcpu_info struct in the shared_info
225	 * page, we use it in the event channel upcall and in some pvclock
226	 * related functions.
227	 */
228	xen_vcpu_info_reset(0);
229
230	xen_panic_handler_init();
231
232	xen_hvm_smp_init();
233	WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_hvm, xen_cpu_dead_hvm));
234	xen_unplug_emulated_devices();
235	x86_init.irqs.intr_init = xen_init_IRQ;
236	xen_hvm_init_time_ops();
237	xen_hvm_init_mmu_ops();
238
239#ifdef CONFIG_KEXEC_CORE
240	machine_ops.shutdown = xen_hvm_shutdown;
241#endif
242#ifdef CONFIG_CRASH_DUMP
243	machine_ops.crash_shutdown = xen_hvm_crash_shutdown;
244#endif
245}
246
247static __init int xen_parse_nopv(char *arg)
248{
249	pr_notice("\"xen_nopv\" is deprecated, please use \"nopv\" instead\n");
250
251	if (xen_cpuid_base())
252		nopv = true;
253	return 0;
254}
255early_param("xen_nopv", xen_parse_nopv);
256
257static __init int xen_parse_no_vector_callback(char *arg)
258{
259	xen_have_vector_callback = false;
260	return 0;
261}
262early_param("xen_no_vector_callback", xen_parse_no_vector_callback);
263
264static __init bool xen_x2apic_available(void)
265{
266	return x2apic_supported();
267}
268
269static bool __init msi_ext_dest_id(void)
270{
271       return cpuid_eax(xen_cpuid_base() + 4) & XEN_HVM_CPUID_EXT_DEST_ID;
272}
273
274static __init void xen_hvm_guest_late_init(void)
275{
276#ifdef CONFIG_XEN_PVH
277	/* Test for PVH domain (PVH boot path taken overrides ACPI flags). */
278	if (!xen_pvh &&
279	    (x86_platform.legacy.rtc || !x86_platform.legacy.no_vga))
280		return;
281
282	/* PVH detected. */
283	xen_pvh = true;
284
285	if (nopv)
286		panic("\"nopv\" and \"xen_nopv\" parameters are unsupported in PVH guest.");
287
288	/* Make sure we don't fall back to (default) ACPI_IRQ_MODEL_PIC. */
289	if (!nr_ioapics && acpi_irq_model == ACPI_IRQ_MODEL_PIC)
290		acpi_irq_model = ACPI_IRQ_MODEL_PLATFORM;
291
292	machine_ops.emergency_restart = xen_emergency_restart;
293	pv_info.name = "Xen PVH";
294#endif
295}
296
297static uint32_t __init xen_platform_hvm(void)
298{
299	uint32_t xen_domain = xen_cpuid_base();
300	struct x86_hyper_init *h = &x86_hyper_xen_hvm.init;
301
302	if (xen_pv_domain())
303		return 0;
304
305	if (xen_pvh_domain() && nopv) {
306		/* Guest booting via the Xen-PVH boot entry goes here */
307		pr_info("\"nopv\" parameter is ignored in PVH guest\n");
308		nopv = false;
309	} else if (nopv && xen_domain) {
310		/*
311		 * Guest booting via normal boot entry (like via grub2) goes
312		 * here.
313		 *
314		 * Use interface functions for bare hardware if nopv,
315		 * xen_hvm_guest_late_init is an exception as we need to
316		 * detect PVH and panic there.
317		 */
318		h->init_platform = x86_init_noop;
319		h->x2apic_available = bool_x86_init_noop;
320		h->init_mem_mapping = x86_init_noop;
321		h->init_after_bootmem = x86_init_noop;
322		h->guest_late_init = xen_hvm_guest_late_init;
323		x86_hyper_xen_hvm.runtime.pin_vcpu = x86_op_int_noop;
324	}
325	return xen_domain;
326}
327
328struct hypervisor_x86 x86_hyper_xen_hvm __initdata = {
329	.name                   = "Xen HVM",
330	.detect                 = xen_platform_hvm,
331	.type			= X86_HYPER_XEN_HVM,
332	.init.init_platform     = xen_hvm_guest_init,
333	.init.x2apic_available  = xen_x2apic_available,
334	.init.init_mem_mapping	= xen_hvm_init_mem_mapping,
335	.init.guest_late_init	= xen_hvm_guest_late_init,
336	.init.msi_ext_dest_id   = msi_ext_dest_id,
337	.runtime.pin_vcpu       = xen_pin_vcpu,
338	.ignore_nopv            = true,
339};
340