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
 26static unsigned long shared_info_pfn;
 27
 28void 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
 40static 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
 64static 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	 * The virtual address of the shared_info page has changed, so
 71	 * the vcpu_info pointer for VCPU 0 is now stale.
 72	 *
 73	 * The prepare_boot_cpu callback will re-initialize it via
 74	 * xen_vcpu_setup, but we can't rely on that to be called for
 75	 * old Xen versions (xen_have_vector_callback == 0).
 76	 *
 77	 * It is, in any case, bad to have a stale vcpu_info pointer
 78	 * so reset it now.
 79	 */
 80	xen_vcpu_info_reset(0);
 81}
 82
 83static void __init init_hvm_pv_info(void)
 84{
 85	int major, minor;
 86	uint32_t eax, ebx, ecx, edx, base;
 87
 88	base = xen_cpuid_base();
 89	eax = cpuid_eax(base + 1);
 90
 91	major = eax >> 16;
 92	minor = eax & 0xffff;
 93	printk(KERN_INFO "Xen version %d.%d.\n", major, minor);
 94
 95	xen_domain_type = XEN_HVM_DOMAIN;
 96
 97	/* PVH set up hypercall page in xen_prepare_pvh(). */
 98	if (xen_pvh_domain())
 99		pv_info.name = "Xen PVH";
100	else {
101		u64 pfn;
102		uint32_t msr;
103
104		pv_info.name = "Xen HVM";
105		msr = cpuid_ebx(base + 2);
106		pfn = __pa(hypercall_page);
107		wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
108	}
109
110	xen_setup_features();
111
112	cpuid(base + 4, &eax, &ebx, &ecx, &edx);
113	if (eax & XEN_HVM_CPUID_VCPU_ID_PRESENT)
114		this_cpu_write(xen_vcpu_id, ebx);
115	else
116		this_cpu_write(xen_vcpu_id, smp_processor_id());
117}
118
119#ifdef CONFIG_KEXEC_CORE
120static void xen_hvm_shutdown(void)
121{
122	native_machine_shutdown();
123	if (kexec_in_progress)
124		xen_reboot(SHUTDOWN_soft_reset);
125}
126
127static void xen_hvm_crash_shutdown(struct pt_regs *regs)
128{
129	native_machine_crash_shutdown(regs);
130	xen_reboot(SHUTDOWN_soft_reset);
131}
132#endif
133
134static int xen_cpu_up_prepare_hvm(unsigned int cpu)
135{
136	int rc = 0;
137
138	/*
139	 * This can happen if CPU was offlined earlier and
140	 * offlining timed out in common_cpu_die().
141	 */
142	if (cpu_report_state(cpu) == CPU_DEAD_FROZEN) {
143		xen_smp_intr_free(cpu);
144		xen_uninit_lock_cpu(cpu);
145	}
146
147	if (cpu_acpi_id(cpu) != U32_MAX)
148		per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu);
149	else
150		per_cpu(xen_vcpu_id, cpu) = cpu;
151	rc = xen_vcpu_setup(cpu);
152	if (rc)
153		return rc;
154
155	if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock))
156		xen_setup_timer(cpu);
157
158	rc = xen_smp_intr_init(cpu);
159	if (rc) {
160		WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n",
161		     cpu, rc);
162	}
163	return rc;
164}
165
166static int xen_cpu_dead_hvm(unsigned int cpu)
167{
168	xen_smp_intr_free(cpu);
169
170	if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock))
171		xen_teardown_timer(cpu);
172
173       return 0;
174}
175
176static void __init xen_hvm_guest_init(void)
177{
178	if (xen_pv_domain())
179		return;
180
181	init_hvm_pv_info();
182
183	reserve_shared_info();
184	xen_hvm_init_shared_info();
185
186	/*
187	 * xen_vcpu is a pointer to the vcpu_info struct in the shared_info
188	 * page, we use it in the event channel upcall and in some pvclock
189	 * related functions.
190	 */
191	xen_vcpu_info_reset(0);
192
193	xen_panic_handler_init();
194
195	if (xen_feature(XENFEAT_hvm_callback_vector))
196		xen_have_vector_callback = 1;
197
198	xen_hvm_smp_init();
199	WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_hvm, xen_cpu_dead_hvm));
200	xen_unplug_emulated_devices();
201	x86_init.irqs.intr_init = xen_init_IRQ;
202	xen_hvm_init_time_ops();
203	xen_hvm_init_mmu_ops();
204
205#ifdef CONFIG_KEXEC_CORE
206	machine_ops.shutdown = xen_hvm_shutdown;
207	machine_ops.crash_shutdown = xen_hvm_crash_shutdown;
208#endif
209}
210
211static bool xen_nopv;
212static __init int xen_parse_nopv(char *arg)
213{
214       xen_nopv = true;
215       return 0;
216}
217early_param("xen_nopv", xen_parse_nopv);
218
219bool xen_hvm_need_lapic(void)
220{
221	if (xen_nopv)
222		return false;
223	if (xen_pv_domain())
224		return false;
225	if (!xen_hvm_domain())
226		return false;
227	if (xen_feature(XENFEAT_hvm_pirqs) && xen_have_vector_callback)
228		return false;
229	return true;
230}
231EXPORT_SYMBOL_GPL(xen_hvm_need_lapic);
232
233static uint32_t __init xen_platform_hvm(void)
234{
235	if (xen_pv_domain() || xen_nopv)
236		return 0;
237
238	return xen_cpuid_base();
239}
240
241static __init void xen_hvm_guest_late_init(void)
242{
243#ifdef CONFIG_XEN_PVH
244	/* Test for PVH domain (PVH boot path taken overrides ACPI flags). */
245	if (!xen_pvh &&
246	    (x86_platform.legacy.rtc || !x86_platform.legacy.no_vga))
247		return;
248
249	/* PVH detected. */
250	xen_pvh = true;
251
252	/* Make sure we don't fall back to (default) ACPI_IRQ_MODEL_PIC. */
253	if (!nr_ioapics && acpi_irq_model == ACPI_IRQ_MODEL_PIC)
254		acpi_irq_model = ACPI_IRQ_MODEL_PLATFORM;
255
256	machine_ops.emergency_restart = xen_emergency_restart;
257	pv_info.name = "Xen PVH";
258#endif
259}
260
261const __initconst struct hypervisor_x86 x86_hyper_xen_hvm = {
262	.name                   = "Xen HVM",
263	.detect                 = xen_platform_hvm,
264	.type			= X86_HYPER_XEN_HVM,
265	.init.init_platform     = xen_hvm_guest_init,
266	.init.x2apic_available  = xen_x2apic_para_available,
267	.init.init_mem_mapping	= xen_hvm_init_mem_mapping,
268	.init.guest_late_init	= xen_hvm_guest_late_init,
269	.runtime.pin_vcpu       = xen_pin_vcpu,
270};