1 // SPDX-License-Identifier: GPL-2.0
3 #include <linux/acpi.h>
5 #include <linux/kexec.h>
6 #include <linux/memblock.h>
8 #include <xen/features.h>
9 #include <xen/events.h>
10 #include <xen/interface/memory.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>
22 #include <asm/xen/cpuid.h>
23 #include <asm/xen/hypervisor.h>
24 #include <asm/xen/page.h>
30 static unsigned long shared_info_pfn
;
32 void xen_hvm_init_shared_info(void)
34 struct xen_add_to_physmap xatp
;
36 xatp
.domid
= DOMID_SELF
;
38 xatp
.space
= XENMAPSPACE_shared_info
;
39 xatp
.gpfn
= shared_info_pfn
;
40 if (HYPERVISOR_memory_op(XENMEM_add_to_physmap
, &xatp
))
44 static void __init
reserve_shared_info(void)
49 * Search for a free page starting at 4kB physical address.
50 * Low memory is preferred to avoid an EPT large page split up
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.
57 !e820__mapped_all(pa
, pa
+ PAGE_SIZE
, E820_TYPE_RAM
) ||
58 memblock_is_reserved(pa
);
62 shared_info_pfn
= PHYS_PFN(pa
);
64 memblock_reserve(pa
, PAGE_SIZE
);
65 HYPERVISOR_shared_info
= early_memremap(pa
, PAGE_SIZE
);
68 static void __init
xen_hvm_init_mem_mapping(void)
70 early_memunmap(HYPERVISOR_shared_info
, PAGE_SIZE
);
71 HYPERVISOR_shared_info
= __va(PFN_PHYS(shared_info_pfn
));
74 * The virtual address of the shared_info page has changed, so
75 * the vcpu_info pointer for VCPU 0 is now stale.
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).
81 * It is, in any case, bad to have a stale vcpu_info pointer
84 xen_vcpu_info_reset(0);
87 static void __init
init_hvm_pv_info(void)
90 uint32_t eax
, ebx
, ecx
, edx
, base
;
92 base
= xen_cpuid_base();
93 eax
= cpuid_eax(base
+ 1);
97 printk(KERN_INFO
"Xen version %d.%d.\n", major
, minor
);
99 xen_domain_type
= XEN_HVM_DOMAIN
;
101 /* PVH set up hypercall page in xen_prepare_pvh(). */
102 if (xen_pvh_domain())
103 pv_info
.name
= "Xen PVH";
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));
114 xen_setup_features();
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
);
120 this_cpu_write(xen_vcpu_id
, smp_processor_id());
123 DEFINE_IDTENTRY_SYSVEC(sysvec_xen_hvm_callback
)
125 struct pt_regs
*old_regs
= set_irq_regs(regs
);
127 inc_irq_stat(irq_hv_callback_count
);
129 xen_hvm_evtchn_do_upcall();
131 set_irq_regs(old_regs
);
134 #ifdef CONFIG_KEXEC_CORE
135 static void xen_hvm_shutdown(void)
137 native_machine_shutdown();
138 if (kexec_in_progress
)
139 xen_reboot(SHUTDOWN_soft_reset
);
142 static void xen_hvm_crash_shutdown(struct pt_regs
*regs
)
144 native_machine_crash_shutdown(regs
);
145 xen_reboot(SHUTDOWN_soft_reset
);
149 static int xen_cpu_up_prepare_hvm(unsigned int cpu
)
154 * This can happen if CPU was offlined earlier and
155 * offlining timed out in common_cpu_die().
157 if (cpu_report_state(cpu
) == CPU_DEAD_FROZEN
) {
158 xen_smp_intr_free(cpu
);
159 xen_uninit_lock_cpu(cpu
);
162 if (cpu_acpi_id(cpu
) != U32_MAX
)
163 per_cpu(xen_vcpu_id
, cpu
) = cpu_acpi_id(cpu
);
165 per_cpu(xen_vcpu_id
, cpu
) = cpu
;
166 rc
= xen_vcpu_setup(cpu
);
170 if (xen_have_vector_callback
&& xen_feature(XENFEAT_hvm_safe_pvclock
))
171 xen_setup_timer(cpu
);
173 rc
= xen_smp_intr_init(cpu
);
175 WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n",
181 static int xen_cpu_dead_hvm(unsigned int cpu
)
183 xen_smp_intr_free(cpu
);
185 if (xen_have_vector_callback
&& xen_feature(XENFEAT_hvm_safe_pvclock
))
186 xen_teardown_timer(cpu
);
191 static void __init
xen_hvm_guest_init(void)
198 reserve_shared_info();
199 xen_hvm_init_shared_info();
202 * xen_vcpu is a pointer to the vcpu_info struct in the shared_info
203 * page, we use it in the event channel upcall and in some pvclock
206 xen_vcpu_info_reset(0);
208 xen_panic_handler_init();
210 if (xen_feature(XENFEAT_hvm_callback_vector
))
211 xen_have_vector_callback
= 1;
214 WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_hvm
, xen_cpu_dead_hvm
));
215 xen_unplug_emulated_devices();
216 x86_init
.irqs
.intr_init
= xen_init_IRQ
;
217 xen_hvm_init_time_ops();
218 xen_hvm_init_mmu_ops();
220 #ifdef CONFIG_KEXEC_CORE
221 machine_ops
.shutdown
= xen_hvm_shutdown
;
222 machine_ops
.crash_shutdown
= xen_hvm_crash_shutdown
;
226 static __init
int xen_parse_nopv(char *arg
)
228 pr_notice("\"xen_nopv\" is deprecated, please use \"nopv\" instead\n");
230 if (xen_cpuid_base())
234 early_param("xen_nopv", xen_parse_nopv
);
236 bool __init
xen_hvm_need_lapic(void)
240 if (!xen_hvm_domain())
242 if (xen_feature(XENFEAT_hvm_pirqs
) && xen_have_vector_callback
)
247 static __init
void xen_hvm_guest_late_init(void)
249 #ifdef CONFIG_XEN_PVH
250 /* Test for PVH domain (PVH boot path taken overrides ACPI flags). */
252 (x86_platform
.legacy
.rtc
|| !x86_platform
.legacy
.no_vga
))
259 panic("\"nopv\" and \"xen_nopv\" parameters are unsupported in PVH guest.");
261 /* Make sure we don't fall back to (default) ACPI_IRQ_MODEL_PIC. */
262 if (!nr_ioapics
&& acpi_irq_model
== ACPI_IRQ_MODEL_PIC
)
263 acpi_irq_model
= ACPI_IRQ_MODEL_PLATFORM
;
265 machine_ops
.emergency_restart
= xen_emergency_restart
;
266 pv_info
.name
= "Xen PVH";
270 static uint32_t __init
xen_platform_hvm(void)
272 uint32_t xen_domain
= xen_cpuid_base();
273 struct x86_hyper_init
*h
= &x86_hyper_xen_hvm
.init
;
278 if (xen_pvh_domain() && nopv
) {
279 /* Guest booting via the Xen-PVH boot entry goes here */
280 pr_info("\"nopv\" parameter is ignored in PVH guest\n");
282 } else if (nopv
&& xen_domain
) {
284 * Guest booting via normal boot entry (like via grub2) goes
287 * Use interface functions for bare hardware if nopv,
288 * xen_hvm_guest_late_init is an exception as we need to
289 * detect PVH and panic there.
291 h
->init_platform
= x86_init_noop
;
292 h
->x2apic_available
= bool_x86_init_noop
;
293 h
->init_mem_mapping
= x86_init_noop
;
294 h
->init_after_bootmem
= x86_init_noop
;
295 h
->guest_late_init
= xen_hvm_guest_late_init
;
296 x86_hyper_xen_hvm
.runtime
.pin_vcpu
= x86_op_int_noop
;
301 struct hypervisor_x86 x86_hyper_xen_hvm __initdata
= {
303 .detect
= xen_platform_hvm
,
304 .type
= X86_HYPER_XEN_HVM
,
305 .init
.init_platform
= xen_hvm_guest_init
,
306 .init
.x2apic_available
= xen_x2apic_para_available
,
307 .init
.init_mem_mapping
= xen_hvm_init_mem_mapping
,
308 .init
.guest_late_init
= xen_hvm_guest_late_init
,
309 .runtime
.pin_vcpu
= xen_pin_vcpu
,