1 // SPDX-License-Identifier: GPL-2.0
3 #include <linux/acpi.h>
5 #include <linux/kexec.h>
6 #include <linux/memblock.h>
7 #include <linux/virtio_anchor.h>
9 #include <xen/features.h>
10 #include <xen/events.h>
12 #include <xen/interface/hvm/hvm_op.h>
13 #include <xen/interface/memory.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>
26 #include <asm/xen/cpuid.h>
27 #include <asm/xen/hypervisor.h>
28 #include <asm/xen/page.h>
34 static unsigned long shared_info_pfn
;
36 __ro_after_init
bool xen_percpu_upcall
;
37 EXPORT_SYMBOL_GPL(xen_percpu_upcall
);
39 void xen_hvm_init_shared_info(void)
41 struct xen_add_to_physmap xatp
;
43 xatp
.domid
= DOMID_SELF
;
45 xatp
.space
= XENMAPSPACE_shared_info
;
46 xatp
.gpfn
= shared_info_pfn
;
47 if (HYPERVISOR_memory_op(XENMEM_add_to_physmap
, &xatp
))
51 static void __init
reserve_shared_info(void)
56 * Search for a free page starting at 4kB physical address.
57 * Low memory is preferred to avoid an EPT large page split up
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.
64 !e820__mapped_all(pa
, pa
+ PAGE_SIZE
, E820_TYPE_RAM
) ||
65 memblock_is_reserved(pa
);
69 shared_info_pfn
= PHYS_PFN(pa
);
71 memblock_reserve(pa
, PAGE_SIZE
);
72 HYPERVISOR_shared_info
= early_memremap(pa
, PAGE_SIZE
);
75 static void __init
xen_hvm_init_mem_mapping(void)
77 early_memunmap(HYPERVISOR_shared_info
, PAGE_SIZE
);
78 HYPERVISOR_shared_info
= __va(PFN_PHYS(shared_info_pfn
));
81 * The virtual address of the shared_info page has changed, so
82 * the vcpu_info pointer for VCPU 0 is now stale.
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).
88 * It is, in any case, bad to have a stale vcpu_info pointer
91 xen_vcpu_info_reset(0);
94 static void __init
init_hvm_pv_info(void)
97 uint32_t eax
, ebx
, ecx
, edx
, base
;
99 base
= xen_cpuid_base();
100 eax
= cpuid_eax(base
+ 1);
103 minor
= eax
& 0xffff;
104 printk(KERN_INFO
"Xen version %d.%d.\n", major
, minor
);
106 xen_domain_type
= XEN_HVM_DOMAIN
;
108 /* PVH set up hypercall page in xen_prepare_pvh(). */
109 if (xen_pvh_domain())
110 pv_info
.name
= "Xen PVH";
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));
121 xen_setup_features();
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
);
127 this_cpu_write(xen_vcpu_id
, smp_processor_id());
130 DEFINE_IDTENTRY_SYSVEC(sysvec_xen_hvm_callback
)
132 struct pt_regs
*old_regs
= set_irq_regs(regs
);
134 if (xen_percpu_upcall
)
137 inc_irq_stat(irq_hv_callback_count
);
139 xen_hvm_evtchn_do_upcall();
141 set_irq_regs(old_regs
);
144 #ifdef CONFIG_KEXEC_CORE
145 static void xen_hvm_shutdown(void)
147 native_machine_shutdown();
148 if (kexec_in_progress
)
149 xen_reboot(SHUTDOWN_soft_reset
);
152 static void xen_hvm_crash_shutdown(struct pt_regs
*regs
)
154 native_machine_crash_shutdown(regs
);
155 xen_reboot(SHUTDOWN_soft_reset
);
159 static int xen_cpu_up_prepare_hvm(unsigned int cpu
)
164 * If a CPU was offlined earlier and offlining timed out then the
165 * lock mechanism is still initialized. Uninit it unconditionally
166 * as it's safe to call even if already uninited. Interrupts and
167 * timer have already been handled in xen_cpu_dead_hvm().
169 xen_uninit_lock_cpu(cpu
);
171 if (cpu_acpi_id(cpu
) != U32_MAX
)
172 per_cpu(xen_vcpu_id
, cpu
) = cpu_acpi_id(cpu
);
174 per_cpu(xen_vcpu_id
, cpu
) = cpu
;
176 if (!xen_have_vector_callback
)
179 if (xen_percpu_upcall
) {
180 rc
= xen_set_upcall_vector(cpu
);
182 WARN(1, "HVMOP_set_evtchn_upcall_vector"
183 " for CPU %d failed: %d\n", cpu
, rc
);
188 if (xen_feature(XENFEAT_hvm_safe_pvclock
))
189 xen_setup_timer(cpu
);
191 rc
= xen_smp_intr_init(cpu
);
193 WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n",
199 static int xen_cpu_dead_hvm(unsigned int cpu
)
201 xen_smp_intr_free(cpu
);
203 if (xen_have_vector_callback
&& xen_feature(XENFEAT_hvm_safe_pvclock
))
204 xen_teardown_timer(cpu
);
208 static void __init
xen_hvm_guest_init(void)
213 if (IS_ENABLED(CONFIG_XEN_VIRTIO_FORCE_GRANT
))
214 virtio_set_mem_acc_cb(xen_virtio_restricted_mem_acc
);
218 reserve_shared_info();
219 xen_hvm_init_shared_info();
222 * xen_vcpu is a pointer to the vcpu_info struct in the shared_info
223 * page, we use it in the event channel upcall and in some pvclock
226 xen_vcpu_info_reset(0);
228 xen_panic_handler_init();
231 WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_hvm
, xen_cpu_dead_hvm
));
232 xen_unplug_emulated_devices();
233 x86_init
.irqs
.intr_init
= xen_init_IRQ
;
234 xen_hvm_init_time_ops();
235 xen_hvm_init_mmu_ops();
237 #ifdef CONFIG_KEXEC_CORE
238 machine_ops
.shutdown
= xen_hvm_shutdown
;
239 machine_ops
.crash_shutdown
= xen_hvm_crash_shutdown
;
243 static __init
int xen_parse_nopv(char *arg
)
245 pr_notice("\"xen_nopv\" is deprecated, please use \"nopv\" instead\n");
247 if (xen_cpuid_base())
251 early_param("xen_nopv", xen_parse_nopv
);
253 static __init
int xen_parse_no_vector_callback(char *arg
)
255 xen_have_vector_callback
= false;
258 early_param("xen_no_vector_callback", xen_parse_no_vector_callback
);
260 static __init
bool xen_x2apic_available(void)
262 return x2apic_supported();
265 static bool __init
msi_ext_dest_id(void)
267 return cpuid_eax(xen_cpuid_base() + 4) & XEN_HVM_CPUID_EXT_DEST_ID
;
270 static __init
void xen_hvm_guest_late_init(void)
272 #ifdef CONFIG_XEN_PVH
273 /* Test for PVH domain (PVH boot path taken overrides ACPI flags). */
275 (x86_platform
.legacy
.rtc
|| !x86_platform
.legacy
.no_vga
))
282 panic("\"nopv\" and \"xen_nopv\" parameters are unsupported in PVH guest.");
284 /* Make sure we don't fall back to (default) ACPI_IRQ_MODEL_PIC. */
285 if (!nr_ioapics
&& acpi_irq_model
== ACPI_IRQ_MODEL_PIC
)
286 acpi_irq_model
= ACPI_IRQ_MODEL_PLATFORM
;
288 machine_ops
.emergency_restart
= xen_emergency_restart
;
289 pv_info
.name
= "Xen PVH";
293 static uint32_t __init
xen_platform_hvm(void)
295 uint32_t xen_domain
= xen_cpuid_base();
296 struct x86_hyper_init
*h
= &x86_hyper_xen_hvm
.init
;
301 if (xen_pvh_domain() && nopv
) {
302 /* Guest booting via the Xen-PVH boot entry goes here */
303 pr_info("\"nopv\" parameter is ignored in PVH guest\n");
305 } else if (nopv
&& xen_domain
) {
307 * Guest booting via normal boot entry (like via grub2) goes
310 * Use interface functions for bare hardware if nopv,
311 * xen_hvm_guest_late_init is an exception as we need to
312 * detect PVH and panic there.
314 h
->init_platform
= x86_init_noop
;
315 h
->x2apic_available
= bool_x86_init_noop
;
316 h
->init_mem_mapping
= x86_init_noop
;
317 h
->init_after_bootmem
= x86_init_noop
;
318 h
->guest_late_init
= xen_hvm_guest_late_init
;
319 x86_hyper_xen_hvm
.runtime
.pin_vcpu
= x86_op_int_noop
;
324 struct hypervisor_x86 x86_hyper_xen_hvm __initdata
= {
326 .detect
= xen_platform_hvm
,
327 .type
= X86_HYPER_XEN_HVM
,
328 .init
.init_platform
= xen_hvm_guest_init
,
329 .init
.x2apic_available
= xen_x2apic_available
,
330 .init
.init_mem_mapping
= xen_hvm_init_mem_mapping
,
331 .init
.guest_late_init
= xen_hvm_guest_late_init
,
332 .init
.msi_ext_dest_id
= msi_ext_dest_id
,
333 .runtime
.pin_vcpu
= xen_pin_vcpu
,