1 // SPDX-License-Identifier: GPL-2.0
5  * Hyper-V. This file is specifically for code that must be
6  * built-in to the kernel image when CONFIG_HYPERV is set
29 #include <linux/dma-map-ops.h>
36  * Hyper-V specific globals so they are shared across all architectures and are
69  * Hyper-V specific initialization and shutdown code that is
95  * the guest page size may not be the same as the Hyper-V page
96  * size. We depend upon kmalloc() aligning power-of-two size
98  * allocated memory appears to Hyper-V as a page of the size
134  * Boolean to control whether to report panic messages over Hyper-V.
142  * reported to Hyper-V on panic.
182 	/* Don't notify Hyper-V unless we have a die oops event or panic. */  in hv_die_panic_notify_crash()
191 		regs = ((struct die_args *)args)->regs;  in hv_die_panic_notify_crash()
195 	 * Hyper-V should be notified only once about a panic/die. If we will  in hv_die_panic_notify_crash()
207  * buffer and call into Hyper-V to transfer the data.
216 	if (detail->reason != KMSG_DUMP_PANIC || !sysctl_record_panic_msg)  in hv_kmsg_dump()
220 	 * Write dump contents to the page. No need to synchronize; panic should  in hv_kmsg_dump()
221 	 * be single-threaded.  in hv_kmsg_dump()
231 	 * registers are no-op when the NOTIFY_MSG flag is set.  in hv_kmsg_dump()
240 	 * Let Hyper-V know there is crash data available along with  in hv_kmsg_dump()
249 	.dump = hv_kmsg_dump,
269 		pr_err("Hyper-V: panic message page memory allocation failed\n");  in hv_kmsg_dump_register()
275 		pr_err("Hyper-V: kmsg dump register error 0x%x\n", ret);  in hv_kmsg_dump_register()
291 	/* Get information about the Hyper-V host version */  in hv_common_init()
293 		pr_info("Hyper-V: Host Build %d.%d.%d.%d-%d-%d\n",  in hv_common_init()
302 	 * Hyper-V expects to get crash register data or kmsg when  in hv_common_init()
312 		pr_info("Hyper-V: enabling crash_kexec_post_notifiers\n");  in hv_common_init()
316 		 * is enabled by default in non-isolated guests and  in hv_common_init()
323 			pr_err("Hyper-V: sysctl table register error");  in hv_common_init()
339 	 * Allocate the per-CPU state for the hypercall input arg.  in hv_common_init()
341 	 * (per-CPU) hypercall input page and thus this failure is  in hv_common_init()
342 	 * fatal on Hyper-V.  in hv_common_init()
347 	/* Allocate the per-CPU state for output arg for root */  in hv_common_init()
357 		return -ENOMEM;  in hv_common_init()
375 	 * the Hyper-V host in ACPI table OEM0.  in ms_hyperv_late_init()
388 	if (strncmp(header->oem_table_id, "MICROSFT", 8))  in ms_hyperv_late_init()
393 	 * no more than 4K bytes is somewhat arbitrary and just protects  in ms_hyperv_late_init()
394 	 * against a malformed table. Hyper-V currently provides 64 bytes,  in ms_hyperv_late_init()
397 	if (header->length < sizeof(*header) + 8 ||  in ms_hyperv_late_init()
398 	    header->length > sizeof(*header) + SZ_4K)  in ms_hyperv_late_init()
401 	length = header->length - sizeof(*header);  in ms_hyperv_late_init()
404 	pr_debug("Hyper-V: Seeding rng with %d random bytes from ACPI table OEM0\n",  in ms_hyperv_late_init()
418 		header->checksum += randomdata[i];  in ms_hyperv_late_init()
422 	for (i = 0; i < sizeof(header->length); i++)  in ms_hyperv_late_init()
423 		header->checksum += ((u8 *)&header->length)[i];  in ms_hyperv_late_init()
424 	header->length = sizeof(*header);  in ms_hyperv_late_init()
425 	for (i = 0; i < sizeof(header->length); i++)  in ms_hyperv_late_init()
426 		header->checksum -= ((u8 *)&header->length)[i];  in ms_hyperv_late_init()
433  * Hyper-V specific initialization and die code for
459 			return -ENOMEM;  in hv_common_cpu_init()
479 		 * hyperv_pcpu_input_arg is not NULL, set_memory_decrypted() ->  in hv_common_cpu_init()
480 		 * ... -> cpa_flush()-> ... -> __send_ipi_mask_ex() tries to  in hv_common_cpu_init()
509 	 * may be used by the Hyper-V vPCI driver in reassigning interrupts  in hv_common_cpu_die()
531 	 * Hypercall input/output addresses should also be 8-byte aligned.  in hv_query_ext_cap()
558 		pr_err("Hyper-V: Extended query capabilities hypercall failed 0x%llx\n",  in hv_query_ext_cap()
580  * Default function to read the Hyper-V reference counter, independent
581  * of whether Hyper-V enlightened clocks/timers are being used. But on
582  * architectures where it is used, Hyper-V enlightenment code in
593 /* These __weak functions provide default "no-op" behavior and
595  * for which the default "no-op" behavior is sufficient can leave
597  * functions in arch-specific code.