1 // SPDX-License-Identifier: GPL-2.0-only
3  * X86 specific Hyper-V initialization code.
10 #define pr_fmt(fmt)  "Hyper-V: " fmt
42 /* Storage to save the hypercall page temporarily for hibernation */
58 		return -EINVAL;  in hyperv_init_ghcb()
71 		return -ENOMEM;  in hyperv_init_ghcb()
103 		 * The VP assist page is an "overlay" page (see Hyper-V TLFS's  in hv_cpu_init()
114 			 * Hyper-V should never specify a VM that is a Confidential  in hv_cpu_init()
117 			 * page in non-root partition here.  in hv_cpu_init()
267 		 * CPU or just disable the feature if there are no online CPUs  in hv_cpu_die()
268 		 * left (happens on hibernation).  in hv_cpu_die()
288 	 * A Generation-2 VM doesn't support legacy PCI/PCIe, so both  in hv_pci_init()
289 	 * raw_pci_ops and raw_pci_ext_ops are NULL, and pci_subsys_init() ->  in hv_pci_init()
290 	 * pcibios_init() doesn't call pcibios_resource_survey() ->  in hv_pci_init()
299 	 * acpi_nfit_register_region() -> acpi_nfit_insert_resource() ->  in hv_pci_init()
311 	/* For Generation-1 VM, we'll proceed in pci_arch_init().  */  in hv_pci_init()
321 		return -EPERM;  in hv_suspend()
325 	 * across hibernation. Setting hv_hypercall_pg to NULL ensures  in hv_suspend()
333 	/* Disable the hypercall page in the hypervisor */  in hv_suspend()
350 	/* Re-enable the hypercall page */  in hv_resume()
385 	 * Still register the LAPIC timer, because the direct-mode STIMER is  in hv_stimer_setup_percpu_clockev()
386 	 * not supported by old versions of Hyper-V. This also allows users  in hv_stimer_setup_percpu_clockev()
407 	input->partition_id = HV_PARTITION_ID_SELF;  in get_vtl()
408 	input->vp_index = HV_VP_INDEX_SELF;  in get_vtl()
409 	input->input_vtl.as_uint8 = 0;  in get_vtl()
410 	input->names[0] = HV_REGISTER_VSM_VP_STATUS;  in get_vtl()
414 		ret = output->values[0].reg8 & HV_X64_VTL_MASK;  in get_vtl()
432  * 2. Register Hyper-V specific clocksource.
433  * 3. Setup Hyper-V specific APIC entry points.
487 	 * page to Hyper-V, e.g. hv_post_message() uses the per-CPU page  in hyperv_init()
552 	 * Some versions of Hyper-V that provide IBT in guest VMs have a bug  in hyperv_init()
556 	 * enabled, and Linux panics. For such buggy versions, disable IBT.  in hyperv_init()
558 	 * Fixed versions of Hyper-V always provide ENDBR64 on the hypercall  in hyperv_init()
559 	 * page, so if future Linux kernel versions enable IBT for 32-bit  in hyperv_init()
567 		pr_warn("Disabling IBT because of Hyper-V bug\n");  in hyperv_init()
573 	 * apic_intr_mode_init() -> x86_platform.apic_post_init() and  in hyperv_init()
574 	 * apic_bsp_setup() -> setup_local_APIC(). The direct-mode STIMER  in hyperv_init()
674 	wrmsrl(HV_X64_MSR_CRASH_P2, regs->ip);  in hyperv_report_panic()
675 	wrmsrl(HV_X64_MSR_CRASH_P3, regs->ax);  in hyperv_report_panic()
676 	wrmsrl(HV_X64_MSR_CRASH_P4, regs->sp);  in hyperv_report_panic()
679 	 * Let Hyper-V know there is crash data available  in hyperv_report_panic()
690 	 * Ensure that we're really on Hyper-V, and not a KVM or Xen  in hv_is_hyperv_initialized()
691 	 * emulation of Hyper-V  in hv_is_hyperv_initialized()