hyperv.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Hyper-V specific functions.
  4 *
  5 * Copyright (C) 2021, Red Hat Inc.
  6 */
  7#include <stdint.h>
  8#include "processor.h"
  9#include "hyperv.h"
 10
 11const struct kvm_cpuid2 *kvm_get_supported_hv_cpuid(void)
 12{
 13	static struct kvm_cpuid2 *cpuid;
 14	int kvm_fd;
 15
 16	if (cpuid)
 17		return cpuid;
 18
 19	cpuid = allocate_kvm_cpuid2(MAX_NR_CPUID_ENTRIES);
 20	kvm_fd = open_kvm_dev_path_or_exit();
 21
 22	kvm_ioctl(kvm_fd, KVM_GET_SUPPORTED_HV_CPUID, cpuid);
 23
 24	close(kvm_fd);
 25	return cpuid;
 26}
 27
 28void vcpu_set_hv_cpuid(struct kvm_vcpu *vcpu)
 29{
 30	static struct kvm_cpuid2 *cpuid_full;
 31	const struct kvm_cpuid2 *cpuid_sys, *cpuid_hv;
 32	int i, nent = 0;
 33
 34	if (!cpuid_full) {
 35		cpuid_sys = kvm_get_supported_cpuid();
 36		cpuid_hv = kvm_get_supported_hv_cpuid();
 37
 38		cpuid_full = allocate_kvm_cpuid2(cpuid_sys->nent + cpuid_hv->nent);
 39		if (!cpuid_full) {
 40			perror("malloc");
 41			abort();
 42		}
 43
 44		/* Need to skip KVM CPUID leaves 0x400000xx */
 45		for (i = 0; i < cpuid_sys->nent; i++) {
 46			if (cpuid_sys->entries[i].function >= 0x40000000 &&
 47			    cpuid_sys->entries[i].function < 0x40000100)
 48				continue;
 49			cpuid_full->entries[nent] = cpuid_sys->entries[i];
 50			nent++;
 51		}
 52
 53		memcpy(&cpuid_full->entries[nent], cpuid_hv->entries,
 54		       cpuid_hv->nent * sizeof(struct kvm_cpuid_entry2));
 55		cpuid_full->nent = nent + cpuid_hv->nent;
 56	}
 57
 58	vcpu_init_cpuid(vcpu, cpuid_full);
 59}
 60
 61const struct kvm_cpuid2 *vcpu_get_supported_hv_cpuid(struct kvm_vcpu *vcpu)
 62{
 63	struct kvm_cpuid2 *cpuid = allocate_kvm_cpuid2(MAX_NR_CPUID_ENTRIES);
 64
 65	vcpu_ioctl(vcpu, KVM_GET_SUPPORTED_HV_CPUID, cpuid);
 66
 67	return cpuid;
 68}
 69
 70bool kvm_hv_cpu_has(struct kvm_x86_cpu_feature feature)
 71{
 72	if (!kvm_has_cap(KVM_CAP_SYS_HYPERV_CPUID))
 73		return false;
 74
 75	return kvm_cpuid_has(kvm_get_supported_hv_cpuid(), feature);
 76}
 77
 78struct hyperv_test_pages *vcpu_alloc_hyperv_test_pages(struct kvm_vm *vm,
 79						       vm_vaddr_t *p_hv_pages_gva)
 80{
 81	vm_vaddr_t hv_pages_gva = vm_vaddr_alloc_page(vm);
 82	struct hyperv_test_pages *hv = addr_gva2hva(vm, hv_pages_gva);
 83
 84	/* Setup of a region of guest memory for the VP Assist page. */
 85	hv->vp_assist = (void *)vm_vaddr_alloc_page(vm);
 86	hv->vp_assist_hva = addr_gva2hva(vm, (uintptr_t)hv->vp_assist);
 87	hv->vp_assist_gpa = addr_gva2gpa(vm, (uintptr_t)hv->vp_assist);
 88
 89	/* Setup of a region of guest memory for the partition assist page. */
 90	hv->partition_assist = (void *)vm_vaddr_alloc_page(vm);
 91	hv->partition_assist_hva = addr_gva2hva(vm, (uintptr_t)hv->partition_assist);
 92	hv->partition_assist_gpa = addr_gva2gpa(vm, (uintptr_t)hv->partition_assist);
 93
 94	/* Setup of a region of guest memory for the enlightened VMCS. */
 95	hv->enlightened_vmcs = (void *)vm_vaddr_alloc_page(vm);
 96	hv->enlightened_vmcs_hva = addr_gva2hva(vm, (uintptr_t)hv->enlightened_vmcs);
 97	hv->enlightened_vmcs_gpa = addr_gva2gpa(vm, (uintptr_t)hv->enlightened_vmcs);
 98
 99	*p_hv_pages_gva = hv_pages_gva;
100	return hv;
101}
102
103int enable_vp_assist(uint64_t vp_assist_pa, void *vp_assist)
104{
105	uint64_t val = (vp_assist_pa & HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_MASK) |
106		HV_X64_MSR_VP_ASSIST_PAGE_ENABLE;
107
108	wrmsr(HV_X64_MSR_VP_ASSIST_PAGE, val);
109
110	current_vp_assist = vp_assist;
111
112	return 0;
113}