xref: /openbmc/linux/arch/x86/kvm/svm/svm_onhyperv.h (revision 887069f4)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * KVM L1 hypervisor optimizations on Hyper-V for SVM.
4  */
5 
6 #ifndef __ARCH_X86_KVM_SVM_ONHYPERV_H__
7 #define __ARCH_X86_KVM_SVM_ONHYPERV_H__
8 
9 #if IS_ENABLED(CONFIG_HYPERV)
10 #include <asm/mshyperv.h>
11 
12 #include "hyperv.h"
13 #include "kvm_onhyperv.h"
14 
15 static struct kvm_x86_ops svm_x86_ops;
16 
17 /*
18  * Hyper-V uses the software reserved 32 bytes in VMCB
19  * control area to expose SVM enlightenments to guests.
20  */
21 struct hv_enlightenments {
22 	struct __packed hv_enlightenments_control {
23 		u32 nested_flush_hypercall:1;
24 		u32 msr_bitmap:1;
25 		u32 enlightened_npt_tlb: 1;
26 		u32 reserved:29;
27 	} __packed hv_enlightenments_control;
28 	u32 hv_vp_id;
29 	u64 hv_vm_id;
30 	u64 partition_assist_page;
31 	u64 reserved;
32 } __packed;
33 
34 /*
35  * Hyper-V uses the software reserved clean bit in VMCB
36  */
37 #define VMCB_HV_NESTED_ENLIGHTENMENTS VMCB_SW
38 
39 int svm_hv_enable_direct_tlbflush(struct kvm_vcpu *vcpu);
40 
41 static inline void svm_hv_init_vmcb(struct vmcb *vmcb)
42 {
43 	struct hv_enlightenments *hve =
44 		(struct hv_enlightenments *)vmcb->control.reserved_sw;
45 
46 	if (npt_enabled &&
47 	    ms_hyperv.nested_features & HV_X64_NESTED_ENLIGHTENED_TLB)
48 		hve->hv_enlightenments_control.enlightened_npt_tlb = 1;
49 }
50 
51 static inline void svm_hv_hardware_setup(void)
52 {
53 	if (npt_enabled &&
54 	    ms_hyperv.nested_features & HV_X64_NESTED_ENLIGHTENED_TLB) {
55 		pr_info("kvm: Hyper-V enlightened NPT TLB flush enabled\n");
56 		svm_x86_ops.tlb_remote_flush = hv_remote_flush_tlb;
57 		svm_x86_ops.tlb_remote_flush_with_range =
58 				hv_remote_flush_tlb_with_range;
59 	}
60 
61 	if (ms_hyperv.nested_features & HV_X64_NESTED_DIRECT_FLUSH) {
62 		int cpu;
63 
64 		pr_info("kvm: Hyper-V Direct TLB Flush enabled\n");
65 		for_each_online_cpu(cpu) {
66 			struct hv_vp_assist_page *vp_ap =
67 				hv_get_vp_assist_page(cpu);
68 
69 			if (!vp_ap)
70 				continue;
71 
72 			vp_ap->nested_control.features.directhypercall = 1;
73 		}
74 		svm_x86_ops.enable_direct_tlbflush =
75 				svm_hv_enable_direct_tlbflush;
76 	}
77 }
78 
79 static inline void svm_hv_vmcb_dirty_nested_enlightenments(
80 		struct kvm_vcpu *vcpu)
81 {
82 	struct vmcb *vmcb = to_svm(vcpu)->vmcb;
83 	struct hv_enlightenments *hve =
84 		(struct hv_enlightenments *)vmcb->control.reserved_sw;
85 
86 	/*
87 	 * vmcb can be NULL if called during early vcpu init.
88 	 * And its okay not to mark vmcb dirty during vcpu init
89 	 * as we mark it dirty unconditionally towards end of vcpu
90 	 * init phase.
91 	 */
92 	if (vmcb_is_clean(vmcb, VMCB_HV_NESTED_ENLIGHTENMENTS) &&
93 	    hve->hv_enlightenments_control.msr_bitmap)
94 		vmcb_mark_dirty(vmcb, VMCB_HV_NESTED_ENLIGHTENMENTS);
95 }
96 
97 static inline void svm_hv_update_vp_id(struct vmcb *vmcb,
98 		struct kvm_vcpu *vcpu)
99 {
100 	struct hv_enlightenments *hve =
101 		(struct hv_enlightenments *)vmcb->control.reserved_sw;
102 	u32 vp_index = kvm_hv_get_vpindex(vcpu);
103 
104 	if (hve->hv_vp_id != vp_index) {
105 		hve->hv_vp_id = vp_index;
106 		vmcb_mark_dirty(vmcb, VMCB_HV_NESTED_ENLIGHTENMENTS);
107 	}
108 }
109 #else
110 
111 static inline void svm_hv_init_vmcb(struct vmcb *vmcb)
112 {
113 }
114 
115 static inline void svm_hv_hardware_setup(void)
116 {
117 }
118 
119 static inline void svm_hv_vmcb_dirty_nested_enlightenments(
120 		struct kvm_vcpu *vcpu)
121 {
122 }
123 
124 static inline void svm_hv_update_vp_id(struct vmcb *vmcb,
125 		struct kvm_vcpu *vcpu)
126 {
127 }
128 #endif /* CONFIG_HYPERV */
129 
130 #endif /* __ARCH_X86_KVM_SVM_ONHYPERV_H__ */
131