xref: /openbmc/linux/arch/x86/kvm/svm/svm_onhyperv.h (revision 56edb6c2)
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 	if (ms_hyperv.nested_features & HV_X64_NESTED_MSR_BITMAP)
51 		hve->hv_enlightenments_control.msr_bitmap = 1;
52 }
53 
54 static inline void svm_hv_hardware_setup(void)
55 {
56 	if (npt_enabled &&
57 	    ms_hyperv.nested_features & HV_X64_NESTED_ENLIGHTENED_TLB) {
58 		pr_info("kvm: Hyper-V enlightened NPT TLB flush enabled\n");
59 		svm_x86_ops.tlb_remote_flush = hv_remote_flush_tlb;
60 		svm_x86_ops.tlb_remote_flush_with_range =
61 				hv_remote_flush_tlb_with_range;
62 	}
63 
64 	if (ms_hyperv.nested_features & HV_X64_NESTED_DIRECT_FLUSH) {
65 		int cpu;
66 
67 		pr_info("kvm: Hyper-V Direct TLB Flush enabled\n");
68 		for_each_online_cpu(cpu) {
69 			struct hv_vp_assist_page *vp_ap =
70 				hv_get_vp_assist_page(cpu);
71 
72 			if (!vp_ap)
73 				continue;
74 
75 			vp_ap->nested_control.features.directhypercall = 1;
76 		}
77 		svm_x86_ops.enable_direct_tlbflush =
78 				svm_hv_enable_direct_tlbflush;
79 	}
80 }
81 
82 static inline void svm_hv_vmcb_dirty_nested_enlightenments(
83 		struct kvm_vcpu *vcpu)
84 {
85 	struct vmcb *vmcb = to_svm(vcpu)->vmcb;
86 	struct hv_enlightenments *hve =
87 		(struct hv_enlightenments *)vmcb->control.reserved_sw;
88 
89 	if (hve->hv_enlightenments_control.msr_bitmap)
90 		vmcb_mark_dirty(vmcb, VMCB_HV_NESTED_ENLIGHTENMENTS);
91 }
92 
93 static inline void svm_hv_update_vp_id(struct vmcb *vmcb,
94 		struct kvm_vcpu *vcpu)
95 {
96 	struct hv_enlightenments *hve =
97 		(struct hv_enlightenments *)vmcb->control.reserved_sw;
98 	u32 vp_index = kvm_hv_get_vpindex(vcpu);
99 
100 	if (hve->hv_vp_id != vp_index) {
101 		hve->hv_vp_id = vp_index;
102 		vmcb_mark_dirty(vmcb, VMCB_HV_NESTED_ENLIGHTENMENTS);
103 	}
104 }
105 #else
106 
107 static inline void svm_hv_init_vmcb(struct vmcb *vmcb)
108 {
109 }
110 
111 static inline void svm_hv_hardware_setup(void)
112 {
113 }
114 
115 static inline void svm_hv_vmcb_dirty_nested_enlightenments(
116 		struct kvm_vcpu *vcpu)
117 {
118 }
119 
120 static inline void svm_hv_update_vp_id(struct vmcb *vmcb,
121 		struct kvm_vcpu *vcpu)
122 {
123 }
124 #endif /* CONFIG_HYPERV */
125 
126 #endif /* __ARCH_X86_KVM_SVM_ONHYPERV_H__ */
127