xref: /linux/arch/x86/kvm/kvm_cache_regs.h (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef ASM_KVM_CACHE_REGS_H
3 #define ASM_KVM_CACHE_REGS_H
4 
5 #include <linux/kvm_host.h>
6 
7 #define KVM_POSSIBLE_CR0_GUEST_BITS	(X86_CR0_TS | X86_CR0_WP)
8 #define KVM_POSSIBLE_CR4_GUEST_BITS				  \
9 	(X86_CR4_PVI | X86_CR4_DE | X86_CR4_PCE | X86_CR4_OSFXSR  \
10 	 | X86_CR4_OSXMMEXCPT | X86_CR4_PGE | X86_CR4_TSD | X86_CR4_FSGSBASE)
11 
12 #define X86_CR0_PDPTR_BITS    (X86_CR0_CD | X86_CR0_NW | X86_CR0_PG)
13 #define X86_CR4_TLBFLUSH_BITS (X86_CR4_PGE | X86_CR4_PCIDE | X86_CR4_PAE | X86_CR4_SMEP)
14 #define X86_CR4_PDPTR_BITS    (X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PAE | X86_CR4_SMEP)
15 
16 static_assert(!(KVM_POSSIBLE_CR0_GUEST_BITS & X86_CR0_PDPTR_BITS));
17 
18 #define BUILD_KVM_GPR_ACCESSORS(lname, uname)				      \
19 static __always_inline unsigned long kvm_##lname##_read(struct kvm_vcpu *vcpu)\
20 {									      \
21 	return vcpu->arch.regs[VCPU_REGS_##uname];			      \
22 }									      \
23 static __always_inline void kvm_##lname##_write(struct kvm_vcpu *vcpu,	      \
24 						unsigned long val)	      \
25 {									      \
26 	vcpu->arch.regs[VCPU_REGS_##uname] = val;			      \
27 }
28 BUILD_KVM_GPR_ACCESSORS(rax, RAX)
29 BUILD_KVM_GPR_ACCESSORS(rbx, RBX)
30 BUILD_KVM_GPR_ACCESSORS(rcx, RCX)
31 BUILD_KVM_GPR_ACCESSORS(rdx, RDX)
32 BUILD_KVM_GPR_ACCESSORS(rbp, RBP)
33 BUILD_KVM_GPR_ACCESSORS(rsi, RSI)
34 BUILD_KVM_GPR_ACCESSORS(rdi, RDI)
35 #ifdef CONFIG_X86_64
36 BUILD_KVM_GPR_ACCESSORS(r8,  R8)
37 BUILD_KVM_GPR_ACCESSORS(r9,  R9)
38 BUILD_KVM_GPR_ACCESSORS(r10, R10)
39 BUILD_KVM_GPR_ACCESSORS(r11, R11)
40 BUILD_KVM_GPR_ACCESSORS(r12, R12)
41 BUILD_KVM_GPR_ACCESSORS(r13, R13)
42 BUILD_KVM_GPR_ACCESSORS(r14, R14)
43 BUILD_KVM_GPR_ACCESSORS(r15, R15)
44 #endif
45 
46 /*
47  * avail  dirty
48  * 0	  0	  register in VMCS/VMCB
49  * 0	  1	  *INVALID*
50  * 1	  0	  register in vcpu->arch
51  * 1	  1	  register in vcpu->arch, needs to be stored back
52  */
53 static inline bool kvm_register_is_available(struct kvm_vcpu *vcpu,
54 					     enum kvm_reg reg)
55 {
56 	return test_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
57 }
58 
59 static inline bool kvm_register_is_dirty(struct kvm_vcpu *vcpu,
60 					 enum kvm_reg reg)
61 {
62 	return test_bit(reg, (unsigned long *)&vcpu->arch.regs_dirty);
63 }
64 
65 static inline void kvm_register_mark_available(struct kvm_vcpu *vcpu,
66 					       enum kvm_reg reg)
67 {
68 	__set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
69 }
70 
71 static inline void kvm_register_mark_dirty(struct kvm_vcpu *vcpu,
72 					   enum kvm_reg reg)
73 {
74 	__set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
75 	__set_bit(reg, (unsigned long *)&vcpu->arch.regs_dirty);
76 }
77 
78 /*
79  * kvm_register_test_and_mark_available() is a special snowflake that uses an
80  * arch bitop directly to avoid the explicit instrumentation that comes with
81  * the generic bitops.  This allows code that cannot be instrumented (noinstr
82  * functions), e.g. the low level VM-Enter/VM-Exit paths, to cache registers.
83  */
84 static __always_inline bool kvm_register_test_and_mark_available(struct kvm_vcpu *vcpu,
85 								 enum kvm_reg reg)
86 {
87 	return arch___test_and_set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
88 }
89 
90 /*
91  * The "raw" register helpers are only for cases where the full 64 bits of a
92  * register are read/written irrespective of current vCPU mode.  In other words,
93  * odds are good you shouldn't be using the raw variants.
94  */
95 static inline unsigned long kvm_register_read_raw(struct kvm_vcpu *vcpu, int reg)
96 {
97 	if (WARN_ON_ONCE((unsigned int)reg >= NR_VCPU_REGS))
98 		return 0;
99 
100 	if (!kvm_register_is_available(vcpu, reg))
101 		kvm_x86_call(cache_reg)(vcpu, reg);
102 
103 	return vcpu->arch.regs[reg];
104 }
105 
106 static inline void kvm_register_write_raw(struct kvm_vcpu *vcpu, int reg,
107 					  unsigned long val)
108 {
109 	if (WARN_ON_ONCE((unsigned int)reg >= NR_VCPU_REGS))
110 		return;
111 
112 	vcpu->arch.regs[reg] = val;
113 	kvm_register_mark_dirty(vcpu, reg);
114 }
115 
116 static inline unsigned long kvm_rip_read(struct kvm_vcpu *vcpu)
117 {
118 	return kvm_register_read_raw(vcpu, VCPU_REGS_RIP);
119 }
120 
121 static inline void kvm_rip_write(struct kvm_vcpu *vcpu, unsigned long val)
122 {
123 	kvm_register_write_raw(vcpu, VCPU_REGS_RIP, val);
124 }
125 
126 static inline unsigned long kvm_rsp_read(struct kvm_vcpu *vcpu)
127 {
128 	return kvm_register_read_raw(vcpu, VCPU_REGS_RSP);
129 }
130 
131 static inline void kvm_rsp_write(struct kvm_vcpu *vcpu, unsigned long val)
132 {
133 	kvm_register_write_raw(vcpu, VCPU_REGS_RSP, val);
134 }
135 
136 static inline u64 kvm_pdptr_read(struct kvm_vcpu *vcpu, int index)
137 {
138 	might_sleep();  /* on svm */
139 
140 	if (!kvm_register_is_available(vcpu, VCPU_EXREG_PDPTR))
141 		kvm_x86_call(cache_reg)(vcpu, VCPU_EXREG_PDPTR);
142 
143 	return vcpu->arch.walk_mmu->pdptrs[index];
144 }
145 
146 static inline void kvm_pdptr_write(struct kvm_vcpu *vcpu, int index, u64 value)
147 {
148 	vcpu->arch.walk_mmu->pdptrs[index] = value;
149 }
150 
151 static inline ulong kvm_read_cr0_bits(struct kvm_vcpu *vcpu, ulong mask)
152 {
153 	ulong tmask = mask & KVM_POSSIBLE_CR0_GUEST_BITS;
154 	if ((tmask & vcpu->arch.cr0_guest_owned_bits) &&
155 	    !kvm_register_is_available(vcpu, VCPU_EXREG_CR0))
156 		kvm_x86_call(cache_reg)(vcpu, VCPU_EXREG_CR0);
157 	return vcpu->arch.cr0 & mask;
158 }
159 
160 static __always_inline bool kvm_is_cr0_bit_set(struct kvm_vcpu *vcpu,
161 					       unsigned long cr0_bit)
162 {
163 	BUILD_BUG_ON(!is_power_of_2(cr0_bit));
164 
165 	return !!kvm_read_cr0_bits(vcpu, cr0_bit);
166 }
167 
168 static inline ulong kvm_read_cr0(struct kvm_vcpu *vcpu)
169 {
170 	return kvm_read_cr0_bits(vcpu, ~0UL);
171 }
172 
173 static inline ulong kvm_read_cr4_bits(struct kvm_vcpu *vcpu, ulong mask)
174 {
175 	ulong tmask = mask & KVM_POSSIBLE_CR4_GUEST_BITS;
176 	if ((tmask & vcpu->arch.cr4_guest_owned_bits) &&
177 	    !kvm_register_is_available(vcpu, VCPU_EXREG_CR4))
178 		kvm_x86_call(cache_reg)(vcpu, VCPU_EXREG_CR4);
179 	return vcpu->arch.cr4 & mask;
180 }
181 
182 static __always_inline bool kvm_is_cr4_bit_set(struct kvm_vcpu *vcpu,
183 					       unsigned long cr4_bit)
184 {
185 	BUILD_BUG_ON(!is_power_of_2(cr4_bit));
186 
187 	return !!kvm_read_cr4_bits(vcpu, cr4_bit);
188 }
189 
190 static inline ulong kvm_read_cr3(struct kvm_vcpu *vcpu)
191 {
192 	if (!kvm_register_is_available(vcpu, VCPU_EXREG_CR3))
193 		kvm_x86_call(cache_reg)(vcpu, VCPU_EXREG_CR3);
194 	return vcpu->arch.cr3;
195 }
196 
197 static inline ulong kvm_read_cr4(struct kvm_vcpu *vcpu)
198 {
199 	return kvm_read_cr4_bits(vcpu, ~0UL);
200 }
201 
202 static inline u64 kvm_read_edx_eax(struct kvm_vcpu *vcpu)
203 {
204 	return (kvm_rax_read(vcpu) & -1u)
205 		| ((u64)(kvm_rdx_read(vcpu) & -1u) << 32);
206 }
207 
208 static inline void enter_guest_mode(struct kvm_vcpu *vcpu)
209 {
210 	vcpu->arch.hflags |= HF_GUEST_MASK;
211 	vcpu->stat.guest_mode = 1;
212 }
213 
214 static inline void leave_guest_mode(struct kvm_vcpu *vcpu)
215 {
216 	vcpu->arch.hflags &= ~HF_GUEST_MASK;
217 
218 	if (vcpu->arch.load_eoi_exitmap_pending) {
219 		vcpu->arch.load_eoi_exitmap_pending = false;
220 		kvm_make_request(KVM_REQ_LOAD_EOI_EXITMAP, vcpu);
221 	}
222 
223 	vcpu->stat.guest_mode = 0;
224 }
225 
226 static inline bool is_guest_mode(struct kvm_vcpu *vcpu)
227 {
228 	return vcpu->arch.hflags & HF_GUEST_MASK;
229 }
230 
231 #endif
232