arch/x86/include/asm/kvm_para.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_X86_KVM_PARA_H
   3 #define _ASM_X86_KVM_PARA_H
   4
   5 #include <asm/processor.h>
   6 #include <asm/alternative.h>
   7 #include <linux/interrupt.h>
   8 #include <uapi/asm/kvm_para.h>
   9
  10 #include <asm/tdx.h>
  11
  12 #ifdef CONFIG_KVM_GUEST
  13 bool kvm_check_and_clear_guest_paused(void);
  14 #else
  15 static inline bool kvm_check_and_clear_guest_paused(void)
  16 {
  17         return false;
  18 }
  19 #endif /* CONFIG_KVM_GUEST */
  20
  21 #define KVM_HYPERCALL \
  22         ALTERNATIVE("vmcall", "vmmcall", X86_FEATURE_VMMCALL)
  23
  24 /* For KVM hypercalls, a three-byte sequence of either the vmcall or the vmmcall
  25  * instruction.  The hypervisor may replace it with something else but only the
  26  * instructions are guaranteed to be supported.
  27  *
  28  * Up to four arguments may be passed in rbx, rcx, rdx, and rsi respectively.
  29  * The hypercall number should be placed in rax and the return value will be
  30  * placed in rax.  No other registers will be clobbered unless explicitly
  31  * noted by the particular hypercall.
  32  */
  33
  34 static inline long kvm_hypercall0(unsigned int nr)
  35 {
  36         long ret;
  37
  38         if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST))
  39                 return tdx_kvm_hypercall(nr, 0, 0, 0, 0);
  40
  41         asm volatile(KVM_HYPERCALL
  42                      : "=a"(ret)
  43                      : "a"(nr)
  44                      : "memory");
  45         return ret;
  46 }
  47
  48 static inline long kvm_hypercall1(unsigned int nr, unsigned long p1)
  49 {
  50         long ret;
  51
  52         if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST))
  53                 return tdx_kvm_hypercall(nr, p1, 0, 0, 0);
  54
  55         asm volatile(KVM_HYPERCALL
  56                      : "=a"(ret)
  57                      : "a"(nr), "b"(p1)
  58                      : "memory");
  59         return ret;
  60 }
  61
  62 static inline long kvm_hypercall2(unsigned int nr, unsigned long p1,
  63                                   unsigned long p2)
  64 {
  65         long ret;
  66
  67         if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST))
  68                 return tdx_kvm_hypercall(nr, p1, p2, 0, 0);
  69
  70         asm volatile(KVM_HYPERCALL
  71                      : "=a"(ret)
  72                      : "a"(nr), "b"(p1), "c"(p2)
  73                      : "memory");
  74         return ret;
  75 }
  76
  77 static inline long kvm_hypercall3(unsigned int nr, unsigned long p1,
  78                                   unsigned long p2, unsigned long p3)
  79 {
  80         long ret;
  81
  82         if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST))
  83                 return tdx_kvm_hypercall(nr, p1, p2, p3, 0);
  84
  85         asm volatile(KVM_HYPERCALL
  86                      : "=a"(ret)
  87                      : "a"(nr), "b"(p1), "c"(p2), "d"(p3)
  88                      : "memory");
  89         return ret;
  90 }
  91
  92 static inline long kvm_hypercall4(unsigned int nr, unsigned long p1,
  93                                   unsigned long p2, unsigned long p3,
  94                                   unsigned long p4)
  95 {
  96         long ret;
  97
  98         if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST))
  99                 return tdx_kvm_hypercall(nr, p1, p2, p3, p4);
 100
 101         asm volatile(KVM_HYPERCALL
 102                      : "=a"(ret)
 103                      : "a"(nr), "b"(p1), "c"(p2), "d"(p3), "S"(p4)
 104                      : "memory");
 105         return ret;
 106 }
 107
 108 static inline long kvm_sev_hypercall3(unsigned int nr, unsigned long p1,
 109                                       unsigned long p2, unsigned long p3)
 110 {
 111         long ret;
 112
 113         asm volatile("vmmcall"
 114                      : "=a"(ret)
 115                      : "a"(nr), "b"(p1), "c"(p2), "d"(p3)
 116                      : "memory");
 117         return ret;
 118 }
 119
 120 #ifdef CONFIG_KVM_GUEST
 121 void kvmclock_init(void);
 122 void kvmclock_disable(void);
 123 bool kvm_para_available(void);
 124 unsigned int kvm_arch_para_features(void);
 125 unsigned int kvm_arch_para_hints(void);
 126 void kvm_async_pf_task_wait_schedule(u32 token);
 127 void kvm_async_pf_task_wake(u32 token);
 128 u32 kvm_read_and_reset_apf_flags(void);
 129 bool __kvm_handle_async_pf(struct pt_regs *regs, u32 token);
 130
 131 DECLARE_STATIC_KEY_FALSE(kvm_async_pf_enabled);
 132
 133 static __always_inline bool kvm_handle_async_pf(struct pt_regs *regs, u32 token)
 134 {
 135         if (static_branch_unlikely(&kvm_async_pf_enabled))
 136                 return __kvm_handle_async_pf(regs, token);
 137         else
 138                 return false;
 139 }
 140
 141 #ifdef CONFIG_PARAVIRT_SPINLOCKS
 142 void __init kvm_spinlock_init(void);
 143 #else /* !CONFIG_PARAVIRT_SPINLOCKS */
 144 static inline void kvm_spinlock_init(void)
 145 {
 146 }
 147 #endif /* CONFIG_PARAVIRT_SPINLOCKS */
 148
 149 #else /* CONFIG_KVM_GUEST */
 150 #define kvm_async_pf_task_wait_schedule(T) do {} while(0)
 151 #define kvm_async_pf_task_wake(T) do {} while(0)
 152
 153 static inline bool kvm_para_available(void)
 154 {
 155         return false;
 156 }
 157
 158 static inline unsigned int kvm_arch_para_features(void)
 159 {
 160         return 0;
 161 }
 162
 163 static inline unsigned int kvm_arch_para_hints(void)
 164 {
 165         return 0;
 166 }
 167
 168 static inline u32 kvm_read_and_reset_apf_flags(void)
 169 {
 170         return 0;
 171 }
 172
 173 static __always_inline bool kvm_handle_async_pf(struct pt_regs *regs, u32 token)
 174 {
 175         return false;
 176 }
 177 #endif
 178
 179 #endif /* _ASM_X86_KVM_PARA_H */