patches/kernel/0014-KVM-x86-emulator-smm-use-smram-structs-in-the-common.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Maxim Levitsky <mlevitsk@redhat.com>
   3 Date: Wed, 3 Aug 2022 18:50:06 +0300
   4 Subject: [PATCH] KVM: x86: emulator/smm: use smram structs in the common code
   5
   6 Switch from using a raw array to 'union kvm_smram'.
   7
   8 Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
   9 Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
  10 ---
  11  arch/x86/include/asm/kvm_host.h |  5 +++--
  12  arch/x86/kvm/emulate.c          | 12 +++++++-----
  13  arch/x86/kvm/kvm_emulate.h      |  3 ++-
  14  arch/x86/kvm/svm/svm.c          |  8 ++++++--
  15  arch/x86/kvm/vmx/vmx.c          |  4 ++--
  16  arch/x86/kvm/x86.c              | 16 ++++++++--------
  17  6 files changed, 28 insertions(+), 20 deletions(-)
  18
  19 diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
  20 index 9217bd6cf0d1..65e05d56602f 100644
  21 --- a/arch/x86/include/asm/kvm_host.h
  22 +++ b/arch/x86/include/asm/kvm_host.h
  23 @@ -202,6 +202,7 @@ typedef enum exit_fastpath_completion fastpath_t;
  24
  25  struct x86_emulate_ctxt;
  26  struct x86_exception;
  27 +union kvm_smram;
  28  enum x86_intercept;
  29  enum x86_intercept_stage;
  30
  31 @@ -1550,8 +1551,8 @@ struct kvm_x86_ops {
  32         void (*setup_mce)(struct kvm_vcpu *vcpu);
  33
  34         int (*smi_allowed)(struct kvm_vcpu *vcpu, bool for_injection);
  35 -       int (*enter_smm)(struct kvm_vcpu *vcpu, char *smstate);
  36 -       int (*leave_smm)(struct kvm_vcpu *vcpu, const char *smstate);
  37 +       int (*enter_smm)(struct kvm_vcpu *vcpu, union kvm_smram *smram);
  38 +       int (*leave_smm)(struct kvm_vcpu *vcpu, const union kvm_smram *smram);
  39         void (*enable_smi_window)(struct kvm_vcpu *vcpu);
  40
  41         int (*mem_enc_ioctl)(struct kvm *kvm, void __user *argp);
  42 diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
  43 index b16353468b61..05c4d9dfbced 100644
  44 --- a/arch/x86/kvm/emulate.c
  45 +++ b/arch/x86/kvm/emulate.c
  46 @@ -2582,16 +2582,18 @@ static int rsm_load_state_64(struct x86_emulate_ctxt *ctxt,
  47  static int em_rsm(struct x86_emulate_ctxt *ctxt)
  48  {
  49         unsigned long cr0, cr4, efer;
  50 -       char buf[512];
  51 +       const union kvm_smram smram;
  52         u64 smbase;
  53         int ret;
  54
  55 +       BUILD_BUG_ON(sizeof(smram) != 512);
  56 +
  57         if ((ctxt->ops->get_hflags(ctxt) & X86EMUL_SMM_MASK) == 0)
  58                 return emulate_ud(ctxt);
  59
  60         smbase = ctxt->ops->get_smbase(ctxt);
  61
  62 -       ret = ctxt->ops->read_phys(ctxt, smbase + 0xfe00, buf, sizeof(buf));
  63 +       ret = ctxt->ops->read_phys(ctxt, smbase + 0xfe00, (void *)&smram, sizeof(smram));
  64         if (ret != X86EMUL_CONTINUE)
  65                 return X86EMUL_UNHANDLEABLE;
  66
  67 @@ -2641,15 +2643,15 @@ static int em_rsm(struct x86_emulate_ctxt *ctxt)
  68          * state (e.g. enter guest mode) before loading state from the SMM
  69          * state-save area.
  70          */
  71 -       if (ctxt->ops->leave_smm(ctxt, buf))
  72 +       if (ctxt->ops->leave_smm(ctxt, &smram))
  73                 goto emulate_shutdown;
  74
  75  #ifdef CONFIG_X86_64
  76         if (emulator_has_longmode(ctxt))
  77 -               ret = rsm_load_state_64(ctxt, buf);
  78 +               ret = rsm_load_state_64(ctxt, (const char *)&smram);
  79         else
  80  #endif
  81 -               ret = rsm_load_state_32(ctxt, buf);
  82 +               ret = rsm_load_state_32(ctxt, (const char *)&smram);
  83
  84         if (ret != X86EMUL_CONTINUE)
  85                 goto emulate_shutdown;
  86 diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h
  87 index 0eb13204bbc2..04ac0cef8b57 100644
  88 --- a/arch/x86/kvm/kvm_emulate.h
  89 +++ b/arch/x86/kvm/kvm_emulate.h
  90 @@ -19,6 +19,7 @@
  91  struct x86_emulate_ctxt;
  92  enum x86_intercept;
  93  enum x86_intercept_stage;
  94 +union kvm_smram;
  95
  96  struct x86_exception {
  97         u8 vector;
  98 @@ -235,7 +236,7 @@ struct x86_emulate_ops {
  99
 100         unsigned (*get_hflags)(struct x86_emulate_ctxt *ctxt);
 101         void (*exiting_smm)(struct x86_emulate_ctxt *ctxt);
 102 -       int (*leave_smm)(struct x86_emulate_ctxt *ctxt, const char *smstate);
 103 +       int (*leave_smm)(struct x86_emulate_ctxt *ctxt, const union kvm_smram *smram);
 104         void (*triple_fault)(struct x86_emulate_ctxt *ctxt);
 105         int (*set_xcr)(struct x86_emulate_ctxt *ctxt, u32 index, u64 xcr);
 106  };
 107 diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
 108 index 44bbf25dfeb9..68c9a771b457 100644
 109 --- a/arch/x86/kvm/svm/svm.c
 110 +++ b/arch/x86/kvm/svm/svm.c
 111 @@ -4299,12 +4299,14 @@ static int svm_smi_allowed(struct kvm_vcpu *vcpu, bool for_injection)
 112         return 1;
 113  }
 114
 115 -static int svm_enter_smm(struct kvm_vcpu *vcpu, char *smstate)
 116 +static int svm_enter_smm(struct kvm_vcpu *vcpu, union kvm_smram *smram)
 117  {
 118         struct vcpu_svm *svm = to_svm(vcpu);
 119         struct kvm_host_map map_save;
 120         int ret;
 121
 122 +       char *smstate = (char *)smram;
 123 +
 124         if (!is_guest_mode(vcpu))
 125                 return 0;
 126
 127 @@ -4346,7 +4348,7 @@ static int svm_enter_smm(struct kvm_vcpu *vcpu, char *smstate)
 128         return 0;
 129  }
 130
 131 -static int svm_leave_smm(struct kvm_vcpu *vcpu, const char *smstate)
 132 +static int svm_leave_smm(struct kvm_vcpu *vcpu, const union kvm_smram *smram)
 133  {
 134         struct vcpu_svm *svm = to_svm(vcpu);
 135         struct kvm_host_map map, map_save;
 136 @@ -4354,6 +4356,8 @@ static int svm_leave_smm(struct kvm_vcpu *vcpu, const char *smstate)
 137         struct vmcb *vmcb12;
 138         int ret;
 139
 140 +       const char *smstate = (const char *)smram;
 141 +
 142         if (!guest_cpuid_has(vcpu, X86_FEATURE_LM))
 143                 return 0;
 144
 145 diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
 146 index be7c19374fdd..26803e4d64c6 100644
 147 --- a/arch/x86/kvm/vmx/vmx.c
 148 +++ b/arch/x86/kvm/vmx/vmx.c
 149 @@ -7725,7 +7725,7 @@ static int vmx_smi_allowed(struct kvm_vcpu *vcpu, bool for_injection)
 150         return !is_smm(vcpu);
 151  }
 152
 153 -static int vmx_enter_smm(struct kvm_vcpu *vcpu, char *smstate)
 154 +static int vmx_enter_smm(struct kvm_vcpu *vcpu, union kvm_smram *smram)
 155  {
 156         struct vcpu_vmx *vmx = to_vmx(vcpu);
 157
 158 @@ -7739,7 +7739,7 @@ static int vmx_enter_smm(struct kvm_vcpu *vcpu, char *smstate)
 159         return 0;
 160  }
 161
 162 -static int vmx_leave_smm(struct kvm_vcpu *vcpu, const char *smstate)
 163 +static int vmx_leave_smm(struct kvm_vcpu *vcpu, const union kvm_smram *smram)
 164  {
 165         struct vcpu_vmx *vmx = to_vmx(vcpu);
 166         int ret;
 167 diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
 168 index 1b6f92546f3d..e48e7b7b8dde 100644
 169 --- a/arch/x86/kvm/x86.c
 170 +++ b/arch/x86/kvm/x86.c
 171 @@ -7853,9 +7853,9 @@ static void emulator_exiting_smm(struct x86_emulate_ctxt *ctxt)
 172  }
 173
 174  static int emulator_leave_smm(struct x86_emulate_ctxt *ctxt,
 175 -                                 const char *smstate)
 176 +                             const union kvm_smram *smram)
 177  {
 178 -       return static_call(kvm_x86_leave_smm)(emul_to_vcpu(ctxt), smstate);
 179 +       return static_call(kvm_x86_leave_smm)(emul_to_vcpu(ctxt), smram);
 180  }
 181
 182  static void emulator_triple_fault(struct x86_emulate_ctxt *ctxt)
 183 @@ -9764,25 +9764,25 @@ static void enter_smm(struct kvm_vcpu *vcpu)
 184         struct kvm_segment cs, ds;
 185         struct desc_ptr dt;
 186         unsigned long cr0;
 187 -       char buf[512];
 188 +       union kvm_smram smram;
 189
 190 -       memset(buf, 0, 512);
 191 +       memset(smram.bytes, 0, sizeof(smram.bytes));
 192  #ifdef CONFIG_X86_64
 193         if (guest_cpuid_has(vcpu, X86_FEATURE_LM))
 194 -               enter_smm_save_state_64(vcpu, buf);
 195 +               enter_smm_save_state_64(vcpu, (char *)&smram);
 196         else
 197  #endif
 198 -               enter_smm_save_state_32(vcpu, buf);
 199 +               enter_smm_save_state_32(vcpu, (char *)&smram);
 200
 201         /*
 202          * Give enter_smm() a chance to make ISA-specific changes to the vCPU
 203          * state (e.g. leave guest mode) after we've saved the state into the
 204          * SMM state-save area.
 205          */
 206 -       static_call(kvm_x86_enter_smm)(vcpu, buf);
 207 +       static_call(kvm_x86_enter_smm)(vcpu, &smram);
 208
 209         kvm_smm_changed(vcpu, true);
 210 -       kvm_vcpu_write_guest(vcpu, vcpu->arch.smbase + 0xfe00, buf, sizeof(buf));
 211 +       kvm_vcpu_write_guest(vcpu, vcpu->arch.smbase + 0xfe00, &smram, sizeof(smram));
 212
 213         if (static_call(kvm_x86_get_nmi_mask)(vcpu))
 214                 vcpu->arch.hflags |= HF_SMM_INSIDE_NMI_MASK;