patches/kernel/0017-KVM-x86-SVM-use-smram-structs.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Maxim Levitsky <mlevitsk@redhat.com>
   3 Date: Wed, 3 Aug 2022 18:50:09 +0300
   4 Subject: [PATCH] KVM: x86: SVM: use smram structs
   5
   6 This removes the last user of put_smstate/GET_SMSTATE so
   7 remove these functions as well.
   8
   9 Also add a sanity check that we don't attempt to enter the SMM
  10 on non long mode capable guest CPU with a running nested guest.
  11
  12 Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
  13 Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
  14 ---
  15  arch/x86/include/asm/kvm_host.h |  6 ------
  16  arch/x86/kvm/svm/svm.c          | 21 ++++++---------------
  17  2 files changed, 6 insertions(+), 21 deletions(-)
  18
  19 diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
  20 index 65e05d56602f..33c14d167de2 100644
  21 --- a/arch/x86/include/asm/kvm_host.h
  22 +++ b/arch/x86/include/asm/kvm_host.h
  23 @@ -2042,12 +2042,6 @@ static inline int kvm_cpu_get_apicid(int mps_cpu)
  24  #endif
  25  }
  26
  27 -#define put_smstate(type, buf, offset, val)                      \
  28 -       *(type *)((buf) + (offset) - 0x7e00) = val
  29 -
  30 -#define GET_SMSTATE(type, buf, offset)         \
  31 -       (*(type *)((buf) + (offset) - 0x7e00))
  32 -
  33  int kvm_cpu_dirty_log_size(void);
  34
  35  int memslot_rmap_alloc(struct kvm_memory_slot *slot, unsigned long npages);
  36 diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
  37 index 68c9a771b457..23ad430207c5 100644
  38 --- a/arch/x86/kvm/svm/svm.c
  39 +++ b/arch/x86/kvm/svm/svm.c
  40 @@ -4305,15 +4305,11 @@ static int svm_enter_smm(struct kvm_vcpu *vcpu, union kvm_smram *smram)
  41         struct kvm_host_map map_save;
  42         int ret;
  43
  44 -       char *smstate = (char *)smram;
  45 -
  46         if (!is_guest_mode(vcpu))
  47                 return 0;
  48
  49 -       /* FED8h - SVM Guest */
  50 -       put_smstate(u64, smstate, 0x7ed8, 1);
  51 -       /* FEE0h - SVM Guest VMCB Physical Address */
  52 -       put_smstate(u64, smstate, 0x7ee0, svm->nested.vmcb12_gpa);
  53 +       smram->smram64.svm_guest_flag = 1;
  54 +       smram->smram64.svm_guest_vmcb_gpa = svm->nested.vmcb12_gpa;
  55
  56         svm->vmcb->save.rax = vcpu->arch.regs[VCPU_REGS_RAX];
  57         svm->vmcb->save.rsp = vcpu->arch.regs[VCPU_REGS_RSP];
  58 @@ -4352,28 +4348,23 @@ static int svm_leave_smm(struct kvm_vcpu *vcpu, const union kvm_smram *smram)
  59  {
  60         struct vcpu_svm *svm = to_svm(vcpu);
  61         struct kvm_host_map map, map_save;
  62 -       u64 saved_efer, vmcb12_gpa;
  63         struct vmcb *vmcb12;
  64         int ret;
  65
  66 -       const char *smstate = (const char *)smram;
  67 -
  68         if (!guest_cpuid_has(vcpu, X86_FEATURE_LM))
  69                 return 0;
  70
  71         /* Non-zero if SMI arrived while vCPU was in guest mode. */
  72 -       if (!GET_SMSTATE(u64, smstate, 0x7ed8))
  73 +       if (!smram->smram64.svm_guest_flag)
  74                 return 0;
  75
  76         if (!guest_cpuid_has(vcpu, X86_FEATURE_SVM))
  77                 return 1;
  78
  79 -       saved_efer = GET_SMSTATE(u64, smstate, 0x7ed0);
  80 -       if (!(saved_efer & EFER_SVME))
  81 +       if (!(smram->smram64.efer & EFER_SVME))
  82                 return 1;
  83
  84 -       vmcb12_gpa = GET_SMSTATE(u64, smstate, 0x7ee0);
  85 -       if (kvm_vcpu_map(vcpu, gpa_to_gfn(vmcb12_gpa), &map) == -EINVAL)
  86 +       if (kvm_vcpu_map(vcpu, gpa_to_gfn(smram->smram64.svm_guest_vmcb_gpa), &map) == -EINVAL)
  87                 return 1;
  88
  89         ret = 1;
  90 @@ -4399,7 +4390,7 @@ static int svm_leave_smm(struct kvm_vcpu *vcpu, const union kvm_smram *smram)
  91         vmcb12 = map.hva;
  92         nested_copy_vmcb_control_to_cache(svm, &vmcb12->control);
  93         nested_copy_vmcb_save_to_cache(svm, &vmcb12->save);
  94 -       ret = enter_svm_guest_mode(vcpu, vmcb12_gpa, vmcb12, false);
  95 +       ret = enter_svm_guest_mode(vcpu, smram->smram64.svm_guest_vmcb_gpa, vmcb12, false);
  96
  97         if (ret)
  98                 goto unmap_save;