KVM: vmx: Unavailable DR4/5 is checked before CPL

[mirror_ubuntu-bionic-kernel.git] / arch / x86 / kvm / x86.c

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 1ab7361594d5f263192fffd7ad30327dacc9b589..7a9cb56407bd62fbac8e4af40aeb9f5bfe0fd71a 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -455,6 +455,16 @@ bool kvm_require_cpl(struct kvm_vcpu *vcpu, int required_cpl)
 }
 EXPORT_SYMBOL_GPL(kvm_require_cpl);
 
+bool kvm_require_dr(struct kvm_vcpu *vcpu, int dr)
+{
+       if ((dr != 4 && dr != 5) || !kvm_read_cr4_bits(vcpu, X86_CR4_DE))
+               return true;
+
+       kvm_queue_exception(vcpu, UD_VECTOR);
+       return false;
+}
+EXPORT_SYMBOL_GPL(kvm_require_dr);
+
 /*
  * This function will be used to read from the physical memory of the currently
  * running guest. The difference to kvm_read_guest_page is that this function
@@ -811,8 +821,6 @@ static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
                        vcpu->arch.eff_db[dr] = val;
                break;
        case 4:
-               if (kvm_read_cr4_bits(vcpu, X86_CR4_DE))
-                       return 1; /* #UD */
                /* fall through */
        case 6:
                if (val & 0xffffffff00000000ULL)
@@ -821,8 +829,6 @@ static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
                kvm_update_dr6(vcpu);
                break;
        case 5:
-               if (kvm_read_cr4_bits(vcpu, X86_CR4_DE))
-                       return 1; /* #UD */
                /* fall through */
        default: /* 7 */
                if (val & 0xffffffff00000000ULL)
@@ -837,27 +843,21 @@ static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
 
 int kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
 {
-       int res;
-
-       res = __kvm_set_dr(vcpu, dr, val);
-       if (res > 0)
-               kvm_queue_exception(vcpu, UD_VECTOR);
-       else if (res < 0)
+       if (__kvm_set_dr(vcpu, dr, val)) {
                kvm_inject_gp(vcpu, 0);
-
-       return res;
+               return 1;
+       }
+       return 0;
 }
 EXPORT_SYMBOL_GPL(kvm_set_dr);
 
-static int _kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val)
+int kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val)
 {
        switch (dr) {
        case 0 ... 3:
                *val = vcpu->arch.db[dr];
                break;
        case 4:
-               if (kvm_read_cr4_bits(vcpu, X86_CR4_DE))
-                       return 1;
                /* fall through */
        case 6:
                if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
@@ -866,23 +866,11 @@ static int _kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val)
                        *val = kvm_x86_ops->get_dr6(vcpu);
                break;
        case 5:
-               if (kvm_read_cr4_bits(vcpu, X86_CR4_DE))
-                       return 1;
                /* fall through */
        default: /* 7 */
                *val = vcpu->arch.dr7;
                break;
        }
-
-       return 0;
-}
-
-int kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val)
-{
-       if (_kvm_get_dr(vcpu, dr, val)) {
-               kvm_queue_exception(vcpu, UD_VECTOR);
-               return 1;
-       }
        return 0;
 }
 EXPORT_SYMBOL_GPL(kvm_get_dr);
@@ -3106,7 +3094,7 @@ static void kvm_vcpu_ioctl_x86_get_debugregs(struct kvm_vcpu *vcpu,
        unsigned long val;
 
        memcpy(dbgregs->db, vcpu->arch.db, sizeof(vcpu->arch.db));
-       _kvm_get_dr(vcpu, 6, &val);
+       kvm_get_dr(vcpu, 6, &val);
        dbgregs->dr6 = val;
        dbgregs->dr7 = vcpu->arch.dr7;
        dbgregs->flags = 0;
@@ -4667,7 +4655,7 @@ static void emulator_wbinvd(struct x86_emulate_ctxt *ctxt)
 
 int emulator_get_dr(struct x86_emulate_ctxt *ctxt, int dr, unsigned long *dest)
 {
-       return _kvm_get_dr(emul_to_vcpu(ctxt), dr, dest);
+       return kvm_get_dr(emul_to_vcpu(ctxt), dr, dest);
 }
 
 int emulator_set_dr(struct x86_emulate_ctxt *ctxt, int dr, unsigned long value)