Make (get|set)_dr() callback return error if it fails instead of
injecting exception behind emulator's back.
Signed-off-by: Gleb Natapov <gleb@xxxxxxxxxx>
---
arch/x86/kvm/emulate.c | 11 ++++++--
arch/x86/kvm/x86.c | 63 ++++++++++++++++++++++++++++-------------------
2 files changed, 45 insertions(+), 29 deletions(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index a876fc0..58ecb00 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -3180,9 +3180,14 @@ twobyte_insn:
goto done;
}
- ops->set_dr(c->modrm_reg,c->regs[c->modrm_rm] &
- ((ctxt->mode == X86EMUL_MODE_PROT64) ? ~0ULL : ~0U),
- ctxt->vcpu);
+ if (ops->set_dr(c->modrm_reg, c->regs[c->modrm_rm] &
+ ((ctxt->mode == X86EMUL_MODE_PROT64) ?
+ ~0ULL : ~0U), ctxt->vcpu) < 0) {
+ /* #UD condition is already handled by the code above */
+ kvm_inject_gp(ctxt->vcpu, 0);
+ goto done;
+ }
+
c->dst.type = OP_NONE; /* no writeback */
break;
case 0x30:
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f57d86a..f1aa678 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -573,7 +573,7 @@ unsigned long kvm_get_cr8(struct kvm_vcpu *vcpu)
}
EXPORT_SYMBOL_GPL(kvm_get_cr8);
-int kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
+static int _kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
{
switch (dr) {
case 0 ... 3:
@@ -582,29 +582,21 @@ 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)) {
- kvm_queue_exception(vcpu, UD_VECTOR);
- return 1;
- }
+ if (kvm_read_cr4_bits(vcpu, X86_CR4_DE))
+ return 1; /* #UD */
/* fall through */
case 6:
- if (val & 0xffffffff00000000ULL) {
- kvm_inject_gp(vcpu, 0);
- return 1;
- }
+ if (val & 0xffffffff00000000ULL)
+ return -1; /* #GP */
vcpu->arch.dr6 = (val & DR6_VOLATILE) | DR6_FIXED_1;
break;
case 5:
- if (kvm_read_cr4_bits(vcpu, X86_CR4_DE)) {
- kvm_queue_exception(vcpu, UD_VECTOR);
- return 1;
- }
+ if (kvm_read_cr4_bits(vcpu, X86_CR4_DE))
+ return 1; /* #UD */
/* fall through */
default: /* 7 */
- if (val & 0xffffffff00000000ULL) {
- kvm_inject_gp(vcpu, 0);
- return 1;
- }
+ if (val & 0xffffffff00000000ULL)
+ return -1; /* #GP */
vcpu->arch.dr7 = (val & DR7_VOLATILE) | DR7_FIXED_1;
if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)) {
kvm_x86_ops->set_dr7(vcpu, vcpu->arch.dr7);
@@ -615,28 +607,37 @@ int kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
return 0;
}
+
+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)
+ kvm_inject_gp(vcpu, 0);
+
+ return res;
+}
EXPORT_SYMBOL_GPL(kvm_set_dr);
-int kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val)
+static 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)) {
- kvm_queue_exception(vcpu, UD_VECTOR);
+ if (kvm_read_cr4_bits(vcpu, X86_CR4_DE))
return 1;
- }
/* fall through */
case 6:
*val = vcpu->arch.dr6;
break;
case 5:
- if (kvm_read_cr4_bits(vcpu, X86_CR4_DE)) {
- kvm_queue_exception(vcpu, UD_VECTOR);
+ if (kvm_read_cr4_bits(vcpu, X86_CR4_DE))
return 1;
- }
/* fall through */
default: /* 7 */
*val = vcpu->arch.dr7;
@@ -645,6 +646,15 @@ int kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val)
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);
static inline u32 bit(int bitno)
@@ -3557,12 +3567,13 @@ int emulate_clts(struct kvm_vcpu *vcpu)
int emulator_get_dr(int dr, unsigned long *dest, struct kvm_vcpu *vcpu)
{
- return kvm_get_dr(vcpu, dr, dest);
+ return _kvm_get_dr(vcpu, dr, dest);
}
int emulator_set_dr(int dr, unsigned long value, struct kvm_vcpu *vcpu)
{
- return kvm_set_dr(vcpu, dr, value);
+
+ return _kvm_set_dr(vcpu, dr, value);
}
void kvm_report_emulation_failure(struct kvm_vcpu *vcpu, const char *context)
--
1.6.5
--
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