* [PATCH] KVM: VMX: Do not skip the instruction if handle_dr injects a fault
@ 2013-12-18 18:16 Jan Kiszka
2013-12-20 18:20 ` Paolo Bonzini
0 siblings, 1 reply; 2+ messages in thread
From: Jan Kiszka @ 2013-12-18 18:16 UTC (permalink / raw)
To: Gleb Natapov, Paolo Bonzini; +Cc: kvm
If kvm_get_dr or kvm_set_dr reports that it raised a fault, we must not
advance the instruction pointer. Otherwise the exception will hit the
wrong instruction.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
arch/x86/kvm/vmx.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 56c654c..ee3bf54 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5141,10 +5141,14 @@ static int handle_dr(struct kvm_vcpu *vcpu)
reg = DEBUG_REG_ACCESS_REG(exit_qualification);
if (exit_qualification & TYPE_MOV_FROM_DR) {
unsigned long val;
- if (!kvm_get_dr(vcpu, dr, &val))
- kvm_register_write(vcpu, reg, val);
+
+ if (kvm_get_dr(vcpu, dr, &val))
+ return 1;
+ kvm_register_write(vcpu, reg, val);
} else
- kvm_set_dr(vcpu, dr, vcpu->arch.regs[reg]);
+ if (kvm_set_dr(vcpu, dr, vcpu->arch.regs[reg]))
+ return 1;
+
skip_emulated_instruction(vcpu);
return 1;
}
--
1.8.1.1.298.ge7eed54
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] KVM: VMX: Do not skip the instruction if handle_dr injects a fault
2013-12-18 18:16 [PATCH] KVM: VMX: Do not skip the instruction if handle_dr injects a fault Jan Kiszka
@ 2013-12-20 18:20 ` Paolo Bonzini
0 siblings, 0 replies; 2+ messages in thread
From: Paolo Bonzini @ 2013-12-20 18:20 UTC (permalink / raw)
To: Jan Kiszka; +Cc: Gleb Natapov, kvm
Il 18/12/2013 19:16, Jan Kiszka ha scritto:
> If kvm_get_dr or kvm_set_dr reports that it raised a fault, we must not
> advance the instruction pointer. Otherwise the exception will hit the
> wrong instruction.
>
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
> arch/x86/kvm/vmx.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 56c654c..ee3bf54 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -5141,10 +5141,14 @@ static int handle_dr(struct kvm_vcpu *vcpu)
> reg = DEBUG_REG_ACCESS_REG(exit_qualification);
> if (exit_qualification & TYPE_MOV_FROM_DR) {
> unsigned long val;
> - if (!kvm_get_dr(vcpu, dr, &val))
> - kvm_register_write(vcpu, reg, val);
> +
> + if (kvm_get_dr(vcpu, dr, &val))
> + return 1;
> + kvm_register_write(vcpu, reg, val);
> } else
> - kvm_set_dr(vcpu, dr, vcpu->arch.regs[reg]);
> + if (kvm_set_dr(vcpu, dr, vcpu->arch.regs[reg]))
> + return 1;
> +
> skip_emulated_instruction(vcpu);
> return 1;
> }
>
Applied to kvm/queue, thanks.
Paolo
^ permalink raw reply [flat|nested] 2+ messages in thread
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