KVM: x86: Allow marking an exception as reinjected

This patch adds logic to kvm/x86 which allows to mark an
injected exception as reinjected. This allows to remove an
ugly hack from svm_complete_interrupts that prevented
exceptions from being reinjected at all in the nested case.
The hack was necessary because an reinjected exception into
the nested guest could cause a nested vmexit emulation. But
reinjected exceptions must not intercept. The downside of
the hack is that a exception that in injected could get
lost.
This patch fixes the problem and puts the code for it into
generic x86 files because. Nested-VMX will likely have the
same problem and could reuse the code.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Joerg Roedel 2010-04-22 12:33:13 +02:00 committed by Avi Kivity
parent c2c63a4939
commit ce7ddec4bb
4 changed files with 32 additions and 12 deletions

View File

@ -312,6 +312,7 @@ struct kvm_vcpu_arch {
struct kvm_queued_exception {
bool pending;
bool has_error_code;
bool reinject;
u8 nr;
u32 error_code;
} exception;
@ -514,7 +515,8 @@ struct kvm_x86_ops {
void (*set_irq)(struct kvm_vcpu *vcpu);
void (*set_nmi)(struct kvm_vcpu *vcpu);
void (*queue_exception)(struct kvm_vcpu *vcpu, unsigned nr,
bool has_error_code, u32 error_code);
bool has_error_code, u32 error_code,
bool reinject);
int (*interrupt_allowed)(struct kvm_vcpu *vcpu);
int (*nmi_allowed)(struct kvm_vcpu *vcpu);
bool (*get_nmi_mask)(struct kvm_vcpu *vcpu);
@ -617,6 +619,8 @@ void kvm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags);
void kvm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr);
void kvm_queue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code);
void kvm_requeue_exception(struct kvm_vcpu *vcpu, unsigned nr);
void kvm_requeue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code);
void kvm_inject_page_fault(struct kvm_vcpu *vcpu, unsigned long cr2,
u32 error_code);
bool kvm_require_cpl(struct kvm_vcpu *vcpu, int required_cpl);

View File

@ -338,7 +338,8 @@ static void skip_emulated_instruction(struct kvm_vcpu *vcpu)
}
static void svm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr,
bool has_error_code, u32 error_code)
bool has_error_code, u32 error_code,
bool reinject)
{
struct vcpu_svm *svm = to_svm(vcpu);
@ -346,7 +347,8 @@ static void svm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr,
* If we are within a nested VM we'd better #VMEXIT and let the guest
* handle the exception
*/
if (nested_svm_check_exception(svm, nr, has_error_code, error_code))
if (!reinject &&
nested_svm_check_exception(svm, nr, has_error_code, error_code))
return;
if (nr == BP_VECTOR && !svm_has(SVM_FEATURE_NRIP)) {
@ -2918,8 +2920,6 @@ static void svm_complete_interrupts(struct vcpu_svm *svm)
svm->vcpu.arch.nmi_injected = true;
break;
case SVM_EXITINTINFO_TYPE_EXEPT:
if (is_nested(svm))
break;
/*
* In case of software exceptions, do not reinject the vector,
* but re-execute the instruction instead. Rewind RIP first
@ -2935,10 +2935,10 @@ static void svm_complete_interrupts(struct vcpu_svm *svm)
}
if (exitintinfo & SVM_EXITINTINFO_VALID_ERR) {
u32 err = svm->vmcb->control.exit_int_info_err;
kvm_queue_exception_e(&svm->vcpu, vector, err);
kvm_requeue_exception_e(&svm->vcpu, vector, err);
} else
kvm_queue_exception(&svm->vcpu, vector);
kvm_requeue_exception(&svm->vcpu, vector);
break;
case SVM_EXITINTINFO_TYPE_INTR:
kvm_queue_interrupt(&svm->vcpu, vector, false);

View File

@ -919,7 +919,8 @@ static void skip_emulated_instruction(struct kvm_vcpu *vcpu)
}
static void vmx_queue_exception(struct kvm_vcpu *vcpu, unsigned nr,
bool has_error_code, u32 error_code)
bool has_error_code, u32 error_code,
bool reinject)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
u32 intr_info = nr | INTR_INFO_VALID_MASK;

View File

@ -265,7 +265,8 @@ static int exception_class(int vector)
}
static void kvm_multiple_exception(struct kvm_vcpu *vcpu,
unsigned nr, bool has_error, u32 error_code)
unsigned nr, bool has_error, u32 error_code,
bool reinject)
{
u32 prev_nr;
int class1, class2;
@ -276,6 +277,7 @@ static void kvm_multiple_exception(struct kvm_vcpu *vcpu,
vcpu->arch.exception.has_error_code = has_error;
vcpu->arch.exception.nr = nr;
vcpu->arch.exception.error_code = error_code;
vcpu->arch.exception.reinject = true;
return;
}
@ -304,10 +306,16 @@ static void kvm_multiple_exception(struct kvm_vcpu *vcpu,
void kvm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr)
{
kvm_multiple_exception(vcpu, nr, false, 0);
kvm_multiple_exception(vcpu, nr, false, 0, false);
}
EXPORT_SYMBOL_GPL(kvm_queue_exception);
void kvm_requeue_exception(struct kvm_vcpu *vcpu, unsigned nr)
{
kvm_multiple_exception(vcpu, nr, false, 0, true);
}
EXPORT_SYMBOL_GPL(kvm_requeue_exception);
void kvm_inject_page_fault(struct kvm_vcpu *vcpu, unsigned long addr,
u32 error_code)
{
@ -324,10 +332,16 @@ EXPORT_SYMBOL_GPL(kvm_inject_nmi);
void kvm_queue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code)
{
kvm_multiple_exception(vcpu, nr, true, error_code);
kvm_multiple_exception(vcpu, nr, true, error_code, false);
}
EXPORT_SYMBOL_GPL(kvm_queue_exception_e);
void kvm_requeue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code)
{
kvm_multiple_exception(vcpu, nr, true, error_code, true);
}
EXPORT_SYMBOL_GPL(kvm_requeue_exception_e);
/*
* Checks if cpl <= required_cpl; if true, return true. Otherwise queue
* a #GP and return false.
@ -4408,7 +4422,8 @@ static void inject_pending_event(struct kvm_vcpu *vcpu)
vcpu->arch.exception.error_code);
kvm_x86_ops->queue_exception(vcpu, vcpu->arch.exception.nr,
vcpu->arch.exception.has_error_code,
vcpu->arch.exception.error_code);
vcpu->arch.exception.error_code,
vcpu->arch.exception.reinject);
return;
}