Gleb Natapov wrote: > On Wed, Nov 11, 2009 at 05:29:47PM -0200, Marcelo Tosatti wrote: >> I suppose a complete fix would be to follow the "Conditions for >> Generating a Double Fault" with support for handling exceptions >> serially. >> >> But this works for me. >> > I prefer proper solution. Like one attached (this is combination of ths > patch by Eddie Dong and my fix):
Nice, preferred here as well. I only have a minor comment below. > > Move Double-Fault generation logic out of page fault > exception generating function to cover more generic case. > > Signed-off-by: Eddie Dong <[email protected]> > Signed-off-by: Gleb Natapov <[email protected]> > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 76c8375..88c4490 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -248,12 +248,61 @@ void kvm_set_apic_base(struct kvm_vcpu *vcpu, u64 data) > } > EXPORT_SYMBOL_GPL(kvm_set_apic_base); > > +#define EXCPT_BENIGN 0 > +#define EXCPT_CONTRIBUTORY 1 > +#define EXCPT_PF 2 > + > +static int exception_class(int vector) > +{ > + if (vector == 14) > + return EXCPT_PF; > + else if (vector == 0 || (vector >= 10 && vector <= 13)) xx_VECTOR? > + return EXCPT_CONTRIBUTORY; > + else > + return EXCPT_BENIGN; > +} > + > +static void kvm_multiple_exception(struct kvm_vcpu *vcpu, > + unsigned nr, bool has_error, u32 error_code) > +{ > + u32 prev_nr; > + int class1, class2; > + > + if (!vcpu->arch.exception.pending) { > + queue: > + vcpu->arch.exception.pending = true; > + vcpu->arch.exception.has_error_code = has_error; > + vcpu->arch.exception.nr = nr; > + vcpu->arch.exception.error_code = error_code; > + return; > + } > + > + /* to check exception */ > + prev_nr = vcpu->arch.exception.nr; > + if (prev_nr == DF_VECTOR) { > + /* triple fault -> shutdown */ > + set_bit(KVM_REQ_TRIPLE_FAULT, &vcpu->requests); > + return; > + } > + class1 = exception_class(prev_nr); > + class2 = exception_class(nr); > + if ((class1 == EXCPT_CONTRIBUTORY && class2 == EXCPT_CONTRIBUTORY) > + || (class1 == EXCPT_PF && class2 != EXCPT_BENIGN)) { > + /* generate double fault per SDM Table 5-5 */ > + vcpu->arch.exception.pending = true; > + vcpu->arch.exception.has_error_code = true; > + vcpu->arch.exception.nr = DF_VECTOR; > + vcpu->arch.exception.error_code = 0; > + } else > + /* replace previous exception with a new one in a hope > + that instruction re-execution will regenerate lost > + exception */ > + goto queue; > +} > + > void kvm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr) > { > - WARN_ON(vcpu->arch.exception.pending); > - vcpu->arch.exception.pending = true; > - vcpu->arch.exception.has_error_code = false; > - vcpu->arch.exception.nr = nr; > + kvm_multiple_exception(vcpu, nr, false, 0); > } > EXPORT_SYMBOL_GPL(kvm_queue_exception); > > @@ -261,25 +310,6 @@ void kvm_inject_page_fault(struct kvm_vcpu *vcpu, > unsigned long addr, > u32 error_code) > { > ++vcpu->stat.pf_guest; > - > - if (vcpu->arch.exception.pending) { > - switch(vcpu->arch.exception.nr) { > - case DF_VECTOR: > - /* triple fault -> shutdown */ > - set_bit(KVM_REQ_TRIPLE_FAULT, &vcpu->requests); > - return; > - case PF_VECTOR: > - vcpu->arch.exception.nr = DF_VECTOR; > - vcpu->arch.exception.error_code = 0; > - return; > - default: > - /* replace previous exception with a new one in a hope > - that instruction re-execution will regenerate lost > - exception */ > - vcpu->arch.exception.pending = false; > - break; > - } > - } > vcpu->arch.cr2 = addr; > kvm_queue_exception_e(vcpu, PF_VECTOR, error_code); > } > @@ -292,11 +322,7 @@ EXPORT_SYMBOL_GPL(kvm_inject_nmi); > > void kvm_queue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 > error_code) > { > - WARN_ON(vcpu->arch.exception.pending); > - vcpu->arch.exception.pending = true; > - vcpu->arch.exception.has_error_code = true; > - vcpu->arch.exception.nr = nr; > - vcpu->arch.exception.error_code = error_code; > + kvm_multiple_exception(vcpu, nr, true, error_code); > } > EXPORT_SYMBOL_GPL(kvm_queue_exception_e); > Jan -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
