Messages in this thread | | | Date | Mon, 28 Jan 2019 17:50:54 +0100 | From | Halil Pasic <> | Subject | Re: [PATCH v6 07/13] KVM: s390: introduce struct kvm_s390_gisa_interrupt |
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On Thu, 24 Jan 2019 13:59:33 +0100 Michael Mueller <mimu@linux.ibm.com> wrote:
> Use this struct analog to the kvm interruption structs > for kvm emulated floating and local interruptions. > Further fields will be added with this series as > required. > > Signed-off-by: Michael Mueller <mimu@linux.ibm.com>
While looking at this I was asking myself what guards against invalid gisa pointer dereference e.g. when pending_irqs() is called (see below).
AFAIU we set up gisa_int.origin only if we have css_general_characteristics.aiv. Opinions?
Anyway if it is a problem, it is a pre-existing one (should be fixed ASAP but does not affect the validity of this patch).
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
> --- > arch/s390/include/asm/kvm_host.h | 6 ++++- > arch/s390/kvm/interrupt.c | 52 +++++++++++++++++++++++----------------- > arch/s390/kvm/kvm-s390.c | 2 +- > 3 files changed, 36 insertions(+), 24 deletions(-) > > diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h > index c259a67c4298..0941571d34eb 100644 > --- a/arch/s390/include/asm/kvm_host.h > +++ b/arch/s390/include/asm/kvm_host.h > @@ -803,6 +803,10 @@ struct kvm_s390_vsie { > struct page *pages[KVM_MAX_VCPUS]; > }; >
[..]
> diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c > index 942cc7d33766..ee91d1de0036 100644 > --- a/arch/s390/kvm/interrupt.c > +++ b/arch/s390/kvm/interrupt.c > @@ -246,7 +246,8 @@ static inline unsigned long pending_irqs_no_gisa(struct kvm_vcpu *vcpu) > static inline unsigned long pending_irqs(struct kvm_vcpu *vcpu) > { > return pending_irqs_no_gisa(vcpu) | > - gisa_get_ipm(vcpu->kvm->arch.gisa) << IRQ_PEND_IO_ISC_7; > + gisa_get_ipm(vcpu->kvm->arch.gisa_int.origin) <<
Unconditional call to gisa_get_ipm(), and get ipm just accesses ->ipm.
> + IRQ_PEND_IO_ISC_7; > } >
[..]
> void kvm_s390_gisa_init(struct kvm *kvm) > { > + struct kvm_s390_gisa_interrupt *gi = &kvm->arch.gisa_int; > + > if (!css_general_characteristics.aiv) > return; > - kvm->arch.gisa = &kvm->arch.sie_page2->gisa; > + gi->origin = &kvm->arch.sie_page2->gisa;
Should stay NULL if !css_general_characteristics.aiv.
> kvm_s390_gisa_clear(kvm); > - VM_EVENT(kvm, 3, "gisa 0x%pK initialized", kvm->arch.gisa); > + VM_EVENT(kvm, 3, "gisa 0x%pK initialized", gi->origin); > } >
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