Re: [PATCH v3 03/12] KVM: s390: add the GIB and its related life-cyle functions

[Michael Mueller <mimu@xxxxxxxxxxxxx>]

On 29.11.18 14:00, David Hildenbrand wrote:
> On 28.11.18 11:19, Michael Mueller wrote:
> > The GIB (Guest Information Block) links the GISA of all guests
> > that have adapter interrupts pending. These interrupts cannot be
> > delivered because no vcpu of these guests is currently running in
> > SIE context. Instead, a GIB alert is issued on the host to schedule
> > these guests to run.
> >
> > This mechanism allows to process adapter interrupts for currently
> > not running guests.
> >
> > The GIB is created during host initialization and associated with
> > the Adapter Interruption Facility in case an Adapter Interruption
> > Virtualization Facility is available.
>
> kvm_s390_gib_init() is not called in this patch (however
> kvm_s390_gib_destroy() is).
>
> So either you are missing that in this patch or your patch description
> is not completely right.

Hey, that sounds a little like pettifoggery... ;)

I will add a sentence like:

"The GIB initialization and thus the activation of the related code
will be done in an upcoming patch of this series."

Is is that you are asking for?


> > Signed-off-by: Michael Mueller <mimu@xxxxxxxxxxxxx>
> > Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
> > Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> > ---
> >   arch/s390/include/asm/kvm_host.h | 10 ++++++++++
> >   arch/s390/kvm/interrupt.c        | 37 +++++++++++++++++++++++++++++++++++++
> >   arch/s390/kvm/kvm-s390.c         |  1 +
> >   arch/s390/kvm/kvm-s390.h         |  2 ++
> >   4 files changed, 50 insertions(+)
> >
> > diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
> > index d5d24889c3bc..537e5e59f27e 100644
> > --- a/arch/s390/include/asm/kvm_host.h
> > +++ b/arch/s390/include/asm/kvm_host.h
> > @@ -785,6 +785,15 @@ struct kvm_s390_gisa {
> >   	};
> >   };
> >   
> > +struct kvm_s390_gib {
> > +	u32 alert_list_origin;
> > +	u32 reserved01;
> > +	u8:5;
> > +	u8  nisc:3;
> > +	u8  reserved03[3];
> > +	u32 reserved04[5];
> > +};
> > +
> >   /*
> >    * sie_page2 has to be allocated as DMA because fac_list, crycb and
> >    * gisa need 31bit addresses in the sie control block.
> > @@ -838,6 +847,7 @@ struct kvm_arch{
> >   	/* subset of available cpu features enabled by user space */
> >   	DECLARE_BITMAP(cpu_feat, KVM_S390_VM_CPU_FEAT_NR_BITS);
> >   	struct kvm_s390_gisa *gisa;
> > +	int gib_in_use;
> >   };
> >   
> >   #define KVM_HVA_ERR_BAD		(-1UL)
> > diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
> > index fcb55b02990e..5d20a0ce8a30 100644
> > --- a/arch/s390/kvm/interrupt.c
> > +++ b/arch/s390/kvm/interrupt.c
> > @@ -31,6 +31,8 @@
> >   #define PFAULT_DONE 0x0680
> >   #define VIRTIO_PARAM 0x0d00
> >   
> > +static struct kvm_s390_gib *gib;
> > +
> >   /* handle external calls via sigp interpretation facility */
> >   static int sca_ext_call_pending(struct kvm_vcpu *vcpu, int *src_id)
> >   {
> > @@ -2899,6 +2901,7 @@ void kvm_s390_gisa_init(struct kvm *kvm)
> >   		kvm->arch.gisa = &kvm->arch.sie_page2->gisa;
> >   		VM_EVENT(kvm, 3, "gisa 0x%pK initialized", kvm->arch.gisa);
> >   		kvm_s390_gisa_clear(kvm);
> > +		kvm->arch.gib_in_use = !!gib;
> >   	}
> >   }
> >   
> > @@ -2908,3 +2911,37 @@ void kvm_s390_gisa_destroy(struct kvm *kvm)
> >   		return;
> >   	kvm->arch.gisa = NULL;
> >   }
> > +
> > +void kvm_s390_gib_destroy(void)
> > +{
> > +	if (!gib)
> > +		return;
> > +	chsc_sgib(0);
> > +	free_page((unsigned long)gib);
> > +	gib = NULL;
> > +}
> > +
> > +int kvm_s390_gib_init(u8 nisc)
> > +{
> > +	if (!css_general_characteristics.aiv) {
> > +		KVM_EVENT(3, "%s", "gib not initialized, no AIV facility");
> > +		return 0;
> > +	}
> > +
> > +	gib = (struct kvm_s390_gib *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
> > +	if (!gib) {
> > +		KVM_EVENT(3, "gib 0x%pK memory allocation failed", gib);
> > +		return -ENOMEM;
> > +	}
> > +
> > +	gib->nisc = nisc;
> > +	if (chsc_sgib((u32)(u64)gib)) {
> > +		KVM_EVENT(3, "gib 0x%pK AIV association failed", gib);
> > +		free_page((unsigned long)gib);
> > +		gib = NULL;
> > +		return -EIO;
> > +	}
> > +
> > +	KVM_EVENT(3, "gib 0x%pK (nisc=%d) initialized", gib, gib->nisc);
> > +	return 0;
> > +}
> > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> > index d9635d21563f..96954871b6a2 100644
> > --- a/arch/s390/kvm/kvm-s390.c
> > +++ b/arch/s390/kvm/kvm-s390.c
> > @@ -444,6 +444,7 @@ int kvm_arch_init(void *opaque)
> >   
> >   void kvm_arch_exit(void)
> >   {
> > +	kvm_s390_gib_destroy();
> >   	debug_unregister(kvm_s390_dbf);
> >   }
> >   
> > diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
> > index 1f6e36cdce0d..1a79105b0e9f 100644
> > --- a/arch/s390/kvm/kvm-s390.h
> > +++ b/arch/s390/kvm/kvm-s390.h
> > @@ -381,6 +381,8 @@ int kvm_s390_get_irq_state(struct kvm_vcpu *vcpu,
> >   void kvm_s390_gisa_init(struct kvm *kvm);
> >   void kvm_s390_gisa_clear(struct kvm *kvm);
> >   void kvm_s390_gisa_destroy(struct kvm *kvm);
> > +int kvm_s390_gib_init(u8 nisc);
> > +void kvm_s390_gib_destroy(void);
> >   
> >   /* implemented in guestdbg.c */
> >   void kvm_s390_backup_guest_per_regs(struct kvm_vcpu *vcpu);

--
Mit freundlichen Grüßen / Kind regards
Michael Müller

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