Re: [PATCH v10 02/26] KVM: s390: introduce and use KVM_REQ_VSIE_RESTART

[Tony Krowiak <akrowiak@xxxxxxxxxxxxx>]

On 09/24/2018 06:49 AM, Christian Borntraeger wrote:
> On 09/12/2018 09:42 PM, Tony Krowiak wrote:
> > From: David Hildenbrand <david@xxxxxxxxxx>
> >
> > When we change the crycb (or execution controls), we also have to make sure
> > that the vSIE shadow datastructures properly consider the changed
> > values before rerunning the vSIE. We can achieve that by simply using a
> > VCPU request now.
> >
> > This has to be a synchronous request (== handled before entering the
> > (v)SIE again).
> >
> > The request will make sure that the vSIE handler is left, and that the
> > request will be processed (NOP), therefore forcing a reload of all
> > vSIE data (including rebuilding the crycb) when re-entering the vSIE
> > interception handler the next time.
> >
> > Reviewed-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
> > Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>
> > Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
> > Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
> > Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
>
>
> same here? First David then Tomy?

Will do.

> otherwise
> Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
>
>
> > ---
> >   arch/s390/include/asm/kvm_host.h |    1 +
> >   arch/s390/kvm/kvm-s390.c         |    7 ++++++-
> >   2 files changed, 7 insertions(+), 1 deletions(-)
> >
> > diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
> > index 29c940b..75d3962 100644
> > --- a/arch/s390/include/asm/kvm_host.h
> > +++ b/arch/s390/include/asm/kvm_host.h
> > @@ -44,6 +44,7 @@
> >   #define KVM_REQ_ICPT_OPEREXC	KVM_ARCH_REQ(2)
> >   #define KVM_REQ_START_MIGRATION KVM_ARCH_REQ(3)
> >   #define KVM_REQ_STOP_MIGRATION  KVM_ARCH_REQ(4)
> > +#define KVM_REQ_VSIE_RESTART	KVM_ARCH_REQ(5)
> >   
> >   #define SIGP_CTRL_C		0x80
> >   #define SIGP_CTRL_SCN_MASK	0x3f
> > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> > index 0b5aff0..876fbb2 100644
> > --- a/arch/s390/kvm/kvm-s390.c
> > +++ b/arch/s390/kvm/kvm-s390.c
> > @@ -844,8 +844,11 @@ void kvm_s390_vcpu_crypto_reset_all(struct kvm *kvm)
> >   
> >   	kvm_s390_vcpu_block_all(kvm);
> >   
> > -	kvm_for_each_vcpu(i, vcpu, kvm)
> > +	kvm_for_each_vcpu(i, vcpu, kvm) {
> >   		kvm_s390_vcpu_crypto_setup(vcpu);
> > +		/* recreate the shadow crycb by leaving the VSIE handler */
> > +		kvm_s390_sync_request(KVM_REQ_VSIE_RESTART, vcpu);
> > +	}
> >   
> >   	kvm_s390_vcpu_unblock_all(kvm);
> >   }
> > @@ -3203,6 +3206,8 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu)
> >   
> >   	/* nothing to do, just clear the request */
> >   	kvm_clear_request(KVM_REQ_UNHALT, vcpu);
> > +	/* we left the vsie handler, nothing to do, just clear the request */
> > +	kvm_clear_request(KVM_REQ_VSIE_RESTART, vcpu);
> >   
> >   	return 0;
> >   }