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Commit 3573602b authored by David Hildenbrand's avatar David Hildenbrand Committed by Christian Borntraeger
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KVM: s390: vsie: support setting the ibc 



As soon as we forward an ibc to guest 2 (indicated via
kvm->arch.model.ibc), he can also use it for guest 3. Let's properly round
the ibc up/down, so we avoid any potential validity icpts from the
underlying SIE, if it doesn't simply round the values.

Acked-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent 06d68a6c

arch/s390/kvm/vsie.c

+21 −0
Original line number Diff line number Diff line
@@ -102,6 +102,26 @@ static int prepare_cpuflags(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 
	return 0;

}



/* shadow (round up/down) the ibc to avoid validity icpt */

static void prepare_ibc(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)

{

	struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;

	struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;

	__u64 min_ibc = (sclp.ibc >> 16) & 0x0fffU;



	scb_s->ibc = 0;

	/* ibc installed in g2 and requested for g3 */

	if (vcpu->kvm->arch.model.ibc && (scb_o->ibc & 0x0fffU)) {

		scb_s->ibc = scb_o->ibc & 0x0fffU;

		/* takte care of the minimum ibc level of the machine */

		if (scb_s->ibc < min_ibc)

			scb_s->ibc = min_ibc;

		/* take care of the maximum ibc level set for the guest */

		if (scb_s->ibc > vcpu->kvm->arch.model.ibc)

			scb_s->ibc = vcpu->kvm->arch.model.ibc;

	}

}



/* unshadow the scb, copying parameters back to the real scb */

static void unshadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)

{
@@ -214,6 +234,7 @@ static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 
	/* MVPG and Protection Exception Interpretation are always available */

	scb_s->eca |= scb_o->eca & 0x01002000U;



	prepare_ibc(vcpu, vsie_page);

out:

	if (rc)

		unshadow_scb(vcpu, vsie_page);