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Commit 1bab1c02 authored by Claudio Imbrenda's avatar Claudio Imbrenda Committed by Christian Borntraeger
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KVM: s390: expose no-DAT to guest and migration support 



The STFLE bit 147 indicates whether the ESSA no-DAT operation code is
valid, the bit is not normally provided to the host; the host is
instead provided with an SCLP bit that indicates whether guests can
support the feature.

This patch:
* enables the STFLE bit in the guest if the corresponding SCLP bit is
  present in the host.
* adds support for migrating the no-DAT bit in the PGSTEs
* fixes the software interpretation of the ESSA instruction that is
  used when migrating, both for the new operation code and for the old
  "set stable", as per specifications.

Signed-off-by: default avatarClaudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Reviewed-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: default avatarCornelia Huck <cohuck@redhat.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent 631aebfe

arch/s390/include/asm/page-states.h

+1 −1
Original line number Diff line number Diff line
@@ -15,6 +15,6 @@ 
#define ESSA_SET_STABLE_IF_RESIDENT	6

#define ESSA_SET_STABLE_NODAT		7



#define ESSA_MAX	ESSA_SET_STABLE_IF_RESIDENT

#define ESSA_MAX	ESSA_SET_STABLE_NODAT



#endif

arch/s390/kvm/kvm-s390.c

+6 −2
Original line number Diff line number Diff line
@@ -1574,7 +1574,7 @@ static int kvm_s390_get_cmma_bits(struct kvm *kvm, 
		if (r < 0)

			pgstev = 0;

		/* save the value */

		res[i++] = (pgstev >> 24) & 0x3;

		res[i++] = (pgstev >> 24) & 0x43;

		/*

		 * if the next bit is too far away, stop.

		 * if we reached the previous "next", find the next one
@@ -1652,7 +1652,7 @@ static int kvm_s390_set_cmma_bits(struct kvm *kvm, 


		pgstev = bits[i];

		pgstev = pgstev << 24;

		mask &= _PGSTE_GPS_USAGE_MASK;

		mask &= _PGSTE_GPS_USAGE_MASK | _PGSTE_GPS_NODAT;

		set_pgste_bits(kvm->mm, hva, mask, pgstev);

	}

	srcu_read_unlock(&kvm->srcu, srcu_idx);
@@ -1929,6 +1929,10 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) 


	set_kvm_facility(kvm->arch.model.fac_mask, 74);

	set_kvm_facility(kvm->arch.model.fac_list, 74);

	if (MACHINE_HAS_TLB_GUEST) {

		set_kvm_facility(kvm->arch.model.fac_mask, 147);

		set_kvm_facility(kvm->arch.model.fac_list, 147);

	}



	kvm->arch.model.cpuid = kvm_s390_get_initial_cpuid();

	kvm->arch.model.ibc = sclp.ibc & 0x0fff;

arch/s390/kvm/priv.c

+5 −1
Original line number Diff line number Diff line
@@ -988,6 +988,8 @@ static inline int do_essa(struct kvm_vcpu *vcpu, const int orc) 
		if (pgstev & _PGSTE_GPS_ZERO)

			res |= 1;

	}

	if (pgstev & _PGSTE_GPS_NODAT)

		res |= 0x20;

	vcpu->run->s.regs.gprs[r1] = res;

	/*

	 * It is possible that all the normal 511 slots were full, in which case
@@ -1027,7 +1029,9 @@ static int handle_essa(struct kvm_vcpu *vcpu) 
		return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);

	/* Check for invalid operation request code */

	orc = (vcpu->arch.sie_block->ipb & 0xf0000000) >> 28;

	if (orc > ESSA_MAX)

	/* ORCs 0-6 are always valid */

	if (orc > (test_kvm_facility(vcpu->kvm, 147) ? ESSA_SET_STABLE_NODAT

						: ESSA_SET_STABLE_IF_RESIDENT))

		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);



	if (likely(!vcpu->kvm->arch.migration_state)) {

arch/s390/mm/pgtable.c

+5 −1
Original line number Diff line number Diff line
@@ -919,7 +919,7 @@ int pgste_perform_essa(struct mm_struct *mm, unsigned long hva, int orc, 
	case ESSA_GET_STATE:

		break;

	case ESSA_SET_STABLE:

		pgstev &= ~_PGSTE_GPS_USAGE_MASK;

		pgstev &= ~(_PGSTE_GPS_USAGE_MASK | _PGSTE_GPS_NODAT);

		pgstev |= _PGSTE_GPS_USAGE_STABLE;

		break;

	case ESSA_SET_UNUSED:
@@ -965,6 +965,10 @@ int pgste_perform_essa(struct mm_struct *mm, unsigned long hva, int orc, 
			pgstev |= _PGSTE_GPS_USAGE_STABLE;

		}

		break;

	case ESSA_SET_STABLE_NODAT:

		pgstev &= ~_PGSTE_GPS_USAGE_MASK;

		pgstev |= _PGSTE_GPS_USAGE_STABLE | _PGSTE_GPS_NODAT;

		break;

	default:

		/* we should never get here! */

		break;