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| author |   Farhan Ali <alifm@linux.vnet.ibm.com> | 2017-02-24 16:12:56 -0500 |
|---|---|---|
| committer |   Christian Borntraeger <borntraeger@de.ibm.com> | 2017-04-21 11:08:11 +0200 |
| commit | 730cd632c4e485b90f97fe998e300045da094938 (patch) | |
| tree | 894c8643cbfbaa47b6973cd34a3e054840513e47 /arch/s390/kvm/priv.c | |
| parent | s390/sclp: Detect KSS facility (diff) | |
| download | linux-dev-730cd632c4e485b90f97fe998e300045da094938.tar.xz linux-dev-730cd632c4e485b90f97fe998e300045da094938.zip | |
KVM: s390: Support keyless subset guest mode
If the KSS facility is available on the machine, we also make it
available for our KVM guests.
The KSS facility bypasses storage key management as long as the guest
does not issue a related instruction. When that happens, the control is
returned to the host, which has to turn off KSS for a guest vcpu
before retrying the instruction.
Signed-off-by: Corey S. McQuay <csmcquay@linux.vnet.ibm.com>
Signed-off-by: Farhan Ali <alifm@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Diffstat (limited to 'arch/s390/kvm/priv.c')
| -rw-r--r-- | arch/s390/kvm/priv.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index 0ffe973535fa..c03106c428cf 100644 --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -198,18 +198,25 @@ static int handle_store_cpu_address(struct kvm_vcpu *vcpu) return 0; } -static int __skey_check_enable(struct kvm_vcpu *vcpu) +int kvm_s390_skey_check_enable(struct kvm_vcpu *vcpu) { int rc = 0; + struct kvm_s390_sie_block *sie_block = vcpu->arch.sie_block; trace_kvm_s390_skey_related_inst(vcpu); - if (!(vcpu->arch.sie_block->ictl & (ICTL_ISKE | ICTL_SSKE | ICTL_RRBE))) + if (!(sie_block->ictl & (ICTL_ISKE | ICTL_SSKE | ICTL_RRBE)) && + !(atomic_read(&sie_block->cpuflags) & CPUSTAT_KSS)) return rc; rc = s390_enable_skey(); VCPU_EVENT(vcpu, 3, "enabling storage keys for guest: %d", rc); - if (!rc) - vcpu->arch.sie_block->ictl &= ~(ICTL_ISKE | ICTL_SSKE | ICTL_RRBE); + if (!rc) { + if (atomic_read(&sie_block->cpuflags) & CPUSTAT_KSS) + atomic_andnot(CPUSTAT_KSS, &sie_block->cpuflags); + else + sie_block->ictl &= ~(ICTL_ISKE | ICTL_SSKE | + ICTL_RRBE); + } return rc; } @@ -218,7 +225,7 @@ static int try_handle_skey(struct kvm_vcpu *vcpu) int rc; vcpu->stat.instruction_storage_key++; - rc = __skey_check_enable(vcpu); + rc = kvm_s390_skey_check_enable(vcpu); if (rc) return rc; if (sclp.has_skey) { @@ -916,7 +923,7 @@ static int handle_pfmf(struct kvm_vcpu *vcpu) } if (vcpu->run->s.regs.gprs[reg1] & PFMF_SK) { - int rc = __skey_check_enable(vcpu); + int rc = kvm_s390_skey_check_enable(vcpu); if (rc) return rc; |