diff options
| author | David Hildenbrand <dahi@linux.vnet.ibm.com> | 2016-03-03 09:48:47 +0100 |
|---|---|---|
| committer | Christian Borntraeger <borntraeger@de.ibm.com> | 2016-06-10 12:07:20 +0200 |
| commit | f9cbd9b02539330ddd349df583fcfc2db8a23b90 (patch) | |
| tree | c4a49b793c57ec1cf50bf3ecc8a8442d4880de8a | |
| parent | c24cc9c8a6ca798427d3ff46b55df8403361df3e (diff) | |
KVM: s390: provide CMMA attributes only if available
Let's not provide the device attribute for cmma enabling and clearing
if the hardware doesn't support it.
This also helps getting rid of the undocumented return value "-EINVAL"
in case CMMA is not available when trying to enable it.
Also properly document the meaning of -EINVAL for CMMA clearing.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
| -rw-r--r-- | Documentation/virtual/kvm/api.txt | 2 | ||||
| -rw-r--r-- | Documentation/virtual/kvm/devices/vm.txt | 3 | ||||
| -rw-r--r-- | arch/s390/kvm/kvm-s390.c | 7 |
3 files changed, 10 insertions, 2 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index a4482cce4bae..4aac3e51bf9f 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -2520,6 +2520,7 @@ Parameters: struct kvm_device_attr Returns: 0 on success, -1 on error Errors: ENXIO: The group or attribute is unknown/unsupported for this device + or hardware support is missing. EPERM: The attribute cannot (currently) be accessed this way (e.g. read-only attribute, or attribute that only makes sense when the device is in a different state) @@ -2547,6 +2548,7 @@ Parameters: struct kvm_device_attr Returns: 0 on success, -1 on error Errors: ENXIO: The group or attribute is unknown/unsupported for this device + or hardware support is missing. Tests whether a device supports a particular attribute. A successful return indicates the attribute is implemented. It does not necessarily diff --git a/Documentation/virtual/kvm/devices/vm.txt b/Documentation/virtual/kvm/devices/vm.txt index 8a458f42ded2..b6cda49f2ba4 100644 --- a/Documentation/virtual/kvm/devices/vm.txt +++ b/Documentation/virtual/kvm/devices/vm.txt @@ -20,7 +20,8 @@ Enables Collaborative Memory Management Assist (CMMA) for the virtual machine. 1.2. ATTRIBUTE: KVM_S390_VM_MEM_CLR_CMMA Parameters: none -Returns: 0 +Returns: -EINVAL if CMMA was not enabled + 0 otherwise Clear the CMMA status for all guest pages, so any pages the guest marked as unused are again used any may not be reclaimed by the host. diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 005e664f6360..f695c6e08337 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -485,7 +485,7 @@ static int kvm_s390_set_mem_control(struct kvm *kvm, struct kvm_device_attr *att unsigned int idx; switch (attr->attr) { case KVM_S390_VM_MEM_ENABLE_CMMA: - ret = -EINVAL; + ret = -ENXIO; if (!sclp.has_cmma) break; @@ -499,6 +499,9 @@ static int kvm_s390_set_mem_control(struct kvm *kvm, struct kvm_device_attr *att mutex_unlock(&kvm->lock); break; case KVM_S390_VM_MEM_CLR_CMMA: + ret = -ENXIO; + if (!sclp.has_cmma) + break; ret = -EINVAL; if (!kvm->arch.use_cmma) break; @@ -964,6 +967,8 @@ static int kvm_s390_vm_has_attr(struct kvm *kvm, struct kvm_device_attr *attr) switch (attr->attr) { case KVM_S390_VM_MEM_ENABLE_CMMA: case KVM_S390_VM_MEM_CLR_CMMA: + ret = sclp.has_cmma ? 0 : -ENXIO; + break; case KVM_S390_VM_MEM_LIMIT_SIZE: ret = 0; break; |