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| author | Dominik Dingel <dingel@linux.vnet.ibm.com> | 2014-04-09 15:13:00 +0400 |
|---|---|---|
| committer | Christian Borntraeger <borntraeger@de.ibm.com> | 2014-04-22 15:24:32 +0400 |
| commit | 4f718eab262868aeab83774ec4ce25e6a9906657 (patch) | |
| tree | e5913e863cea1909a1cac6b9f1cafcf4f57ef446 | |
| parent | b31605c12f4edda7a40ad9f86985739666298c31 (diff) | |
| download | linux-4f718eab262868aeab83774ec4ce25e6a9906657.tar.xz | |
KVM: s390: Exploiting generic userspace interface for cmma
To enable CMMA and to reset its state we use the vm kvm_device ioctls,
encapsulating attributes within the KVM_S390_VM_MEM_CTRL group.
Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
| -rw-r--r-- | Documentation/virtual/kvm/devices/vm.txt | 16 | ||||
| -rw-r--r-- | arch/s390/include/uapi/asm/kvm.h | 7 | ||||
| -rw-r--r-- | arch/s390/kvm/kvm-s390.c | 43 |
3 files changed, 66 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/devices/vm.txt b/Documentation/virtual/kvm/devices/vm.txt index 562bee6e600b..0d16f96c0eac 100644 --- a/Documentation/virtual/kvm/devices/vm.txt +++ b/Documentation/virtual/kvm/devices/vm.txt @@ -8,3 +8,19 @@ and controls. The groups and attributes per virtual machine, if any, are architecture specific. + +1. GROUP: KVM_S390_VM_MEM_CTRL +Architectures: s390 + +1.1. ATTRIBUTE: KVM_S390_VM_MEM_CTRL +Parameters: none +Returns: -EBUSY if already a vcpus is defined, otherwise 0 + +Enables CMMA for the virtual machine + +1.2. ATTRIBUTE: KVM_S390_VM_CLR_CMMA +Parameteres: none +Returns: 0 + +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/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h index c003c6a73b1e..e35c79821d29 100644 --- a/arch/s390/include/uapi/asm/kvm.h +++ b/arch/s390/include/uapi/asm/kvm.h @@ -54,6 +54,13 @@ struct kvm_s390_io_adapter_req { __u64 addr; }; +/* kvm attr_group on vm fd */ +#define KVM_S390_VM_MEM_CTRL 0 + +/* kvm attributes for mem_ctrl */ +#define KVM_S390_VM_MEM_ENABLE_CMMA 0 +#define KVM_S390_VM_MEM_CLR_CMMA 1 + /* for KVM_GET_REGS and KVM_SET_REGS */ struct kvm_regs { /* general purpose regs for s390 */ diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index fc2fe49488c0..fe2396cc0856 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -258,11 +258,43 @@ static int kvm_vm_ioctl_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap) return r; } +static int kvm_s390_mem_control(struct kvm *kvm, struct kvm_device_attr *attr) +{ + int ret; + unsigned int idx; + switch (attr->attr) { + case KVM_S390_VM_MEM_ENABLE_CMMA: + ret = -EBUSY; + mutex_lock(&kvm->lock); + if (atomic_read(&kvm->online_vcpus) == 0) { + kvm->arch.use_cmma = 1; + ret = 0; + } + mutex_unlock(&kvm->lock); + break; + case KVM_S390_VM_MEM_CLR_CMMA: + mutex_lock(&kvm->lock); + idx = srcu_read_lock(&kvm->srcu); + page_table_reset_pgste(kvm->arch.gmap->mm, 0, TASK_SIZE, false); + srcu_read_unlock(&kvm->srcu, idx); + mutex_unlock(&kvm->lock); + ret = 0; + break; + default: + ret = -ENXIO; + break; + } + return ret; +} + static int kvm_s390_vm_set_attr(struct kvm *kvm, struct kvm_device_attr *attr) { int ret; switch (attr->group) { + case KVM_S390_VM_MEM_CTRL: + ret = kvm_s390_mem_control(kvm, attr); + break; default: ret = -ENXIO; break; @@ -281,6 +313,17 @@ static int kvm_s390_vm_has_attr(struct kvm *kvm, struct kvm_device_attr *attr) int ret; switch (attr->group) { + case KVM_S390_VM_MEM_CTRL: + switch (attr->attr) { + case KVM_S390_VM_MEM_ENABLE_CMMA: + case KVM_S390_VM_MEM_CLR_CMMA: + ret = 0; + break; + default: + ret = -ENXIO; + break; + } + break; default: ret = -ENXIO; break; |