diff options
| -rw-r--r-- | Documentation/virtual/kvm/devices/vm.txt | 14 | ||||
| -rw-r--r-- | arch/s390/include/uapi/asm/kvm.h | 1 | ||||
| -rw-r--r-- | arch/s390/kvm/kvm-s390.c | 65 |
3 files changed, 77 insertions, 3 deletions
diff --git a/Documentation/virtual/kvm/devices/vm.txt b/Documentation/virtual/kvm/devices/vm.txt index d426fc87fe93..c3b17c61b7dd 100644 --- a/Documentation/virtual/kvm/devices/vm.txt +++ b/Documentation/virtual/kvm/devices/vm.txt @@ -24,3 +24,17 @@ 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. + +1.3. ATTRIBUTE KVM_S390_VM_MEM_LIMIT_SIZE +Parameters: in attr->addr the address for the new limit of guest memory +Returns: -EFAULT if the given address is not accessible + -EINVAL if the virtual machine is of type UCONTROL + -E2BIG if the given guest memory is to big for that machine + -EBUSY if a vcpu is already defined + -ENOMEM if not enough memory is available for a new shadow guest mapping + 0 otherwise + +Allows userspace to query the actual limit and set a new limit for +the maximum guest memory size. The limit will be rounded up to +2048 MB, 4096 GB, 8192 TB respectively, as this limit is governed by +the number of page table levels. diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h index 48eda3ab4944..9c01159cf667 100644 --- a/arch/s390/include/uapi/asm/kvm.h +++ b/arch/s390/include/uapi/asm/kvm.h @@ -61,6 +61,7 @@ struct kvm_s390_io_adapter_req { /* kvm attributes for mem_ctrl */ #define KVM_S390_VM_MEM_ENABLE_CMMA 0 #define KVM_S390_VM_MEM_CLR_CMMA 1 +#define KVM_S390_VM_MEM_LIMIT_SIZE 2 /* for KVM_GET_REGS and KVM_SET_REGS */ struct kvm_regs { diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 529f7905b341..14cdf1c3b995 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -261,7 +261,24 @@ 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) +static int kvm_s390_get_mem_control(struct kvm *kvm, struct kvm_device_attr *attr) +{ + int ret; + + switch (attr->attr) { + case KVM_S390_VM_MEM_LIMIT_SIZE: + ret = 0; + if (put_user(kvm->arch.gmap->asce_end, (u64 __user *)attr->addr)) + ret = -EFAULT; + break; + default: + ret = -ENXIO; + break; + } + return ret; +} + +static int kvm_s390_set_mem_control(struct kvm *kvm, struct kvm_device_attr *attr) { int ret; unsigned int idx; @@ -283,6 +300,36 @@ static int kvm_s390_mem_control(struct kvm *kvm, struct kvm_device_attr *attr) mutex_unlock(&kvm->lock); ret = 0; break; + case KVM_S390_VM_MEM_LIMIT_SIZE: { + unsigned long new_limit; + + if (kvm_is_ucontrol(kvm)) + return -EINVAL; + + if (get_user(new_limit, (u64 __user *)attr->addr)) + return -EFAULT; + + if (new_limit > kvm->arch.gmap->asce_end) + return -E2BIG; + + ret = -EBUSY; + mutex_lock(&kvm->lock); + if (atomic_read(&kvm->online_vcpus) == 0) { + /* gmap_alloc will round the limit up */ + struct gmap *new = gmap_alloc(current->mm, new_limit); + + if (!new) { + ret = -ENOMEM; + } else { + gmap_free(kvm->arch.gmap); + new->private = kvm; + kvm->arch.gmap = new; + ret = 0; + } + } + mutex_unlock(&kvm->lock); + break; + } default: ret = -ENXIO; break; @@ -296,7 +343,7 @@ static int kvm_s390_vm_set_attr(struct kvm *kvm, struct kvm_device_attr *attr) switch (attr->group) { case KVM_S390_VM_MEM_CTRL: - ret = kvm_s390_mem_control(kvm, attr); + ret = kvm_s390_set_mem_control(kvm, attr); break; default: ret = -ENXIO; @@ -308,7 +355,18 @@ static int kvm_s390_vm_set_attr(struct kvm *kvm, struct kvm_device_attr *attr) static int kvm_s390_vm_get_attr(struct kvm *kvm, struct kvm_device_attr *attr) { - return -ENXIO; + int ret; + + switch (attr->group) { + case KVM_S390_VM_MEM_CTRL: + ret = kvm_s390_get_mem_control(kvm, attr); + break; + default: + ret = -ENXIO; + break; + } + + return ret; } static int kvm_s390_vm_has_attr(struct kvm *kvm, struct kvm_device_attr *attr) @@ -320,6 +378,7 @@ 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: + case KVM_S390_VM_MEM_LIMIT_SIZE: ret = 0; break; default: |