diff options
| -rw-r--r-- | Documentation/virt/kvm/api.rst | 18 | ||||
| -rw-r--r-- | Documentation/virt/kvm/devices/vm.rst | 4 | ||||
| -rw-r--r-- | arch/s390/kvm/kvm-s390.c | 43 |
3 files changed, 46 insertions, 19 deletions
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index deb494f759ed..8cd7fd05d53b 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -4449,6 +4449,18 @@ not holding a previously reported uncorrected error). :Parameters: struct kvm_s390_cmma_log (in, out) :Returns: 0 on success, a negative value on error +Errors: + + ====== ============================================================= + ENOMEM not enough memory can be allocated to complete the task + ENXIO if CMMA is not enabled + EINVAL if KVM_S390_CMMA_PEEK is not set but migration mode was not enabled + EINVAL if KVM_S390_CMMA_PEEK is not set but dirty tracking has been + disabled (and thus migration mode was automatically disabled) + EFAULT if the userspace address is invalid or if no page table is + present for the addresses (e.g. when using hugepages). + ====== ============================================================= + This ioctl is used to get the values of the CMMA bits on the s390 architecture. It is meant to be used in two scenarios: @@ -4529,12 +4541,6 @@ mask is unused. values points to the userspace buffer where the result will be stored. -This ioctl can fail with -ENOMEM if not enough memory can be allocated to -complete the task, with -ENXIO if CMMA is not enabled, with -EINVAL if -KVM_S390_CMMA_PEEK is not set but migration mode was not enabled, with --EFAULT if the userspace address is invalid or if no page table is -present for the addresses (e.g. when using hugepages). - 4.108 KVM_S390_SET_CMMA_BITS ---------------------------- diff --git a/Documentation/virt/kvm/devices/vm.rst b/Documentation/virt/kvm/devices/vm.rst index 60acc39e0e93..147efec626e5 100644 --- a/Documentation/virt/kvm/devices/vm.rst +++ b/Documentation/virt/kvm/devices/vm.rst @@ -302,6 +302,10 @@ Allows userspace to start migration mode, needed for PGSTE migration. Setting this attribute when migration mode is already active will have no effects. +Dirty tracking must be enabled on all memslots, else -EINVAL is returned. When +dirty tracking is disabled on any memslot, migration mode is automatically +stopped. + :Parameters: none :Returns: -ENOMEM if there is not enough free memory to start migration mode; -EINVAL if the state of the VM is invalid (e.g. no memory defined); diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index e4890e04b210..cb72f9a09fb3 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -5633,23 +5633,40 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, if (kvm_s390_pv_get_handle(kvm)) return -EINVAL; - if (change == KVM_MR_DELETE || change == KVM_MR_FLAGS_ONLY) - return 0; + if (change != KVM_MR_DELETE && change != KVM_MR_FLAGS_ONLY) { + /* + * A few sanity checks. We can have memory slots which have to be + * located/ended at a segment boundary (1MB). The memory in userland is + * ok to be fragmented into various different vmas. It is okay to mmap() + * and munmap() stuff in this slot after doing this call at any time + */ - /* A few sanity checks. We can have memory slots which have to be - located/ended at a segment boundary (1MB). The memory in userland is - ok to be fragmented into various different vmas. It is okay to mmap() - and munmap() stuff in this slot after doing this call at any time */ + if (new->userspace_addr & 0xffffful) + return -EINVAL; - if (new->userspace_addr & 0xffffful) - return -EINVAL; + size = new->npages * PAGE_SIZE; + if (size & 0xffffful) + return -EINVAL; - size = new->npages * PAGE_SIZE; - if (size & 0xffffful) - return -EINVAL; + if ((new->base_gfn * PAGE_SIZE) + size > kvm->arch.mem_limit) + return -EINVAL; + } - if ((new->base_gfn * PAGE_SIZE) + size > kvm->arch.mem_limit) - return -EINVAL; + if (!kvm->arch.migration_mode) + return 0; + + /* + * Turn off migration mode when: + * - userspace creates a new memslot with dirty logging off, + * - userspace modifies an existing memslot (MOVE or FLAGS_ONLY) and + * dirty logging is turned off. + * Migration mode expects dirty page logging being enabled to store + * its dirty bitmap. + */ + if (change != KVM_MR_DELETE && + !(new->flags & KVM_MEM_LOG_DIRTY_PAGES)) + WARN(kvm_s390_vm_stop_migration(kvm), + "Failed to stop migration mode"); return 0; } |