diff options
| -rw-r--r-- | Documentation/virt/kvm/api.rst | 7 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 12 |
2 files changed, 19 insertions, 0 deletions
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index e264ebc35e27..70254eaa5229 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -6489,3 +6489,10 @@ processor's dirty page buffers into the kernel buffer (with dirty bitmaps, the flushing is done by the KVM_GET_DIRTY_LOG ioctl). To achieve that, one needs to kick the vcpu out of KVM_RUN using a signal. The resulting vmexit ensures that all dirty GFNs are flushed to the dirty rings. + +NOTE: the capability KVM_CAP_DIRTY_LOG_RING and the corresponding +ioctl KVM_RESET_DIRTY_RINGS are mutual exclusive to the existing ioctls +KVM_GET_DIRTY_LOG and KVM_CLEAR_DIRTY_LOG. After enabling +KVM_CAP_DIRTY_LOG_RING with an acceptable dirty ring size, the virtual +machine will switch to ring-buffer dirty page tracking and further +KVM_GET_DIRTY_LOG or KVM_CLEAR_DIRTY_LOG ioctls will fail. diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 78ef414512bf..110aa5cc0c93 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1426,6 +1426,10 @@ int kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log, unsigned long n; unsigned long any = 0; + /* Dirty ring tracking is exclusive to dirty log tracking */ + if (kvm->dirty_ring_size) + return -ENXIO; + *memslot = NULL; *is_dirty = 0; @@ -1487,6 +1491,10 @@ static int kvm_get_dirty_log_protect(struct kvm *kvm, struct kvm_dirty_log *log) unsigned long *dirty_bitmap_buffer; bool flush; + /* Dirty ring tracking is exclusive to dirty log tracking */ + if (kvm->dirty_ring_size) + return -ENXIO; + as_id = log->slot >> 16; id = (u16)log->slot; if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS) @@ -1595,6 +1603,10 @@ static int kvm_clear_dirty_log_protect(struct kvm *kvm, unsigned long *dirty_bitmap_buffer; bool flush; + /* Dirty ring tracking is exclusive to dirty log tracking */ + if (kvm->dirty_ring_size) + return -ENXIO; + as_id = log->slot >> 16; id = (u16)log->slot; if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS) |