diff options
Diffstat (limited to 'Documentation/virtual')
| -rw-r--r-- | Documentation/virtual/kvm/api.txt | 42 | ||||
| -rw-r--r-- | Documentation/virtual/kvm/devices/vm.txt | 3 |
2 files changed, 17 insertions, 28 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 5b505520a616..8ffd9beb931b 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -69,23 +69,6 @@ by and on behalf of the VM's process may not be freed/unaccounted when the VM is shut down. -It is important to note that althought VM ioctls may only be issued from -the process that created the VM, a VM's lifecycle is associated with its -file descriptor, not its creator (process). In other words, the VM and -its resources, *including the associated address space*, are not freed -until the last reference to the VM's file descriptor has been released. -For example, if fork() is issued after ioctl(KVM_CREATE_VM), the VM will -not be freed until both the parent (original) process and its child have -put their references to the VM's file descriptor. - -Because a VM's resources are not freed until the last reference to its -file descriptor is released, creating additional references to a VM via -via fork(), dup(), etc... without careful consideration is strongly -discouraged and may have unwanted side effects, e.g. memory allocated -by and on behalf of the VM's process may not be freed/unaccounted when -the VM is shut down. - - 3. Extensions ------------- @@ -347,7 +330,7 @@ They must be less than the value that KVM_CHECK_EXTENSION returns for the KVM_CAP_MULTI_ADDRESS_SPACE capability. The bits in the dirty bitmap are cleared before the ioctl returns, unless -KVM_CAP_MANUAL_DIRTY_LOG_PROTECT is enabled. For more information, +KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is enabled. For more information, see the description of the capability. 4.9 KVM_SET_MEMORY_ALIAS @@ -1117,9 +1100,8 @@ struct kvm_userspace_memory_region { This ioctl allows the user to create, modify or delete a guest physical memory slot. Bits 0-15 of "slot" specify the slot id and this value should be less than the maximum number of user memory slots supported per -VM. The maximum allowed slots can be queried using KVM_CAP_NR_MEMSLOTS, -if this capability is supported by the architecture. Slots may not -overlap in guest physical address space. +VM. The maximum allowed slots can be queried using KVM_CAP_NR_MEMSLOTS. +Slots may not overlap in guest physical address space. If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 of "slot" specifies the address space which is being modified. They must be @@ -3810,7 +3792,7 @@ to I/O ports. 4.117 KVM_CLEAR_DIRTY_LOG (vm ioctl) -Capability: KVM_CAP_MANUAL_DIRTY_LOG_PROTECT +Capability: KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 Architectures: x86 Type: vm ioctl Parameters: struct kvm_dirty_log (in) @@ -3831,8 +3813,9 @@ The ioctl clears the dirty status of pages in a memory slot, according to the bitmap that is passed in struct kvm_clear_dirty_log's dirty_bitmap field. Bit 0 of the bitmap corresponds to page "first_page" in the memory slot, and num_pages is the size in bits of the input bitmap. -Both first_page and num_pages must be a multiple of 64. For each bit -that is set in the input bitmap, the corresponding page is marked "clean" +first_page must be a multiple of 64; num_pages must also be a multiple of +64 unless first_page + num_pages is the size of the memory slot. For each +bit that is set in the input bitmap, the corresponding page is marked "clean" in KVM's dirty bitmap, and dirty tracking is re-enabled for that page (for example via write-protection, or by clearing the dirty bit in a page table entry). @@ -3842,10 +3825,10 @@ the address space for which you want to return the dirty bitmap. They must be less than the value that KVM_CHECK_EXTENSION returns for the KVM_CAP_MULTI_ADDRESS_SPACE capability. -This ioctl is mostly useful when KVM_CAP_MANUAL_DIRTY_LOG_PROTECT +This ioctl is mostly useful when KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is enabled; for more information, see the description of the capability. However, it can always be used as long as KVM_CHECK_EXTENSION confirms -that KVM_CAP_MANUAL_DIRTY_LOG_PROTECT is present. +that KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is present. 4.118 KVM_GET_SUPPORTED_HV_CPUID @@ -4807,7 +4790,7 @@ and injected exceptions. * For the new DR6 bits, note that bit 16 is set iff the #DB exception will clear DR6.RTM. -7.18 KVM_CAP_MANUAL_DIRTY_LOG_PROTECT +7.18 KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 Architectures: all Parameters: args[0] whether feature should be enabled or not @@ -4830,6 +4813,11 @@ while userspace can see false reports of dirty pages. Manual reprotection helps reducing this time, improving guest performance and reducing the number of dirty log false positives. +KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 was previously available under the name +KVM_CAP_MANUAL_DIRTY_LOG_PROTECT, but the implementation had bugs that make +it hard or impossible to use it correctly. The availability of +KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 signals that those bugs are fixed. +Userspace should not try to use KVM_CAP_MANUAL_DIRTY_LOG_PROTECT. 8. Other capabilities. ---------------------- diff --git a/Documentation/virtual/kvm/devices/vm.txt b/Documentation/virtual/kvm/devices/vm.txt index 95ca68d663a4..4ffb82b02468 100644 --- a/Documentation/virtual/kvm/devices/vm.txt +++ b/Documentation/virtual/kvm/devices/vm.txt @@ -141,7 +141,8 @@ struct kvm_s390_vm_cpu_subfunc { u8 pcc[16]; # valid with Message-Security-Assist-Extension 4 u8 ppno[16]; # valid with Message-Security-Assist-Extension 5 u8 kma[16]; # valid with Message-Security-Assist-Extension 8 - u8 reserved[1808]; # reserved for future instructions + u8 kdsa[16]; # valid with Message-Security-Assist-Extension 9 + u8 reserved[1792]; # reserved for future instructions }; Parameters: address of a buffer to load the subfunction blocks from. |