cap: add DirtyLogRing cap

The capability is used for the KVM dirty ring interface for tracking
dirtied pages.

Signed-off-by: David Kleymann <[email protected]>

Author: davidkleymann

kvm-ioctls/CHANGELOG.md

@@ -2,6 +2,27 @@
 
 ## Upcoming Release
 
+
+### Fixed
+
+- Fixed `VmFd::enable_cap` available for all architectures
+
+### Added
+
+- Added `KvmDirtyLogRing` structure to mmap the dirty log ring.
+- Added `KVM_DIRTY_GFN_F_DIRTY` and `KVM_DIRTY_GFN_F_RESET` bitflags.
+- Added `KvmDirtyLogRing` iterator type for accessing dirty log entries.
+- Added `dirty_log_ring` field to `VcpuFd` to access per-vCpu dirty rings.
+- Inserted fences in KvmDirtyLogRing iterator `next` for architectures with weak memory consistency that require Acquire/Release
+- Added `DirtyLogRingInfo` struct and `dirty_log_ring_info` field to `VmFd` to
+  track dirty ring configuration.
+- Added `enable_dirty_log_ring` function on `VmFd` to check corresponding 
+  capabilities and enable KVM's dirty log ring.
+- Added `VcpuFd::dirty_log_ring_iter()` to iterate over dirty guest frame numbers.
+- Added `VmFd::reset_dirty_rings()` to reset all dirty rings for the VM.
+
+- Plumb through KVM_CAP_DIRTY_LOG_RING as DirtyLogRing cap.
+
 ## v0.24.0
 
 ### Added

kvm-ioctls/src/cap.rs

@@ -169,4 +169,5 @@ pub enum Cap {
     NestedState = KVM_CAP_NESTED_STATE,
     #[cfg(target_arch = "x86_64")]
     X2ApicApi = KVM_CAP_X2APIC_API,
+    DirtyLogRing = KVM_CAP_DIRTY_LOG_RING,
 }