Firecracker now lets guests move a virtio-pci BAR
Brief
A move outside the 64-bit MMIO window is refused.
Notes
Relocate: 4b4aa4944457 (Ilias Stamatis). PR #6095. A moved BAR survives snapshot restore.
Seccomp allowlist, not a bypass: d86d2472289a adds KVM_IOEVENTFD on the vCPU thread. PR #6094.
Free BAR on detach: 5916117221b1 PR #6136. Tests 35a041fd0cf2, abf5bcd089a6.
Not a recast of restore-swallow 7ffe7376. Not the ignored 761f88fb BAR-validation bundle.
Commit 4b4aa49444573fd5eed953633decae582b2cb2d3