Jiri Denemark ac120f1855 cpu: x86: Check for invalid CPU data from hypervisor
Recently a kernel bug caused QEMU to report a CPU feature as enabled
while listing it in the "unavailable-features" list of features that
were requested, but could not be enabled. The feature was actually
enabled, but we marked it as disabled when starting a domain. Later when
the domain is migrated, the destination requests the feature to be
disabled, which breaks the guest ABI or if we are lucky QEMU just fails
to load the migration stream.

Let's make similar bugs more visible in the future by refusing to even
start the domain.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2024-03-05 16:00:19 +01:00
..
2024-02-26 11:03:51 +01:00
2024-01-15 14:56:35 +01:00
2024-02-26 11:03:51 +01:00
2024-02-02 10:58:21 +01:00
2024-02-02 10:58:21 +01:00

       libvirt library code README
       ===========================

The directory provides the bulk of the libvirt codebase. Everything
except for the libvirtd daemon and client tools. The build uses a
large number of libtool convenience libraries - one for each child
directory, and then links them together for the final libvirt.so,
although some bits get linked directly to libvirtd daemon instead.

The files directly in this directory are supporting the public API
entry points & data structures.

There are two core shared modules to be aware of:

 * util/  - a collection of shared APIs that can be used by any
            code. This directory is always in the include path
            for all things built

 * conf/  - APIs for parsing / manipulating all the official XML
            files used by the public API. This directory is only
            in the include path for driver implementation modules

 * vmx/   - VMware VMX config handling (used by esx/ and vmware/)


Then there are the hypervisor implementations:

 * bhyve         - bhyve - The BSD Hypervisor
 * esx/          - VMware ESX and GSX support using vSphere API over SOAP
 * hyperv/       - Microsoft Hyper-V support using WinRM
 * lxc/          - Linux Native Containers
 * openvz/       - OpenVZ containers using cli tools
 * qemu/         - QEMU / KVM using qemu CLI/monitor
 * remote/       - Generic libvirt native RPC client
 * test/         - A "mock" driver for testing
 * vbox/         - Virtual Box using native API
 * vmware/       - VMware Workstation and Player using the vmrun tool
 * xen/          - Xen using hypercalls, XenD SEXPR & XenStore


Finally some secondary drivers that are shared for several HVs.
Currently these are used by LXC, OpenVZ, QEMU and Xen drivers.
The ESX, Hyper-V, Remote, Test & VirtualBox drivers all
implement the secondary drivers directly

 * cpu/          - CPU feature management
 * interface/    - Host network interface management
 * network/      - Virtual NAT networking
 * nwfilter/     - Network traffic filtering rules
 * node_device/  - Host device enumeration
 * secret/       - Secret management
 * security/     - Mandatory access control drivers
 * storage/      - Storage management drivers


Since both the hypervisor and secondary drivers can be built as
dlopen()able modules, it is *FORBIDDEN* to have build dependencies
between these directories. Drivers are only allowed to depend on
the public API, and the internal APIs in the util/ and conf/
directories