https://bugzilla.redhat.com/show_bug.cgi?id=1441662
when I was enhancing libvirt's guest CPU configuration code to be able
to really ensure stable guest CPU ABI, I added a new attribute
//cpu/@check which is nicely backward compatible... an old libvirt will
just ignore it. However, even if check='full' will be ignored, an old
libvirt will still see the updated CPU definition (features added or
removed by the hypervisor will be shown there). And because we need QEMU
2.9.0 to check what features are going to be added or removed before we
actually start the domain, migrating such domain to an older libvirt or
QEMU may fail if QEMU enables a feature which is not supported by the
host CPU. Known features causing problems are, e.g., x2apic, hypervisor,
and arat. To make things even worse, updating a CPU definition with the
automatically added/removed features can be done since QEMU 1.5.0.
Even save/restore or snapshot revert on a single host running new
libvirt and QEMU < 2.9.0 is now affected by this regression.
This series fixes the regression by storing the original guest CPU
definition in migratable XML and sending the updated CPU in a side
channel (a migration or save cookie).
Version 2:
- see individual patches for changes
Jiri Denemark (20):
conf: Make error reporting in virCPUDefIsEqual optional
conf: Refactor virCPUDefParseXML
conf: Make virDomainSnapshotDefFormat easier to read
conf: Pass xmlopt to virDomainSnapshotDefFormat
qemu: Rename xml_len in virQEMUSaveHeader as data_len
qemu: Fix memory leaks in qemuDomainSaveImageOpen
qemu: Introduce virQEMUSaveData{New,Free}
qemu: Introduce virQEMUSaveDataFinish
qemu: Refactor qemuDomainSaveHeader
qemu: Introduce virQEMUSaveData structure
conf: Introduce virSaveCookie
conf: Add save cookie callbacks to xmlopt
qemu: Implement virSaveCookie object and callbacks
qemu: Store save cookie in save images and snapshots
qemu: Remember CPU def from domain start
qemu: Report the original CPU in migratable xml
qemu: Always send persistent XML during migration
qemu: Send updated CPU in migration cookie
qemu: Store updated CPU in save cookie
qemu: Use updated CPU when starting QEMU if possible
docs/formatsnapshot.html.in | 6 +
docs/schemas/domainsnapshot.rng | 7 +
po/POTFILES.in | 1 +
src/Makefile.am | 1 +
src/bhyve/bhyve_domain.c | 2 +-
src/conf/cpu_conf.c | 192 ++++++++--------
src/conf/cpu_conf.h | 12 +-
src/conf/domain_conf.c | 30 ++-
src/conf/domain_conf.h | 7 +-
src/conf/snapshot_conf.c | 40 +++-
src/conf/snapshot_conf.h | 3 +
src/conf/virsavecookie.c | 144 ++++++++++++
src/conf/virsavecookie.h | 62 +++++
src/cpu/cpu.c | 5 +-
src/esx/esx_driver.c | 2 +-
src/libvirt_private.syms | 10 +
src/libxl/libxl_conf.c | 2 +-
src/lxc/lxc_conf.c | 2 +-
src/openvz/openvz_driver.c | 2 +-
src/phyp/phyp_driver.c | 2 +-
src/qemu/qemu_capabilities.c | 2 +-
src/qemu/qemu_conf.c | 3 +-
src/qemu/qemu_domain.c | 207 +++++++++++++++--
src/qemu/qemu_domain.h | 22 ++
src/qemu/qemu_driver.c | 468 ++++++++++++++++++++++++++------------
src/qemu/qemu_migration.c | 18 +-
src/qemu/qemu_migration_cookie.c | 31 ++-
src/qemu/qemu_migration_cookie.h | 5 +
src/qemu/qemu_process.c | 37 ++-
src/qemu/qemu_process.h | 2 +
src/security/virt-aa-helper.c | 2 +-
src/test/test_driver.c | 3 +-
src/uml/uml_driver.c | 2 +-
src/vbox/vbox_common.c | 6 +-
src/vmware/vmware_driver.c | 3 +-
src/vmx/vmx.c | 2 +-
src/vz/vz_driver.c | 3 +-
src/xen/xen_driver.c | 2 +-
src/xenapi/xenapi_driver.c | 2 +-
tests/bhyveargv2xmltest.c | 2 +-
tests/cputest.c | 5 +-
tests/domainsnapshotxml2xmltest.c | 1 +
tests/testutils.c | 2 +-
43 files changed, 1047 insertions(+), 315 deletions(-)
create mode 100644 src/conf/virsavecookie.c
create mode 100644 src/conf/virsavecookie.h
--
2.13.0