Re: [Qemu-devel] [PATCH v4 00/16] pc: add CPU hot-add/hot-remove with device_add/device_del

[Igor Mammedov]

On Wed, 10 Aug 2016 15:56:24 +0200
Eduardo Otubo <address@hidden> wrote:

> On Tue, Jul 19, 2016 at 12=59=36AM +0300, Michael S. Tsirkin wrote:
> > On Thu, Jul 14, 2016 at 06:54:29PM +0200, Igor Mammedov wrote:  
> > > Changelog:  
> > 
> > So for pc and apic bits:
> > 
> > Reviewed-by: Michael S. Tsirkin <address@hidden>
> > 
> > Since Eduardo picked up first part of this, feel free
> > to merge the rest too.  
> 
> Hi Igor,
> 
> I was a little curios about the state of this feature. Is this going to
> make it to 2.7?
it's merged

> 
> Best regards,
> 
> > 
> > 
> >   
> > >   since v3:
> > >     * rebase on top of x86-next tree as it's already applied 1-6/19 from 
> > > v3
> > >       (so they are could be omitted from v4)
> > >     * set apic-state to NULL after destroying it in unrealize()
> > >     * fix places where I forgot to print X86CPUTopoInfo fields as %u
> > >     * move "pc: implement query-hotpluggable-cpus callback" after
> > >       patch that enables device_add cpu
> > >     * extract counting of present cpus in possible_cpus into a separate 
> > > helper
> > >     * newly added patches:
> > >         * pc: forbid BSP removal
> > >         * pc: enforce adding CPUs contiguously and removing them in 
> > > opposit order
> > >         * apic: kvm-apic: fix crash due to access to freed memory region
> > >     * update Reviewed-bys
> > >   since v2:
> > >     * use 0xFFFFFFFF for UNASSIGNED_APIC_ID instead of UINT32_MAX
> > >     * add comment why 0xFFFFFFFF could be used for UNASSIGNED_APIC_ID
> > >     * print topo ids is unsigned
> > >     * print APIC ID as hex
> > >     * print topo ids calculated from APIC ID beside it
> > >     * add extra patch to fix migration failure due to APIC's instance_id 
> > > mismatch
> > >   since v1:
> > >     * s/pc_find_cpu/pc_find_cpu_slot/ + add comment to it
> > >     * add more sanity checks for socket-id/core-id/thread-id and 'apic'
> > >       properties
> > >     * include device_del cpu patches and related fixes to x86 CPU/apic
> > > 
> > > Series enabling usage of -device/device_add for adding CPUs as devices
> > > and device_del for removing them. Using -device/device_add in combination
> > > with query-hotpluggable-cpus QMP command allows to hotplug CPUs at any
> > > not used possition and then safely migrate QEMU instance by specifying
> > > hotadded CPUs on target with help of -device CLI option like with any
> > > other device.
> > > Having been able to replicate exact topology on taggert with -device CPUs
> > > also opens poosibility to hot-remove CPUs, which this series does by
> > > enabling to use device_del with x86 CPUs.
> > > 
> > > 
> > > git tree for testing:
> > >   https://github.com/imammedo/qemu.git dev_del_cpu_v4
> > > for viewing:
> > >   https://github.com/imammedo/qemu/commits/dev_del_cpu_v4
> > > 
> > > Tested with RHEL7.2 guest including ping/pong migration with 
> > > adding/removing
> > > CPUs in between.
> > > 
> > > CC: address@hidden
> > > CC: address@hidden
> > > CC: address@hidden
> > > CC: address@hidden
> > > CC: Bandan Das <address@hidden>
> > > 
> > > Igor Mammedov (16):
> > >   pc: set APIC ID based on socket/core/thread ids if it's not been set
> > >     yet
> > >   pc: delay setting number of boot CPUs to machine_done time
> > >   pc: register created initial and hotpluged CPUs in one place
> > >     pc_cpu_plug()
> > >   pc: forbid BSP removal
> > >   pc: enforce adding CPUs contiguously and removing them in opposit
> > >     order
> > >   pc: cpu: allow device_add to be used with x86 cpu
> > >   pc: implement query-hotpluggable-cpus callback
> > >   apic: move MAX_APICS check to 'apic' class
> > >   apic: drop APICCommonState.idx and use APIC ID as index in
> > >     local_apics[]
> > >   apic: kvm-apic: fix crash due to access to freed memory region
> > >   (kvm)apic: add unrealize callbacks
> > >   apic: use apic_id as apic's migration instance_id
> > >   target-i386: cpu: do not ignore error and fix apic parent
> > >   target-i386: fix apic object leak when CPU is deleted
> > >   target-i386: add x86_cpu_unrealizefn()
> > >   pc: make device_del CPU work for x86 CPUs
> > > 
> > >  include/hw/i386/apic_internal.h |   5 +-
> > >  include/hw/i386/pc.h            |   5 ++
> > >  hw/i386/kvm/apic.c              |   9 +-
> > >  hw/i386/pc.c                    | 183 
> > > ++++++++++++++++++++++++++++++++++------
> > >  hw/intc/apic.c                  |  26 +++++-
> > >  hw/intc/apic_common.c           |  33 ++++++--
> > >  qmp-commands.hx                 |  15 ++++
> > >  target-i386/cpu.c               |  23 ++++-
> > >  8 files changed, 251 insertions(+), 48 deletions(-)
> > > 
> > > -- 
> > > 2.7.4  
>