Re: [RFC v1] arm/virt: Add memory hot remove support
Hi Shameer,
On 3/26/20 12:14 PM, Shameerali Kolothum Thodi wrote:
> Hi Eric,
>
>> -Original Message-
>> From: Auger Eric [mailto:eric.au...@redhat.com]
>> Sent: 26 March 2020 11:01
>> To: Shameerali Kolothum Thodi ;
>> qemu-devel@nongnu.org; qemu-...@nongnu.org
>> Cc: imamm...@redhat.com; peter.mayd...@linaro.org; m...@redhat.com;
>> xuwei (O) ; Zengtao (B) ;
>> Linuxarm ; Anshuman Khandual
>>
>> Subject: Re: [RFC v1] arm/virt: Add memory hot remove support
>>
>> Hi Shameer,
>>
>> On 3/18/20 1:37 PM, Shameer Kolothum wrote:
>>> This adds support for memory hot remove on arm/virt that
>>> uses acpi ged device.
>>
>> I gave this a try and it works fine if the PCDIMM slot was initially
>> hotplugged:
>> (QEMU) object-add qom-type=memory-backend-ram id=mem1
>> props.size=4294967296
>> {"return": {}}
>> (QEMU) device_add driver=pc-dimm id=pcdimm1 memdev=mem1
>> (QEMU) device_del id=pcdimm1
>> {"return": {}}
>>
>> on guest I can see:
>> [ 82.466321] Offlined Pages 262144
>> [ 82.541712] Offlined Pages 262144
>> [ 82.589236] Offlined Pages 262144
>> [ 82.969166] Offlined Pages 262144
>>
>> However I noticed that if qemu is launched directly with
>>
>> -m 16G,maxmem=32G,slots=2 \
>> -object memory-backend-ram,id=mem1,size=4G \
>> -device pc-dimm,memdev=mem1,id=dimm1,driver=pc-dimm -device
>>
>> and then in the qmp shell:
>> (QEMU) device_del id=dimm1
>>
>> the hot-unplug fails in guest:
>>
>> [ 78.897407] Offlined Pages 262144
>> [ 79.260811] Offlined Pages 262144
>> [ 79.308105] Offlined Pages 262144
>> [ 79.333675] page:fe00137d1f40 refcount:1 mapcount:0
>> mapping:0004ea9f20b1 index:0xaaab11c6e
>> [ 79.335927] anon flags: 0x17880024(uptodate|active|swapbacked)
>> [ 79.337571] raw: 17880024 dead0100
>> dead0122
>> 0004ea9f20b1
>> [ 79.339502] raw: 000aaab11c6e 0001
>> 0004fd4e3000
>> [ 79.341701] page dumped because: unmovable page
>> [ 79.342887] page->mem_cgroup:0004fd4e3000
>> [ 79.354729] page:fe00137d1f40 refcount:1 mapcount:0
>> mapping:0004ea9f20b1 index:0xaaab11c6e
>> [ 79.357012] anon flags: 0x17880024(uptodate|active|swapbacked)
>> [ 79.358658] raw: 17880024 dead0100
>> dead0122
>> 0004ea9f20b1
>> [ 79.360611] raw: 000aaab11c6e 0001
>> 0004fd4e3000
>> [ 79.362560] page dumped because: unmovable page
>> [ 79.363742] page->mem_cgroup:0004fd4e3000
>> [ 79.368636] memory memory20: Offline failed.
>>
>> I did not expect this. The PCDIMM slot in that case does not seem to be
>> interpreted as a hot-unpluggable one (?). I added Anshuman in cc.
>
> Could you please try adding "movable_node" to qemu guest kernel command line
> params.
> This will prevent any kernel allocation from hotplugable memory nodes which I
> think is
> causing the behavior you are seeing.
Effectively, when adding the movable_node option in the guest kernel
parameters, I get the following traces:
[ 29.581418] Offlined Pages 262144
[ 29.663605] Offlined Pages 262144
[ 29.714225] Offlined Pages 262144
[ 30.222953] Offlined Pages 262144
[ 30.314288] Built 1 zonelists, mobility grouping on. Total pages:
4076898
[ 30.316067] Policy zone: Normal
Thanks
Eric
>
> Thanks,
> Shameer
>
>
>> Thanks
>>
>> Eric
>>
>>
>>
>>>
>>> Signed-off-by: Shameer Kolothum
>>> ---
>>> -RFC because linux kernel support for mem hot remove is just queued
>>> for 5.7[1].
>>> -Tested with guest kernel 5.6-rc5 + [1]
>>>
>>> 1. https://patchwork.kernel.org/cover/11419301/
>>> ---
>>> hw/acpi/generic_event_device.c | 28 +
>>> hw/arm/virt.c | 56
>> --
>>> 2 files changed, 82 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/hw/acpi/generic_event_device.c
>> b/hw/acpi/generic_event_device.c
>>> index 021ed2bf23..3e28c110fa 100644
>>> --- a/hw/acpi/generic_event_device.c
>>> +++ b/hw/acpi/generic_event_device.c
>>> @@ -182,6 +182,32 @@ static void
>> acpi_ged_device_plug_cb(HotplugHandler *hotplug_dev,
>>> }
>>> }
>>>
>>> +static void acpi_ged_unplug_request_cb(HotplugHandler *hotp
RE: [RFC v1] arm/virt: Add memory hot remove support
Hi Eric,
> -Original Message-
> From: Auger Eric [mailto:eric.au...@redhat.com]
> Sent: 26 March 2020 11:01
> To: Shameerali Kolothum Thodi ;
> qemu-devel@nongnu.org; qemu-...@nongnu.org
> Cc: imamm...@redhat.com; peter.mayd...@linaro.org; m...@redhat.com;
> xuwei (O) ; Zengtao (B) ;
> Linuxarm ; Anshuman Khandual
>
> Subject: Re: [RFC v1] arm/virt: Add memory hot remove support
>
> Hi Shameer,
>
> On 3/18/20 1:37 PM, Shameer Kolothum wrote:
> > This adds support for memory hot remove on arm/virt that
> > uses acpi ged device.
>
> I gave this a try and it works fine if the PCDIMM slot was initially
> hotplugged:
> (QEMU) object-add qom-type=memory-backend-ram id=mem1
> props.size=4294967296
> {"return": {}}
> (QEMU) device_add driver=pc-dimm id=pcdimm1 memdev=mem1
> (QEMU) device_del id=pcdimm1
> {"return": {}}
>
> on guest I can see:
> [ 82.466321] Offlined Pages 262144
> [ 82.541712] Offlined Pages 262144
> [ 82.589236] Offlined Pages 262144
> [ 82.969166] Offlined Pages 262144
>
> However I noticed that if qemu is launched directly with
>
> -m 16G,maxmem=32G,slots=2 \
> -object memory-backend-ram,id=mem1,size=4G \
> -device pc-dimm,memdev=mem1,id=dimm1,driver=pc-dimm -device
>
> and then in the qmp shell:
> (QEMU) device_del id=dimm1
>
> the hot-unplug fails in guest:
>
> [ 78.897407] Offlined Pages 262144
> [ 79.260811] Offlined Pages 262144
> [ 79.308105] Offlined Pages 262144
> [ 79.333675] page:fe00137d1f40 refcount:1 mapcount:0
> mapping:0004ea9f20b1 index:0xaaab11c6e
> [ 79.335927] anon flags: 0x17880024(uptodate|active|swapbacked)
> [ 79.337571] raw: 17880024 dead0100
> dead0122
> 0004ea9f20b1
> [ 79.339502] raw: 000aaab11c6e 0001
> 0004fd4e3000
> [ 79.341701] page dumped because: unmovable page
> [ 79.342887] page->mem_cgroup:0004fd4e3000
> [ 79.354729] page:fe00137d1f40 refcount:1 mapcount:0
> mapping:0004ea9f20b1 index:0xaaab11c6e
> [ 79.357012] anon flags: 0x17880024(uptodate|active|swapbacked)
> [ 79.358658] raw: 17880024 dead0100
> dead0122
> 0004ea9f20b1
> [ 79.360611] raw: 000aaab11c6e 0001
> 0004fd4e3000
> [ 79.362560] page dumped because: unmovable page
> [ 79.363742] page->mem_cgroup:0004fd4e3000
> [ 79.368636] memory memory20: Offline failed.
>
> I did not expect this. The PCDIMM slot in that case does not seem to be
> interpreted as a hot-unpluggable one (?). I added Anshuman in cc.
Could you please try adding "movable_node" to qemu guest kernel command line
params.
This will prevent any kernel allocation from hotplugable memory nodes which I
think is
causing the behavior you are seeing.
Thanks,
Shameer
> Thanks
>
> Eric
>
>
>
> >
> > Signed-off-by: Shameer Kolothum
> > ---
> > -RFC because linux kernel support for mem hot remove is just queued
> > for 5.7[1].
> > -Tested with guest kernel 5.6-rc5 + [1]
> >
> > 1. https://patchwork.kernel.org/cover/11419301/
> > ---
> > hw/acpi/generic_event_device.c | 28 +
> > hw/arm/virt.c | 56
> --
> > 2 files changed, 82 insertions(+), 2 deletions(-)
> >
> > diff --git a/hw/acpi/generic_event_device.c
> b/hw/acpi/generic_event_device.c
> > index 021ed2bf23..3e28c110fa 100644
> > --- a/hw/acpi/generic_event_device.c
> > +++ b/hw/acpi/generic_event_device.c
> > @@ -182,6 +182,32 @@ static void
> acpi_ged_device_plug_cb(HotplugHandler *hotplug_dev,
> > }
> > }
> >
> > +static void acpi_ged_unplug_request_cb(HotplugHandler *hotplug_dev,
> > + DeviceState *dev, Error
> **errp)
> > +{
> > +AcpiGedState *s = ACPI_GED(hotplug_dev);
> > +
> > +if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> > +acpi_memory_unplug_request_cb(hotplug_dev,
> >memhp_state, dev, errp);
> > +} else {
> > +error_setg(errp, "acpi: device unplug request for unsupported
> device"
> > + " type: %s", object_get_typename(OBJECT(dev)));
> > +}
> > +}
> > +
> > +static void acpi_ged_unplug_cb(HotplugHandler *hotplug_dev,
> > + DeviceState *dev, Error **errp)
> > +{
> > +AcpiGedState *s = ACPI_GED(hotplug_dev);
> > +
> > +if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> > +
Re: [RFC v1] arm/virt: Add memory hot remove support
Hi Shameer,
On 3/18/20 1:37 PM, Shameer Kolothum wrote:
> This adds support for memory hot remove on arm/virt that
> uses acpi ged device.
I gave this a try and it works fine if the PCDIMM slot was initially
hotplugged:
(QEMU) object-add qom-type=memory-backend-ram id=mem1 props.size=4294967296
{"return": {}}
(QEMU) device_add driver=pc-dimm id=pcdimm1 memdev=mem1
(QEMU) device_del id=pcdimm1
{"return": {}}
on guest I can see:
[ 82.466321] Offlined Pages 262144
[ 82.541712] Offlined Pages 262144
[ 82.589236] Offlined Pages 262144
[ 82.969166] Offlined Pages 262144
However I noticed that if qemu is launched directly with
-m 16G,maxmem=32G,slots=2 \
-object memory-backend-ram,id=mem1,size=4G \
-device pc-dimm,memdev=mem1,id=dimm1,driver=pc-dimm -device
and then in the qmp shell:
(QEMU) device_del id=dimm1
the hot-unplug fails in guest:
[ 78.897407] Offlined Pages 262144
[ 79.260811] Offlined Pages 262144
[ 79.308105] Offlined Pages 262144
[ 79.333675] page:fe00137d1f40 refcount:1 mapcount:0
mapping:0004ea9f20b1 index:0xaaab11c6e
[ 79.335927] anon flags: 0x17880024(uptodate|active|swapbacked)
[ 79.337571] raw: 17880024 dead0100 dead0122
0004ea9f20b1
[ 79.339502] raw: 000aaab11c6e 0001
0004fd4e3000
[ 79.341701] page dumped because: unmovable page
[ 79.342887] page->mem_cgroup:0004fd4e3000
[ 79.354729] page:fe00137d1f40 refcount:1 mapcount:0
mapping:0004ea9f20b1 index:0xaaab11c6e
[ 79.357012] anon flags: 0x17880024(uptodate|active|swapbacked)
[ 79.358658] raw: 17880024 dead0100 dead0122
0004ea9f20b1
[ 79.360611] raw: 000aaab11c6e 0001
0004fd4e3000
[ 79.362560] page dumped because: unmovable page
[ 79.363742] page->mem_cgroup:0004fd4e3000
[ 79.368636] memory memory20: Offline failed.
I did not expect this. The PCDIMM slot in that case does not seem to be
interpreted as a hot-unpluggable one (?). I added Anshuman in cc.
Thanks
Eric
>
> Signed-off-by: Shameer Kolothum
> ---
> -RFC because linux kernel support for mem hot remove is just queued
> for 5.7[1].
> -Tested with guest kernel 5.6-rc5 + [1]
>
> 1. https://patchwork.kernel.org/cover/11419301/
> ---
> hw/acpi/generic_event_device.c | 28 +
> hw/arm/virt.c | 56 --
> 2 files changed, 82 insertions(+), 2 deletions(-)
>
> diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c
> index 021ed2bf23..3e28c110fa 100644
> --- a/hw/acpi/generic_event_device.c
> +++ b/hw/acpi/generic_event_device.c
> @@ -182,6 +182,32 @@ static void acpi_ged_device_plug_cb(HotplugHandler
> *hotplug_dev,
> }
> }
>
> +static void acpi_ged_unplug_request_cb(HotplugHandler *hotplug_dev,
> + DeviceState *dev, Error **errp)
> +{
> +AcpiGedState *s = ACPI_GED(hotplug_dev);
> +
> +if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> +acpi_memory_unplug_request_cb(hotplug_dev, >memhp_state, dev,
> errp);
> +} else {
> +error_setg(errp, "acpi: device unplug request for unsupported device"
> + " type: %s", object_get_typename(OBJECT(dev)));
> +}
> +}
> +
> +static void acpi_ged_unplug_cb(HotplugHandler *hotplug_dev,
> + DeviceState *dev, Error **errp)
> +{
> +AcpiGedState *s = ACPI_GED(hotplug_dev);
> +
> +if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> +acpi_memory_unplug_cb(>memhp_state, dev, errp);
> +} else {
> +error_setg(errp, "acpi: device unplug for unsupported device"
> + " type: %s", object_get_typename(OBJECT(dev)));
> +}
> +}
> +
> static void acpi_ged_send_event(AcpiDeviceIf *adev, AcpiEventStatusBits ev)
> {
> AcpiGedState *s = ACPI_GED(adev);
> @@ -286,6 +312,8 @@ static void acpi_ged_class_init(ObjectClass *class, void
> *data)
> dc->vmsd = _acpi_ged;
>
> hc->plug = acpi_ged_device_plug_cb;
> +hc->unplug_request = acpi_ged_unplug_request_cb;
> +hc->unplug = acpi_ged_unplug_cb;
>
> adevc->send_event = acpi_ged_send_event;
> }
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index 94f93dda54..91974e4e80 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -2096,11 +2096,62 @@ static void
> virt_machine_device_plug_cb(HotplugHandler *hotplug_dev,
> }
> }
>
> +static void virt_dimm_unplug_request(HotplugHandler *hotplug_dev,
> + DeviceState *dev, Error **errp)
> +{
> +VirtMachineState *vms = VIRT_MACHINE(hotplug_dev);
> +Error *local_err = NULL;
> +
> +if (!vms->acpi_dev) {
> +error_setg(errp,
> + "memory hotplug is not enabled: missing acpi-ged device");
> +goto out;
> +}
> +
> +hotplug_handler_unplug_request(HOTPLUG_HANDLER(vms->acpi_dev), dev,
> +
Re: [RFC v1] arm/virt: Add memory hot remove support
On Wed, 18 Mar 2020 12:37:22 +
Shameer Kolothum wrote:
> This adds support for memory hot remove on arm/virt that
> uses acpi ged device.
>
> Signed-off-by: Shameer Kolothum
Looks fine to me,
please repost once 5.0 is released.
> ---
> -RFC because linux kernel support for mem hot remove is just queued
> for 5.7[1].
> -Tested with guest kernel 5.6-rc5 + [1]
>
> 1. https://patchwork.kernel.org/cover/11419301/
> ---
> hw/acpi/generic_event_device.c | 28 +
> hw/arm/virt.c | 56 --
> 2 files changed, 82 insertions(+), 2 deletions(-)
>
> diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c
> index 021ed2bf23..3e28c110fa 100644
> --- a/hw/acpi/generic_event_device.c
> +++ b/hw/acpi/generic_event_device.c
> @@ -182,6 +182,32 @@ static void acpi_ged_device_plug_cb(HotplugHandler
> *hotplug_dev,
> }
> }
>
> +static void acpi_ged_unplug_request_cb(HotplugHandler *hotplug_dev,
> + DeviceState *dev, Error **errp)
> +{
> +AcpiGedState *s = ACPI_GED(hotplug_dev);
> +
> +if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> +acpi_memory_unplug_request_cb(hotplug_dev, >memhp_state, dev,
> errp);
> +} else {
> +error_setg(errp, "acpi: device unplug request for unsupported device"
> + " type: %s", object_get_typename(OBJECT(dev)));
> +}
> +}
> +
> +static void acpi_ged_unplug_cb(HotplugHandler *hotplug_dev,
> + DeviceState *dev, Error **errp)
> +{
> +AcpiGedState *s = ACPI_GED(hotplug_dev);
> +
> +if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> +acpi_memory_unplug_cb(>memhp_state, dev, errp);
> +} else {
> +error_setg(errp, "acpi: device unplug for unsupported device"
> + " type: %s", object_get_typename(OBJECT(dev)));
> +}
> +}
> +
> static void acpi_ged_send_event(AcpiDeviceIf *adev, AcpiEventStatusBits ev)
> {
> AcpiGedState *s = ACPI_GED(adev);
> @@ -286,6 +312,8 @@ static void acpi_ged_class_init(ObjectClass *class, void
> *data)
> dc->vmsd = _acpi_ged;
>
> hc->plug = acpi_ged_device_plug_cb;
> +hc->unplug_request = acpi_ged_unplug_request_cb;
> +hc->unplug = acpi_ged_unplug_cb;
>
> adevc->send_event = acpi_ged_send_event;
> }
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index 94f93dda54..91974e4e80 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -2096,11 +2096,62 @@ static void
> virt_machine_device_plug_cb(HotplugHandler *hotplug_dev,
> }
> }
>
> +static void virt_dimm_unplug_request(HotplugHandler *hotplug_dev,
> + DeviceState *dev, Error **errp)
> +{
> +VirtMachineState *vms = VIRT_MACHINE(hotplug_dev);
> +Error *local_err = NULL;
> +
> +if (!vms->acpi_dev) {
> +error_setg(errp,
> + "memory hotplug is not enabled: missing acpi-ged device");
> +goto out;
> +}
> +
> +hotplug_handler_unplug_request(HOTPLUG_HANDLER(vms->acpi_dev), dev,
> + _err);
> +out:
> +error_propagate(errp, local_err);
> +}
> +
> +static void virt_dimm_unplug(HotplugHandler *hotplug_dev,
> + DeviceState *dev, Error **errp)
> +{
> +VirtMachineState *vms = VIRT_MACHINE(hotplug_dev);
> +Error *local_err = NULL;
> +
> +hotplug_handler_unplug(HOTPLUG_HANDLER(vms->acpi_dev), dev, _err);
> +if (local_err) {
> +goto out;
> +}
> +
> +pc_dimm_unplug(PC_DIMM(dev), MACHINE(vms));
> +object_property_set_bool(OBJECT(dev), false, "realized", NULL);
> +
> + out:
> +error_propagate(errp, local_err);
> +}
> +
> static void virt_machine_device_unplug_request_cb(HotplugHandler
> *hotplug_dev,
>DeviceState *dev, Error **errp)
> {
> -error_setg(errp, "device unplug request for unsupported device"
> - " type: %s", object_get_typename(OBJECT(dev)));
> +if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> +virt_dimm_unplug_request(hotplug_dev, dev, errp);
> +} else {
> +error_setg(errp, "device unplug request for unsupported device"
> + " type: %s", object_get_typename(OBJECT(dev)));
> +}
> +}
> +
> +static void virt_machine_device_unplug_cb(HotplugHandler *hotplug_dev,
> + DeviceState *dev, Error **errp)
> +{
> +if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> +virt_dimm_unplug(hotplug_dev, dev, errp);
> +} else {
> +error_setg(errp, "virt: device unplug for unsupported device"
> + " type: %s", object_get_typename(OBJECT(dev)));
> +}
> }
>
> static HotplugHandler *virt_machine_get_hotplug_handler(MachineState
> *machine,
> @@ -2181,6 +2232,7 @@ static void virt_machine_class_init(ObjectClass *oc,
> void *data)
>
