On Fri, 30 May 2014 19:48:13 +1000 Peter Crosthwaite <peter.crosthwa...@xilinx.com> wrote:
> On Fri, May 30, 2014 at 7:01 PM, Igor Mammedov <imamm...@redhat.com> wrote: > > On Fri, 30 May 2014 00:21:27 +1000 > > Peter Crosthwaite <peter.crosthwa...@xilinx.com> wrote: > > > >> On Tue, May 27, 2014 at 11:01 PM, Igor Mammedov <imamm...@redhat.com> > >> wrote: > >> > From: Vasilis Liaskovitis <vasilis.liaskovi...@profitbricks.com> > >> > > >> > Each hotplug-able memory slot is a DimmDevice. > >> > A hot-add operation for a DIMM: > >> > - creates a new DimmDevice and makes hotplug controller to map it into > >> > guest address space > >> > > >> > Hotplug operations are done through normal device_add commands. > >> > For migration case, all hotplugged DIMMs on source should be specified > >> > on target's command line using '-device' option with properties set to > >> > the same values as on source. > >> > > >> > To simplify review, patch introduces only DimmDevice QOM skeleton that > >> > will be extended by following patches to implement actual memory hotplug > >> > and related functions. > >> > > >> > Signed-off-by: Vasilis Liaskovitis <vasilis.liaskovi...@profitbricks.com> > >> > Signed-off-by: Igor Mammedov <imamm...@redhat.com> > >> > --- > >> > v4: > >> > drop DimmBus in favor of bus-less device hotplug > >> > rename property/field 'start' to 'addr' > >> > use defines for property names > >> > v3: > >> > pc: compile memhotplug on i386 target too > >> > v2: > >> > fix typo s/DimmBus/DimmDevice/ in doc comment > >> > s/klass/oc/;s/*/parent_obj/;a/gtk-doc markup/ > >> > --- > >> > default-configs/i386-softmmu.mak | 1 + > >> > default-configs/x86_64-softmmu.mak | 1 + > >> > hw/Makefile.objs | 1 + > >> > hw/mem/Makefile.objs | 1 + > >> > hw/mem/dimm.c | 103 > >> > ++++++++++++++++++++++++++++++++++++ > >> > include/hw/mem/dimm.h | 73 +++++++++++++++++++++++++ > >> > 6 files changed, 180 insertions(+), 0 deletions(-) > >> > create mode 100644 hw/mem/Makefile.objs > >> > create mode 100644 hw/mem/dimm.c > >> > create mode 100644 include/hw/mem/dimm.h > >> > > >> > diff --git a/default-configs/i386-softmmu.mak > >> > b/default-configs/i386-softmmu.mak > >> > index 37ef90f..8e08841 100644 > >> > --- a/default-configs/i386-softmmu.mak > >> > +++ b/default-configs/i386-softmmu.mak > >> > @@ -44,3 +44,4 @@ CONFIG_APIC=y > >> > CONFIG_IOAPIC=y > >> > CONFIG_ICC_BUS=y > >> > CONFIG_PVPANIC=y > >> > +CONFIG_MEM_HOTPLUG=y > >> > diff --git a/default-configs/x86_64-softmmu.mak > >> > b/default-configs/x86_64-softmmu.mak > >> > index 31bddce..66557ac 100644 > >> > --- a/default-configs/x86_64-softmmu.mak > >> > +++ b/default-configs/x86_64-softmmu.mak > >> > @@ -44,3 +44,4 @@ CONFIG_APIC=y > >> > CONFIG_IOAPIC=y > >> > CONFIG_ICC_BUS=y > >> > CONFIG_PVPANIC=y > >> > +CONFIG_MEM_HOTPLUG=y > >> > diff --git a/hw/Makefile.objs b/hw/Makefile.objs > >> > index d178b65..52a1464 100644 > >> > --- a/hw/Makefile.objs > >> > +++ b/hw/Makefile.objs > >> > @@ -29,6 +29,7 @@ devices-dirs-$(CONFIG_SOFTMMU) += usb/ > >> > devices-dirs-$(CONFIG_VIRTIO) += virtio/ > >> > devices-dirs-$(CONFIG_SOFTMMU) += watchdog/ > >> > devices-dirs-$(CONFIG_SOFTMMU) += xen/ > >> > +devices-dirs-$(CONFIG_MEM_HOTPLUG) += mem/ > >> > devices-dirs-y += core/ > >> > common-obj-y += $(devices-dirs-y) > >> > obj-y += $(devices-dirs-y) > >> > diff --git a/hw/mem/Makefile.objs b/hw/mem/Makefile.objs > >> > new file mode 100644 > >> > index 0000000..7563ef5 > >> > --- /dev/null > >> > +++ b/hw/mem/Makefile.objs > >> > @@ -0,0 +1 @@ > >> > +common-obj-$(CONFIG_MEM_HOTPLUG) += dimm.o > >> > diff --git a/hw/mem/dimm.c b/hw/mem/dimm.c > >> > new file mode 100644 > >> > index 0000000..bb81679 > >> > --- /dev/null > >> > +++ b/hw/mem/dimm.c > >> > @@ -0,0 +1,103 @@ > >> > +/* > >> > + * Dimm device for Memory Hotplug > >> > + * > >> > + * Copyright ProfitBricks GmbH 2012 > >> > + * Copyright (C) 2014 Red Hat Inc > >> > + * > >> > + * This library is free software; you can redistribute it and/or > >> > + * modify it under the terms of the GNU Lesser General Public > >> > + * License as published by the Free Software Foundation; either > >> > + * version 2 of the License, or (at your option) any later version. > >> > + * > >> > + * This library is distributed in the hope that it will be useful, > >> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > >> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > >> > + * Lesser General Public License for more details. > >> > + * > >> > + * You should have received a copy of the GNU Lesser General Public > >> > + * License along with this library; if not, see > >> > <http://www.gnu.org/licenses/> > >> > + */ > >> > + > >> > +#include "hw/mem/dimm.h" > >> > +#include "qemu/config-file.h" > >> > +#include "qapi/visitor.h" > >> > + > >> > +static Property dimm_properties[] = { > >> > + DEFINE_PROP_UINT64(DIMM_ADDR_PROP, DimmDevice, addr, 0), > >> > >> One of the long-standing rules of sysbus device design, is devices > >> should not have awareness of their memory mappings. Especially in > >> cases where that mapping is handled by buses and controllers (which is > >> the case in DIMM? - does the actual DIMM card have any awareness of > >> its own mapping?). > > Actual DIMM probably is not aware of address, and it doesn't use it by > > itself for any purpose. > > However it's important from interface POV, when user needs to add DIMM > > device > > at a specific address using CLI, -device_add dimm,addr=foo serves as a > > convenient way to carry that information to component that will do actual > > mapping and other components that will need it. > > In PC it's machine (servers as controller) and ACPI device, which implements > > APCI part of memory hotplug interface. > > > > Real HW doesn't need it since, it's fixed amount of slots and limited size > > of > > DIMMs supported by chipset, so it just hard-codes possible addresses > > for each slot. For VM it would severely limit flexibility though, > > forcing user to decide at QEMU startup time DIMM sizes per slot, > > he'd like to hot-add at runtime. So ability to hot-add arbitrary sized > > DIMMs, > > would require at migration time an interface that allows to say at what > > address dimm was mapped. Using dimm.addr for it is logical choice from user > > POV and provides simple and clear interface. > > > > > >> > >> That said I'm generally against that policy as sometimes devices > >> really do know their absolute address in real HW implementation. So > >> despite being generally against an old consensus I think this might be > >> ok. > >> > >> > + DEFINE_PROP_UINT32(DIMM_NODE_PROP, DimmDevice, node, 0), > >> > + DEFINE_PROP_INT32(DIMM_SLOT_PROP, DimmDevice, slot, > >> > DIMM_UNASSIGNED_SLOT), > >> > >> I think this slot property may however reduce the re-usability of DIMM > >> beyond PC. Is the concept of enumerated DIMM slots a DIMM level > >> feature or is it more PC specific? > > it's more a shortcut of place where to add device, similarly as we use 'bus' > > for specifying where to add device. > > So "bus=" args are parsed by the hotplug handling code in that case. > Perhaps this can be done the same - addr, slot and friends are parsed > by your machine level busless hotpug handling and passes info to > PC/ACPI and mapping code where they are actually used. Then you can > remove the PCisms from DIMM completely. Do you mean to extend current device_add hotplug mechanism, so that hotplug controller, would consume its own specific options that define how/where device should be added from what was supplied by -device dimm,foo... ??? PS: Is it ok to do on top of this series? /including renaming DimmDevice -> DIMMDevice/ > > Regards, > Peter > > > Slot was a natural choice since DIMMs are > > plugged in them. > > It's optional from DIMM POV though, so if user doesn't care he can ignore > > it. > > > > It also simplifies internal handling of hot-plugging a device on PC as it's > > serves as simple ID in interface between QEMU and ACPI tables. > > > > > >> > >> > + DEFINE_PROP_END_OF_LIST(), > >> > +}; > >> > + > >> > +static void dimm_get_size(Object *obj, Visitor *v, void *opaque, > >> > + const char *name, Error **errp) > >> > +{ > >> > + int64_t value; > >> > + MemoryRegion *mr; > >> > + DimmDevice *dimm = DIMM(obj); > >> > + > >> > + mr = host_memory_backend_get_memory(dimm->hostmem, errp); > >> > + value = memory_region_size(mr); > >> > + > >> > + visit_type_int(v, &value, name, errp); > >> > +} > >> > + > >> > +static void dimm_initfn(Object *obj) > >> > +{ > >> > + DimmDevice *dimm = DIMM(obj); > >> > + > >> > + object_property_add(obj, DIMM_SIZE_PROP, "int", dimm_get_size, > >> > + NULL, NULL, NULL, &error_abort); > >> > + object_property_add_link(obj, DIMM_MEMDEV_PROP, TYPE_MEMORY_BACKEND, > >> > + (Object **)&dimm->hostmem, > >> > + qdev_prop_allow_set_link_before_realize, > >> > + OBJ_PROP_LINK_UNREF_ON_RELEASE, > >> > + &error_abort); > >> > +} > >> > + > >> > +static void dimm_realize(DeviceState *dev, Error **errp) > >> > +{ > >> > + DimmDevice *dimm = DIMM(dev); > >> > + > >> > + if (!dimm->hostmem) { > >> > + error_setg(errp, "'" DIMM_MEMDEV_PROP "' property is not set"); > >> > + return; > >> > + } > >> > + > >> > + if (!dev->id) { > >> > + error_setg(errp, "'id' property is not set"); > >> > >> Can't implement an "anonymous" (or whatever) default? > > This check can be dropped to allow anonymous DIMMs. > > > > out of scope: > > Perhaps we should fix qdev_device_add(), to assign 'id' if it's missing > > using the name it auto-generates for child. > > > >> > >> > + return; > >> > + } > >> > +} > >> > + > >> > +static MemoryRegion *dimm_get_memory_region(DimmDevice *dimm) > >> > +{ > >> > + return host_memory_backend_get_memory(dimm->hostmem, &error_abort); > >> > +} > >> > + > >> > +static void dimm_class_init(ObjectClass *oc, void *data) > >> > +{ > >> > + DeviceClass *dc = DEVICE_CLASS(oc); > >> > + DimmDeviceClass *ddc = DIMM_CLASS(oc); > >> > + > >> > + dc->realize = dimm_realize; > >> > + dc->props = dimm_properties; > >> > + > >> > + ddc->get_memory_region = dimm_get_memory_region; > >> > +} > >> > + > >> > +static TypeInfo dimm_info = { > >> > + .name = TYPE_DIMM, > >> > + .parent = TYPE_DEVICE, > >> > + .instance_size = sizeof(DimmDevice), > >> > + .instance_init = dimm_initfn, > >> > + .class_init = dimm_class_init, > >> > + .class_size = sizeof(DimmDeviceClass), > >> > +}; > >> > + > >> > +static void dimm_register_types(void) > >> > +{ > >> > + type_register_static(&dimm_info); > >> > +} > >> > + > >> > +type_init(dimm_register_types) > >> > diff --git a/include/hw/mem/dimm.h b/include/hw/mem/dimm.h > >> > new file mode 100644 > >> > index 0000000..8839fb9 > >> > --- /dev/null > >> > +++ b/include/hw/mem/dimm.h > >> > @@ -0,0 +1,73 @@ > >> > +/* > >> > + * DIMM device > >> > + * > >> > + * Copyright ProfitBricks GmbH 2012 > >> > + * Copyright (C) 2013 Red Hat Inc > >> > + * > >> > + * Authors: > >> > + * Vasilis Liaskovitis <vasilis.liaskovi...@profitbricks.com> > >> > + * Igor Mammedov <imamm...@redhat.com> > >> > + * > >> > + * This work is licensed under the terms of the GNU GPL, version 2 or > >> > later. > >> > + * See the COPYING file in the top-level directory. > >> > + * > >> > + */ > >> > + > >> > +#ifndef QEMU_DIMM_H > >> > +#define QEMU_DIMM_H > >> > + > >> > +#include "exec/memory.h" > >> > +#include "sysemu/hostmem.h" > >> > +#include "hw/qdev.h" > >> > + > >> > +#define DEFAULT_DIMMSIZE (1024*1024*1024) > >> > + > >> > +#define TYPE_DIMM "dimm" > >> > +#define DIMM(obj) \ > >> > + OBJECT_CHECK(DimmDevice, (obj), TYPE_DIMM) > >> > +#define DIMM_CLASS(oc) \ > >> > + OBJECT_CLASS_CHECK(DimmDeviceClass, (oc), TYPE_DIMM) > >> > +#define DIMM_GET_CLASS(obj) \ > >> > + OBJECT_GET_CLASS(DimmDeviceClass, (obj), TYPE_DIMM) > >> > + > >> > +#define DIMM_ADDR_PROP "addr" > >> > +#define DIMM_SLOT_PROP "slot" > >> > +#define DIMM_NODE_PROP "node" > >> > +#define DIMM_SIZE_PROP "size" > >> > +#define DIMM_MEMDEV_PROP "memdev" > >> > + > >> > +#define DIMM_UNASSIGNED_SLOT -1 > >> > + > >> > +/** > >> > + * DimmDevice: > >> > + * @addr: starting guest physical address, where @DimmDevice is mapped. > >> > + * Default value: 0, means that address is auto-allocated. > >> > + * @node: numa node to which @DimmDevice is attached. > >> > + * @slot: slot number into which @DimmDevice is plugged in. > >> > + * Default value: -1, means that slot is auto-allocated. > >> > + * @hostmem: host memory backend providing memory for @DimmDevice > >> > + */ > >> > +typedef struct DimmDevice { > >> > >> DIMMDevice > > ok > > > >> > >> > + /* private */ > >> > + DeviceState parent_obj; > >> > + > >> > + /* public */ > >> > + ram_addr_t addr; > >> > + uint32_t node; > >> > + int32_t slot; > >> > + HostMemoryBackend *hostmem; > >> > +} DimmDevice; > >> > + > >> > +/** > >> > + * DimmDeviceClass: > >> > + * @get_memory_region: returns #MemoryRegion associated with @dimm > >> > + */ > >> > +typedef struct DimmDeviceClass { > >> > >> DIMMDeviceClass > > ok > > > >> > >> > + /* private */ > >> > + DeviceClass parent_class; > >> > + > >> > + /* public */ > >> > + MemoryRegion *(*get_memory_region)(DimmDevice *dimm); > >> > >> This would simply become a link getter if we had QOMified MemoryRegions :) > >> > >> Regards, > >> Peter > >> > >> > +} DimmDeviceClass; > >> > + > >> > +#endif > >> > -- > >> > 1.7.1 > >> > > >> > > >> > > > > > > -- > > Regards, > > Igor > > -- Regards, Igor
