On Fri, May 30, 2014 at 8:31 PM, Igor Mammedov <imamm...@redhat.com> wrote: > 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... > ??? >
Yes I think that general problem is worth solving. But not needed yet in this series. I think this is better solved by simply acknowleding that this API is PC specific and not claiming it to be generic DIMM (I replied with fuller explanation before I saw this mail). > PS: > Is it ok to do on top of this series? I guess so, but is there a commiter out there wanting to take this as is yet? Theres a few trivials as well as the mr->parent simplificaiton (plus whatever others come up with). > /including renaming DimmDevice -> DIMMDevice/ > Are the conflicts bad on the rebase? I notice also you have some patches that are already merged which is another good reason for a respin. Regards, Peter > >> >> 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 >