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Re: [Qemu-devel] [RFC PATCH 1/3] hw/arm/virt: add hotplug memory support
From: |
Igor Mammedov |
Subject: |
Re: [Qemu-devel] [RFC PATCH 1/3] hw/arm/virt: add hotplug memory support |
Date: |
Mon, 1 Aug 2016 09:46:07 +0200 |
On Mon, 1 Aug 2016 00:35:35 +0000
"address@hidden" <address@hidden> wrote:
> Hi Peter,
>
> Thanks a lot for your comments! I answered in line below.
>
> > -----Original Message-----
> > From: Peter Maydell [mailto:address@hidden
> > Sent: Saturday, July 30, 2016 3:10 AM
> > To: 이광우(LEE KWANGWOO) MS SW
> > Cc: Xiao Guangrong; Michael S. Tsirkin; Igor Mammedov; Paolo Bonzini;
> > Richard Henderson; Eduardo
> > Habkost; Shannon Zhao; Shannon Zhao; QEMU Developers; qemu-arm; 정우석(CHUNG
> > WOO SUK) MS SW; 김현철(KIM
> > HYUNCHUL) MS SW
> > Subject: Re: [RFC PATCH 1/3] hw/arm/virt: add hotplug memory support
> >
> > On 20 July 2016 at 01:49, Kwangwoo Lee <address@hidden> wrote:
> > > Add hotplug memory feature on aarch64 virt platfom. This patch is
> > > required to emulate a DIMM type memory like NVDIMM.
> > >
> > > Signed-off-by: Kwangwoo Lee <address@hidden>
> > > ---
> > > default-configs/aarch64-softmmu.mak | 1 +
> > > hw/arm/virt.c | 110
> > > ++++++++++++++++++++++++++++++++++++
> > > include/hw/arm/virt.h | 3 +
> > > 3 files changed, 114 insertions(+)
> > >
> > > diff --git a/default-configs/aarch64-softmmu.mak
> > > b/default-configs/aarch64-softmmu.mak
> > > index 2449483..5790cd2 100644
> > > --- a/default-configs/aarch64-softmmu.mak
> > > +++ b/default-configs/aarch64-softmmu.mak
> > > @@ -7,3 +7,4 @@ CONFIG_AUX=y
> > > CONFIG_DDC=y
> > > CONFIG_DPCD=y
> > > CONFIG_XLNX_ZYNQMP=y
> > > +CONFIG_MEM_HOTPLUG=y
> > > diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> > > index a193b5a..f7ff411 100644
> > > --- a/hw/arm/virt.c
> > > +++ b/hw/arm/virt.c
> > > @@ -58,6 +58,8 @@
> > > #include "hw/smbios/smbios.h"
> > > #include "qapi/visitor.h"
> > > #include "standard-headers/linux/input.h"
> > > +#include "hw/mem/pc-dimm.h"
> > > +#include "hw/acpi/acpi.h"
> > >
> > > /* Number of external interrupt lines to configure the GIC with */
> > > #define NUM_IRQS 256
> > > @@ -91,6 +93,7 @@ typedef struct {
> > > bool secure;
> > > bool highmem;
> > > int32_t gic_version;
> > > + MemoryHotplugState hotplug_memory;
> > > } VirtMachineState;
> > >
> > > #define TYPE_VIRT_MACHINE MACHINE_TYPE_NAME("virt")
> > > @@ -1376,6 +1379,40 @@ static void machvirt_init(MachineState *machine)
> > > guest_info_state->machine_done.notify = virt_guest_info_machine_done;
> > > qemu_add_machine_init_done_notifier(&guest_info_state->machine_done);
> > >
> > > + /* initialize hotplug memory address space */
> > > + if (machine->ram_size < machine->maxram_size) {
> > > + ram_addr_t hotplug_mem_size = machine->maxram_size -
> > > machine->ram_size;
> > > +
> > > + if (machine->ram_slots > ACPI_MAX_RAM_SLOTS) {
> > > + error_report("unsupported amount of memory slots: %"PRIu64,
> >
> > "number of"
>
> OK. I'll fix this.
>
> > > + machine->ram_slots);
> > > + exit(EXIT_FAILURE);
> > > + }
> > > +
> > > + if (QEMU_ALIGN_UP(machine->maxram_size,
> > > + TARGET_PAGE_SIZE) != machine->maxram_size) {
> > > + error_report("maximum memory size must by aligned to
> > > multiple of "
> >
> > "must be"
>
> OK. I'll fix this
>
> > > + "%d bytes", TARGET_PAGE_SIZE);
> > > + exit(EXIT_FAILURE);
> > > + }
> > > +
> > > + vms->hotplug_memory.base =
> > > + ROUND_UP(vbi->memmap[VIRT_MEM].base +
> > > machine->ram_size,
> > > +
> > > ARCH_VIRT_HOTPLUG_MEM_ALIGN);
> > > +
> > > + if ((vms->hotplug_memory.base + hotplug_mem_size) <
> > > + hotplug_mem_size) {
> >
> > This expression is confusing. Is it trying to test for overflow?
> > When can that happen?
>
> Ah.. you are right. No need to check this. I'll remove this. Thanks!
>
> > > + error_report("unsupported amount of maximum memory: "
> > > RAM_ADDR_FMT,
> > > + machine->maxram_size);
> > > + exit(EXIT_FAILURE);
> > > + }
> > > +
> > > + memory_region_init(&vms->hotplug_memory.mr, OBJECT(vms),
> > > + "hotplug-memory", hotplug_mem_size);
> > > + memory_region_add_subregion(sysmem, vms->hotplug_memory.base,
> > > + &vms->hotplug_memory.mr);
> > > + }
> > > +
> > > vbi->bootinfo.ram_size = machine->ram_size;
> > > vbi->bootinfo.kernel_filename = machine->kernel_filename;
> > > vbi->bootinfo.kernel_cmdline = machine->kernel_cmdline;
> > > @@ -1448,9 +1485,75 @@ static void virt_set_gic_version(Object *obj,
> > > const char *value, Error **errp)
> > > }
> > > }
> > >
> > > +static void virt_dimm_plug(HotplugHandler *hotplug_dev,
> > > + DeviceState *dev, Error **errp)
> > > +{
> > > + VirtMachineState *vms = VIRT_MACHINE(hotplug_dev);
> > > + PCDIMMDevice *dimm = PC_DIMM(dev);
> > > + PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);
> > > + MemoryRegion *mr = ddc->get_memory_region(dimm);
> > > + Error *local_err = NULL;
> > > + uint64_t align = memory_region_get_alignment(mr);
> > > +
> > > + pc_dimm_memory_plug(dev, &vms->hotplug_memory, mr, align,
> > > &local_err);
> > > + if (local_err) {
> > > + goto out;
> > > + }
> > > +
> > > +out:
> > > + error_propagate(errp, local_err);
> > > +}
> > > +
> > > +static void virt_dimm_unplug(HotplugHandler *hotplug_dev,
> > > + DeviceState *dev, Error **errp)
> > > +{
> > > + VirtMachineState *vms = VIRT_MACHINE(hotplug_dev);
> > > + PCDIMMDevice *dimm = PC_DIMM(dev);
> > > + PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);
> > > + MemoryRegion *mr = ddc->get_memory_region(dimm);
> > > + Error *local_err = NULL;
> > > +
> > > + pc_dimm_memory_unplug(dev, &vms->hotplug_memory, mr);
> > > + object_unparent(OBJECT(dev));
> > > +
> > > + error_propagate(errp, local_err);
> > > +}
> > > +
> > > +static void virt_machinedevice_plug_cb(HotplugHandler *hotplug_dev,
> > > + DeviceState *dev, Error **errp)
> > > +{
> > > + if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> > > + virt_dimm_plug(hotplug_dev, dev, errp);
> > > + } else {
> > > + error_setg(errp, "acpi: device plug request for not supported
> > > device"
> >
> > "unsupported"
>
> OK. Will fix.
>
> > > + " type: %s", object_get_typename(OBJECT(dev)));
> > > + }
> > > +}
> > > +
> > > +static void virt_machinedevice_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, "acpi: device unplug for not supported device"
> >
> > "unsupported"
>
> OK. Will fix.
>
> > > + " type: %s", object_get_typename(OBJECT(dev)));
> > > + }
> > > +}
> > > +
> > > +static HotplugHandler *virt_get_hotplug_handler(MachineState *machine,
> > > + DeviceState *dev)
> > > +{
> > > + if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> > > + return HOTPLUG_HANDLER(machine);
> > > + }
> > > + return NULL;
> > > +}
> > > +
> > > static void virt_machine_class_init(ObjectClass *oc, void *data)
> > > {
> > > MachineClass *mc = MACHINE_CLASS(oc);
> > > + HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(oc);
> > >
> > > mc->init = machvirt_init;
> > > /* Start max_cpus at the maximum QEMU supports. We'll further
> > > restrict
> > > @@ -1462,6 +1565,9 @@ static void virt_machine_class_init(ObjectClass
> > > *oc, void *data)
> > > mc->block_default_type = IF_VIRTIO;
> > > mc->no_cdrom = 1;
> > > mc->pci_allow_0_address = true;
> > > + mc->get_hotplug_handler = virt_get_hotplug_handler;
> > > + hc->plug = virt_machinedevice_plug_cb;
> > > + hc->unplug = virt_machinedevice_unplug_cb;
> > > }
> > >
> > > static const TypeInfo virt_machine_info = {
> > > @@ -1471,6 +1577,10 @@ static const TypeInfo virt_machine_info = {
> > > .instance_size = sizeof(VirtMachineState),
> > > .class_size = sizeof(VirtMachineClass),
> > > .class_init = virt_machine_class_init,
> > > + .interfaces = (InterfaceInfo[]) {
> > > + { TYPE_HOTPLUG_HANDLER },
> > > + { }
> > > + },
> > > };
> > >
> > > static void machvirt_machine_init(void)
> > > diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
> > > index 9650193..35aa3cc 100644
> > > --- a/include/hw/arm/virt.h
> > > +++ b/include/hw/arm/virt.h
> > > @@ -45,6 +45,9 @@
> > >
> > > #define PPI(irq) ((irq) + 16)
> > >
> > > +/* 1GB alignment for hotplug memory region */
> > > +#define ARCH_VIRT_HOTPLUG_MEM_ALIGN (1ULL << 30)
> >
> > Where does the 1GB alignment come from? Why do we need 1GB
> > alignment for the base but only 1KB alignment for the size?
>
> The alignment value of hotplug_memory.base referred from i386 pc.c and ppc
> spapr.c.
> Could you suggest a proper range for this?
Base alignment comes from max supported hugepage size, while
size alignment should depend on backend's page size.
>
> > > +
> > > enum {
> > > VIRT_FLASH,
> > > VIRT_MEM,
> > > --
> > > 2.5.0
> >
> > thanks
> > -- PMM
>
> Best Regards,
> Kwangwoo Lee
- Re: [Qemu-devel] [RFC PATCH 1/3] hw/arm/virt: add hotplug memory support,
Igor Mammedov <=