On Fri, Mar 31, 2017 at 04:41:44PM +0800, Haozhong Zhang wrote: > If option 'reserved-size=RSVD' is present, QEMU will reserve an > address range of size 'RSVD' after the ending address of pc-dimm > device. > > For the following example, > -object memory-backend-file,id=mem0,size=4G,... > -device nvdimm,id=dimm0,memdev=mem0,reserved-size=4K,...
"reserved-size" is not a clear name. I suggest calling the property
"num-flush-hints" (default 0). QEMU can calculate the actual size in
bytes.
-device nvdimm,num-flush-hints=1
QEMU will use one flush hint and reserve enough space (e.g. 1 page) for
the MMIO region.
> -device pc-dimm,id=dimm1,...
> if dimm0 is allocated to address N ~ N+4G, the address range of
> dimm1 will start from N+4G+4K or higher.
>
> Its current usage is to reserve spaces for flush hint addresses
> of nvdimm devices.
>
> Signed-off-by: Haozhong Zhang <haozhong.zh...@intel.com>
> ---
> hw/mem/pc-dimm.c | 48
> +++++++++++++++++++++++++++++++++++++++++++++---
> include/hw/mem/pc-dimm.h | 2 ++
> 2 files changed, 47 insertions(+), 3 deletions(-)
>
> diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
> index 9e8dab0..13dcd71 100644
> --- a/hw/mem/pc-dimm.c
> +++ b/hw/mem/pc-dimm.c
> @@ -28,6 +28,7 @@
> #include "sysemu/kvm.h"
> #include "trace.h"
> #include "hw/virtio/vhost.h"
> +#include "exec/address-spaces.h"
>
> typedef struct pc_dimms_capacity {
> uint64_t size;
> @@ -44,7 +45,12 @@ void pc_dimm_memory_plug(DeviceState *dev,
> MemoryHotplugState *hpms,
> MemoryRegion *vmstate_mr = ddc->get_vmstate_memory_region(dimm);
> Error *local_err = NULL;
> uint64_t existing_dimms_capacity = 0;
> - uint64_t addr;
> + uint64_t addr, size = memory_region_size(mr);
> +
> + size += object_property_get_int(OBJECT(dimm), PC_DIMM_RSVD_PROP,
> &local_err);
> + if (local_err) {
> + goto out;
> + }
>
> addr = object_property_get_int(OBJECT(dimm), PC_DIMM_ADDR_PROP,
> &local_err);
> if (local_err) {
> @@ -54,7 +60,7 @@ void pc_dimm_memory_plug(DeviceState *dev,
> MemoryHotplugState *hpms,
> addr = pc_dimm_get_free_addr(hpms->base,
> memory_region_size(&hpms->mr),
> !addr ? NULL : &addr, align,
> - memory_region_size(mr), &local_err);
> + size, &local_err);
> if (local_err) {
> goto out;
> }
> @@ -64,7 +70,7 @@ void pc_dimm_memory_plug(DeviceState *dev,
> MemoryHotplugState *hpms,
> goto out;
> }
>
> - if (existing_dimms_capacity + memory_region_size(mr) >
> + if (existing_dimms_capacity + size >
> machine->maxram_size - machine->ram_size) {
> error_setg(&local_err, "not enough space, currently 0x%" PRIx64
> " in use of total hot pluggable 0x" RAM_ADDR_FMT,
> @@ -315,6 +321,9 @@ uint64_t pc_dimm_get_free_addr(uint64_t
> address_space_start,
> PCDIMMDevice *dimm = item->data;
> uint64_t dimm_size = object_property_get_int(OBJECT(dimm),
> PC_DIMM_SIZE_PROP,
> + errp) +
> + object_property_get_int(OBJECT(dimm),
> + PC_DIMM_RSVD_PROP,
> errp);
> if (errp && *errp) {
> goto out;
> @@ -382,6 +391,37 @@ static void pc_dimm_check_memdev_is_busy(Object *obj,
> const char *name,
> error_propagate(errp, local_err);
> }
>
> +static void pc_dimm_get_reserved_size(Object *obj, Visitor *v, const char
> *name,
> + void *opaque, Error **errp)
> +{
> + PCDIMMDevice *dimm = PC_DIMM(obj);
> + uint64_t value = dimm->reserved_size;
> +
> + visit_type_size(v, name, &value, errp);
> +}
> +
> +static void pc_dimm_set_reserved_size(Object *obj, Visitor *v, const char
> *name,
> + void *opaque, Error **errp)
> +{
> + PCDIMMDevice *dimm = PC_DIMM(obj);
> + Error *local_err = NULL;
> + uint64_t value;
> +
> + if (dimm->reserved_size) {
> + error_setg(&local_err, "cannot change 'reserved-size'");
> + goto out;
> + }
> +
> + visit_type_size(v, name, &value, &local_err);
> + if (local_err) {
> + goto out;
> + }
> + dimm->reserved_size = value;
> +
> + out:
> + error_propagate(errp, local_err);
> +}
> +
> static void pc_dimm_init(Object *obj)
> {
> PCDIMMDevice *dimm = PC_DIMM(obj);
> @@ -393,6 +433,8 @@ static void pc_dimm_init(Object *obj)
> pc_dimm_check_memdev_is_busy,
> OBJ_PROP_LINK_UNREF_ON_RELEASE,
> &error_abort);
> + object_property_add(obj, PC_DIMM_RSVD_PROP, "int",
> pc_dimm_get_reserved_size,
> + pc_dimm_set_reserved_size, NULL, NULL, &error_abort);
> }
>
> static void pc_dimm_realize(DeviceState *dev, Error **errp)
> diff --git a/include/hw/mem/pc-dimm.h b/include/hw/mem/pc-dimm.h
> index 1e483f2..99c4dfd 100644
> --- a/include/hw/mem/pc-dimm.h
> +++ b/include/hw/mem/pc-dimm.h
> @@ -33,6 +33,7 @@
> #define PC_DIMM_NODE_PROP "node"
> #define PC_DIMM_SIZE_PROP "size"
> #define PC_DIMM_MEMDEV_PROP "memdev"
> +#define PC_DIMM_RSVD_PROP "reserved-size"
>
> #define PC_DIMM_UNASSIGNED_SLOT -1
>
> @@ -53,6 +54,7 @@ typedef struct PCDIMMDevice {
> uint64_t addr;
> uint32_t node;
> int32_t slot;
> + uint64_t reserved_size;
> HostMemoryBackend *hostmem;
> } PCDIMMDevice;
>
> --
> 2.10.1
>
>
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