Hello Thomas,
>
> QEMU currently crashes when trying to use a 'pc-dimm' on the pseries
> machine without specifying its 'memdev' property. This happens because
> pc_dimm_get_memory_region() does not check whether the 'memdev' property
> has properly been set by the user. Looking closer at this function, it's
> also obvious that it is using &error_abort to call another function - and
> this is bad in a function that is used in the hot-plugging calling chain
> since this can also cause QEMU to exit unexpectedly.
In place of checking if 'memdev' is already allocated/present while fetching
'get_functions' every place. If 'memdev' is required for memory hotplug
operation
can we just put a check at some common place and don't start or instantiate if
'memdev' is not present.
I can see:
'pc_dimm_realize' function checks for : in my case prints warning
and avoid Qemu to start.
...
...
if (!dimm->hostmem) {
error_setg(errp, "'" PC_DIMM_MEMDEV_PROP "' property is not set");
return;
}
...
Thanks,
Pankaj
>
> So let's fix these issues in a proper way now: Add a "Error **errp"
> parameter to pc_dimm_get_memory_region() which we use in case the 'memdev'
> property has not been set by the user, and which we can use instead of
> the &error_abort, and change the callers of get_memory_region() to make
> use of this "errp" parameter for proper error checking.
>
> Signed-off-by: Thomas Huth <th...@redhat.com>
> ---
> hw/i386/pc.c | 14 ++++++++++++--
> hw/mem/nvdimm.c | 2 +-
> hw/mem/pc-dimm.c | 14 +++++++++++---
> hw/ppc/spapr.c | 42 ++++++++++++++++++++++++++++++------------
> include/hw/mem/pc-dimm.h | 2 +-
> 5 files changed, 55 insertions(+), 19 deletions(-)
>
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 5943539..2108104 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -1691,10 +1691,15 @@ static void pc_dimm_plug(HotplugHandler *hotplug_dev,
> PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
> PCDIMMDevice *dimm = PC_DIMM(dev);
> PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);
> - MemoryRegion *mr = ddc->get_memory_region(dimm);
> + MemoryRegion *mr;
> uint64_t align = TARGET_PAGE_SIZE;
> bool is_nvdimm = object_dynamic_cast(OBJECT(dev), TYPE_NVDIMM);
>
> + mr = ddc->get_memory_region(dimm, &local_err);
> + if (local_err) {
> + goto out;
> + }
> +
> if (memory_region_get_alignment(mr) && pcmc->enforce_aligned_dimm) {
> align = memory_region_get_alignment(mr);
> }
> @@ -1758,10 +1763,15 @@ static void pc_dimm_unplug(HotplugHandler
> *hotplug_dev,
> PCMachineState *pcms = PC_MACHINE(hotplug_dev);
> PCDIMMDevice *dimm = PC_DIMM(dev);
> PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);
> - MemoryRegion *mr = ddc->get_memory_region(dimm);
> + MemoryRegion *mr;
> HotplugHandlerClass *hhc;
> Error *local_err = NULL;
>
> + mr = ddc->get_memory_region(dimm, &local_err);
> + if (local_err) {
> + goto out;
> + }
> +
> hhc = HOTPLUG_HANDLER_GET_CLASS(pcms->acpi_dev);
> hhc->unplug(HOTPLUG_HANDLER(pcms->acpi_dev), dev, &local_err);
>
> diff --git a/hw/mem/nvdimm.c b/hw/mem/nvdimm.c
> index db896b0..952fce5 100644
> --- a/hw/mem/nvdimm.c
> +++ b/hw/mem/nvdimm.c
> @@ -71,7 +71,7 @@ static void nvdimm_init(Object *obj)
> NULL, NULL);
> }
>
> -static MemoryRegion *nvdimm_get_memory_region(PCDIMMDevice *dimm)
> +static MemoryRegion *nvdimm_get_memory_region(PCDIMMDevice *dimm, Error
> **errp)
> {
> NVDIMMDevice *nvdimm = NVDIMM(dimm);
>
> diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
> index ea67b46..bdf6649 100644
> --- a/hw/mem/pc-dimm.c
> +++ b/hw/mem/pc-dimm.c
> @@ -363,7 +363,10 @@ static void pc_dimm_get_size(Object *obj, Visitor *v,
> const char *name,
> PCDIMMDevice *dimm = PC_DIMM(obj);
> PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(obj);
>
> - mr = ddc->get_memory_region(dimm);
> + mr = ddc->get_memory_region(dimm, errp);
> + if (!mr) {
> + return;
> + }
> value = memory_region_size(mr);
>
> visit_type_uint64(v, name, &value, errp);
> @@ -411,9 +414,14 @@ static void pc_dimm_unrealize(DeviceState *dev, Error
> **errp)
> host_memory_backend_set_mapped(dimm->hostmem, false);
> }
>
> -static MemoryRegion *pc_dimm_get_memory_region(PCDIMMDevice *dimm)
> +static MemoryRegion *pc_dimm_get_memory_region(PCDIMMDevice *dimm, Error
> **errp)
> {
> - return host_memory_backend_get_memory(dimm->hostmem, &error_abort);
> + if (!dimm->hostmem) {
> + error_setg(errp, "'" PC_DIMM_MEMDEV_PROP "' property must be set");
> + return NULL;
> + }
> +
> + return host_memory_backend_get_memory(dimm->hostmem, errp);
> }
>
> static MemoryRegion *pc_dimm_get_vmstate_memory_region(PCDIMMDevice *dimm)
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index f7a1972..cec441c 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -2772,10 +2772,15 @@ static void spapr_memory_plug(HotplugHandler
> *hotplug_dev, DeviceState *dev,
> sPAPRMachineState *ms = SPAPR_MACHINE(hotplug_dev);
> PCDIMMDevice *dimm = PC_DIMM(dev);
> PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);
> - MemoryRegion *mr = ddc->get_memory_region(dimm);
> - uint64_t align = memory_region_get_alignment(mr);
> - uint64_t size = memory_region_size(mr);
> - uint64_t addr;
> + MemoryRegion *mr;
> + uint64_t align, size, addr;
> +
> + mr = ddc->get_memory_region(dimm, &local_err);
> + if (local_err) {
> + goto out;
> + }
> + align = memory_region_get_alignment(mr);
> + size = memory_region_size(mr);
>
> pc_dimm_memory_plug(dev, &ms->hotplug_memory, mr, align, &local_err);
> if (local_err) {
> @@ -2808,10 +2813,16 @@ static void spapr_memory_pre_plug(HotplugHandler
> *hotplug_dev, DeviceState *dev,
> {
> PCDIMMDevice *dimm = PC_DIMM(dev);
> PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);
> - MemoryRegion *mr = ddc->get_memory_region(dimm);
> - uint64_t size = memory_region_size(mr);
> + MemoryRegion *mr;
> + uint64_t size;
> char *mem_dev;
>
> + mr = ddc->get_memory_region(dimm, errp);
> + if (!mr) {
> + return;
> + }
> + size = memory_region_size(mr);
> +
> if (size % SPAPR_MEMORY_BLOCK_SIZE) {
> error_setg(errp, "Hotplugged memory size must be a multiple of "
> "%lld MB", SPAPR_MEMORY_BLOCK_SIZE / M_BYTE);
> @@ -2882,7 +2893,7 @@ static sPAPRDIMMState
> *spapr_recover_pending_dimm_state(sPAPRMachineState *ms,
> {
> sPAPRDRConnector *drc;
> PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);
> - MemoryRegion *mr = ddc->get_memory_region(dimm);
> + MemoryRegion *mr = ddc->get_memory_region(dimm, &error_abort);
> uint64_t size = memory_region_size(mr);
> uint32_t nr_lmbs = size / SPAPR_MEMORY_BLOCK_SIZE;
> uint32_t avail_lmbs = 0;
> @@ -2912,7 +2923,7 @@ void spapr_lmb_release(DeviceState *dev)
> sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_hotplug_handler(dev));
> PCDIMMDevice *dimm = PC_DIMM(dev);
> PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);
> - MemoryRegion *mr = ddc->get_memory_region(dimm);
> + MemoryRegion *mr = ddc->get_memory_region(dimm, &error_abort);
> sPAPRDIMMState *ds = spapr_pending_dimm_unplugs_find(spapr,
> PC_DIMM(dev));
>
> /* This information will get lost if a migration occurs
> @@ -2945,12 +2956,19 @@ static void
> spapr_memory_unplug_request(HotplugHandler *hotplug_dev,
> Error *local_err = NULL;
> PCDIMMDevice *dimm = PC_DIMM(dev);
> PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);
> - MemoryRegion *mr = ddc->get_memory_region(dimm);
> - uint64_t size = memory_region_size(mr);
> - uint32_t nr_lmbs = size / SPAPR_MEMORY_BLOCK_SIZE;
> - uint64_t addr_start, addr;
> + MemoryRegion *mr;
> + uint32_t nr_lmbs;
> + uint64_t size, addr_start, addr;
> int i;
> sPAPRDRConnector *drc;
> +
> + mr = ddc->get_memory_region(dimm, &local_err);
> + if (local_err) {
> + goto out;
> + }
> + size = memory_region_size(mr);
> + nr_lmbs = size / SPAPR_MEMORY_BLOCK_SIZE;
> +
> addr_start = object_property_get_uint(OBJECT(dimm), PC_DIMM_ADDR_PROP,
> &local_err);
> if (local_err) {
> diff --git a/include/hw/mem/pc-dimm.h b/include/hw/mem/pc-dimm.h
> index 1e483f2..6f8c3eb 100644
> --- a/include/hw/mem/pc-dimm.h
> +++ b/include/hw/mem/pc-dimm.h
> @@ -71,7 +71,7 @@ typedef struct PCDIMMDeviceClass {
>
> /* public */
> void (*realize)(PCDIMMDevice *dimm, Error **errp);
> - MemoryRegion *(*get_memory_region)(PCDIMMDevice *dimm);
> + MemoryRegion *(*get_memory_region)(PCDIMMDevice *dimm, Error **errp);
> MemoryRegion *(*get_vmstate_memory_region)(PCDIMMDevice *dimm);
> } PCDIMMDeviceClass;
>
> --
> 1.8.3.1
>
>
>
