If a CPU is hot removed while hotplug of the same is still in progress,
the guest crashes. Prevent this by ensuring that detach is done only
after attach has completed.
The existing code already prevents such race for PCI hotplug. However
given that CPU is a logical DR unlike PCI and starts with ISOLATED
state, we need a logic that works for CPU too.
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
[Don't set awaiting_attach for PCI devices]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Currently spapr doesn't support "aborting" hotplug of PCI
devices by allowing device_del to immediately remove the
device if we haven't signalled the presence of the device
to the guest.
In the past this wasn't an issue, since we always immediately
signalled device attach and simply relied on full guest-aware
add->remove path for device removal. However, as of 788d259,
we now defer signalling for PCI functions until function 0
is attached, so now we need to deal with these "abort" operations
for cases where a user hotplugs a non-0 function, then opts to
remove it prior hotplugging function 0. Currently they'd have to
reboot before the unplug completed. PCIe multifunction hotplug
does not have this requirement however, so from a management
implementation perspective it would be good to address this within
the same release as 788d259.
We accomplish this by simply adding a 'signalled' flag to track
whether a device hotplug event has been sent to the guest. If it
hasn't, we allow immediate removal under the assumption that the
guest will not be using the device. Devices present at boot/reset
time are also assumed to be 'signalled'.
For CPU/memory/etc, signalling will still happen immediately
as part of device_add, so only PCI functions should be affected.
Cc: bharata@linux.vnet.ibm.com
Cc: david@gibson.dropbear.id.au
Cc: sbhat@linux.vnet.ibm.com
Cc: qemu-ppc@nongnu.org
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
[dwg: This fixes a regression where an incorrect hot-add of a non-zero
function can no longer be backed out until function 0 is added]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Certain methods in sPAPRDRConnector objects are only ever called by
RTAS and in many cases are responsible for the logic that determines
the RTAS return codes.
Rather than having a level of indirection requiring RTAS code to
re-interpret return values from such methods to determine the
appropriate return code, just pass them through directly.
This requires changing method return types to uint32_t to match the
type of values currently passed to RTAS helpers.
In the case of read accesses like drc->entity_sense() where we weren't
previously reporting any errors, just the read value, we modify the
function to return RTAS return code, and pass the read value back via
reference.
Suggested-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Suggested-by: David Gibson <david@gibson.dropbear.id.au>
Cc: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
If drmgr is used in the guest to hotplug a device before a device_add
has been issued via the QEMU monitor, QEMU segfaults in configure_connector
call. This occurs due to accessing of NULL FDT which otherwise would have
been created and associated with the DRC during device_add command.
Check for NULL FDT and return failure from configure_connector call.
As per PAPR+, an error value of -9003 seems appropriate for this failure.
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This function handles generation of ibm,drc-* array device tree
properties to describe DRC topology to guests. This will by used
by the guest to direct RTAS calls to manage any dynamic resources
we associate with a particular DR Connector as part of
hotplug/unplug.
Since general management of boot-time device trees are handled
outside of sPAPRDRConnector, we insert these values blindly given
an FDT and offset. A mask of sPAPRDRConnector types is given to
instruct us on what types of connectors entries should be generated
for, since descriptions for different connectors may live in
different parts of the device tree.
Based on code originally written by Nathan Fontenot.
Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
This device emulates a firmware abstraction used by pSeries guests to
manage hotplug/dynamic-reconfiguration of host-bridges, PCI devices,
memory, and CPUs. It is conceptually similar to an SHPC device,
complete with LED indicators to identify individual slots to physical
physical users and indicate when it is safe to remove a device. In
some cases it is also used to manage virtualized resources, such a
memory, CPUs, and physical-host bridges, which in the case of pSeries
guests are virtualized resources where the physical components are
managed by the host.
Guests communicate with these DR Connectors using RTAS calls,
generally by addressing the unique DRC index associated with a
particular connector for a particular resource. For introspection
purposes we expose this state initially as QOM properties, and
in subsequent patches will introduce the RTAS calls that make use of
it. This constitutes to the 'guest' interface.
On the QEMU side we provide an attach/detach interface to associate
or cleanup a DeviceState with a particular sPAPRDRConnector in
response to hotplug/unplug, respectively. This constitutes the
'physical' interface to the DR Connector.
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
