The pseries machines introduced the concept of 'unplug timeout' for CPU
hotunplugs. The idea was to circunvent a deficiency in the pSeries
specification (PAPR), that currently does not define a proper way for
the hotunplug to fail. If the guest refuses to release the CPU (see [1]
for an example) there is no way for QEMU to detect the failure.
Further discussions about how to send a QAPI event to inform about the
hotunplug timeout [2] exposed problems that weren't predicted back when
the idea was developed. Other QEMU machines don't have any type of
hotunplug timeout mechanism for any device, e.g. ACPI based machines
have a way to make hotunplug errors visible to the hypervisor. This
would make this timeout mechanism exclusive to pSeries, which is not
ideal.
The real problem is that a QAPI event that reports hotunplug timeouts
puts the management layer (namely Libvirt) in a weird spot. We're not
telling that the hotunplug failed, because we can't be 100% sure of
that, and yet we're resetting the unplug state back, preventing any
DEVICE_DEL events to reach out in case the guest decides to release the
device. Libvirt would need to inspect the guest itself to see if the
device was released or not, otherwise the internal domain states will be
inconsistent. Moreover, Libvirt already has an 'unplug timeout'
concept, and a QEMU side timeout would need to be juggled together with
the existing Libvirt timeout.
All this considered, this solution ended up creating more trouble than
it solved. This patch reverts the 3 commits that introduced the timeout
mechanism for CPU hotplugs in pSeries machines.
This reverts commit 4515a5f786
"qemu_timer.c: add timer_deadline_ms() helper"
This reverts commit d1c2e3ce3d
"spapr_drc.c: add hotunplug timeout for CPUs"
This reverts commit 51254ffb32
"spapr_drc.c: introduce unplug_timeout_timer"
[1] https://bugzilla.redhat.com/show_bug.cgi?id=1911414
[2] https://lists.gnu.org/archive/html/qemu-devel/2021-03/msg04682.html
CC: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210401000437.131140-2-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
spapr_memory_unplug() is the last step of the hot unplug sequence.
It is indirectly called by:
spapr_lmb_release()
hotplug_handler_unplug()
and spapr_lmb_release() already buys us that DIMM unplug state is
present : it gets restored with spapr_recover_pending_dimm_state()
if missing.
g_assert() that spapr_pending_dimm_unplugs_find() cannot return NULL
in spapr_memory_unplug() to make this clear and silence Coverity.
Fixes: Coverity CID 1450767
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <161562021166.948373.15092876234470478331.stgit@bahia.lan>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Recent changes allowed the pSeries machine to rollback the hotunplug
process for the DIMM when the guest kernel signals, via a
reconfiguration of the DR connector, that it's not going to release the
LMBs.
Let's also warn QAPI listerners about it. One place to do it would be
right after the unplug state is cleaned up,
spapr_clear_pending_dimm_unplug_state(). This would mean that the
function is now doing more than cleaning up the pending dimm state
though.
This patch does the following changes in spapr.c:
- send a QAPI event to inform that we experienced a failure in the
hotunplug of the DIMM;
- rename spapr_clear_pending_dimm_unplug_state() to
spapr_memory_unplug_rollback(). This is a better fit for what the
function is now doing, and it makes callers care more about what the
function goal is and less about spapr.c internals such as clearing
the pending dimm unplug state.
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210302141019.153729-3-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
We are asserting the existence of the first DRC LMB after sending unplug
requests to all LMBs of the DIMM, where every DRC is being asserted
inside the loop. This means that the first DRC is being asserted twice.
Remove the duplicated assert.
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210302141019.153729-2-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Both CPU hotunplug and PC_DIMM unplug reports an user warning,
mentioning that the hotunplug is in progress, if consecutive
'device_del' are issued in quick succession.
Do the same for PHBs in spapr_phb_unplug_request().
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210226163301.419727-4-danielhb413@gmail.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Handling errors in memory hotunplug in the pSeries machine is more
complex than any other device type, because there are all the
complications that other devices has, and more.
For instance, determining a timeout for a DIMM hotunplug must consider
if it's a Hash-MMU or a Radix-MMU guest, because Hash guests takes
longer to hotunplug DIMMs. The size of the DIMM is also a factor, given
that longer DIMMs naturally takes longer to be hotunplugged from the
kernel. And there's also the guest memory usage to be considered: if
there's a process that is consuming memory that would be lost by the
DIMM unplug, the kernel will postpone the unplug process until the
process finishes, and then initiate the regular hotunplug process. The
first two considerations are manageable, but the last one is a deal
breaker.
There is no sane way for the pSeries machine to determine the memory
load in the guest when attempting a DIMM hotunplug - and even if there
was a way, the guest can start using all the RAM in the middle of the
unplug process and invalidate our previous assumptions - and in result
we can't even begin to calculate a timeout for the operation. This means
that we can't implement a viable timeout mechanism for memory unplug in
pSeries.
Going back to why we would consider an unplug timeout, the reason is
that we can't know if the kernel is giving up the unplug. Turns out
that, sometimes, we can. Consider a failed memory hotunplug attempt
where the kernel will error out with the following message:
'pseries-hotplug-mem: Memory indexed-count-remove failed, adding any
removed LMBs'
This happens when there is a LMB that the kernel gave up in removing,
and the LMBs previously marked for removal are now being added back.
This happens in the pseries kernel in [1], dlpar_memory_remove_by_ic()
into dlpar_add_lmb(), and after that update_lmb_associativity_index().
In this function, the kernel is configuring the LMB DRC connector again.
Note that this is a valid usage in LOPAR, as stated in section
"ibm,configure-connector RTAS Call":
'A subsequent sequence of calls to ibm,configure-connector with the same
entry from the “ibm,drc-indexes” or “ibm,drc-info” property will restart
the configuration of devices which were not completely configured.'
We can use this kernel behavior in our favor. If a DRC connector
reconfiguration for a LMB that we marked as unplug pending happens, this
indicates that the kernel changed its mind about the unplug and is
reasserting that it will keep using all the LMBs of the DIMM. In this
case, it's safe to assume that the whole DIMM device unplug was
cancelled.
This patch hops into rtas_ibm_configure_connector() and, in the scenario
described above, clear the unplug state for the DIMM device. This will
not solve all the problems we still have with memory unplug, but it will
cover this case where the kernel reconfigures LMBs after a failed
unplug. We are a bit more resilient, without using an unreliable
timeout, and we didn't make the remaining error cases any worse.
[1] arch/powerpc/platforms/pseries/hotplug-memory.c
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210222194531.62717-6-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
There is a reliable way to make a CPU hotunplug fail in the pseries
machine. Hotplug a CPU A, then offline all other CPUs inside the guest
but A. When trying to hotunplug A the guest kernel will refuse to do it,
because A is now the last online CPU of the guest. PAPR has no 'error
callback' in this situation to report back to the platform, so the guest
kernel will deny the unplug in silent and QEMU will never know what
happened. The unplug pending state of A will remain until the guest is
shutdown or rebooted.
Previous attempts of fixing it (see [1] and [2]) were aimed at trying to
mitigate the effects of the problem. In [1] we were trying to guess
which guest CPUs were online to forbid hotunplug of the last online CPU
in the QEMU layer, avoiding the scenario described above because QEMU is
now failing in behalf of the guest. This is not robust because the last
online CPU of the guest can change while we're in the middle of the
unplug process, and our initial assumptions are now invalid. In [2] we
were accepting that our unplug process is uncertain and the user should
be allowed to spam the IRQ hotunplug queue of the guest in case the CPU
hotunplug fails.
This patch presents another alternative, using the timeout
infrastructure introduced in the previous patch. CPU hotunplugs in the
pSeries machine will now timeout after 15 seconds. This is a long time
for a single CPU unplug to occur, regardless of guest load - although
the user is *strongly* encouraged to *not* hotunplug devices from a
guest under high load - and we can be sure that something went wrong if
it takes longer than that for the guest to release the CPU (the same
can't be said about memory hotunplug - more on that in the next patch).
Timing out the unplug operation will reset the unplug state of the CPU
and allow the user to try it again, regardless of the error situation
that prevented the hotunplug to occur. Of all the not so pretty
fixes/mitigations for CPU hotunplug errors in pSeries, timing out the
operation is an admission that we have no control in the process, and
must assume the worst case if the operation doesn't succeed in a
sensible time frame.
[1] https://lists.gnu.org/archive/html/qemu-devel/2021-01/msg03353.html
[2] https://lists.gnu.org/archive/html/qemu-devel/2021-01/msg04400.html
Reported-by: Xujun Ma <xuma@redhat.com>
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1911414
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210222194531.62717-5-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
spapr_drc_detach() is not the best name for what the function does. The
function does not detach the DRC, it makes an uncommited attempt to do
it. It'll mark the DRC as pending unplug, via the 'unplug_request'
flag, and only if the DRC state is drck->empty_state it will detach the
DRC, via spapr_drc_release().
This is a contrast with its pair spapr_drc_attach(), where the function
is indeed creating the DRC QOM object. If you know what
spapr_drc_attach() does, you can be misled into thinking that
spapr_drc_detach() is removing the DRC from QEMU internal state, which
isn't true.
The current role of this function is better described as a request for
detach, since there's no guarantee that we're going to detach the DRC in
the end. Rename the function to spapr_drc_unplug_request to reflect
what is is doing.
The initial idea was to change the name to spapr_drc_detach_request(),
and later on change the unplug_request flag to detach_request. However,
unplug_request is a migratable boolean for a long time now and renaming
it is not worth the trouble. spapr_drc_unplug_request() setting
drc->unplug_request is more natural than spapr_drc_detach_request
setting drc->unplug_request.
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210222194531.62717-3-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
We'll need to check the initial value given to spapr->gpu_numa_id when
building the rtas DT, so put it in a helper for easier access and to
avoid repetition.
Tested-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210128174213.1349181-3-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This function is used only in spapr_numa.c.
Tested-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210128174213.1349181-2-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
It is currently not possible to perform a strict boot from USB storage:
$ qemu-system-ppc64 -accel kvm -nodefaults -nographic -serial stdio \
-boot strict=on \
-device qemu-xhci \
-device usb-storage,drive=disk,bootindex=0 \
-blockdev driver=file,node-name=disk,filename=fedora-ppc64le.qcow2
SLOF **********************************************************************
QEMU Starting
Build Date = Jul 17 2020 11:15:24
FW Version = git-e18ddad8516ff2cf
Press "s" to enter Open Firmware.
Populating /vdevice methods
Populating /vdevice/vty@71000000
Populating /vdevice/nvram@71000001
Populating /pci@800000020000000
00 0000 (D) : 1b36 000d serial bus [ usb-xhci ]
No NVRAM common partition, re-initializing...
Scanning USB
XHCI: Initializing
USB Storage
SCSI: Looking for devices
101000000000000 DISK : "QEMU QEMU HARDDISK 2.5+"
Using default console: /vdevice/vty@71000000
Welcome to Open Firmware
Copyright (c) 2004, 2017 IBM Corporation All rights reserved.
This program and the accompanying materials are made available
under the terms of the BSD License available at
http://www.opensource.org/licenses/bsd-license.php
Trying to load: from: /pci@800000020000000/usb@0/storage@1/disk@101000000000000 ...
E3405: No such device
E3407: Load failed
Type 'boot' and press return to continue booting the system.
Type 'reset-all' and press return to reboot the system.
Ready!
0 >
The device tree handed over by QEMU to SLOF indeed contains:
qemu,boot-list =
"/pci@800000020000000/usb@0/storage@1/disk@101000000000000 HALT";
but the device node is named usb-xhci@0, not usb@0.
This happens because the firmware names of PCI devices returned
by get_boot_devices_list() come from pcibus_get_fw_dev_path(),
while the sPAPR PHB code uses a different naming scheme for
device nodes. This inconsistency has always been there but it was
hidden for a long time because SLOF used to rename USB device
nodes, until this commit, merged in QEMU 4.2.0 :
commit 85164ad4ed
Author: Alexey Kardashevskiy <aik@ozlabs.ru>
Date: Wed Sep 11 16:24:32 2019 +1000
pseries: Update SLOF firmware image
This fixes USB host bus adapter name in the device tree to match QEMU's
one.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Fortunately, sPAPR implements the firmware path provider interface.
This provides a way to override the default firmware paths.
Just factor out the sPAPR PHB naming logic from spapr_dt_pci_device()
to a helper, and use it in the sPAPR firmware path provider hook.
Fixes: 85164ad4ed ("pseries: Update SLOF firmware image")
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20210122170157.246374-1-groug@kaod.org>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
In the CPU hotunplug bug [1] the guest kernel throws a scary
message in dmesg:
pseries-hotplug-cpu: Failed to offline CPU <NULL>, rc: -16
The reason isn't related to the bug though. This happens because the
kernel file arch/powerpc/platform/pseries/hotplug-cpu.c, function
dlpar_cpu_remove(), is not finding the device_node.name of the offending
CPU.
We're not populating the 'name' property for hotplugged CPUs. Since the
kernel relies on device_node.name for identifying CPU nodes, and the
CPUs that are coldplugged has the 'name' property filled by SLOF, this
is creating an unneeded inconsistency between hotplug and coldplug CPUs
in the kernel.
Let's fill the 'name' property for hotplugged CPUs as well. This will
make the guest dmesg throws a less intimidating message when we try to
unplug the last online CPU:
pseries-hotplug-cpu: Failed to offline CPU PowerPC,POWER9@1, rc: -16
[1] https://bugzilla.redhat.com/1911414
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210120232305.241521-3-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Next patch will use the 'nodename' string in spapr_core_dt_populate()
after the point it's being freed today.
Instead of moving 'g_free(nodename)' around, let's do a QoL change in
both CPU DT functions where 'nodename' is being freed, and use
g_autofree to avoid the 'g_free()' call altogether.
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210120232305.241521-2-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Some upcoming POWER machines have a system called PEF (Protected
Execution Facility) which uses a small ultravisor to allow guests to
run in a way that they can't be eavesdropped by the hypervisor. The
effect is roughly similar to AMD SEV, although the mechanisms are
quite different.
Most of the work of this is done between the guest, KVM and the
ultravisor, with little need for involvement by qemu. However qemu
does need to tell KVM to allow secure VMs.
Because the availability of secure mode is a guest visible difference
which depends on having the right hardware and firmware, we don't
enable this by default. In order to run a secure guest you need to
create a "pef-guest" object and set the confidential-guest-support
property to point to it.
Note that this just *allows* secure guests, the architecture of PEF is
such that the guest still needs to talk to the ultravisor to enter
secure mode. Qemu has no direct way of knowing if the guest is in
secure mode, and certainly can't know until well after machine
creation time.
To start a PEF-capable guest, use the command line options:
-object pef-guest,id=pef0 -machine confidential-guest-support=pef0
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Since commit 1e8b5b1aa1 ("spapr: Allow memory unplug to always succeed")
trying to unplug memory from a guest that doesn't support it (eg. rhel6)
no longer generates an error like it used to. Instead, it leaves the
memory around : only a subsequent reboot or manual use of drmgr within
the guest can complete the hot-unplug sequence. A flag was added to
SpaprMachineClass so that this new behavior only applies to the default
machine type.
We can do better. CAS processes all pending hot-unplug requests. This
means that we don't really care about what the guest supports if
the hot-unplug request happens before CAS.
All guests that we care for, even old ones, set enough bits in OV5
that lead to a non-empty bitmap in spapr->ov5_cas. Use that as a
heuristic to decide if CAS has already occured or not.
Always accept unplug requests that happen before CAS since CAS will
process them. Restore the previous behavior of rejecting them after
CAS when we know that the guest doesn't support memory hot-unplug.
This behavior is suitable for all machine types : this allows to
drop the pre_6_0_memory_unplug flag.
Fixes: 1e8b5b1aa1 ("spapr: Allow memory unplug to always succeed")
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <161012708715.801107.11418801796987916516.stgit@bahia.lan>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Documentation of object_child_foreach_recursive() clearly stipulates
that "it is forbidden to add or remove children from @obj from the @fn
callback". But this is exactly what we do during machine reset. The call
to spapr_drc_reset() can finalize the hot-unplug sequence of a PHB or a
PCI bridge, both of which will then in turn destroy their PCI DRCs. This
could potentially invalidate the iterator used by do_object_child_foreach().
It is pure luck that this haven't caused any issues so far.
Use spapr_drc_reset_all() since it can cope with DRC removal.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20201218103400.689660-5-groug@kaod.org>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Tested-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
It is currently impossible to hot-unplug a memory device between
machine reset and CAS.
(qemu) device_del dimm1
Error: Memory hot unplug not supported for this guest
This limitation was introduced in order to provide an explicit
error path for older guests that didn't support hot-plug event
sources (and thus memory hot-unplug).
The linux kernel has been supporting these since 4.11. All recent
enough guests are thus capable of handling the removal of a memory
device at all time, including during early boot.
Lift the limitation for the latest machine type. This means that
trying to unplug memory from a guest that doesn't support it will
likely just do nothing and the memory will only get removed at
next reboot. Such older guests can still get the existing behavior
by using an older machine type.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <160794035064.23292.17560963281911312439.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Section 13.5.2 of LoPAPR mandates various DR related indentifiers
for all hot-pluggable entities to be exposed in the "ibm,drc-indexes",
"ibm,drc-power-domains", "ibm,drc-names" and "ibm,drc-types" properties
of their parent node. These properties are created with spapr_dt_drc().
PHBs and LMBs are both children of the machine. Their DR identifiers
are thus supposed to be exposed in the afore mentioned properties of
the root node.
When PHB hot-plug support was added, an extra call to spapr_dt_drc()
was introduced: this overwrites the existing properties, previously
populated with the LMB identifiers, and they end up containing only
PHB identifiers. This went unseen so far because linux doesn't care,
but this is still not conformant with LoPAPR.
Fortunately spapr_dt_drc() is able to handle multiple DR entity types
at the same time. Use that to handle DR indentifiers for PHBs and LMBs
with a single call to spapr_dt_drc(). While here also account for PMEM
DR identifiers, which were forgotten when NVDIMM hot-plug support was
added. Also add an assert to prevent further misuse of spapr_dt_drc().
With -m 1G,maxmem=2G,slots=8 passed on the QEMU command line we get:
Without this patch:
/proc/device-tree/ibm,drc-indexes
0000001f 20000001 20000002 20000003
20000000 20000005 20000006 20000007
20000004 20000009 20000008 20000010
20000011 20000012 20000013 20000014
20000015 20000016 20000017 20000018
20000019 2000000a 2000000b 2000000c
2000000d 2000000e 2000000f 2000001a
2000001b 2000001c 2000001d 2000001e
These are the DRC indexes for the 31 possible PHBs.
With this patch:
/proc/device-tree/ibm,drc-indexes
0000002b 90000000 90000001 90000002
90000003 90000004 90000005 90000006
90000007 20000001 20000002 20000003
20000000 20000005 20000006 20000007
20000004 20000009 20000008 20000010
20000011 20000012 20000013 20000014
20000015 20000016 20000017 20000018
20000019 2000000a 2000000b 2000000c
2000000d 2000000e 2000000f 2000001a
2000001b 2000001c 2000001d 2000001e
80000004 80000005 80000006 80000007
And now we also have the 4 ((2G - 1G) / 256M) LMBs and the
8 (slots) PMEMs.
Fixes: 3998ccd092 ("spapr: populate PHB DRC entries for root DT node")
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <160794479566.35245.17809158217760761558.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
All memory DRC objects are created during machine init. It is thus safe
to assume spapr_drc_by_id() cannot return NULL when hot-plug/unplugging
memory.
Make this clear with an assertion, like the code already does a few lines
above when looping over memory DRCs. This fixes Coverity reports 1437757
and 1437758.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <160805381160.228955.5388294067094240175.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Since NVDIMM support was introduced on pseries machine,
it ignored machine's nvdimm=on|off option and effectively
was always enabled on machines that support NVDIMM.
Later on commit
(28f5a71621 ppc/spapr_nvdimm: do not enable support with 'nvdimm=off')
makes QEMU error out in case user explicitly set 'nvdimm=off'
on CLI by peeking at machine_opts.
However that's a workaround and leaves 'nvdimms_state->is_enabled'
in inconsistent state (false) when it should be set true
by default.
Instead of using on machine_opts, set default to true for pseries
machine in initfn time. If user sets manually 'nvdimm=off'
it will overwrite default value to false and QEMU will error
as expected without need to peek into machine_opts.
That way pseries will have, nvdimm enabled by default and
will honor user provided 'nvdimm=on|off'.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20201208164606.4109134-1-imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
spapr_kvm_type() is considering 'vm_type=NULL' as a valid input, where
the function returns 0. This is relying on the current QEMU machine
options handling logic, where the absence of the 'kvm-type' option
will be reflected as 'vm_type=NULL' in this function.
This is not robust, and will break if QEMU options code decides to propagate
something else in the case mentioned above (e.g. an empty string instead
of NULL).
Let's avoid this entirely by setting a non-NULL default value in case of
no user input for 'kvm-type'. spapr_kvm_type() was changed to handle 3 fixed
values of kvm-type: "auto", "hv", and "pr", with "auto" being the default
if no kvm-type was set by the user. This allows us to always be predictable
regardless of any enhancements/changes made in QEMU options mechanics.
While we're at it, let's also document in 'kvm-type' description the
already existing default mode, now named 'auto'. The information provided
about it is based on how the pseries kernel handles the KVM_CREATE_VM
ioctl(), where the default value '0' makes the kernel choose an available
KVM module to use, giving precedence to kvm_hv. This logic is described in
the kernel source file arch/powerpc/kvm/powerpc.c, function kvm_arch_init_vm().
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20201210145517.1532269-2-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
All users are passing &error_abort already. Document the fact
that spapr_drc_attach() should only be passed a free DRC, which
is supposedly the case if appropriate checking is done earlier.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20201201113728.885700-5-groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
spapr_core_pre_plug() already guarantees that the slot for the given core
ID is available. It is thus safe to assume that spapr_find_cpu_slot()
returns a slot during plug. Turn the error path into an assertion.
It is also safe to assume that no device is attached to the corresponding
DRC and that spapr_drc_attach() shouldn't fail.
Pass &error_abort to spapr_drc_attach() and simplify error handling.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20201201113728.885700-4-groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
When a CPU is hot-plugged, we set its compat mode to match the boot
CPU, which was either set by machine reset or by CAS. This is currently
handled in the plug handler after the core got realized. Potential errors
of ppc_set_compat() are propagated to the hot-plug logic.
Handling errors this late in the hot-plug sequence is generally frown
upon. Ideally, we should do sanity checks in a pre-plug handler and pass
&error_abort to ppc_set_compat() in the plug handler.
We can filter out some error cases of ppc_set_compat() by calling
ppc_check_compat() at pre-plug. But ppc_set_compat() also sets the
compat register in KVM, and KVM doesn't provide any API that would
allow to check valid compat mode settings beforehand.
However, at this point we know that the compat mode was already
successfully set for the boot CPU. Since this all boils down to
setting a register with the very same value that was valid
for the boot CPU, it should definitely not fail for hot-plugged
CPUS.
Pass &error_abort to ppc_set_compat().
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20201201113728.885700-3-groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This hack registers dummy VMState entries of ICPs in order to
support migration of old pseries machine types that used to
create all smp.max_cpus possible ICPs at machine init.
Part of the work is to unregister the dummy entries when plugging
an actual vCPU core, and to register them back when unplugging the
core. The code that unregisters the dummy ICPs in spapr_core_plug()
is misplaced: if ppc_set_compat() fails afterwards, the hotplug
operation will be cancelled and the dummy ICPs won't be registered
back since the unplug handler isn't called.
Unregister the dummy ICPs at the end of spapr_core_plug().
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20201201113728.885700-2-groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
There can be only one TPM proxy at a time. This is currently
checked at plug time. But this can be detected at pre-plug in
order to error out earlier.
This allows to get rid of error handling in the plug handler.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20201120234208.683521-9-groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
We currently detect that a PHB index is already in use at plug time.
But this can be decteted at pre-plug in order to error out earlier.
This allows to pass &error_abort to spapr_drc_attach() and to end
up with a plug handler that doesn't need to report errors anymore.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20201120234208.683521-8-groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Read documentation in "qapi/error.h" and changelog of commit
e3fe3988d7 ("error: Document Error API usage rules") for
rationale.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20201120234208.683521-7-groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Pre-plug of a memory device, be it an NVDIMM or a PC-DIMM, ensures
that the memory slot is available and that addresses don't overlap
with existing memory regions. The corresponding DRCs in the LMB
and PMEM namespaces are thus necessarily attachable at plug time.
Pass &error_abort to spapr_drc_attach() in spapr_add_lmbs() and
spapr_add_nvdimm(). This allows to greatly simplify error handling
on the plug path.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20201120234208.683521-3-groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
serial_hd(i) is NULL if and only if i >= serial_max_hds(). Test
serial_hd(i) instead of bounding the loop at serial_max_hds(),
thus removing one more function that vl.c is expected to export.
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20201026143028.3034018-11-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add 6.0 machine types for arm/i440fx/q35/s390x/spapr.
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20201109173928.1001764-1-cohuck@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Sometimes QEMU needs to allocate the HPT in userspace, namely with TCG
or PR KVM. This is performed with qemu_memalign() because of alignment
requirements. Like glib's allocators, its behaviour is to abort on OOM
instead of returning NULL.
This could be changed to qemu_try_memalign(), but in the specific case
of spapr_reallocate_hpt(), the outcome would be to terminate QEMU anyway
since no HPT means no MMU for the guest. Drop the dead code instead.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <160398562892.32380.15006707861753544263.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
spapr_reallocate_hpt() has three users, two of which pass &error_fatal
and the third one, htab_load(), passes &local_err, uses it to detect
failures and simply propagates -EINVAL up to vmstate_load(), which will
cause QEMU to exit. It is thus confusing that spapr_reallocate_hpt()
doesn't return right away when an error is detected in some cases. Also,
the comment suggesting that the caller is welcome to try to carry on
seems like a remnant in this respect.
This can be improved:
- change spapr_reallocate_hpt() to always report a negative errno on
failure, either as reported by KVM or -ENOSPC if the HPT is smaller
than what was asked,
- use that to detect failures in htab_load() which is preferred over
checking &local_err,
- propagate this negative errno to vmstate_load() because it is more
accurate than propagating -EINVAL for all possible errors.
[dwg: Fix compile error due to omitted prelim patch]
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <160371605460.305923.5890143959901241157.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
If kvmppc_load_htab_chunk() fails, its return value is propagated up
to vmstate_load(). It should thus be a negative errno, not -1 (which
maps to EPERM and would lure the user into thinking that the problem
is necessarily related to a lack of privilege).
Return the error reported by KVM or ENOSPC in case of short write.
While here, propagate the error message through an @errp argument
and have the caller to print it with error_report_err() instead
of relying on fprintf().
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <160371604713.305923.5264900354159029580.stgit@bahia.lan>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Hints should be added with the dedicated error_append_hint() API
because we don't want to print them when using QMP. This requires
to insert ERRP_GUARD as explained in "qapi/error.h".
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <160371604030.305923.17464161378167312662.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
As recommended in "qapi/error.h", add a bool return value to
spapr_add_lmbs() and spapr_add_nvdimm(), and use them instead
of local_err in spapr_memory_plug().
This allows to get rid of the error propagation overhead.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <160309734178.2739814.3488437759887793902.stgit@bahia.lan>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Both PC_DIMM_SLOT_PROP and PC_DIMM_ADDR_PROP are defined in the
default property list of the PC DIMM device class:
DEFINE_PROP_UINT64(PC_DIMM_ADDR_PROP, PCDIMMDevice, addr, 0),
DEFINE_PROP_INT32(PC_DIMM_SLOT_PROP, PCDIMMDevice, slot,
PC_DIMM_UNASSIGNED_SLOT),
They should thus be always gettable for both PC DIMMs and NVDIMMs.
An error in getting them can only be the result of a programming
error. It doesn't make much sense to propagate the error in this
case. Abort instead.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <160309732180.2739814.7243774674998010907.stgit@bahia.lan>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The PC_DIMM_SLOT_PROP property is defined as:
DEFINE_PROP_INT32(PC_DIMM_SLOT_PROP, PCDIMMDevice, slot,
PC_DIMM_UNASSIGNED_SLOT),
Use object_property_get_int() instead of object_property_get_uint().
Since spapr_memory_plug() only gets called if pc_dimm_pre_plug()
succeeded, we expect to have a valid >= 0 slot number, either because
the user passed a valid slot number or because pc_dimm_get_free_slot()
picked one up for us.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <160309730758.2739814.15821922745424652642.stgit@bahia.lan>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The PC_DIMM_ADDR_PROP property is defined as:
DEFINE_PROP_UINT64(PC_DIMM_ADDR_PROP, PCDIMMDevice, addr, 0),
Use object_property_get_uint() instead of object_property_get_int().
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <160309729609.2739814.4996614957953215591.stgit@bahia.lan>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
pc_dimm_plug() doesn't use it. It only aborts on error.
Drop @errp and adapt the callers accordingly.
[dwg: Removed unused label to fix compile]
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <160309728447.2739814.12831204841251148202.stgit@bahia.lan>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The spapr_create_nvdimm_dr_connectors() function doesn't need to access
any internal details of the sPAPR NVDIMM implementation. Also, pretty
much like for the LMBs, only spapr_machine_init() is responsible for the
creation of DR connectors for NVDIMMs.
Make this clear by making this function static in hw/ppc/spapr.c.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <160249772183.757627.7396780936543977766.stgit@bahia.lan>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The changes to come to NUMA support are all guest visible. In
theory we could just create a new 5_1 class option flag to
avoid the changes to cascade to 5.1 and under. The reality is that
these changes are only relevant if the machine has more than one
NUMA node. There is no need to change guest behavior that has
been around for years needlesly.
This new helper will be used by the next patches to determine
whether we should retain the (soon to be) legacy NUMA behavior
in the pSeries machine. The new behavior will only be exposed
if:
- machine is pseries-5.2 and newer;
- more than one NUMA node is declared in NUMA state.
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20201007172849.302240-2-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
As recommended in "qapi/error.h", return true on success and false on
failure. This allows to reduce error propagation overhead in the callers.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200914123505.612812-14-groug@kaod.org>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
As recommended in "qapi/error.h", return true on success and false on
failure. This allows to reduce error propagation overhead in the callers.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200914123505.612812-13-groug@kaod.org>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
As recommended in "qapi/error.h", return true on success and false on
failure. This allows to reduce error propagation overhead in the callers.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200914123505.612812-11-groug@kaod.org>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
As recommended in "qapi/error.h", return true on success and false on
failure. This allows to reduce error propagation overhead in the callers.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200914123505.612812-9-groug@kaod.org>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Now that ppc_set_compat() indicates success/failure with a return
value, use it and reduce error propagation overhead.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200914123505.612812-5-groug@kaod.org>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The nested KVM code does not yet support HPT guests. Calling the
KVM_CAP_PPC_ALLOC_HTAB ioctl currently leads to KVM setting the guest
as HPT and erroneously executing code in L1 that should only run in
hypervisor mode, leading to an exception in the L1 vcpu thread when it
enters the nested guest.
This can be reproduced with -machine max-cpu-compat=power8 in the L2
guest command line.
The KVM code has since been modified to fail the ioctl when running in
a nested environment so QEMU needs to be able to handle that. This
patch provides an error message informing the user about the lack of
support for HPT in nested guests.
Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20200911043123.204162-1-farosas@linux.ibm.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
