Commit graph

205 commits

Author SHA1 Message Date
Daniel Henrique Barboza c363a37a45 target/ppc: 'PVR != host PVR' in KVM_SET_SREGS workaround
Commit d5fc133eed ("ppc: Rework CPU compatibility testing
across migration") changed the way cpu_post_load behaves with
the PVR setting, causing an unexpected bug in KVM-HV migrations
between hosts that are compatible (POWER8 and POWER8E, for example).
Even with pvr_match() returning true, the guest freezes right after
cpu_post_load. The reason is that the guest kernel can't handle a
different PVR value other that the running host in KVM_SET_SREGS.

In [1] it was discussed the possibility of a new KVM capability
that would indicate that the guest kernel can handle a different
PVR in KVM_SET_SREGS. Even if such feature is implemented, there is
still the problem with older kernels that will not have this capability
and will fail to migrate.

This patch implements a workaround for that scenario. If running
with KVM, check if the guest kernel does not have the capability
(named here as 'cap_ppc_pvr_compat'). If it doesn't, calls
kvmppc_is_pr() to see if the guest is running in KVM-HV. If all this
happens, set env->spr[SPR_PVR] to the same value as the current
host PVR. This ensures that we allow migrations with 'close enough'
PVRs to still work in KVM-HV but also makes the code ready for
this new KVM capability when it is done.

A new function called 'kvmppc_pvr_workaround_required' was created
to encapsulate the conditions said above and to avoid calling too
many kvm.c internals inside cpu_post_load.

[1] https://lists.gnu.org/archive/html/qemu-ppc/2017-06/msg00503.html

Signed-off-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com>
[dwg: Fix for the case of using TCG on a PPC host]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-08-22 21:26:19 +10:00
David Gibson b8af5b2d5f target/ppc: Add stub implementation of the PSSCR
The PSSCR register added in POWER9 controls certain power saving mode
behaviours.  Mostly, it's not relevant to TCG, however because qemu
doesn't know about it yet, it doesn't synchronize the state with KVM,
and thus it doesn't get migrated.

To fix that, this adds a minimal stub implementation of the register.
This isn't complete, even to the extent that an implementation is
possible in TCG, just enough to get migration working.  We need to
come back later and at least properly filter the various fields in the
register based on privilege level.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
2017-08-09 11:46:44 +10:00
David Gibson 650f3287ab target/ppc: Implement TIDR
This adds a trivial implementation of the TIDR register added in
POWER9.  This isn't particularly important to qemu directly - it's
used by accelerator modules that we don't emulate.

However, since qemu isn't aware of it, its state is not synchronized
with KVM and therefore not migrated, which can be a problem.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
2017-08-09 11:46:44 +10:00
Greg Kurz e7bab9a256 ppc: fix double-free in cpu_post_load()
When running nested with KVM PR, ppc_set_compat() fails and QEMU crashes
because of "double free or corruption (!prev)". The crash happens because
error_report_err() has already called error_free().

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-08-09 11:46:44 +10:00
KONRAD Frederic 89fca22f21 booke206: fix MAS update on tlb miss
When a tlb instruction miss happen, rw is set to 0 at the bottom
of cpu_ppc_handle_mmu_fault which cause the MAS update function to miss
the SAS and TS bit in MAS6, MAS1 in booke206_update_mas_tlb_miss.

Just calling booke206_update_mas_tlb_miss with rw = 2 solve the issue.

Signed-off-by: KONRAD Frederic <frederic.konrad@adacore.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-08-09 11:46:44 +10:00
Philippe Mathieu-Daudé 87e0331c5a docs: fix broken paths to docs/devel/tracing.txt
With the move of some docs/ to docs/devel/ on ac06724a71,
no references were updated.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2017-07-31 13:12:53 +03:00
Markus Armbruster d2f95f4d48 qapi: Use QNull for a more regular visit_type_null()
Make visit_type_null() take an @obj argument like its buddies.  This
helps keep the next commit simple.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
2017-07-24 13:35:11 +02:00
Peter Maydell 95a5befc2f Use qemu_tolower() and qemu_toupper(), not tolower() and toupper()
On NetBSD, where tolower() and toupper() are implemented using an
array lookup, the compiler warns if you pass a plain 'char'
to these functions:

gdbstub.c:914:13: warning: array subscript has type 'char'

This reflects the fact that toupper() and tolower() give
undefined behaviour if they are passed a value that isn't
a valid 'unsigned char' or EOF.

We have qemu_tolower() and qemu_toupper() to avoid this problem;
use them.

(The use in scsi-generic.c does not trigger the warning because
it passes a uint8_t; we switch it anyway, for consistency.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> for the s390 part.
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Message-id: 1500568290-7966-1-git-send-email-peter.maydell@linaro.org
2017-07-21 10:32:41 +01:00
Lluís Vilanova 9c489ea6be tcg: Pass generic CPUState to gen_intermediate_code()
Needed to implement a target-agnostic gen_intermediate_code()
in the future.

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Alex Benneé <alex.benee@linaro.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Message-Id: <150002025498.22386.18051908483085660588.stgit@frigg.lan>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-07-19 14:45:16 -07:00
Philippe Mathieu-Daudé e2622073e0 target/ppc: optimize various functions using extract op
Done with the Coccinelle semantic patch
scripts/coccinelle/tcg_gen_extract.cocci.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20170718045540.16322-6-f4bug@amsat.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-07-19 14:45:16 -07:00
Cédric Le Goater 346ebfc6fb target/ppc: fix CPU hotplug when radix is enabled (TCG)
But when a guest initializes radix mode, it issues a H_REGISTER_PROC_TBL
to update the LPCR of all CPUs. Hot-plugged CPUs inherit from the same
setting under KVM but not under TCG. So, Let's check for radix and update
the default LPCR to keep new CPUs in sync.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-07-17 15:07:05 +10:00
David Gibson b55d295e3e pseries: Allow HPT resizing with KVM
So far, qemu implements the PAPR Hash Page Table (HPT) resizing extension
with TCG.  The same implementation will work with KVM PR, but we don't
currently allow that.  For KVM HV we can only implement resizing with the
assistance of the host kernel, which needs a new capability and ioctl()s.

This patch adds support for testing the new KVM capability and implementing
the resize in terms of KVM facilities when necessary.  If we're running on
a kernel which doesn't have the new capability flag at all, we fall back to
testing for PR vs. HV KVM using the same hack that we already use in a
number of places for older kernels.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-07-17 15:07:05 +10:00
David Gibson 0b0b831016 pseries: Implement HPT resizing
This patch implements hypercalls allowing a PAPR guest to resize its own
hash page table.  This will eventually allow for more flexible memory
hotplug.

The implementation is partially asynchronous, handled in a special thread
running the hpt_prepare_thread() function.  The state of a pending resize
is stored in SPAPR_MACHINE->pending_hpt.

The H_RESIZE_HPT_PREPARE hypercall will kick off creation of a new HPT, or,
if one is already in progress, monitor it for completion.  If there is an
existing HPT resize in progress that doesn't match the size specified in
the call, it will cancel it, replacing it with a new one matching the
given size.

The H_RESIZE_HPT_COMMIT completes transition to a resized HPT, and can only
be called successfully once H_RESIZE_HPT_PREPARE has successfully
completed initialization of a new HPT.  The guest must ensure that there
are no concurrent accesses to the existing HPT while this is called (this
effectively means stop_machine() for Linux guests).

For now H_RESIZE_HPT_COMMIT goes through the whole old HPT, rehashing each
HPTE into the new HPT.  This can have quite high latency, but it seems to
be of the order of typical migration downtime latencies for HPTs of size
up to ~2GiB (which would be used in a 256GiB guest).

In future we probably want to move more of the rehashing to the "prepare"
phase, by having H_ENTER and other hcalls update both current and
pending HPTs.  That's a project for another day, but should be possible
without any changes to the guest interface.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-07-17 15:07:05 +10:00
David Gibson 30f4b05bd0 pseries: Stubs for HPT resizing
This introduces stub implementations of the H_RESIZE_HPT_PREPARE and
H_RESIZE_HPT_COMMIT hypercalls which we hope to add in a PAPR
extension to allow run time resizing of a guest's hash page table.  It
also adds a new machine property for controlling whether this new
facility is available.

For now we only allow resizing with TCG, allowing it with KVM will require
kernel changes as well.

Finally, it adds a new string to the hypertas property in the device
tree, advertising to the guest the availability of the HPT resizing
hypercalls.  This is a tentative suggested value, and would need to be
standardized by PAPR before being merged.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
2017-07-17 15:07:05 +10:00
Fam Zheng 1b6b7d109e qdev: Add const qualifier to PropertyInfo definitions
The remaining non-const ones are in e1000e which modifies description at
runtime. They can be addressed separatedly.

Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20170714021509.23681-6-famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-07-14 12:04:42 +02:00
Greg Kurz 92e926e1e3 ppc/kvm: have the "family" CPU alias to point to TYPE_HOST_POWERPC_CPU
When running KVM on POWER, we allow the user to pass "-cpu POWERx" instead
of "-cpu host". This is achieved by patching the ppc_cpu_aliases[] array
so that "POWERx" points to the CPU class with the same PVR as the host CPU.
This causes CPUs to be instantiated from this CPU class instead of the
TYPE_HOST_POWERPC_CPU class which is used with "-cpu host". These CPUs thus
miss all the KVM specific tuning from kvmppc_host_cpu_class_init().

This currently causes QEMU with "-cpu POWER9" to fail when running KVM on a
POWER9 DD1 host:

qemu-system-ppc64: Register sync failed... If you're using kvm-hv.ko, only
 "-cpu host" is possible
kvm_init_vcpu failed: Invalid argument

Let's have the "POWERx" alias to point to TYPE_HOST_POWERPC_CPU directly,
so that "-cpu POWERx" instantiates CPUs from the same class as "-cpu host".

Signed-off-by: Greg Kurz <groug@kaod.org>
Tested-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-07-11 11:04:02 +10:00
Suraj Jitindar Singh 95cb065776 target/ppc: Add debug function for radix mmu translation
In target/ppc/mmu-hash64.c there already exists the function
ppc_hash64_get_phys_page_debug() to get the physical (real) address for
a given effective address in hash mode.

Implement the function ppc_radix64_get_phys_page_debug() to allow a real
address to be obtained for a given effective address in radix mode.
This is used when a debugger is attached to qemu.

Previously we just had a comment saying this is unimplemented which then
fell through to the default case and caused an abort due to
unrecognised mmu model as the default had no case for the V3 mmu, which
was misleading at best.

We reuse ppc_radix64_walk_tree() which is used by the radix fault
handler since the process of walking the radix tree is identical.

Reported-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-07-11 11:04:02 +10:00
Suraj Jitindar Singh 6a042827b6 target/ppc: Refactor tcg radix mmu code
The mmu-radix64.c file implements functions to enable the radix mmu
emulation in tcg mode. There is a function ppc_radix64_walk_tree() which
performs the radix tree walk and also implicitly checks the pte
protection.

Move the protection checking of the pte from the ppc_radix64_walk_tree()
function into the caller. This means the ppc_radix64_walk_tree() function
can be used without protection checking which is useful for debugging.

ppc_radix64_walk_tree() no longer needs to take the rwx and prot variables.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-07-11 11:04:02 +10:00
Aaron Larson 0ee604abce target-ppc: SPR_BOOKE_ESR not set on FP exceptions
Properly set the book E exception syndrome register when a floating
point exception occurs.

Currently on a book E processor, the POWERPC_EXCP_FP exception handler
fails to set "env->spr[SPR_BOOKE_ESR] = ESR_FP;" as required by the
book E specification.

Signed-off-by: Aaron Larson <alarson@ddci.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-07-11 11:04:01 +10:00
Bharata B Rao fd35656368 target/ppc: Proper cleanup when ppc_cpu_realizefn fails
If ppc_cpu_realizefn() fails after cpu_exec_realizefn() has been
called, we will have to undo whatever cpu_exec_realizefn() did
by explicitly calling cpu_exec_unrealizeffn() which is currently
missing. Failure to do this proper cleanup will result in CPU
which was never fully realized to linger on the cpus list causing
SIGSEGV later (for eg when running "info cpus").

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-06-30 14:03:31 +10:00
Suraj Jitindar Singh 35068bd15e target/ppc: Fix return value in tcg radix mmu fault handler
The mmu fault handler should return 0 if it was able to successfully
handle the fault and a positive value otherwise.

Currently the tcg radix mmu fault handler will return 1 after
successfully handling a fault in virtual mode. This is incorrect
so fix it so that it returns 0 in this case.

The handler already correctly returns 0 when a fault was handled
in real mode and 1 if an interrupt was generated.

Fixes: d5fee0bbe6 ("target/ppc: Implement ISA V3.00 radix page fault handler")

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-06-30 14:03:31 +10:00
Thomas Huth f1c29ebc51 target/ppc/excp_helper: Take BQL before calling cpu_interrupt()
Since the introduction of MTTCG, using the msgsnd instruction
abort()s if being called without holding the BQL. So let's protect
that part of the code now with qemu_mutex_lock_iothread().

Buglink: https://bugs.launchpad.net/qemu/+bug/1694998
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-06-30 14:03:31 +10:00
David Gibson d5fc133eed ppc: Rework CPU compatibility testing across migration
Migrating between different CPU versions is a bit complicated for ppc.
A long time ago, we ensured identical CPU versions at either end by
checking the PVR had the same value.  However, this breaks under KVM
HV, because we always have to use the host's PVR - it's not
virtualized.  That would mean we couldn't migrate between hosts with
different PVRs, even if the CPUs are close enough to compatible in
practice (sometimes identical cores with different surrounding logic
have different PVRs, so this happens in practice quite often).

So, we removed the PVR check, but instead checked that several flags
indicating supported instructions matched.  This turns out to be a bad
idea, because those instruction masks are not architected information, but
essentially a TCG implementation detail.  So changes to qemu internal CPU
modelling can break migration - this happened between qemu-2.6 and
qemu-2.7.  That was addressed by 146c11f1 "target-ppc: Allow eventual
removal of old migration mistakes".

Now, verification of CPU compatibility across a migration basically doesn't
happen.  We simply ignore the PVR of the incoming migration, and hope the
cpu on the destination is close enough to work.

Now that we've cleaned up handling of processor compatibility modes
for pseries machine type, we can do better.  For new machine types
(pseries-2.10+) We allow migration if:

    * The source and destination PVRs are for the same type of CPU, as
      determined by CPU class's pvr_match function
OR  * When the source was in a compatibility mode, and the destination CPU
      supports the same compatibility mode

For older machine types we retain the existing behaviour - current CAS
code will usually set a compat mode which would break backwards
migration if we made them use the new behaviour. [Fixed from an
earlier version by Greg Kurz].

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Tested-by: Andrea Bolognani <abologna@redhat.com>
2017-06-30 14:03:31 +10:00
David Gibson 7843c0d60d pseries: Move CPU compatibility property to machine
Server class POWER CPUs have a "compat" property, which is used to set the
backwards compatibility mode for the processor.  However, this only makes
sense for machine types which don't give the guest access to hypervisor
privilege - otherwise the compatibility level is under the guest's control.

To reflect this, this removes the CPU 'compat' property and instead
creates a 'max-cpu-compat' property on the pseries machine.  Strictly
speaking this breaks compatibility, but AFAIK the 'compat' option was
never (directly) used with -device or device_add.

The option was used with -cpu.  So, to maintain compatibility, this
patch adds a hack to the cpu option parsing to strip out any compat
options supplied with -cpu and set them on the machine property
instead of the now deprecated cpu property.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Tested-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Tested-by: Greg Kurz <groug@kaod.org>
Tested-by: Andrea Bolognani <abologna@redhat.com>
2017-06-30 14:03:31 +10:00
Halil Pasic d2164ad35c vmstate: error hint for failed equal checks
In some cases a failing VMSTATE_*_EQUAL does not mean we detected a bug,
but it's actually the best we can do. Especially in these cases a verbose
error message is required.

Let's introduce infrastructure for specifying a error hint to be used if
equal check fails. Let's do this by adding a parameter to the _EQUAL
macros called _err_hint. Also change all current users to pass NULL as
last parameter so nothing changes for them.

Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>

Message-Id: <20170623144823.42936-1-pasic@linux.vnet.ibm.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2017-06-28 11:18:44 +02:00
Greg Kurz 2d3e302ec2 target/ppc: fix memory leak in kvmppc_is_mem_backend_page_size_ok()
The string returned by object_property_get_str() is dynamically allocated.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-06-08 11:05:31 +10:00
Greg Kurz ec69355bef target/ppc: pass const string to kvmppc_is_mem_backend_page_size_ok()
This function has three implementations. Two are stubs that do nothing
and the third one only passes the obj_path argument to:

Object *object_resolve_path(const char *path, bool *ambiguous);

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-06-08 11:05:31 +10:00
Igor Mammedov 15f8b14228 numa: move numa_node from CPUState into target specific classes
Move vcpu's associated numa_node field out of generic CPUState
into inherited classes that actually care about cpu<->numa mapping,
i.e: ARMCPU, PowerPCCPU, X86CPU.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <1496161442-96665-6-git-send-email-imammedo@redhat.com>
[ehabkost: s/CPU is belonging to/CPU belongs to/ on comments]
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2017-06-05 14:59:09 -03:00
Nikunj A Dadhania a8b7373421 target/ppc: reset reservation in do_rfi()
For transitioning back to userspace after the interrupt.

Suggested-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-05-24 11:39:52 +10:00
Thomas Huth e9edd931eb target/ppc: Avoid printing wrong aliases in CPU help text
When running with KVM, we update the "family" CPU alias to point
to the right host CPU type, so that it for example possible to
use "-cpu POWER8" on a POWER8NVL host. However, the function for
printing the list of available CPU models is called earlier than
the KVM setup code, so the output of "-cpu help" is wrong in that
case. Since it would be somewhat ugly anyway to have different
help texts depending on whether "-enable-kvm" has been specified
or not, we should better always print the same text, so fix this
issue by printing "alias for preferred XXX CPU" instead.

Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-05-11 09:45:15 +10:00
David Gibson 5f3066d8b1 target/ppc: Allow workarounds for POWER9 DD1
POWER9 DD1 silicon has some bugs which mean it a) isn't really compliant
with the ISA v3.00 and b) require a number of special workarounds in the
kernel.

At the moment, qemu isn't aware of DD1.  For TCG we don't really want it to
be (why bother emulating buggy silicon).  But with KVM, the guest does need
to be aware of DD1 so it can apply the necessary workarounds.

Meanwhile, the feature negotiation between qemu and the guest strongly
favours architected compatibility modes to "raw" CPU modes.  In combination
with the above, this means the guest sees architected POWER9 mode, and
doesn't apply the DD1 workarounds.  Well, unless it has yet another
workaround to partially ignore what qemu tells it.

This patch addresses this by disabling support for compatibility modes when
using KVM on a POWER9 DD1 host.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-05-11 09:45:15 +10:00
Suraj Jitindar Singh d5fee0bbe6 target/ppc: Implement ISA V3.00 radix page fault handler
ISA V3.00 introduced a new radix mmu model. Implement the page fault
handler for this so we can run a tcg guest in radix mode and perform
address translation correctly.

In real mode (mmu turned off) addresses are masked to remove the top
4 bits and then are subject to partition scoped translation, since we only
support pseries at this stage it is only necessary to perform the masking
and then we're done.

In virtual mode (mmu turned on) address translation if performed as
follows:

1. Use the quadrant to determine the fully qualified address.

The fully qualified address is defined as the combination of the effective
address, the effective logical partition id (LPID) and the effective
process id (PID). Based on the quadrant (EA63:62) we set the pid and lpid
like so:

quadrant 0: lpid = LPIDR, pid = PIDR
quadrant 1: HV only (not allowed in pseries)
quadrant 2: HV only (not allowed in pseries)
quadrant 3: lpid = LPIDR, pid = 0

If we can't get the fully qualified address we raise a segment interrupt.

2. Find the guest radix tree

We ask the virtual hypervisor for the partition table which was registered
with H_REGISTER_PROC_TBL which points us to the process table in guest
memory. We then index this table by pid to get the process table entry
which points us to the appropriate radix tree to translate the address.

If the process table isn't big enough to contain an entry for the current
pid then we raise a storage interrupt.

3. Walk the radix tree

Next we walk the radix tree where each level is a table of page directory
entries indexed by some number of bits from the effective address, where
the number of bits is determined by the table size. We continue to walk
the tree (while entries are valid and the table is of minimum size) until
we reach a table of page table entries, indicated by having the leaf bit
set. The appropriate pte is then checked for sufficient access permissions,
the reference and change bits are updated and the real address is
calculated from the real page number bits of the pte and the low bits of
the effective address.

If we can't find an entry or can't access the entry bacause of permissions
then we raise a storage interrupt.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
[dwg: Add missing parentheses to macro]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-05-11 09:45:15 +10:00
Suraj Jitindar Singh c88305027d target/ppc: Change tlbie invalid fields for POWER9 support
The tlbie[l] instructions are used to invalidate TLB entries used to cache
address translations.

In ISAv3.00 (POWER9) more fields were added to the tblie[l] instructions
which were previously invalid. We don't care about any of these new fields
since we just invalidate the whole world anyway but we need to not
cause an illegal instruction exception when the instructions are called.
We also don't want to allow an older processor to have these fields set
since that would be invalid.

Add a new GEN_HANDLER for the ISAv3 instructions with the correct invalid
mask. These will only be generated to a POWER9 processor for now based on
the instruction flag. Also remove the PPC_MEM_TLBIE instruction flag from
the POWER9 processor definition to ensure the old tlbie isn't generated.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-05-11 09:45:15 +10:00
Suraj Jitindar Singh c6fd28fd57 target/ppc: Update tlbie to check privilege level based on GTSE
The Guest Translation Shootdown Enable (GTSE) bit in the Logical Partition
Control Register (LPCR) can be set to enable a guest to use the tlbie
instruction directly to invalidate translations.

When the GTSE bit is set then the tlbie instruction is supervisor
privileged, otherwise it is hypervisor privileged.

Add a guest translation shootdown enable (gtse) field to the diassembly
context and use this to check the correct privilege level at code
generation time.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-05-11 09:45:15 +10:00
Nikunj A Dadhania 139d9023f1 target/ppc: do not reset reserve_addr in exec_enter
In case when atomic operation is not supported, exit_atomic is called
and we stop the world and execute the atomic operation. This results
in a following call chain:

tcg_gen_atomic_cmpxchg_tl()
  -> gen_helper_exit_atomic()
     -> HELPER(exit_atomic)
        -> cpu_loop_exit_atomic() -> EXCP_ATOMIC
           -> qemu_tcg_cpu_thread_fn() => case EXCP_ATOMIC
              -> cpu_exec_step_atomic()
                 -> cpu_step_atomic()
                    -> cc->cpu_exec_enter() = ppc_cpu_exec_enter()
                       Sets env->reserve_addr = -1;

But by the time it return back, the reservation is erased and the code
fails, this continues forever and the lock is never taken.

Instead set this in powerpc_excp()

Now that ppc_cpu_exec_enter() doesn't have anything meaningful to do,
let us get rid of the function.

Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-05-11 09:45:15 +10:00
Nikunj A Dadhania f0b0685d66 tcg: enable MTTCG by default for PPC64 on x86
This enables the multi-threaded system emulation by default for PPC64
guests using the x86_64 TCG back-end.

Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-05-11 09:45:15 +10:00
Nikunj A Dadhania 4771df23ed target/ppc: Generate fence operations
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-05-11 09:45:14 +10:00
Nikunj A Dadhania 253ce7b2cf target/ppc: Emulate LL/SC using cmpxchg helpers
Emulating LL/SC with cmpxchg is not correct, since it can suffer from
the ABA problem. However, portable parallel code is written assuming
only cmpxchg which means that in practice this is a viable alternative.

Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-05-11 09:45:14 +10:00
David Gibson c364946dd5 target/ppc: Style fixes
This makes a small step fixing one of many style problems that exist in
the older ppc code.  This removes spaces between function (or macro) name
and the following '('.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-04-26 12:41:56 +10:00
Bernhard Kaindl b1c897d587 e500,book3s: mfspr 259: Register mapped/aliased SPRG3 user read
This patch registers mfspr 259 for Book3S and e500 family cores
following this research:

mfspr 259 provides read-only mapped user access to SPRG3(SPR 275) according to:

- PowerISA 2.02, Book III (documents implementation starting with POWER4+ @ p20)
- IBM PowerPC 970MP RISC Microprocessor User's Manual v2.1, page 48
- Amit Singh: "Mac OS X Internals: A Systems Approach" on 970 and 970FX cores:
  He demonstrates mfspr 259 reading TLS data from Mac OS X on G5 on page 588
- NXP documents it in the Core Reference Manuals of: e500, e500mc and e5500
- getcpu() of the 32 & 64-bit Book3S Linux vDSOs use it to read the core number

mfspr 259 does not appear to be implemented in these cores according to:

- 74xx series: MPC7410/MPC7400 and MPC7450 RISC Microprocessor Reference Manuals
- 4xx series:  PPC440 Processor User's Manual, Revision 1.09 by AMCC
- 750 series:  IBM PowerPC 750CL RISC Microprocessor User's Manual
- e200 series: e200z4 Power Architectureâ Core Reference Manual

Implementation: gen_spr_usprg3() is called from init_proc_book3s_common()
(covers the 970 and POWER cores) and init_proc_e500() (covers the e500 family)
to register spr_read_ureg() in the same way which it already provides
the mapped SPR access for SPR_USPRG4-7 in gen_spr_usprgh() for cores
which have the same read-only mapped SPRG register access for SPRG4-7.

Verified using Linux by pinning a thread to a core and checking sched_getcpu()
using qemu-system-ppc64 -M pseries -cpu POWER8 using MTTCG on a x86_64 host.

Signed-off-by: Bernhard Kaindl <bernhard.kaindl@thalesgroup.com>
Reviewed-by: Stefan Resch <stefan.resch@thalesgroup.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-04-26 12:41:56 +10:00
Suraj Jitindar Singh 31b2b0f846 target/ppc: Flush TLB on write to PIDR
The PIDR (process id register) is used to store the id of the currently
running process, which is used to select the process table entry used to
perform address translation. This means that when we write to this register
all the translations in the TLB become outdated as they are for a
previously running process. Thus when this register is written to we need
to invalidate the TLB entries to ensure stale entries aren't used to
to perform translation for the new process, which would result in at best
segfaults or alternatively just random memory being accessed.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
[dwg: Fixed compile error for 32-bit targets]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-04-26 12:41:56 +10:00
Anton Blanchard b88290cd9e target/ppc: Fix size of struct PPCElfPrstatus
gdb refuses to parse QEMU memory dumps because struct PPCElfPrstatus
is the wrong size. Fix it.

Signed-off-by: Anton Blanchard <anton@samba.org>
Fixes: e62fbc54d4 ("target-ppc: dump-guest-memory support")
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-04-26 12:41:55 +10:00
Cédric Le Goater ad5d1add86 ppc/xics: introduce an 'intc' backlink under PowerPCCPU
Today, the ICPState array of the sPAPR machine is indexed with
'cpu_index' of the CPUState. This numbering of CPUs is internal to
QEMU and the guest only knows about what is exposed in the device
tree, that is the 'cpu_dt_id'. This is why sPAPR uses the helper
xics_get_cpu_index_by_dt_id() to do the mapping in a couple of places.

To provide a more generic XICS layer, we need to abstract the IRQ
'server' number and remove any assumption made on its nature. It
should not be used as a 'cpu_index' for lookups like xics_cpu_setup()
and xics_cpu_destroy() do.

To reach that goal, we choose to introduce a generic 'intc' backlink
under PowerPCCPU, and let the machine core init routine do the
ICPState lookup. The resulting object is passed on to xics_cpu_setup()
which does the store under PowerPCCPU. The IRQ 'server' number in XICS
is now generic. sPAPR uses 'cpu_dt_id' and PowerNV will use 'PIR'
number.

This also has the benefit of simplifying the sPAPR hcall routines
which do not need to do any ICPState lookups anymore.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-04-26 12:00:42 +10:00
Suraj Jitindar Singh ccd531b9c9 target/ppc: Add ibm,processor-radix-AP-encodings for TCG
The ibm,processor-radix-AP-encodings device tree property of the cpu node
is used to specify the radix mode supported page sizes of the processor
to the guest os. Contained in the top 3 bits of the msb is the actual
page size (AP) encoding associated with the corresponding radix mode
supported page size. Add this property for a TCG guest, note the TCG code
is capable of translating any format so just add the 4 default page sizes.

The ibm,processor-radix-AP-encodings device tree property is defined as:
One to n cells in ascending order of radix mode supported page sizes
encoded as BE ints (32bit on ppc) in the form:
0bxxxyyyyyyyyyyyyyyyyyyyyyyyyyyyyy
- 0bxxx -> AP encoding
- 0byyyyyyyyyyyyyyyyyyyyyyyyyyyyy -> supported page size encoded as a shift

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-04-26 12:00:42 +10:00
Alexey Kardashevskiy 3dc410ae83 target-ppc/kvm: Enable in-kernel TCE acceleration for multi-tce
This enables in-kernel handling of H_PUT_TCE_INDIRECT and
H_STUFF_TCE hypercalls. The host kernel support is there since v4.6,
in particular d3695aa4f452
("KVM: PPC: Add support for multiple-TCE hcalls").

H_PUT_TCE is already accelerated and does not need any special enablement.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-04-26 12:00:41 +10:00
Suraj Jitindar Singh b4db54132f target/ppc: Implement H_REGISTER_PROCESS_TABLE H_CALL
The H_REGISTER_PROCESS_TABLE H_CALL is used by a guest to indicate to the
hypervisor where in memory its process table is and how translation should
be performed using this process table.

Provide the implementation of this H_CALL for a guest.

We first check for invalid flags, then parse the flags to determine the
operation, and then check the other parameters for valid values based on
the operation (register new table/deregister table/maintain registration).
The process table is then stored in the appropriate location and registered
with the hypervisor (if running under KVM), and the LPCR_[UPRT/GTSE] bits
are updated as required.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
[dwg: Correct missing prototype and uninitialized variable]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-04-26 12:00:41 +10:00
Sam Bobroff cf1c4cce7c target-ppc: support KVM_CAP_PPC_MMU_RADIX, KVM_CAP_PPC_MMU_HASH_V3
Query and cache the value of two new KVM capabilities that indicate
KVM's support for new radix and hash modes of the MMU.

Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-04-26 12:00:41 +10:00
Sam Bobroff c64abd1f9c spapr: Add ibm,processor-radix-AP-encodings to the device tree
Use the new ioctl, KVM_PPC_GET_RMMU_INFO, to fetch radix MMU
information from KVM and present the page encodings in the device tree
under ibm,processor-radix-AP-encodings. This provides page size
information to the guest which is necessary for it to use radix mode.

Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
[dwg: Compile fix for 32-bit targets, style nit fix]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-04-26 12:00:41 +10:00
Alexey Kardashevskiy d6ee2a7c85 target-ppc: kvm: make use of KVM_CREATE_SPAPR_TCE_64
KVM_CAP_SPAPR_TCE capability allows creating TCE tables in KVM which
allows having in-kernel acceleration for H_PUT_TCE_xxx hypercalls.
However it only supports 32bit DMA windows at zero bus offset.

There is a new KVM_CAP_SPAPR_TCE_64 capability which supports 64bit
window size, variable page size and bus offset.

This makes use of the new capability. The kernel headers are already
updated as the kernel support went in to v4.6.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-04-26 12:00:41 +10:00
Sam Bobroff f3d9f303ac target/ppc: Improve accuracy of guest HTM availability on P8s
On Power8 hosts it is currently theoretically possible for QEMU/KVM-HV guests
to receive a ibm,pa-features property indicating that HTM support is available
when it is not.  The situation would occur if the platform firmware of
a Power8 host cleared the HTM bit of the ibm,pa-features property.
QEMU would query KVM for the availability of HTM, which will return no
support, but workaround code in kvm_arch_init_vcpu() would then
re-enable it because KVM_HV is in use and the processor is P8.

This patch adjusts the workaround in kvm_arch_init_vcpu() so that it does not
enable HTM (in the above case) unless the host kernel indicates to the QEMU
process, via the auxiliary vector, that userspace can use HTM (via the HWCAP2
bit KVM_FEATURE2_HTM).

The reason to use the value from the auxiliary vector is that it is
set based only on what the host kernel found in the ibm,pa-features
HTM bit at boot time.

Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-04-26 12:00:41 +10:00