Commit Graph

68 Commits

Author SHA1 Message Date
Benjamin Herrenschmidt a790e82b13 target/ppc: Add POWER9 exception model
And use it to get the correct HILE bit in HID0

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190215161648.9600-7-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-02-26 09:21:24 +11:00
Benjamin Herrenschmidt 1e7fd61d97 target/ppc: Rename "in_pm_state" to "resume_as_sreset"
To better reflect what this does, as it's specific to some of the
P7/P8/P9 PM states, not generic.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190215161648.9600-6-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-02-26 09:21:24 +11:00
Benjamin Herrenschmidt dead760b00 target/ppc: Move "wakeup reset" code to a separate function
This moves the code to handle waking up from the 0x100 vector
from powerpc_excp() to a separate function, as the former is
already way too big as it is.

No functional change.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190215161648.9600-5-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-02-26 09:21:24 +11:00
Benjamin Herrenschmidt 21c0d66a9c target/ppc: Fix support for "STOP light" states on POWER9
STOP must act differently based on PSSCR:EC on POWER9. When set, it
acts like the P7/P8 power management instructions and wake up at 0x100
based on the wakeup conditions in LPCR.

When PSSCR:EC is clear however it will wakeup at the next instruction
after STOP (if EE is clear) or take the corresponding interrupts (if
EE is set).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190215161648.9600-4-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-02-26 09:21:24 +11:00
Benjamin Herrenschmidt 3621e2c960 target/ppc: Don't clobber MSR:EE on PM instructions
When issuing a power management instruction, we set MSR:EE
to force ppc_hw_interrupt() into calling powerpc_excp()
to deal with the fact that on P7 and P8, the system reset
caused by the wakeup needs to be generated regardless of
the MSR:EE value (using LPCR only).

This however means that the OS will see a bogus SRR1:EE
value which is a problem. It also prevents properly
implementing P9 STOP "light".

So fix this by instead putting some logic in ppc_hw_interrupt()
to decide whether to deliver or not by taking into account the
fact that we are waking up from sleep.

The LPCR isn't checked as this is done in the has_work() test.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190215161648.9600-3-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-02-26 09:21:24 +11:00
Benjamin Herrenschmidt 154c69f2b8 target/ppc: Fix nip on power management instructions
Those instructions currently raise an exception from within
the helper. This tends to result in a bogus nip value in
the env context (typically the beginning of the TB). Such
a helper needs a gen_update_nip() first.

This fixes it with a different approach which is to throw the
exception from translate.c instead of the helper using
gen_exception_nip() which does the right thing. Exception
EXCP_HLT is also used instead of POWERPC_EXCP_STOP to effectively
exit from the CPU execution loop.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[clg : modified the commit log to comment the use of EXCP_HLT instead
       of POWERPC_EXCP_STOP]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190215161648.9600-2-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-02-26 09:21:24 +11:00
Benjamin Herrenschmidt 4c668f4a3d target/ppc: Remove some #if 0'ed code
Some debug stuff we don't need to keep there

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190128094625.4428-7-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-02-17 21:54:02 +11:00
Roman Kapl 0e3bf48909 ppc: add DBCR based debugging
Add support for DBCR (debug control register) based debugging as used on
BookE ppc. So far supports only branch and single-step events, but these are
the important ones. GDB in Linux guest can now do single-stepping.

Signed-off-by: Roman Kapl <rka@sysgo.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-08-21 14:28:45 +10:00
Richard Henderson 0f3110fa67 target/ppc: Add do_unaligned_access hook
This allows faults from MO_ALIGN to have the same effect
as from gen_check_align.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-07-03 09:56:52 +10:00
Cédric Le Goater 7af1e7b022 target/ppc: add support for hypervisor doorbells on book3s CPUs
The hypervisor doorbells are used by skiboot and Linux on POWER9
processors to wake up secondaries.

This adds processor control support to the Server architecture by
reusing the Embedded support. They are very similar, only the bits
definition of the CPU identifier differ.

Still to be done is message broadcast to all threads of the same
processor.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-01-20 17:15:05 +11:00
Cédric Le Goater 0bfc0cf0af target/ppc: add support for POWER9 HILE
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-01-17 09:35:24 +11:00
Richard Purdie 044897ef4a target/ppc: Fix system lockups caused by interrupt_request state corruption
Occasionally in Linux guests on x86_64 we're seeing logs like:

ppc_set_irq: 0x55b4e0d562f0 n_IRQ 8 level 1 => pending 00000100req 00000004

when they should read:

ppc_set_irq: 0x55b4e0d562f0 n_IRQ 8 level 1 => pending 00000100req 00000002

The "00000004" is CPU_INTERRUPT_EXITTB yet the code calls
cpu_interrupt(cs, CPU_INTERRUPT_HARD) ("00000002") in this function
just before the log message. Something is causing the HARD bit setting
to get lost.

The knock on effect of losing that bit is the decrementer timer interrupts
don't get delivered which causes the guest to sit idle in its idle handler
and 'hang'.

The issue occurs due to races from code which sets CPU_INTERRUPT_EXITTB.

Rather than poking directly into cs->interrupt_request, that code needs to:

a) hold BQL
b) use the cpu_interrupt() helper

This patch fixes the call sites to do this, fixing the hang. The calls
are made from a variety of contexts so a helper function is added to handle
the necessary locking. This can likely be improved and optimised in the future
but it ensures the code is correct and doesn't lockup as it stands today.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-12-05 12:28:42 +11:00
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
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
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
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
David Gibson 1d1be34d26 ppc: Clean up and QOMify hypercall emulation
The pseries machine type is a bit unusual in that it runs a paravirtualized
guest.  The guest expects to interact with a hypervisor, and qemu
emulates the functions of that hypervisor directly, rather than executing
hypervisor code within the emulated system.

To implement this in TCG, we need to intercept hypercall instructions and
direct them to the machine's hypercall handlers, rather than attempting to
perform a privilege change within TCG.  This is controlled by a global
hook - cpu_ppc_hypercall.

This cleanup makes the handling a little cleaner and more extensible than
a single global variable.  Instead, each CPU to have hypercalls intercepted
has a pointer set to a QOM object implementing a new virtual hypervisor
interface.  A method in that interface is called by TCG when it sees a
hypercall instruction.  It's possible we may want to add other methods in
future.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
2017-01-31 10:10:13 +11:00
Thomas Huth fcf5ef2ab5 Move target-* CPU file into a target/ folder
We've currently got 18 architectures in QEMU, and thus 18 target-xxx
folders in the root folder of the QEMU source tree. More architectures
(e.g. RISC-V, AVR) are likely to be included soon, too, so the main
folder of the QEMU sources slowly gets quite overcrowded with the
target-xxx folders.
To disburden the main folder a little bit, let's move the target-xxx
folders into a dedicated target/ folder, so that target-xxx/ simply
becomes target/xxx/ instead.

Acked-by: Laurent Vivier <laurent@vivier.eu> [m68k part]
Acked-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de> [tricore part]
Acked-by: Michael Walle <michael@walle.cc> [lm32 part]
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> [s390x part]
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> [s390x part]
Acked-by: Eduardo Habkost <ehabkost@redhat.com> [i386 part]
Acked-by: Artyom Tarasenko <atar4qemu@gmail.com> [sparc part]
Acked-by: Richard Henderson <rth@twiddle.net> [alpha part]
Acked-by: Max Filippov <jcmvbkbc@gmail.com> [xtensa part]
Reviewed-by: David Gibson <david@gibson.dropbear.id.au> [ppc part]
Acked-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com> [cris&microblaze part]
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> [unicore32 part]
Signed-off-by: Thomas Huth <thuth@redhat.com>
2016-12-20 21:52:12 +01:00