The privileged message send and clear instructions (msgsndp & msgclrp)
are privileged, but will generate a hypervisor facility unavailable
exception if not enabled in the HFSCR and executed in privileged
non-hypervisor state.
Add checks when accessing the DPDES register and when using the
msgsndp and msgclrp isntructions.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20200120104935.24449-3-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The Processor Control facility for POWER8 processors and later
provides a mechanism for the hypervisor to send messages to other
threads in the system (msgsnd instruction) and cause hypervisor-level
exceptions. Privileged non-hypervisor programs can also send messages
(msgsndp instruction) but are restricted to the threads of the same
subprocessor and cause privileged-level exceptions.
The Directed Privileged Doorbell Exception State (DPDES) register
reflects the state of pending privileged doorbell exceptions and can
be used to modify that state. The register can be used to read and
modify the state of privileged doorbell exceptions for all threads of
a subprocessor and thus is a shared facility for that subprocessor.
The register can be read/written by the hypervisor and read by the
supervisor if enabled in the HFSCR, otherwise a hypervisor facility
unavailable exception is generated.
The privileged message send and clear instructions (msgsndp & msgclrp)
are used to generate and clear the presence of a directed privileged
doorbell exception, respectively. The msgsndp instruction can be used
to target any thread of the current subprocessor, msgclrp acts on the
thread issuing the instruction. These instructions are privileged, but
will generate a hypervisor facility unavailable exception if not
enabled in the HFSCR and executed in privileged non-hypervisor
state. The HV facility unavailable exception will be addressed in
other patch.
Add and implement this register and instructions by reading or
modifying the pending interrupt state of the cpu.
Note that TCG only supports one thread per core and so we only need to
worry about the cpu making the access.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20200120104935.24449-2-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The exception vector offset calculation was moved into a function but
the case when AIL=0 was not checked.
The reason we got away with this is that the sole caller of
ppc_excp_vector_offset checks the AIL before calling the function:
/* Handle AIL */
if (ail) {
...
vector |= ppc_excp_vector_offset(cs, ail);
}
Fixes: 2586a4d7a0 ("target/ppc: Move exception vector offset computation into a function")
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20191217142512.574075-1-farosas@linux.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Cleanup in the boilerplate that each target must define.
Replace ppc_env_get_cpu with env_archcpu. The combination
CPU(ppc_env_get_cpu) should have used ENV_GET_CPU to begin;
use env_cpu now.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This controls whether the External Interrupt (0x500) can be
delivered to the hypervisor or not.
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: <20190215161648.9600-11-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This adds support for delivering that exception
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: <20190215161648.9600-9-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
It's very easy for the CPU specific has_work() implementation
and the logic in ppc_hw_interrupt() to be subtly out of sync.
This can occasionally allow a CPU to wakeup from a PM state
and resume executing past the PM instruction when it should
resume at the 0x100 vector.
This detects if it happens and aborts, making it a lot easier
to catch such bugs when testing rather than chasing obscure
guest misbehaviour.
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: <20190215161648.9600-8-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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> [crisµblaze part]
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> [unicore32 part]
Signed-off-by: Thomas Huth <thuth@redhat.com>
