Commit Graph

43 Commits

Author SHA1 Message Date
Nicholas Piggin
526cdce771 target/ppc: Add POWER10 exception model
POWER10 adds a new bit that modifies interrupt behaviour, LPCR[HAIL],
and it removes support for the LPCR[AIL]=0b10 mode.

Reviewed-by: Cédric Le Goater <clg@kaod.org>
Tested-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20210501072436.145444-3-npiggin@gmail.com>
[dwg: Corrected tab indenting]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2021-05-04 13:12:46 +10:00
Nicholas Piggin
8b7e6b07a4 target/ppc: rework AIL logic in interrupt delivery
The AIL logic is becoming unmanageable spread all over powerpc_excp(),
and it is slated to get even worse with POWER10 support.

Move it all to a new helper function.

Reviewed-by: Cédric Le Goater <clg@kaod.org>
Tested-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20210501072436.145444-2-npiggin@gmail.com>
[dwg: Corrected tab indenting]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2021-05-04 13:12:02 +10:00
Nicholas Piggin
9827f20863 target/ppc: Fix POWER9 radix guest HV interrupt AIL behaviour
ISA v3.0 radix guest execution has a quirk in AIL behaviour such that
the LPCR[AIL] value can apply to hypervisor interrupts.

This affects machines that emulate HV=1 mode (i.e., powernv9).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20210415054227.1793812-2-npiggin@gmail.com>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2021-05-04 11:41:25 +10:00
Richard Henderson
f43520e5b2 target/ppc: Create helper_scv
Perform the test against FSCR_SCV at runtime, in the helper.

This means we can remove the incorrect set against SCV in
ppc_tr_init_disas_context and do not need to add an HFLAGS bit.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210323184340.619757-6-richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2021-05-04 11:41:24 +10:00
Greg Kurz
d57d72a874 target/ppc: Introduce an mmu_is_64bit() helper
Callers don't really need to know how 64-bit MMU model enums are
computed. Hide this in a helper.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20201209173536.1437351-3-groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-12-14 15:54:12 +11:00
Chetan Pant
6bd039cdbe powerpc tcg: Fix Lesser GPL version number
There is no "version 2" of the "Lesser" General Public License.
It is either "GPL version 2.0" or "Lesser GPL version 2.1".
This patch replaces all occurrences of "Lesser GPL version 2" with
"Lesser GPL version 2.1" in comment section.

Signed-off-by: Chetan Pant <chetan4windows@gmail.com>
Message-Id: <20201019061126.3102-1-chetan4windows@gmail.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2020-11-15 16:38:50 +01:00
Chen Qun
295397f53c target/ppc/excp_helper: Add a fallthrough for fix compiler warning
When using -Wimplicit-fallthrough in our CFLAGS, the compiler showed warning:
../target/ppc/excp_helper.c: In function ‘powerpc_excp’:
../target/ppc/excp_helper.c:529:13: warning: this statement may fall through [-Wimplicit-fallthrough=]
  529 |         msr |= env->error_code;
      |         ~~~~^~~~~~~~~~~~~~~~~~
../target/ppc/excp_helper.c:530:5: note: here
  530 |     case POWERPC_EXCP_HDECR:     /* Hypervisor decrementer exception         */
      |     ^~~~

Add the corresponding "fall through" comment to fix it.

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
Message-Id: <20201028055107.2170401-1-kuhn.chenqun@huawei.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-11-05 12:18:47 +11:00
zhaolichang
136fbf654d ppc/: fix some comment spelling errors
I found that there are many spelling errors in the comments of qemu/target/ppc.
I used spellcheck to check the spelling errors and found some errors in the folder.

Signed-off-by: zhaolichang <zhaolichang@huawei.com>
Reviewed-by: David Edmondson <david.edmondson@oracle.com>
Message-Id: <20201009064449.2336-3-zhaolichang@huawei.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-10-28 01:08:53 +11:00
Leonardo Bras
0911a60c76 ppc/spapr: Add hotremovable flag on DIMM LMBs on drmem_v2
On reboot, all memory that was previously added using object_add and
device_add is placed in this DIMM area.

The new SPAPR_LMB_FLAGS_HOTREMOVABLE flag helps Linux to put this memory in
the correct memory zone, so no unmovable allocations are made there,
allowing the object to be easily hot-removed by device_del and
object_del.

This new flag was accepted in Power Architecture documentation.

Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
Reviewed-by: Bharata B Rao <bharata@linux.ibm.com>
Message-Id: <20200511200201.58537-1-leobras.c@gmail.com>
[dwg: Fixed syntax error spotted by Cédric Le Goater]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-05-27 15:29:36 +10:00
Nicholas Piggin
3c89b8d6ac target/ppc: Add support for scv and rfscv instructions
POWER9 adds scv and rfscv instructions and the system call vectored
interrupt. Linux does not support this instruction yet but it has
been tested with a modified kernel that runs on real hardware.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20200507115328.789175-1-npiggin@gmail.com>
[dwg: Corrected an overlong line]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-05-27 15:29:24 +10:00
Greg Kurz
ececb880d6 target/ppc: Untabify excp_helper.c
Some tabs crept in with a recent change.

Fixes: 6dc6b55791 "target/ppc: Improve syscall exception logging"
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <158886788307.1560068.14096740175576278978.stgit@bahia.lan>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-05-27 15:27:29 +10:00
Cédric Le Goater
d04ea940c5 target/ppc: Add support for Radix partition-scoped translation
The Radix tree translation model currently supports process-scoped
translation for the PowerNV machine (Hypervisor mode) and for the
pSeries machine (Guest mode). Guests running under an emulated
Hypervisor (PowerNV machine) require a new type of Radix translation,
called partition-scoped, which is missing today.

The Radix tree translation is a 2 steps process. The first step,
process-scoped translation, converts an effective Address to a guest
real address, and the second step, partition-scoped translation,
converts a guest real address to a host real address.

There are difference cases to covers :

* Hypervisor real mode access: no Radix translation.

* Hypervisor or host application access (quadrant 0 and 3) with
  relocation on: process-scoped translation.

* Guest OS real mode access: only partition-scoped translation.

* Guest OS real or guest application access (quadrant 0 and 3) with
  relocation on: both process-scoped translation and partition-scoped
  translations.

* Hypervisor access in quadrant 1 and 2 with relocation on: both
  process-scoped translation and partition-scoped translations.

The radix tree partition-scoped translation is performed using tables
pointed to by the first double-word of the Partition Table Entries and
process-scoped translation uses tables pointed to by the Process Table
Entries (second double-word of the Partition Table Entries).

Both partition-scoped and process-scoped translations process are
identical and thus the radix tree traversing code is largely reused.
However, errors in partition-scoped translations generate hypervisor
exceptions.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20200403140056.59465-5-clg@kaod.org>
[dwg: Fixup from Greg Kurz folded in]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-05-07 11:10:50 +10:00
Nicholas Piggin
b5b7f39181 ppc/spapr: tweak change system reset helper
Rather than have the helper take an optional vector address
override, instead have its caller modify env->nip itself.
This is more consistent when adding pnv nmi support, and also
with mce injection added later.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20200325144147.221875-2-npiggin@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-05-07 11:10:50 +10:00
Nicholas Piggin
6dc6b55791 target/ppc: Improve syscall exception logging
system calls (at least in Linux) use registers r3-r8 for inputs, so
include those registers in the dump.

This also adds a mode for PAPR hcalls, which have a different calling
convention.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20200317054918.199161-1-npiggin@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-05-07 11:10:50 +10:00
Nicholas Piggin
9aa2528070 target/ppc: allow ppc_cpu_do_system_reset to take an alternate vector
Provide for an alternate delivery location, -1 defaults to the
architected address.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20200316142613.121089-7-npiggin@gmail.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-03-17 17:00:22 +11:00
Nicholas Piggin
ad77c6ca0c ppc/spapr: Fix FWNMI machine check interrupt delivery
FWNMI machine check delivery misses a few things that will make it fail
with TCG at least (which we would like to allow in future to improve
testing).

It's not nice to scatter interrupt delivery logic around the tree, so
move it to excp_helper.c and share code where possible.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20200316142613.121089-5-npiggin@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-03-17 17:00:22 +11:00
Cédric Le Goater
493028d8d7 target/ppc: add support for Hypervisor Facility Unavailable Exception
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>
2020-02-02 14:07:57 +11:00
Cédric Le Goater
5ba7ba1da0 target/ppc: Add privileged message send facilities
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>
2020-02-02 14:07:57 +11:00
Fabiano Rosas
bc5fdfc0a1 target/ppc: Handle AIL=0 in ppc_excp_vector_offset
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>
2020-01-08 11:01:59 +11:00
Richard Henderson
db70b31144 target/ppc: Use env_cpu, env_archcpu
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>
2019-06-10 07:03:42 -07:00
David Gibson
47733729b0 target/ppc: Style fixes for excp_helper.c
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>
2019-04-26 10:42:38 +10:00
Fabiano Rosas
2586a4d7a0 target/ppc: Move exception vector offset computation into a function
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Message-Id: <20190228225759.21328-2-farosas@linux.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-03-12 14:33:04 +11:00
Benjamin Herrenschmidt
6eebe6dccb target/ppc: Add support for LPCR:HEIC on POWER9
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>
2019-02-26 09:21:25 +11:00
Benjamin Herrenschmidt
d8ce5fd664 target/ppc: Add Hypervisor Virtualization Interrupt on POWER9
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>
2019-02-26 09:21:24 +11:00
Benjamin Herrenschmidt
f8154fd22b target/ppc: Detect erroneous condition in interrupt delivery
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>
2019-02-26 09:21:24 +11:00
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