Adds migration support for Branch History Rolling
Buffer (BHRB) internal state.
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Glenn Miles <milesg@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
This commit is preparatory to the addition of Branch History
Rolling Buffer (BHRB) functionality, which is being provided
today starting with the P8 processor.
BHRB uses several SPR register fields to control whether or not
a branch instruction's address (and sometimes target address)
should be recorded. Checking each of these fields with each
branch instruction using jitted code would lead to a significant
decrease in performance.
Therefore, it was decided that BHRB configuration bits that are
not expected to change frequently should have their state summarized
in an hflag so that the amount of checking done by jitted code can
be reduced.
This commit contains the changes for summarizing the state of the
following register fields in the HFLAGS_BHRB_ENABLE hflag:
MMCR0[FCP] - Determines if BHRB recording is frozen in the
problem state
MMCR0[FCPC] - A modifier for MMCR0[FCP]
MMCRA[BHRBRD] - Disables all BHRB recording for a thread
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Glenn Miles <milesg@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
ppc only migrates reserve_addr, so the destination machine can get a
valid reservation with an incorrect reservation value of 0. Prior to
commit 392d328abe ("target/ppc: Ensure stcx size matches larx"),
this could permit a stcx. to incorrectly succeed. That commit
inadvertently fixed that bug because the target machine starts with an
impossible reservation size of 0, so any stcx. will fail.
This behaviour is permitted by the ISA because reservation loss may
have implementation-dependent cause. What's more, with KVM machines it
is impossible save or reasonably restore reservation state. However if
the vmstate is being used for record-replay, the reservation must be
saved and restored exactly in order for execution from snapshot to
match the record.
This patch deprecates the existing incomplete reserve_addr vmstate,
and adds a new vmstate subsection with complete reservation state.
The new vmstate is needed only when record-replay mode is active.
Acked-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
TCG does not maintain the DEC reigster in the SPR array, so it does get
migrated. TCG also needs to re-start the decrementer timer on the
destination machine.
Load and store the decrementer into the SPR when migrating. This works
for the level-triggered (book3s) decrementer, and should be compatible
with existing KVM machines that do keep the DEC value there.
This fixes lost decrementer interrupt on migration that can cause
hangs, as well as other problems including record-replay bugs.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
ISA v2.07S introduced the watchpoint facility based on the DAWR0
and DAWRX0 SPRs. Implement this in TCG.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
ISA v2.07S introduced the breakpoint facility based on the CIABR SPR.
Implement this in TCG.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
"qemu/main-loop.h" declares functions related to QEMU's
main loop mutex, which these files don't access. Remove
the unused "qemu/main-loop.h" header.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230828221314.18435-8-philmd@linaro.org>
Some of the PMU hflags bits can go out of synch, for example a store to
MMCR0 with PMCjCE=1 fails to update hflags correctly and results in
hflags mismatch:
qemu: fatal: TCG hflags mismatch (current:0x2408003d rebuilt:0x240a003d)
This can be reproduced by running perf on a recent machine.
Some of the fragility here is the duplication of PMU hflags calculations.
This change consolidates that in a single place to update pmu-related
hflags, to be called after a well defined state changes.
The post-load PMU update is pulled out of the MSR update because it does
not depend on the MSR value.
Fixes: 8b3d1c49a9 ("target/ppc: Add new PMC HFLAGS")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20230530130447.372617-1-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
ppc_cpu_compare_class_pvr_mask() should match the best CPU class in the
family, because it is used by the KVM subsystem to find the host CPU
class. Since commit 03ae4133ab ("target-ppc: Add pvr_match()
callback"), it matches any class in the family (the first one in the
comparison list).
Since commit f30c843ced ("ppc/pnv: Introduce PowerNV machines with
fixed CPU models"), pnv has relied on pnv_match having these new
semantics to check machine compatibility with a CPU family.
Resolve this by adding a parameter to the pvr_match function to select
the best or any match, and restore the old behaviour for the KVM case.
Prior to this fix, e.g., a POWER9 DD2.3 KVM host matches to the
power9_v1.0 class (because that happens to be the first POWER9 family
CPU compared). After the patch, it matches the power9_v2.0 class.
This approach requires pnv_match contain knowledge of the CPU classes
implemented in the same family, which feels ugly. But pushing the 'best'
match down to the class would still require they know about one another
which is not obviously much better. For now this gets things working.
Fixes: 03ae4133ab ("target-ppc: Add pvr_match() callback")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20220731013358.170187-1-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
This allows an x86 host to no-op lwsyncs, and ppc host can use lwsync
rather than sync.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220519135908.21282-5-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
msr_ts macro hides the usage of env->msr, which is a bad
behavior. Substitute it with FIELD_EX64 calls that explicitly use
env->msr as a parameter.
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Víctor Colombo <victor.colombo@eldorado.org.br>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220504210541.115256-19-victor.colombo@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
This is an exclusive TCG helper. Gating it with CONFIG_TCG and changing
meson.build accordingly will prevent problems --disable-tcg and
--disable-linux-user later on.
We're also changing the uses of !kvm_enabled() to tcg_enabled() to avoid
adding "defined(CONFIG_TCG)" ifdefs, since tcg_enabled() will be
defaulted to false with --disable-tcg and the block will always be
skipped.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20220225101140.1054160-2-danielhb413@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
The PowerPC 601 processor is the first generation of processors to
implement the PowerPC architecture. It was designed as a bridge
processor and also could execute most of the instructions of the
previous POWER architecture. It was found on the first Macs and IBM
RS/6000 workstations.
There is not much interest in keeping the CPU model of this
POWER-PowerPC bridge processor. We have the 603 and 604 CPU models of
the 60x family which implement the complete PowerPC instruction set.
Cc: "Hervé Poussineau" <hpoussin@reactos.org>
Cc: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20220203142756.1302515-1-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
The migration code will not look at a VMStateDescription's
minimum_version_id_old field unless that VMSD has set the
load_state_old field to something non-NULL. (The purpose of
minimum_version_id_old is to specify what migration version is needed
for the code in the function pointed to by load_state_old to be able
to handle it on incoming migration.)
We have exactly one VMSD which still has a load_state_old,
in the PPC CPU; every other VMSD which sets minimum_version_id_old
is doing so unnecessarily. Delete all the unnecessary ones.
Commit created with:
sed -i '/\.minimum_version_id_old/d' $(git grep -l '\.minimum_version_id_old')
with the one legitimate use then hand-edited back in.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
It missed vmstate_ppc_cpu.
Commit c8f49e6b93 ("target/ppc: remove 401/403 CPUs") left a few
things behind.
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20220117091541.1615807-1-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20220118104150.1899661-3-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
This breaks migration compatibility from (very) old versions of
QEMU. This should not be a problem for the pseries machine for which
migration is only supported on recent QEMUs ( > 2.x). There is no
clear status on what is supported or not for the other machines. Let's
move forward and remove the .load_state_old handler.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20220118104150.1899661-2-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
This is the combination of frozen bit and counter type, on a per
counter basis. So far this is only used by HFLAGS_INSN_CNT, but
will be used more later.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
[danielhb: fixed PMC4 cyc_cnt shift, insn run latch code,
MMCR0_FC handling, "PMC[1-6]" comment]
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20220103224746.167831-2-danielhb413@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Updated the code in machine.c to use the generic ppc_{store,get}_vscr
instead of helper style functions, so it can build without TCG
Signed-off-by: Bruno Larsen (billionai) <bruno.larsen@eldorado.org.br>
Message-Id: <20210512140813.112884-7-bruno.larsen@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
We weren't recording MSR_GS in hflags, which means that BookE
memory accesses were essentially random vs Guest State.
Instead of adding this bit directly, record the completed mmu
indexes instead. This makes it obvious that we are recording
exactly the information that we need.
This also means that we can stop directly recording MSR_IR.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210323184340.619757-9-richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Extract post_load_update_msr to share between cpu_load_old
and cpu_post_load in updating the msr.
Suggested-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210323184340.619757-2-richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
We have eliminated all normal uses of hflags_nmsr. We need
not even compute it except when we want to migrate. Rename
the field to emphasize this.
Remove the fixme comment for migrating access_type. This value
is only ever used with the current executing instruction, and
is never live when the cpu is halted for migration.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210315184615.1985590-6-richard.henderson@linaro.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
In ppc_store_msr we call hreg_compute_hflags, which itself
calls hreg_compute_mem_idx. Rely on ppc_store_msr to update
everything required by the msr update.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210315184615.1985590-5-richard.henderson@linaro.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Match cpu_post_load in using ppc_store_msr to set all of
the cpu state implied by the value of msr. Do not restore
hflags or hflags_nmsr, as we recompute them in ppc_store_msr.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210315184615.1985590-4-richard.henderson@linaro.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Commit 8118f0950f "migration: Append JSON description of migration
stream" needs a JSON writer. The existing qobject_to_json() wasn't a
good fit, because it requires building a QObject to convert. Instead,
migration got its very own JSON writer, in commit 190c882ce2 "QJSON:
Add JSON writer". It tacitly limits numbers to int64_t, and strings
contents to characters that don't need escaping, unlike
qobject_to_json().
The previous commit factored the JSON writer out of qobject_to_json().
Replace migration's JSON writer by it.
Cc: Juan Quintela <quintela@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20201211171152.146877-17-armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
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>
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>
VMState handlers are supposed to return negative errno values on failure.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200914123505.612812-4-groug@kaod.org>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
hw/boards.h pulls in almost 60 headers. The less we include it into
headers, the better. As a first step, drop superfluous inclusions,
and downgrade some more to what's actually needed. Gets rid of just
one inclusion into a header.
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-23-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
In my "build everything" tree, changing qemu/main-loop.h triggers a
recompile of some 5600 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h). It includes block/aio.h,
which in turn includes qemu/event_notifier.h, qemu/notify.h,
qemu/processor.h, qemu/qsp.h, qemu/queue.h, qemu/thread-posix.h,
qemu/thread.h, qemu/timer.h, and a few more.
Include qemu/main-loop.h only where it's needed. Touching it now
recompiles only some 1700 objects. For block/aio.h and
qemu/event_notifier.h, these numbers drop from 5600 to 2800. For the
others, they shrink only slightly.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190812052359.30071-21-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
In my "build everything" tree, changing hw/hw.h triggers a recompile
of some 2600 out of 6600 objects (not counting tests and objects that
don't depend on qemu/osdep.h).
The previous commits have left only the declaration of hw_error() in
hw/hw.h. This permits dropping most of its inclusions. Touching it
now recompiles less than 200 objects.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-19-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
This allows to drop the CONFIG_KVM guard from the code.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <156051056289.224162.15553539098911498678.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
No header includes qemu-common.h after this commit, as prescribed by
qemu-common.h's file comment.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-5-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
include/hw/arm/xlnx-zynqmp.h hw/arm/nrf51_soc.c hw/arm/msf2-soc.c
block/qcow2-refcount.c block/qcow2-cluster.c block/qcow2-cache.c
target/arm/cpu.h target/lm32/cpu.h target/m68k/cpu.h target/mips/cpu.h
target/moxie/cpu.h target/nios2/cpu.h target/openrisc/cpu.h
target/riscv/cpu.h target/tilegx/cpu.h target/tricore/cpu.h
target/unicore32/cpu.h target/xtensa/cpu.h; bsd-user/main.c and
net/tap-bsd.c fixed up]
When VSX support was initially added, the fpr registers were added at
offset 0 of the VSR register and the vsrl registers were added at offset
1. This is in contrast to the VMX registers (the last 32 VSX registers) which
are stored in host-endian order.
Switch the fpr/vsrl registers so that the lower 32 VSX registers are now also
stored in host endian order to match the VMX registers. This ensures that TCG
vector operations involving mixed VMX and VSX registers will function
correctly.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20190307180520.13868-7-mark.cave-ayland@ilande.co.uk>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This is required before changing the representation of the register.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190215100058.20015-14-mark.cave-ayland@ilande.co.uk>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The VSX register array is a block of 64 128-bit registers where the first 32
registers consist of the existing 64-bit FP registers extended to 128-bit
using new VSR registers, and the last 32 registers are the VMX 128-bit
registers as show below:
64-bit 64-bit
+--------------------+--------------------+
| FP0 | | VSR0
+--------------------+--------------------+
| FP1 | | VSR1
+--------------------+--------------------+
| ... | ... | ...
+--------------------+--------------------+
| FP30 | | VSR30
+--------------------+--------------------+
| FP31 | | VSR31
+--------------------+--------------------+
| VMX0 | VSR32
+-----------------------------------------+
| VMX1 | VSR33
+-----------------------------------------+
| ... | ...
+-----------------------------------------+
| VMX30 | VSR62
+-----------------------------------------+
| VMX31 | VSR63
+-----------------------------------------+
In order to allow for future conversion of VSX instructions to use TCG vector
operations, recreate the same layout using an aligned version of the existing
vsr register array.
Since the old fpr and avr register arrays are removed, the existing callers
must also be updated to use the correct offset in the vsr register array. This
also includes switching the relevant VMState fields over to using subarrays
to make sure that migration is preserved.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Because they are supposed to remain const.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20181114132931.22624-1-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Rename the 2.13 machines to match the number we're going to
use for the next release.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-id: 20180522104000.9044-5-peter.maydell@linaro.org
The pseries-2.7 and older machine types require CPUPPCState::insns_flags
to be strictly equal between source and destination. This checking is
abusive and breaks migration of KVM guests when the host CPU models
are different, even if they are compatible enough to allow the guest
to run transparently. This buggy behaviour was fixed for pseries-2.8
and we added some hacks to allow backward migration of older machine
types. These hacks assume that the CPU belongs to the POWER8 family,
which was true for most KVM based setup we cared about at the time.
But now POWER9 systems are coming, and backward migration of pre 2.8
guests running in POWER8 architected mode from a POWER9 host to a
POWER8 host is broken:
qemu-system-ppc64: error while loading state for instance 0x0 of device
'cpu'
qemu-system-ppc64: load of migration failed: Invalid argument
This happens because POWER9 doesn't set PPC_MEM_TLBIE in insns_flags,
while POWER8 does. Let's force PPC_MEM_TLBIE in the migration hack to
fix the issue. This is an acceptable hack because these old machine
types only support CPU models that do set PPC_MEM_TLBIE.
Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The env->slb_nr field gives the size of the SLB (Segment Lookaside Buffer).
This is another static-after-initialization parameter of the specific
version of the 64-bit hash MMU in the CPU. So, this patch folds the field
into PPCHash64Options with the other hash MMU options.
This is a bit more complicated that the things previously put in there,
because slb_nr was foolishly included in the migration stream. So we need
some of the usual dance to handle backwards compatible migration.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
21b786f "PowerPC: Add TS bits into msr_mask" added the transaction states
to msr_mask for recent POWER CPUs to allow correct migration of machines
that are in certain interim transactional memory states.
This was correct, but unfortunately breaks backwards of pseries-2.7 and
earlier machine types which (stupidly) transferred the msr_mask in the
migration stream and failed if it wasn't equal on each end.
This works around the problem by masking out the new MSR bits in the
compatibility code to send the msr_mask on old machine types.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Tested-by: Greg Kurz <groug@kaod.org>
Tested-by: Lukáš Doktor <ldoktor@redhat.com>
The msr invalidation code (commits 993eb and 2360b) inverts all
bits except MSR_TGPR and MSR_HVB. On non PowerPC 601 processors
this leads to incorrect change of excp_prefix in hreg_store_msr()
function. The problem is that new msr value get multiplied by msr_mask
and inverted msr does not, thus values of MSR_EP bit in new msr value
and inverted msr are distinct, so that excp_prefix changes but should
not.
Signed-off-by: Kurban Mallachiev <mallachiev@ispras.ru>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
cpu->compat_pvr is used to store the current compat mode of the cpu.
On the receiving side during incoming migration we check compatibility
with the compat mode by calling ppc_set_compat(). However we fail to set
the compat mode with the hypervisor since the "new" compat mode doesn't
differ from the current (due to a "cpu->compat_pvr != compat_pvr" check).
This means that kvm runs the vcpus without a compat mode, which is the
incorrect behaviour. The implication being that a compatibility mode
will never be in effect after migration.
To fix this so that the compat mode is correctly set with the
hypervisor, store the desired compat mode and reset cpu->compat_pvr to
zero before calling ppc_set_compat().
Fixes: 5dfaa532 ("ppc: fix ppc_set_compat() with KVM PR")
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Modify the pre_save method on VMStateDescription to return an int
rather than void so that it potentially can fail.
Changed zillions of devices to make them return 0; the only
case I've made it return non-0 is hw/intc/s390_flic_kvm.c that already
had an error_report/return case.
Note: If you add an error exit in your pre_save you must emit
an error_report to say why.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20170925112917.21340-2-dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
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>
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>
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>
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>
The pseries machine type implements the behaviour of a PAPR compliant
hypervisor, without actually executing such a hypervisor on the virtual
CPU. To do this we need some hooks in the CPU code to make hypervisor
facilities get redirected to the machine instead of emulated internally.
For hypercalls this is managed through the cpu->vhyp field, which points
to a QOM interface with a method implementing the hypercall.
For the hashed page table (HPT) - also a hypervisor resource - we use an
older hack. CPUPPCState has an 'external_htab' field which when non-NULL
indicates that the HPT is stored in qemu memory, rather than within the
guest's address space.
For consistency - and to make some future extensions easier - this merges
the external HPT mechanism into the vhyp mechanism. Methods are added
to vhyp for the basic operations the core hash MMU code needs: map_hptes()
and unmap_hptes() for reading the HPT, store_hpte() for updating it and
hpt_mask() to retrieve its size.
To match this, the pseries machine now sets these vhyp fields in its
existing vhyp class, rather than reaching into the cpu object to set the
external_htab field.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
