Various spelling mistakes in comments.
Detected with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220430185654.5855-1-Julia.Lawall@inria.fr
With power7 and above we expect the cpu to support keys. The
number of keys are firmware controlled based on device tree.
PR KVM do not expose key details via device tree. Hence when running with PR KVM
we do run with MMU_FTR_KEY support disabled. But we can still
get updates on UAMOR. Hence ignore access to them and for mfstpr return
0 indicating no AMR/IAMR update is no allowed.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201127044424.40686-3-aneesh.kumar@linux.ibm.com
In the current kvm version, 'kvm_run' has been included in the 'kvm_vcpu'
structure. For historical reasons, many kvm-related function parameters
retain the 'kvm_run' and 'kvm_vcpu' parameters at the same time. This
patch does a unified cleanup of these remaining redundant parameters.
Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not write to the free
software foundation 51 franklin street fifth floor boston ma 02110
1301 usa
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 67 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141333.953658117@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Recent kernels, since commit e15a4fea4d ("powerpc/64s/hash: Add
some SLB debugging tests", 2018-10-03) use the slbfee. instruction,
which PR KVM currently does not have code to emulate. Consequently
recent kernels fail to boot under PR KVM. This adds emulation of
slbfee., enabling these kernels to boot successfully.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
When running a nested (L2) guest the guest (L1) hypervisor will use
the H_TLB_INVALIDATE hcall when it needs to change the partition
scoped page tables or the partition table which it manages. It will
use this hcall in the situations where it would use a partition-scoped
tlbie instruction if it were running in hypervisor mode.
The H_TLB_INVALIDATE hcall can invalidate different scopes:
Invalidate TLB for a given target address:
- This invalidates a single L2 -> L1 pte
- We need to invalidate any L2 -> L0 shadow_pgtable ptes which map the L2
address space which is being invalidated. This is because a single
L2 -> L1 pte may have been mapped with more than one pte in the
L2 -> L0 page tables.
Invalidate the entire TLB for a given LPID or for all LPIDs:
- Invalidate the entire shadow_pgtable for a given nested guest, or
for all nested guests.
Invalidate the PWC (page walk cache) for a given LPID or for all LPIDs:
- We don't cache the PWC, so nothing to do.
Invalidate the entire TLB, PWC and partition table for a given/all LPIDs:
- Here we re-read the partition table entry and remove the nested state
for any nested guest for which the first doubleword of the partition
table entry is now zero.
The H_TLB_INVALIDATE hcall takes as parameters the tlbie instruction
word (of which only the RIC, PRS and R fields are used), the rS value
(giving the lpid, where required) and the rB value (giving the IS, AP
and EPN values).
[paulus@ozlabs.org - adapted to having the partition table in guest
memory, added the H_TLB_INVALIDATE implementation, removed tlbie
instruction emulation, reworded the commit message.]
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When the 'regs' field was added to struct kvm_vcpu_arch, the code
was changed to use several of the fields inside regs (e.g., gpr, lr,
etc.) but not the ccr field, because the ccr field in struct pt_regs
is 64 bits on 64-bit platforms, but the cr field in kvm_vcpu_arch is
only 32 bits. This changes the code to use the regs.ccr field
instead of cr, and changes the assembly code on 64-bit platforms to
use 64-bit loads and stores instead of 32-bit ones.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
tabort. will perform transaction failure recording and the recording
depends on TEXASR FS bit. Currently the TEXASR FS bit is retrieved
after tabort., when the TEXASR FS bit is already been updated by
tabort. itself.
This patch corrects this behavior by retrieving TEXASR val before
tabort.
tabort. will not immediately leads to transaction failure handling
in suspend state. So this patch also remove the mtspr on TEXASR/TFIAR
registers to avoid TM bad thing exception.
Fixes: 26798f88d5 ("KVM: PPC: Book3S PR: Add emulation for tabort. in privileged state")
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
The treclaim. emulation needs to record failure status in the TEXASR
register if the transaction had not previously failed. However, the
current code first does kvmppc_save_tm_pr() (which does a treclaim.
itself) and then checks the failure summary bit in TEXASR after that.
Since treclaim. itself causes transaction failure, the FS bit is
always set, so we were never updating TEXASR with the failure cause
supplied by the guest as the RA parameter to the treclaim. instruction.
This caused the tm-unavailable test in tools/testing/selftests/powerpc/tm
to fail.
To fix this, we need to read TEXASR before calling kvmppc_save_tm_pr(),
and base the final value of TEXASR on that value.
Fixes: 03c81682a9 ("KVM: PPC: Book3S PR: Add emulation for treclaim.")
Reviewed-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Currently guest kernel doesn't handle TAR facility unavailable and it
always runs with TAR bit on. PR KVM will lazily enable TAR. TAR is not
a frequent-use register and it is not included in SVCPU struct.
Due to the above, the checkpointed TAR val might be a bogus TAR val.
To solve this issue, we will make vcpu->arch.fscr tar bit consistent
with shadow_fscr when TM is enabled.
At the end of emulating treclaim., the correct TAR val need to be loaded
into the register if FSCR_TAR bit is on.
At the beginning of emulating trechkpt., TAR needs to be flushed so that
the right tar val can be copied into tar_tm.
Tested with:
tools/testing/selftests/powerpc/tm/tm-tar
tools/testing/selftests/powerpc/ptrace/ptrace-tm-tar (remove DSCR/PPR
related testing).
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Currently PR KVM doesn't support transaction memory in guest privileged
state.
This patch adds a check at setting guest msr, so that we can never return
to guest with PR=0 and TS=0b10. A tabort will be emulated to indicate
this and fail transaction immediately.
[paulus@ozlabs.org - don't change the TM_CAUSE_MISC definition, instead
use TM_CAUSE_KVM_FAC_UNAV.]
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Currently privileged-state guest will be run with TM disabled.
Although the privileged-state guest cannot initiate a new transaction,
it can use tabort to terminate its problem state's transaction.
So it is still necessary to emulate tabort. for privileged-state guest.
Tested with:
https://github.com/justdoitqd/publicFiles/blob/master/test_tabort.c
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This patch adds host emulation when guest PR KVM executes "trechkpt.",
which is a privileged instruction and will trap into host.
We firstly copy vcpu ongoing content into vcpu tm checkpoint
content, then perform kvmppc_restore_tm_pr() to do trechkpt.
with updated vcpu tm checkpoint values.
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This patch adds support for "treclaim." emulation when PR KVM guest
executes treclaim. and traps to host.
We will firstly do treclaim. and save TM checkpoint. Then it is
necessary to update vcpu current reg content with checkpointed vals.
When rfid into guest again, those vcpu current reg content (now the
checkpoint vals) will be loaded into regs.
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Currently the kernel doesn't use transaction memory.
And there is an issue for privileged state in the guest that:
tbegin/tsuspend/tresume/tabort TM instructions can impact MSR TM bits
without trapping into the PR host. So following code will lead to a
false mfmsr result:
tbegin <- MSR bits update to Transaction active.
beq <- failover handler branch
mfmsr <- still read MSR bits from magic page with
transaction inactive.
It is not an issue for non-privileged guest state since its mfmsr is
not patched with magic page and will always trap into the PR host.
This patch will always fail tbegin attempt for privileged state in the
guest, so that the above issue is prevented. It is benign since
currently (guest) kernel doesn't initiate a transaction.
Test case:
https://github.com/justdoitqd/publicFiles/blob/master/test_tbegin_pr.c
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
The mfspr/mtspr on TM SPRs(TEXASR/TFIAR/TFHAR) are non-privileged
instructions and can be executed by PR KVM guest in problem state
without trapping into the host. We only emulate mtspr/mfspr
texasr/tfiar/tfhar in guest PR=0 state.
When we are emulating mtspr tm sprs in guest PR=0 state, the emulation
result needs to be visible to guest PR=1 state. That is, the actual TM
SPR val should be loaded into actual registers.
We already flush TM SPRs into vcpu when switching out of CPU, and load
TM SPRs when switching back.
This patch corrects mfspr()/mtspr() emulation for TM SPRs to make the
actual source/dest be the actual TM SPRs.
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This patch adds 2 new APIs: kvmppc_copyto_vcpu_tm() and
kvmppc_copyfrom_vcpu_tm(). These 2 APIs will be used to copy from/to TM
data between VCPU_TM/VCPU area.
PR KVM will use these APIs for treclaim. or trechkpt. emulation.
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
According to ISA specification for RFID, in MSR TM disabled and TS
suspended state (S0), if the target MSR is TM disabled and TS state is
inactive (N0), rfid should suppress this update.
This patch makes the RFID emulation of PR KVM consistent with this.
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
According to the PowerISA 2.07, mtspr and mfspr should not always
generate an illegal instruction exception when being used with an
undefined SPR, but rather treat the instruction as a NOP or inject a
privilege exception in some cases, too - depending on the SPR number.
Also turn the printk here into a ratelimited print statement, so that
the guest can not flood the dmesg log of the host by issueing lots of
illegal mtspr/mfspr instruction here.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
The MMCR2 register is available twice, one time with number 785
(privileged access), and one time with number 769 (unprivileged,
but it can be disabled completely). In former times, the Linux
kernel was using the unprivileged register 769 only, but since
commit 8dd75ccb57 ("powerpc: Use privileged SPR number
for MMCR2"), it uses the privileged register 785 instead.
The KVM-PR code then of course also switched to use the SPR 785,
but this is causing older guest kernels to crash, since these
kernels still access 769 instead. So to support older kernels
with KVM-PR again, we have to support register 769 in KVM-PR, too.
Fixes: 8dd75ccb57
Cc: stable@vger.kernel.org # v3.10+
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
POWER8 has one virtual timebase (VTB) register per subcore, not one
per CPU thread. The HV KVM code currently treats VTB as a per-thread
register, which can lead to spurious soft lockup messages from guests
which use the VTB as the time source for the soft lockup detector.
(CPUs before POWER8 did not have the VTB register.)
For HV KVM, this fixes the problem by making only the primary thread
in each virtual core save and restore the VTB value. With this,
the VTB state becomes part of the kvmppc_vcore structure. This
also means that "piggybacking" of multiple virtual cores onto one
subcore is not possible on POWER8, because then the virtual cores
would share a single VTB register.
PR KVM emulates a VTB register, which is per-vcpu because PR KVM
has no notion of CPU threads or SMT. For PR KVM we move the VTB
state into the kvmppc_vcpu_book3s struct.
Cc: stable@vger.kernel.org # v3.14+
Reported-by: Thomas Huth <thuth@redhat.com>
Tested-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
When compiling the KVM code for POWER with "make C=1", sparse
complains about functions missing proper prototypes and a 64-bit
constant missing the ULL prefix. Let's fix this by making the
functions static or by including the proper header with the
prototypes, and by appending a ULL prefix to the constant
PPC_MPPE_ADDRESS_MASK.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
We handle FSCR feature bits (well, TAR only really today) lazily when the guest
starts using them. So when a guest activates the bit and later uses that feature
we enable it for real in hardware.
However, when the guest stops using that bit we don't stop setting it in
hardware. That means we can potentially lose a trap that the guest expects to
happen because it thinks a feature is not active.
This patch adds support to drop TAR when then guest turns it off in FSCR. While
at it it also restricts FSCR access to 64bit systems - 32bit ones don't have it.
Signed-off-by: Alexander Graf <agraf@suse.de>
Writing to IC is not allowed in the privileged mode.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
virtual time base register is a per VM, per cpu register that needs
to be saved and restored on vm exit and entry. Writing to VTB is not
allowed in the privileged mode.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[agraf: fix compile error]
Signed-off-by: Alexander Graf <agraf@suse.de>
We use time base for PURR and SPURR emulation with PR KVM since we
are emulating a single threaded core. When using time base
we need to make sure that we don't accumulate time spent in the host
in PURR and SPURR value.
Also we don't need to emulate mtspr because both the registers are
hypervisor resource.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
There are LE Linux guests out there that don't handle hypercalls correctly.
Instead of interpreting the instruction stream from device tree as big endian
they assume it's a little endian instruction stream and fail.
When we see an illegal instruction from such a byte reversed instruction stream,
bail out graciously and just declare every hcall as error.
Signed-off-by: Alexander Graf <agraf@suse.de>
Use make_dsisr instead of open coding it. This also have
the added benefit of handling alignment interrupt on additional
instructions.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Although it's optional, IBM POWER cpus always had DAR value set on
alignment interrupt. So don't try to compute these values.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
POWER8 introduces transactional memory which brings along a number of new
registers and MSR bits.
Implementing all of those is a pretty big headache, so for now let's at least
emulate enough to make Linux's context switching code happy.
Signed-off-by: Alexander Graf <agraf@suse.de>
POWER8 introduces a new facility called the "Event Based Branch" facility.
It contains of a few registers that indicate where a guest should branch to
when a defined event occurs and it's in PR mode.
We don't want to really enable EBB as it will create a big mess with !PR guest
mode while hardware is in PR and we don't really emulate the PMU anyway.
So instead, let's just leave it at emulation of all its registers.
Signed-off-by: Alexander Graf <agraf@suse.de>
POWER8 introduced a new interrupt type called "Facility unavailable interrupt"
which contains its status message in a new register called FSCR.
Handle these exits and try to emulate instructions for unhandled facilities.
Follow-on patches enable KVM to expose specific facilities into the guest.
Signed-off-by: Alexander Graf <agraf@suse.de>
In parallel to the Processor ID Register (PIR) threaded POWER8 also adds a
Thread ID Register (TIR). Since PR KVM doesn't emulate more than one thread
per core, we can just always expose 0 here.
Signed-off-by: Alexander Graf <agraf@suse.de>
When we expose a POWER8 CPU into the guest, it will start accessing PMU SPRs
that we don't emulate. Just ignore accesses to them.
Signed-off-by: Alexander Graf <agraf@suse.de>
The shared (magic) page is a data structure that contains often used
supervisor privileged SPRs accessible via memory to the user to reduce
the number of exits we have to take to read/write them.
When we actually share this structure with the guest we have to maintain
it in guest endianness, because some of the patch tricks only work with
native endian load/store operations.
Since we only share the structure with either host or guest in little
endian on book3s_64 pr mode, we don't have to worry about booke or book3s hv.
For booke, the shared struct stays big endian. For book3s_64 hv we maintain
the struct in host native endian, since it never gets shared with the guest.
For book3s_64 pr we introduce a variable that tells us which endianness the
shared struct is in and route every access to it through helper inline
functions that evaluate this variable.
Signed-off-by: Alexander Graf <agraf@suse.de>
This patch add a new callback kvmppc_ops. This will help us in enabling
both HV and PR KVM together in the same kernel. The actual change to
enable them together is done in the later patch in the series.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[agraf: squash in booke changes]
Signed-off-by: Alexander Graf <agraf@suse.de>
Currently PR-style KVM keeps the volatile guest register values
(R0 - R13, CR, LR, CTR, XER, PC) in a shadow_vcpu struct rather than
the main kvm_vcpu struct. For 64-bit, the shadow_vcpu exists in two
places, a kmalloc'd struct and in the PACA, and it gets copied back
and forth in kvmppc_core_vcpu_load/put(), because the real-mode code
can't rely on being able to access the kmalloc'd struct.
This changes the code to copy the volatile values into the shadow_vcpu
as one of the last things done before entering the guest. Similarly
the values are copied back out of the shadow_vcpu to the kvm_vcpu
immediately after exiting the guest. We arrange for interrupts to be
still disabled at this point so that we can't get preempted on 64-bit
and end up copying values from the wrong PACA.
This means that the accessor functions in kvm_book3s.h for these
registers are greatly simplified, and are same between PR and HV KVM.
In places where accesses to shadow_vcpu fields are now replaced by
accesses to the kvm_vcpu, we can also remove the svcpu_get/put pairs.
Finally, on 64-bit, we don't need the kmalloc'd struct at all any more.
With this, the time to read the PVR one million times in a loop went
from 567.7ms to 575.5ms (averages of 6 values), an increase of about
1.4% for this worse-case test for guest entries and exits. The
standard deviation of the measurements is about 11ms, so the
difference is only marginally significant statistically.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
We don't emulate breakpoints yet, so just ignore reads and writes
to / from DABR.
This fixes booting of more recent Linux guest kernels for me.
Reported-by: Nello Martuscielli <ppc.addon@gmail.com>
Tested-by: Nello Martuscielli <ppc.addon@gmail.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Currently the instruction emulator code returns EMULATE_EXIT_USER
and common code initializes the "run->exit_reason = .." and
"vcpu->arch.hcall_needed = .." with one fixed reason.
But there can be different reasons when emulator need to exit
to user space. To support that the "run->exit_reason = .."
and "vcpu->arch.hcall_needed = .." initialization is moved a
level up to emulator.
Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Instruction emulation return EMULATE_DO_PAPR when it requires
exit to userspace on book3s. Similar return is required
for booke. EMULATE_DO_PAPR reads out to be confusing so it is
renamed to EMULATE_EXIT_USER.
Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
On mfspr/mtspr emulation path Book3E's MMUCFG SPR with value 1015 clashes
with G4's MSSSR0 SPR. Move MSSSR0 emulation from generic part to Books3S.
MSSSR0 also clashes with Book3S's DABRX SPR. DABRX was not explicitly
handled so Book3S execution flow will behave as before.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
When running on top of pHyp, the hypercall instruction "sc 1" goes
straight into pHyp without trapping in supervisor mode.
So if we want to support PAPR guest in this configuration we need to
add a second way of accessing PAPR hypercalls, preferably with the
exact same semantics except for the instruction.
So let's overlay an officially reserved instruction and emulate PAPR
hypercalls whenever we hit that one.
Signed-off-by: Alexander Graf <agraf@suse.de>
This adds basic emulation of the PURR and SPURR registers. We assume
we are emulating a single-threaded core, so these advance at the same
rate as the timebase. A Linux kernel running on a POWER7 expects to
be able to access these registers and is not prepared to handle a
program interrupt on accessing them.
This also adds a very minimal emulation of the DSCR (data stream
control register). Writes are ignored and reads return zero.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
When reading and writing SPRs, every SPR emulation piece had to read
or write the respective GPR the value was read from or stored in itself.
This approach is pretty prone to failure. What if we accidentally
implement mfspr emulation where we just do "break" and nothing else?
Suddenly we would get a random value in the return register - which is
always a bad idea.
So let's consolidate the generic code paths and only give the core
specific SPR handling code readily made variables to read/write from/to.
Functionally, this patch doesn't change anything, but it increases the
readability of the code and makes is less prone to bugs.
Signed-off-by: Alexander Graf <agraf@suse.de>
Instructions on PPC are pretty similarly encoded. So instead of
every instruction emulation code decoding the instruction fields
itself, we can move that code to more generic places and rely on
the compiler to optimize the unused bits away.
This has 2 advantages. It makes the code smaller and it makes the
code less error prone, as the instruction fields are always
available, so accidental misusage is reduced.
Functionally, this patch doesn't change anything.
Signed-off-by: Alexander Graf <agraf@suse.de>
When running the 64-bit Book3s PR code without CONFIG_PREEMPT_NONE, we were
doing a few things wrong, most notably access to PACA fields without making
sure that the pointers stay stable accross the access (preempt_disable()).
This patch moves to_svcpu towards a get/put model which allows us to disable
preemption while accessing the shadow vcpu fields in the PACA. That way we
can run preemptible and everyone's happy!
Reported-by: Jörg Sommer <joerg@alea.gnuu.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Recent Linux versions use the CFAR and PURR SPRs, but don't really care about
their contents (yet). So for now, we can simply return 0 when the guest wants
to read them.
Signed-off-by: Alexander Graf <agraf@suse.de>
Julia Lawall