Now that we are no longer switching on the mmu in realmode
mce handler, Revert the commit 4ff753feab02("powerpc/pseries:
Avoid using addr_to_pfn in real mode") partially, which
introduced functions mce_handle_err_virtmode/realmode() to
separate mce handler code which needed translation to enabled.
In realmode mce handler we use irq_work_queue() to defer
the processing of mce events, irq_work_queue() can only
be called when translation is enabled because it touches
memory outside RMA, hence we enable translation before
calling irq_work_queue and disable on return, though it
is not safe to do
Trace IMC (In-Memory collection counters) in powerpc is
useful for application level profiling. For trace_imc,
presently task context (task_ctx_nr) is set to
perf_hw_context. But perf_hw_context is to be used for
cpu PMU. So for trace_imc, even though it is per thread
PMU, it is preferred to use
Kees Cook writes:
> On Mon, Nov 22, 2021 at 04:43:36PM +1100, Michael Ellerman wrote:
>> LEROY Christophe writes:
>> > Le 18/11/2021 à 21:36, Kees Cook a écrit :
>> >> In preparation for FORTIFY_SOURCE performing compile-time and run-time
>> >> field bounds checking for memset(), avoid
On 11/22/21 3:20 AM, Juergen Gross wrote:
On 22.10.21 08:47, Juergen Gross wrote:
Today the non-essential pv devices are hard coded in the xenbus driver
and this list is lacking multiple entries.
This series reworks the detection logic of non-essential devices by
adding a flag for that
Mahesh Salgaonkar writes:
> When certain PHB HW failure causes phyp to recover PHB, it marks the PE
> state as temporarily unavailable until recovery is complete. This also
> triggers an EEH handler in Linux which needs to notify drivers, and perform
> recovery. But before notifying the driver
There is no need to user boiler plate code to specify a set of base
directories we're going to stuff sysctls under. Simplify this by using
register_sysctl() and specifying the directory path directly.
// pycocci sysctl-subdir-register-sysctl-simplify.cocci PATH
@c1@
expression E1;
identifier
This is the 2nd set of kernel/sysctl.c cleanups. The diff stat should
reflect how this is a much better way to deal with theses. Fortunately
coccinelle can be used to ensure correctness for most of these and/or
future merge conflicts.
Note that since this is part of a larger effort to cleanup
From: Xiaoming Ni
There is no need to user boiler plate code to specify a set of base
directories we're going to stuff sysctls under. Simplify this by using
register_sysctl() and specifying the directory path directly.
Move inotify_user sysctl to inotify_user.c while at it to remove clutter
There is no need to user boiler plate code to specify a set of base
directories we're going to stuff sysctls under. Simplify this by using
register_sysctl() and specifying the directory path directly.
// pycocci sysctl-subdir-register-sysctl-simplify.cocci lib/test_sysctl.c
@c1@
expression E1;
From: Xiaoming Ni
The kernel/sysctl.c is a kitchen sink where everyone leaves
their dirty dishes, this makes it very difficult to maintain.
To help with this maintenance let's start by moving sysctls to
places where they actually belong. The proc sysctl maintainers
do not want to know what
There is no need to user boiler plate code to specify a set of base
directories we're going to stuff sysctls under. Simplify this by using
register_sysctl() and specifying the directory path directly.
// pycocci sysctl-subdir-register-sysctl-simplify.cocci drivers/char/hpet.c
@c1@
expression E1;
There is no need to user boiler plate code to specify a set of base
directories we're going to stuff sysctls under. Simplify this by using
register_sysctl() and specifying the directory path directly.
// pycocci sysctl-subdir-register-sysctl-simplify.cocci PATH
@c1@
expression E1;
identifier
There is no need to user boiler plate code to specify a set of base
directories we're going to stuff sysctls under. Simplify this by using
register_sysctl() and specifying the directory path directly.
// pycocci sysctl-subdir-register-sysctl-simplify.cocci PATH
@c1@
expression E1;
identifier
There is no need to user boiler plate code to specify a set of base
directories we're going to stuff sysctls under. Simplify this by using
register_sysctl() and specifying the directory path directly.
// pycocci sysctl-subdir-register-sysctl-simplify.cocci PATH
@c1@
expression E1;
identifier
This is a note to let you know that I've just added the patch titled
signal/powerpc: On swapcontext failure force SIGSEGV
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
On 11/23/21 17:35, Zi Yan wrote:
> On 19 Nov 2021, at 10:15, Zi Yan wrote:
From what my understanding, cma required alignment of
max(MAX_ORDER - 1, pageblock_order), because when MIGRATE_CMA was
introduced,
__free_one_page() does not prevent merging two different pageblocks,
On 17.11.21 04:04, Zi Yan wrote:
> On 16 Nov 2021, at 3:58, David Hildenbrand wrote:
>
>> On 15.11.21 20:37, Zi Yan wrote:
>>> From: Zi Yan
>>>
>>> Hi David,
>>
>> Hi,
>>
>> thanks for looking into this.
>>
Hi,
sorry for the delay, I wasn't "actually working" last week, so now I'm
back from
From: Vitaly Kuznetsov
[ Upstream commit b7915d55b1ac0e68a7586697fa2d06c018135c49 ]
It doesn't make sense to return the recommended maximum number of
vCPUs which exceeds the maximum possible number of vCPUs.
Signed-off-by: Vitaly Kuznetsov
Message-Id:
From: Vitaly Kuznetsov
[ Upstream commit b7915d55b1ac0e68a7586697fa2d06c018135c49 ]
It doesn't make sense to return the recommended maximum number of
vCPUs which exceeds the maximum possible number of vCPUs.
Signed-off-by: Vitaly Kuznetsov
Message-Id:
From: Vitaly Kuznetsov
[ Upstream commit b7915d55b1ac0e68a7586697fa2d06c018135c49 ]
It doesn't make sense to return the recommended maximum number of
vCPUs which exceeds the maximum possible number of vCPUs.
Signed-off-by: Vitaly Kuznetsov
Message-Id:
From: Vitaly Kuznetsov
[ Upstream commit b7915d55b1ac0e68a7586697fa2d06c018135c49 ]
It doesn't make sense to return the recommended maximum number of
vCPUs which exceeds the maximum possible number of vCPUs.
Signed-off-by: Vitaly Kuznetsov
Message-Id:
From: Vitaly Kuznetsov
[ Upstream commit b7915d55b1ac0e68a7586697fa2d06c018135c49 ]
It doesn't make sense to return the recommended maximum number of
vCPUs which exceeds the maximum possible number of vCPUs.
Signed-off-by: Vitaly Kuznetsov
Message-Id:
From: Vitaly Kuznetsov
[ Upstream commit b7915d55b1ac0e68a7586697fa2d06c018135c49 ]
It doesn't make sense to return the recommended maximum number of
vCPUs which exceeds the maximum possible number of vCPUs.
Signed-off-by: Vitaly Kuznetsov
Message-Id:
From: Vitaly Kuznetsov
[ Upstream commit b7915d55b1ac0e68a7586697fa2d06c018135c49 ]
It doesn't make sense to return the recommended maximum number of
vCPUs which exceeds the maximum possible number of vCPUs.
Signed-off-by: Vitaly Kuznetsov
Message-Id:
On 19 Nov 2021, at 10:15, Zi Yan wrote:
> On 19 Nov 2021, at 7:33, Vlastimil Babka wrote:
>
>> On 11/15/21 20:37, Zi Yan wrote:
>>> From: Zi Yan
>>>
>>> Hi David,
>>>
>>> You suggested to make alloc_contig_range() deal with pageblock_order
>>> instead of
>>> MAX_ORDER - 1 and get rid of
On Tue, Nov 16, 2021 at 11:38:01AM +0200, Andy Shevchenko wrote:
> On Mon, Nov 15, 2021 at 10:24:36PM +, Leo Li wrote:
> > > From: Andy Shevchenko
> > > Sent: Monday, November 15, 2021 5:30 AM
> > > On Wed, Nov 10, 2021 at 12:59:52PM +0200, Andy Shevchenko wrote:
>
> ...
>
> > > > v2:
When certain PHB HW failure causes phyp to recover PHB, it marks the PE
state as temporarily unavailable until recovery is complete. This also
triggers an EEH handler in Linux which needs to notify drivers, and perform
recovery. But before notifying the driver about the pci error it uses
On POWER9 and newer, rather than the complex HMI synchronisation and
subcore state, have each thread un-apply the guest TB offset before
calling into the early HMI handler.
This allows the subcore state to be avoided, including subcore enter
/ exit guest, which includes an expensive divide that
The P9 path uses vc->dpdes only for msgsndp / SMT emulation. This adds
an ordering requirement between vcpu->doorbell_request and vc->dpdes for
no real benefit. Use vcpu->doorbell_request directly.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv.c | 18 ++
This goes further to removing vcores from the P9 path. Also avoid the
memset in favour of explicitly initialising all fields.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv.c | 60 +---
1 file changed, 35 insertions(+), 25 deletions(-)
diff --git
The P9 path always uses one vcpu per vcore, so none of the vcore, locks,
stolen time, blocking logic, shared waitq, etc., is required.
Remove most of it.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv.c | 147 ---
1 file changed, 85 insertions(+),
cpu_in_guest is set to determine if a CPU needs to be IPI'ed to exit
the guest and notice the need_tlb_flush bit.
This can be implemented as a global per-CPU pointer to the currently
running guest instead of per-guest cpumasks, saving 2 atomics per
entry/exit. P7/8 doesn't require cpu_in_guest,
The mmu will almost always be ready.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index e532a7010dba..4056605d3367 100644
---
kvm_hstate.in_guest provides the equivalent of MSR[RI]=0 protection,
and it covers the existing MSR[RI]=0 section in late entry and early
exit, so clearing and setting MSR[RI] in those cases does not
actually do anything useful.
Remove the RI manipulation and replace it with comments. Make the
slbmfee/slbmfev instructions are very expensive, moreso than a regular
mfspr instruction, so minimising them significantly improves hash guest
exit performance. The slbmfev is only required if slbmfee found a valid
SLB entry.
Signed-off-by: Nicholas Piggin
---
Rearrange the MSR saving on entry so it does not follow the mtmsrd to
disable interrupts, avoiding a possible RAW scoreboard stall.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/include/asm/kvm_book3s_64.h | 2 +
arch/powerpc/kvm/book3s_hv.c | 18 ++-
mftb() is expensive and one can be avoided on nested guest dispatch.
If the time checking code distinguishes between the L0 timer and the
nested HV timer, then both can be tested in the same place with the
same mftb() value.
This also nicely illustrates the relationship between the L0 and nested
Use the existing TLB flushing logic to IPI the previous CPU and run the
necessary barriers before running a guest vCPU on a new physical CPU,
to do the necessary radix GTSE barriers for handling the case of an
interrupted guest tlbie sequence.
This requires the vCPU TLB flush sequence that is
This creates separate functions for old and new paths for vCPU TLB
flushing, which will reduce complexity of the next change.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/include/asm/kvm_ppc.h| 3 +-
arch/powerpc/kvm/book3s_hv_builtin.c | 53 ---
This also moves the PSSCR update in nested entry to avoid a SPR
scoreboard stall.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv.c | 7 +--
arch/powerpc/kvm/book3s_hv_p9_entry.c | 26 +++---
2 files changed, 24 insertions(+), 9 deletions(-)
diff
Some of the DAWR SPR access is already predicated on dawr_enabled(),
apply this to the remainder of the accesses.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv_p9_entry.c | 34 ---
1 file changed, 20 insertions(+), 14 deletions(-)
diff --git
Tighten up partition switching code synchronisation and comments.
In particular, hwsync ; isync is required after the last access that is
performed in the context of a partition, before the partition is
switched away from.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_64_entry.S
Linux implements SPR save/restore including storage space for registers
in the task struct for process context switching. Make use of this
similarly to the way we make use of the context switching fp/vec save
restore.
This improves code reuse, allows some stack space to be saved, and helps
with
Use HFSCR facility disabling to implement demand faulting for TM, with
a hysteresis counter similar to the load_fp etc counters in context
switching that implement the equivalent demand faulting for userspace
facilities.
This speeds up guest entry/exit by avoiding the register save/restore
when a
Use HFSCR facility disabling to implement demand faulting for EBB, with
a hysteresis counter similar to the load_fp etc counters in context
switching that implement the equivalent demand faulting for userspace
facilities.
This speeds up guest entry/exit by avoiding the register save/restore
when
This avoids more scoreboard stalls and reduces mtSPRs.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv_p9_entry.c | 73 ---
1 file changed, 43 insertions(+), 30 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c
Use CPU_FTR_P9_RADIX_PREFETCH_BUG to apply the workaround, to test for
DD2.1 and below processors. This saves a mtSPR in guest entry.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv.c | 3 ++-
arch/powerpc/kvm/book3s_hv_p9_entry.c | 6 --
2 files changed, 6
This moves PMU switch to guest as late as possible in entry, and switch
back to host as early as possible at exit. This helps the host get the
most perf coverage of KVM entry/exit code as possible.
This is slightly suboptimal for SPR scheduling point of view when the
PMU is enabled, but when perf
If TM is not active, only TM register state needs to be saved and
restored, avoiding several mfmsr/mtmsrd instructions and improving
performance.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv_p9_entry.c | 27 +++
1 file changed, 23 insertions(+), 4
Move register saving and loading from kvmhv_p9_guest_entry() into the HV
and nested entry handlers.
Accesses are scheduled to reduce mtSPR / mfSPR interleaving which
reduces SPR scoreboard stalls.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv.c | 79
Move the part of the guest entry which is specific to nested HV into its
own function. This is just refactoring.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv.c | 125 +++
1 file changed, 67 insertions(+), 58 deletions(-)
diff --git
Move the P9 guest/host register switching functions to the built-in
P9 entry code, and export it for nested to use as well.
This allows more flexibility in scheduling these supervisor privileged
SPR accesses with the HV privileged and PR SPR accesses in the low level
entry code.
Signed-off-by:
This should be no functional difference but makes the caller easier
to read.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv.c | 65 +++-
1 file changed, 41 insertions(+), 24 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv.c
This juggles SPR switching on the entry and exit sides to be more
symmetric, which makes the next refactoring patch possible with no
functional change.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv.c | 8
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git
Keep better track of the current SPR value in places where
they are to be loaded with a new context, to reduce expensive
mtSPR operations.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv.c | 51 ++--
1 file changed, 31 insertions(+), 20 deletions(-)
Avoid interleaving mfSPR and mtSPR to reduce SPR scoreboard stalls.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv.c | 8
arch/powerpc/kvm/book3s_hv_p9_entry.c | 19 +++
2 files changed, 15 insertions(+), 12 deletions(-)
diff --git
Reduce the number of mfTB executed by passing the current timebase
around entry and exit code rather than read it multiple times.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/include/asm/kvm_book3s_64.h | 2 +-
arch/powerpc/kvm/book3s_hv.c | 88 +---
Move the TB updates between saving and loading guest and host SPRs,
to improve scheduling by keeping issue-NTC operations together as
much as possible.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv_p9_entry.c | 36 +--
1 file changed, 18 insertions(+), 18
Change dec_expires to be relative to the guest timebase, and allow
it to be moved into low level P9 guest entry functions, to improve
SPR access scheduling.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/include/asm/kvm_book3s.h | 6 +++
arch/powerpc/include/asm/kvm_host.h | 2 +-
Small cleanup makes it a bit easier to match up entry and exit
operations.
Reviewed-by: Fabiano Rosas
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv.c | 11 +--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv.c
Moving the mtmsrd after the host SPRs are saved and before the guest
SPRs start to be loaded can prevent an SPR scoreboard stall (because
the mtmsrd is L=1 type which does not cause context synchronisation.
This is also now more convenient to combined with the mtmsrd L=0
instruction to enable
This reduces the number of mtmsrd required to enable facility bits when
saving/restoring registers, by having the KVM code set all bits up front
rather than using individual facility functions that set their particular
MSR bits.
Reviewed-by: Fabiano Rosas
Signed-off-by: Nicholas Piggin
---
Move the SPR update into its relevant helper function. This will
help with SPR scheduling improvements in later changes.
Reviewed-by: Fabiano Rosas
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git
Processors that support KVM HV do not require read-modify-write of
the CTRL SPR to set/clear their thread's runlatch. Just write 1 or 0
to it.
Reviewed-by: Fabiano Rosas
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv.c| 2 +-
arch/powerpc/kvm/book3s_hv_rmhandlers.S
Factor duplicated code into a helper function.
Reviewed-by: Fabiano Rosas
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv.c | 24
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
The pmcregs_in_use field in the guest VPA can not be trusted to reflect
what the guest is doing with PMU SPRs, so the PMU must always be managed
(stopped) when exiting the guest, and SPR values set when entering the
guest to ensure it can't cause a covert channel or otherwise cause other
guests or
Rather than guest/host save/retsore functions, implement context switch
functions that take care of details like the VPA update for nested.
The reason to split these kind of helpers into explicit save/load
functions is mainly to schedule SPR access nicely, but PMU is a special
case where the load
Implement the P9 path PMU save/restore code in C, and remove the
POWER9/10 code from the P7/8 path assembly.
Cc: Madhavan Srinivasan
Reviewed-by: Athira Jajeev
Signed-off-by: Nicholas Piggin
---
arch/powerpc/include/asm/asm-prototypes.h | 5 -
arch/powerpc/kvm/book3s_hv.c | 221
It can be useful in simulators (with very constrained environments)
to allow some PMCs to run from boot so they can be sampled directly
by a test harness, rather than having to run perf.
A previous change freezes counters at boot by default, so provide
a boot time option to un-freeze (plus a bit
KVM PMU management code looks for particular frozen/disabled bits in
the PMU registers so it knows whether it must clear them when coming
out of a guest or not. Setting this up helps KVM make these optimisations
without getting confused. Longer term the better approach might be to
move guest/host
Provide a config option that controls the workaround added by commit
63279eeb7f93 ("KVM: PPC: Book3S HV: Always save guest pmu for guest
capable of nesting"). The option defaults to y for now, but is expected
to go away within a few releases.
Nested capable guests running with the earlier commit
This register controls supervisor SPR modifications, and as such is only
relevant for KVM. KVM always sets AMOR to ~0 on guest entry, and never
restores it coming back out to the host, so it can be kept constant and
avoid the mtSPR in KVM guest entry.
Reviewed-by: Fabiano Rosas
Signed-off-by:
HV interrupts may be taken with the MMU enabled when radix guests are
running. Enable LPCR[HAIL] on ISA v3.1 processors for radix guests.
Make this depend on the host LPCR[HAIL] being enabled. Currently that is
always enabled, but having this test means any issue that might require
LPCR[HAIL] to
Rather than have KVM look up the host timer and fiddle with the
irq-work internal details, have the powerpc/time.c code provide a
function for KVM to re-arm the Linux timer code when exiting a
guest.
This is implementation has an improvement over existing code of
marking a decrementer interrupt
mftb is serialising (dispatch next-to-complete) so it is heavy weight
for a mfspr. Avoid reading it multiple times in the entry or exit paths.
A small number of cycles delay to timers is tolerable.
Reviewed-by: Fabiano Rosas
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv.c
On processors that don't suppress the HDEC exceptions when LPCR[HDICE]=0,
this could help reduce needless guest exits due to leftover exceptions on
entering the guest.
Reviewed-by: Alexey Kardashevskiy
Signed-off-by: Nicholas Piggin
---
arch/powerpc/include/asm/time.h | 2 ++
There is no need to save away the host DEC value, as it is derived
from the host timer subsystem which maintains the next timer time,
so it can be restored from there.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/include/asm/time.h | 5 +
arch/powerpc/kernel/time.c | 1 +
The host Linux timer code arms the decrementer with the value
'decrementers_next_tb - current_tb' using set_dec(), which stores
val - 1 on Book3S-64, which is not quite the same as what KVM does
to re-arm the host decrementer when exiting the guest.
This shouldn't be a significant change, but it
The TIDR SPR only exists on POWER9. Avoid accessing it when the
feature bit for it is not set.
Reviewed-by: Fabiano Rosas
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv.c | 12
arch/powerpc/xmon/xmon.c | 10 --
2 files changed, 16 insertions(+), 6
This removes a missed remnant of the WORT SPR.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/platforms/powernv/idle.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/arch/powerpc/platforms/powernv/idle.c
b/arch/powerpc/platforms/powernv/idle.c
index e3ffdc8e8567..86e787502e42 100644
---
This reduces radix guest full entry/exit latency on POWER9 and POWER10
by 2x.
Nested HV guests should see smaller improvements in their L1 entry/exit,
but this is also combined with most L0 speedups also applying to nested
entry. nginx localhost throughput test in a SMP nested guest is improved
On Sun, Nov 21, 2021 at 6:25 PM David Woodhouse wrote:
>
> From: David Woodhouse
>
> Signed-off-by: David Woodhouse
Looks good to me.
For KVM RISC-V,
Acked-by: Anup Patel
Reviewed-by: Anup Patel
Thanks,
Anup
> ---
> arch/riscv/kvm/Makefile | 6 +-
> 1 file changed, 1 insertion(+), 5
Livepatching a loaded module involves applying relocations through
apply_relocate_add(), which attempts to write to read-only memory when
CONFIG_STRICT_MODULE_RWX=y. Work around this by performing these
writes through the text poke area by using patch_instruction().
R_PPC_REL24 is the only
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