Hi Nicholas,
I love your patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v5.14-rc3 next-20210723]
[cannot apply to powerpc/next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest
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 sh
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.
XXX: verify msgsndp / DPDES emulation works properly.
Signed-off-by: Nicholas Piggin
---
arch/pow
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 | 61 +---
1 file changed, 35 insertions(+), 26 deletions(-)
diff --git a
The P9 path always uses one vcpu per vcore, so none of the 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, no
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 ee4e38cf5df4..2bd000e2c269 100644
--- a/arch/powerpc/kvm/book
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
---
arch/powerpc/kvm/book3s_hv_p9_entry
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 ++-
arch/powerpc/kvm/book3s_h
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 results in more IPIs than the TLB flush logic req
This also moves the PSSCR update in nested entry to avoid a SPR
scoreboard stall.
-45 cycles (6276) POWER9 virt-mode NULL hcall
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv.c | 7 +--
arch/powerpc/kvm/book3s_hv_p9_entry.c | 26 +++---
2 files c
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 a/arch/powerp
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.
-301 cycles (6319) POWER9 virt-mode NULL hcall
Signed-off-by: Nicholas Pi
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 av
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 a
This avoids more scoreboard stalls and reduces mtSPRs.
-193 cycles (6985) POWER9 virt-mode NULL hcall
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/book3
Use CPU_FTR_P9_RADIX_PREFETCH_BUG for this, to test for DD2.1 and below
processors.
-43 cycles (7178) POWER9 virt-mode NULL hcall
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 insertions(+),
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.
-348 cycles (7218) POWER9 virt-mode NULL hcall
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv_p9_entry.c | 23 +++
1 file changed, 19 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kvm/bo
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.
XXX +212 cycles here somewhere (7566), investigate POWER9 virt-mode NULL hcall
Signed-off-by: Nich
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 a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 977712eb74e0..cb66c9534dbf 100644
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: Ni
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 b/arch/powerpc/kvm/
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 a/arch
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.
-73 cycles (7354) POWER9 virt-mode NULL hcall
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv.c | 64 ++--
1 f
Avoid interleaving mfSPR and mtSPR.
-151 cycles (7427) POWER9 virt-mode NULL hcall
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 --g
Reduce the number of mfTB executed by passing the current timebase
around entry and exit code rather than read it multiple times.
-213 cycles (7578) POWER9 virt-mode NULL hcall
Signed-off-by: Nicholas Piggin
---
arch/powerpc/include/asm/kvm_book3s_64.h | 2 +-
arch/powerpc/kvm/book3s_hv.c
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 +-
arch/
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 b/arch/powerpc/kvm/b
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 faci
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.
-42 cycles (7803) POWER9 virt-mode NULL hcall
Signed-off-by: Nichola
Move the SPR update into its relevant helper function. This will
help with SPR scheduling improvements in later changes.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/pow
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.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv.c| 2 +-
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 15 ++-
2 files
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
in
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.
-449 cycles (8533) POWER9 virt-mode NULL hcall
Signed-off-by: Nicholas Piggin
---
arch/powerpc/include/asm/asm-prototypes.h | 5 -
arch/powerpc/kvm/book3s_hv.c | 205 +
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 m
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 P
Revert the workaround added by commit 63279eeb7f93a ("KVM: PPC: Book3S
HV: Always save guest pmu for guest capable of nesting").
Nested capable guests running with the earlier commit ("KVM: PPC: Book3S
HV Nested: Indicate guest PMU in-use in VPA") will now indicate the PMU
in-use status of their g
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.
-21 cycles (9116) cycles POWER9 virt-mode NULL
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 be
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 as
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.
-118 cycles (9137) POWER9 virt-mode NULL hcall
Reviewed-by: Fabiano Rosas
Signed-off-by: Nicholas
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 ++
arch/powerpc
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 +
arch/powe
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 m
This register is not architected and not implemented in POWER9 or 10,
it just reads back zeroes for compatibility.
-78 cycles (9255) cycles POWER9 virt-mode NULL hcall
Reviewed-by: Fabiano Rosas
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv.c | 3 ---
arch/powerpc/plat
After the L1 saves its PMU SPRs but before loading the L2's PMU SPRs,
switch the pmcregs_in_use field in the L1 lppaca to the value advertised
by the L2 in its VPA. On the way out of the L2, set it back after saving
the L2 PMU registers (if they were in-use).
This transfers the PMU liveness indica
From: Fabiano Rosas
If the nested hypervisor has no access to a facility because it has
been disabled by the host, it should also not be able to see the
Hypervisor Facility Unavailable that arises from one of its guests
trying to access the facility.
This patch turns a HFU that happened in L2 in
From: Fabiano Rosas
As one of the arguments of the H_ENTER_NESTED hypercall, the nested
hypervisor (L1) prepares a structure containing the values of various
hypervisor-privileged registers with which it wants the nested guest
(L2) to run. Since the nested HV runs in supervisor mode it needs the
The softpatch interrupt sets HSRR0 to the faulting instruction +4, so
it should subtract 4 for the faulting instruction address. Also have it
emulate and deliver HFAC interrupts correctly, which is important for
nested HV and facility demand-faulting in future.
Signed-off-by: Nicholas Piggin
---
TM fake-suspend emulation is only used by POWER9. Remove it from the old
code path.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 42 -
1 file changed, 42 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
b/arch/powerpc/kvm
This reduces radix guest full entry/exit latency on POWER9 and POWER10
by almost 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 impr
CPU feature flags work best when they are named for behaviour, not for
the CPU variant that first introduced them. Later revisions might also
contain the behaviour, for example. It's confusing for a POWER9 DD2.2
to have CPU_FTR_POWER9_DD2_1, but it's not confusing if DD2.1 and DD2.2
both have CPU_F
DD2.3 missed out on getting its feature flag bits.
This meant when booting with dt-cpu-ftrs, CPU_FTR_P9_TM_HV_ASSIST is
missing (unless the firmware contains it, which mine does not seem to).
And when booting without, CPU_FTR_P9_TM_XER_SO_BUG is set.
In practice this doesn't make any difference t
On Thu, Jul 22, 2021 at 01:04:42PM +0530, Aneesh Kumar K.V wrote:
> David Gibson writes:
>
> > On Mon, Jun 28, 2021 at 08:41:17PM +0530, Aneesh Kumar K.V wrote:
> >> PAPR interface currently supports two different ways of communicating
> >> resource
> >> grouping details to the OS. These are ref
On Thu, Jul 22, 2021 at 12:37:46PM +0530, Aneesh Kumar K.V wrote:
> David Gibson writes:
>
> > On Mon, Jun 28, 2021 at 08:41:15PM +0530, Aneesh Kumar K.V wrote:
> >> The associativity details of the newly added resourced are collected from
> >> the hypervisor via "ibm,configure-connector" rtas ca
On Thu, Jul 22, 2021 at 12:39:27PM +0530, Aneesh Kumar K.V wrote:
> David Gibson writes:
>
> > On Mon, Jun 28, 2021 at 08:41:16PM +0530, Aneesh Kumar K.V wrote:
> >> This helper is only used with the dispatch trace log collection.
> >> A later patch will add Form2 affinity support and this change
On Thu, Jul 22, 2021 at 10:47:49AM +0530, Aneesh Kumar K.V wrote:
> On 7/22/21 8:06 AM, David Gibson wrote:
> > On Thu, Jul 22, 2021 at 11:59:15AM +1000, David Gibson wrote:
> > > On Mon, Jun 28, 2021 at 08:41:12PM +0530, Aneesh Kumar K.V wrote:
> > > > No functional change in this patch.
> > >
>
config
arm allmodconfig
i386 randconfig-c001-20210725
i386 randconfig-c001-20210726
m68k hp300_defconfig
sh kfr2r09_defconfig
m68k sun3x_defconfig
armmvebu_v7_defconf
allyesconfig
i386 randconfig-c001-20210725
i386 randconfig-c001-20210726
arm pxa_defconfig
armspear6xx_defconfig
mips mtx1_defconfig
powerpc cm5200_defconfig
Excerpts from Fabiano Rosas's message of July 23, 2021 8:12 am:
> As one of the arguments of the H_ENTER_NESTED hypercall, the nested
> hypervisor (L1) prepares a structure containing the values of various
> hypervisor-privileged registers with which it wants the nested guest
> (L2) to run. Since t
Geoff Levand a écrit :
Fixes several DMA mapping problems with the PS3's gelic network driver:
* Change from checking the return value of dma_map_single to using the
dma_mapping_error routine.
* Use the correct buffer length when mapping the RX skb.
* Improved error checking and debug lo
Geoff Levand a écrit :
Add new helper routine gelic_work_to_card that converts a work_struct
to a gelic_card.
Adding a function is it really needed as it is used only once ?
Christophe
Signed-off-by: Geoff Levand
---
drivers/net/ethernet/toshiba/ps3_gelic_net.c | 8 ++--
1 file chan
Geoff Levand a écrit :
In an effort to make the PS3 gelic driver easier to maintain, rename
the gelic_card_init_chain parameter 'no' to 'descr_count'.
Not sure you really need a so long name. 'count' should be good enough.
Read https://www.kernel.org/doc/html/latest/process/coding-style.html
Geoff Levand a écrit :
Add a new preprocessor macro BUG_ON_DEBUG, that expands to BUG_ON when
the preprocessor macro DEBUG is defined, or to WARN_ON when DEBUG is not
defined. Also, replace all occurrences of BUG_ON with BUG_ON_DEBUG.
Why is BUG_ON() needed at all if WARN_ON() is enough ?
Y
The pull request you sent on Mon, 26 Jul 2021 00:20:47 +1000:
> https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git
> tags/powerpc-5.14-3
has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/3c0ce1497a449b0d150b455628947152c5f6216a
Thank you!
--
Deet-doot-d
The ARRAY_SIZE is the macro definition of sizeof(a)/sizeof(a[0]) and
it is more compact and formal to get a array size.
Signed-off-by: Jason Wang
---
arch/powerpc/xmon/ppc-opc.c | 12
1 file changed, 4 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/xmon/ppc-opc.c b/arch/po
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA256
Hi Linus,
Please pull some more powerpc fixes for 5.14:
The following changes since commit e73f0f0ee7541171d89f2e2491130c7771ba58d3:
Linux 5.14-rc1 (2021-07-11 15:07:40 -0700)
are available in the git repository at:
https://git.kernel.org/pu
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