- 03 Dec, 2020 40 commits
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Athira Rajeev authored
In Power9, L2/L3 bus events are always available as a "bank" of 4 events. To obtain the counts for any of the l2/l3 bus events in a given bank, the user will have to program PMC4 with corresponding l2/l3 bus event for that bank. Commit 59029136 ("powerpc/perf: Add constraints for power9 l2/l3 bus events") enforced this rule in Power9. But this is not valid for Power10, since in Power10 Monitor Mode Control Register2 (MMCR2) has bits to configure l2/l3 event bits. Hence remove this PMC4 constraint check from power10. Since the l2/l3 bits in MMCR2 are not per-pmc, patch handles group constrints checks for l2/l3 bits in MMCR2. Fixes: a64e697c ("powerpc/perf: power10 Performance Monitoring support") Signed-off-by:
Athira Rajeev <atrajeev@linux.vnet.ibm.com> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1606409684-1589-3-git-send-email-atrajeev@linux.vnet.ibm.com
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Athira Rajeev authored
power10 uses bit 9 of the raw event code as RADIX_SCOPE_QUAL. This bit is used for enabling the radix process events. Patch fixes the PMU counter support functions to program bit 18 of MMCR1 ( Monitor Mode Control Register1 ) with the RADIX_SCOPE_QUAL bit value. Since this field is not per-pmc, add this to PMU group constraints to make sure events in a group will have same bit value for this field. Use bit 21 as constraint bit field for radix_scope_qual. Patch also updates the power10 raw event encoding layout information, format field and constraints bit layout to include the radix_scope_qual bit. Fixes: a64e697c ("powerpc/perf: power10 Performance Monitoring support") Signed-off-by:
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Aneesh Kumar K.V authored
If FTR_BOOK3S_KUAP is disabled, kernel will continue to run with the same AMR value with which it was entered. Hence there is a high chance that we can return without restoring the AMR value. This also helps the case when applications are not using the pkey feature. In this case, different applications will have the same AMR values and hence we can avoid restoring AMR in this case too. Also avoid isync() if not really needed. Do the same for IAMR. null-syscall benchmark results: With smap/smep disabled: Without patch: 957.95 ns 2778.17 cycles With patch: 858.38 ns 2489.30 cycles With smap/smep enabled: Without patch: 1017.26 ns 2950.36 cycles With patch: 1021.51 ns 2962.44 cycles Signed-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by:
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Aneesh Kumar K.V authored
Don't enable KUEP/KUAP if we support less than or equal to 3 keys. Signed-off-by:
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Aneesh Kumar K.V authored
Signed-off-by:
Sandipan Das <sandipan@linux.ibm.com> Signed-off-by:
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Aneesh Kumar K.V authored
Signed-off-by:
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Aneesh Kumar K.V authored
Radix use IAMR Key 0 and hash translation use IAMR key 3. Signed-off-by:
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Aneesh Kumar K.V authored
Radix use AMR Key 0 and hash translation use AMR key 3. Signed-off-by:
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Aneesh Kumar K.V authored
With hash translation use DSISR_KEYFAULT to identify a wrong access. With Radix we look at the AMR value and type of fault. Signed-off-by:
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Aneesh Kumar K.V authored
If an application has configured address protection such that read/write is denied using pkey even the kernel should receive a FAULT on accessing the same. This patch use user AMR value stored in pt_regs.amr to achieve the same. Signed-off-by:
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Aneesh Kumar K.V authored
Now that kernel correctly store/restore userspace AMR/IAMR values, avoid manipulating AMR and IAMR from the kernel on behalf of userspace. Signed-off-by:
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Aneesh Kumar K.V authored
We will remove thread.amr/iamr/uamor in a later patch Signed-off-by:
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Aneesh Kumar K.V authored
On fork, we inherit from the parent and on exec, we should switch to default_amr values. Also, avoid changing the AMR register value within the kernel. The kernel now runs with different AMR values. Signed-off-by:
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Aneesh Kumar K.V authored
Child thread.kuap value is inherited from the parent in copy_thread_tls. We still need to make sure when the child returns from a fork in the kernel we start with the kernel default AMR value. Signed-off-by:
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Aneesh Kumar K.V authored
This prepare kernel to operate with a different value than userspace AMR/IAMR. For this, AMR/IAMR need to be saved and restored on entry and return from the kernel. With KUAP we modify kernel AMR when accessing user address from the kernel via copy_to/from_user interfaces. We don't need to modify IAMR value in similar fashion. If MMU_FTR_PKEY is enabled we need to save AMR/IAMR in pt_regs on entering kernel from userspace. If not we can assume that AMR/IAMR is not modified from userspace. We need to save AMR if we have MMU_FTR_BOOK3S_KUAP feature enabled and we are interrupted within kernel. This is required so that if we get interrupted within copy_to/from_user we continue with the right AMR value. If we hae MMU_FTR_BOOK3S_KUEP enabled we need to restore IAMR on return to userspace beause kernel will be running with a different IAMR value. Signed-off-by:
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Aneesh Kumar K.V authored
In later patches during exec, we would like to access default regs.amr to control access to the user mapping. Having thread.regs set early makes the code changes simpler. Signed-off-by:
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Aneesh Kumar K.V authored
This patch updates kernel hash page table entries to use storage key 3 for its mapping. This implies all kernel access will now use key 3 to control READ/WRITE. The patch also prevents the allocation of key 3 from userspace and UAMOR value is updated such that userspace cannot modify key 3. Signed-off-by:
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Aneesh Kumar K.V authored
This is in preparation to adding support for kuap with hash translation. In preparation for that rename/move kuap related functions to non radix names. Also move the feature bit closer to MMU_FTR_KUEP. MMU_FTR_KUEP is renamed to MMU_FTR_BOOK3S_KUEP to indicate the feature is only relevant to BOOK3S_64 Signed-off-by:
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Aneesh Kumar K.V authored
The next set of patches adds support for kuep with hash translation. In preparation for that rename/move kuap related functions to non radix names. Also set MMU_FTR_KUEP and add the missing isync(). Signed-off-by:
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Aneesh Kumar K.V authored
The next set of patches adds support for kuap with hash translation. In preparation for that rename/move kuap related functions to non radix names. Signed-off-by:
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Aneesh Kumar K.V authored
This patch consolidates UAMOR update across pkey, kuap and kuep features. The boot cpu initialize UAMOR via pkey init and both radix/hash do the secondary cpu UAMOR init in early_init_mmu_secondary. We don't check for mmu_feature in radix secondary init because UAMOR is a supported SPRN with all CPUs supporting radix translation. The old code was not updating UAMOR if we had smap disabled and smep enabled. This change handles that case. Signed-off-by:
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Aneesh Kumar K.V authored
The config CONFIG_PPC_PKEY is used to select the base support that is required for PPC_MEM_KEYS, KUAP, and KUEP. Adding this dependency reduces the code complexity(in terms of #ifdefs) and enables us to move some of the initialization code to pkeys.c Signed-off-by:
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Aneesh Kumar K.V authored
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:
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Aneesh Kumar K.V authored
This will be used by the following patches Signed-off-by:
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Nicholas Piggin authored
Since ISA v3.0, SLB no longer uses the slb_cache, and stab_rr is no longer correlated with SLB allocation. Move those to pre-3.0. While here, improve some alignments and reduce whitespace. Signed-off-by:
Nicholas Piggin <npiggin@gmail.com> Signed-off-by:
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Nicholas Piggin authored
"Host" caused machine check is printed when the kernel sees a MCE hit in this kernel or userspace, and "Guest" if it hit one of its guests. This is confusing when a guest kernel handles a hypervisor- delivered MCE, it also prints "Host". Just remove "Host". "Guest" is adequate to make the distinction. Signed-off-by:
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Nicholas Piggin authored
Don't treat ERAT MCEs as SLB, don't save the SLB and use a specific ERAT flush to recover it. Signed-off-by:
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Nicholas Piggin authored
Harmless HMI errors can be triggered by guests in some cases, and don't contain much useful information anyway. Ratelimit these to avoid flooding the console/logs. Signed-off-by:
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Nicholas Piggin authored
A number of machine check exceptions are triggerable by the guest. Ratelimit these to avoid a guest flooding the host console and logs. Signed-off-by:
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Nicholas Piggin authored
Guests that can deal with machine checks would actually prefer the hypervisor not to try recover for them. For example if SLB multi-hits are recovered by the hypervisor by clearing the SLB then the guest will not be able to log the contents and debug its programming error. If guests don't register for FWNMI, they may not be so capable and so the hypervisor will continue to recover for those. Signed-off-by:
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Nicholas Piggin authored
KVM has strategies to perform machine check recovery. If a MCE hits in a guest, have the low level handler just decode and save the MCE but not try to recover anything, so KVM can deal with it. The host does not own SLBs and does not need to report the SLB state in case of a multi-hit for example, or know about the virtual memory map of the guest. UE and memory poisoning of guest pages in the host is one thing that is possibly not completely robust at the moment, but this too needs to go via KVM (possibly via the guest and back out to host via hcall) rather than being handled at a low level in the host handler. Signed-off-by:
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Uwe Kleine-König authored
The driver core ignores the return value of struct device_driver::remove because there is only little that can be done. For the shutdown callback it's ps3_system_bus_shutdown() which ignores the return value. To simplify the quest to make struct device_driver::remove return void, let struct ps3_system_bus_driver::remove return void, too. All users already unconditionally return 0, this commit makes it obvious that returning an error code is a bad idea and ensures future users behave accordingly. Signed-off-by:
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by:
Geert Uytterhoeven <geert@linux-m68k.org> Acked-by:
Takashi Iwai <tiwai@suse.de> Signed-off-by:
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Uwe Kleine-König authored
The remove callback is only called for devices that were probed successfully before. As the matching probe function cannot complete without error if dev->match_id != PS3_MATCH_ID_SOUND, we don't have to check this here. Signed-off-by:
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Srikar Dronamraju authored
If its a shared LPAR but not a KVM guest, then see if the vCPU is related to the calling vCPU. On PowerVM, only cores can be preempted. So if one vCPU is a non-preempted state, we can decipher that all other vCPUs sharing the same core are in non-preempted state. Performance results: $ perf stat -r 5 -a perf bench sched pipe -l 10000000 (lesser time is better) powerpc/next 35,107,951.20 msec cpu-clock # 255.898 CPUs utilized ( +- 0.31% ) 23,655,348 context-switches # 0.674 K/sec ( +- 3.72% ) 14,465 cpu-migrations # 0.000 K/sec ( +- 5.37% ) 82,463 page-faults # 0.002 K/sec ( +- 8.40% ) 1,127,182,328,206 cycles # 0.032 GHz ( +- 1.60% ) (66.67%) 78,587,300,622 stalled-cycles-frontend # 6.97% frontend cycles idle ( +- 0.08% ) (50.01%) 654,124,218,432 stalled-cycles-backend # 58.03% backend cycles idle ( +- 1.74% ) (50.01%) 834,013,059,242 instructions # 0.74 insn per cycle # 0.78 stalled cycles per insn ( +- 0.73% ) (66.67%) 132,911,454,387 branches # 3.786 M/sec ( +- 0.59% ) (50.00%) 2,890,882,143 branch-misses # 2.18% of all branches ( +- 0.46% ) (50.00%) 137.195 +- 0.419 seconds time elapsed ( +- 0.31% ) powerpc/next + patchset 29,981,702.64 msec cpu-clock # 255.881 CPUs utilized ( +- 1.30% ) 40,162,456 context-switches # 0.001 M/sec ( +- 0.01% ) 1,110 cpu-migrations # 0.000 K/sec ( +- 5.20% ) 62,616 page-faults # 0.002 K/sec ( +- 3.93% ) 1,430,030,626,037 cycles # 0.048 GHz ( +- 1.41% ) (66.67%) 83,202,707,288 stalled-cycles-frontend # 5.82% frontend cycles idle ( +- 0.75% ) (50.01%) 744,556,088,520 stalled-cycles-backend # 52.07% backend cycles idle ( +- 1.39% ) (50.01%) 940,138,418,674 instructions # 0.66 insn per cycle # 0.79 stalled cycles per insn ( +- 0.51% ) (66.67%) 146,452,852,283 branches # 4.885 M/sec ( +- 0.80% ) (50.00%) 3,237,743,996 branch-misses # 2.21% of all branches ( +- 1.18% ) (50.01%) 117.17 +- 1.52 seconds time elapsed ( +- 1.30% ) This is around 14.6% improvement in performance. Signed-off-by:Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by:
Waiman Long <longman@redhat.com> [mpe: Fold in performance results from cover letter] Signed-off-by:
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Srikar Dronamraju authored
Introduce a static branch that would be set during boot if the OS happens to be a KVM guest. Subsequent checks to see if we are on KVM will rely on this static branch. This static branch would be used in vcpu_is_preempted() in a subsequent patch. Signed-off-by:
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Srikar Dronamraju authored
We want to reuse the is_kvm_guest() name in a subsequent patch but with a new body. Hence rename is_kvm_guest() to check_kvm_guest(). No additional changes. Signed-off-by:
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Srikar Dronamraju authored
Only code/declaration movement, in anticipation of doing a KVM-aware vcpu_is_preempted(). No additional changes. Signed-off-by:
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Nicholas Piggin authored
It's often useful to know the register state for interrupts in the stack frame. In the below example (with this patch applied), the important information is the state of the page fault. A blatant case like this probably rather should have the page fault regs passed down to the warning, but quite often there are less obvious cases where an interrupt shows up that might give some more clues. The downside is longer and more complex bug output. Bug: Write fault blocked by AMR! WARNING: CPU: 0 PID: 72 at arch/powerpc/include/asm/book3s/64/kup-radix.h:164 __do_page_fault+0x880/0xa90 Modules linked in: CPU: 0 PID: 72 Comm: systemd-gpt-aut Not tainted NIP: c00000000006e2f0 LR: c00000000006e2ec CTR: 0000000000000000 REGS: c00000000a4f3420 TRAP: 0700 MSR: 8000000000021033 <SF,ME,IR,DR,RI,LE> CR: 28002840 XER: 20040000 CFAR: c000000000128be0 IRQMASK: 3 GPR00: c00000000006e2ec c00000000a4f36c0 c0000000014f0700 0000000000000020 GPR04: 0000000000000001 c000000001290f50 0000000000000001 c000000001290f80 GPR08: c000000001612b08 0000000000000000 0000000000000000 00000000ffffe0f7 GPR12: 0000000048002840 c0000000016e0000 c00c000000021c80 c000000000fd6f60 GPR16: 0000000000000000 c00000000a104698 0000000000000003 c0000000087f0000 GPR20: 0000000000000100 c0000000070330b8 0000000000000000 0000000000000004 GPR24: 0000000002000000 0000000000000300 0000000002000000 c00000000a5b0c00 GPR28: 0000000000000000 000000000a000000 00007fffb2a90038 c00000000a4f3820 NIP [c00000000006e2f0] __do_page_fault+0x880/0xa90 LR [c00000000006e2ec] __do_page_fault+0x87c/0xa90 Call Trace: [c00000000a4f36c0] [c00000000006e2ec] __do_page_fault+0x87c/0xa90 (unreliable) [c00000000a4f3780] [c000000000e1c034] do_page_fault+0x34/0x90 [c00000000a4f37b0] [c000000000008908] data_access_common_virt+0x158/0x1b0 --- interrupt: 300 at __copy_tofrom_user_base+0x9c/0x5a4 NIP: c00000000009b028 LR: c000000000802978 CTR: 0000000000000800 REGS: c00000000a4f3820 TRAP: 0300 MSR: 800000000280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 24004840 XER: 00000000 CFAR: c00000000009aff4 DAR: 00007fffb2a90038 DSISR: 0a000000 IRQMASK: 0 GPR00: 0000000000000000 c00000000a4f3ac0 c0000000014f0700 00007fffb2a90028 GPR04: c000000008720010 0000000000010000 0000000000000000 0000000000000000 GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000001 GPR12: 0000000000004000 c0000000016e0000 c00c000000021c80 c000000000fd6f60 GPR16: 0000000000000000 c00000000a104698 0000000000000003 c0000000087f0000 GPR20: 0000000000000100 c0000000070330b8 0000000000000000 0000000000000004 GPR24: c00000000a4f3c80 c000000008720000 0000000000010000 0000000000000000 GPR28: 0000000000010000 0000000008720000 0000000000010000 c000000001515b98 NIP [c00000000009b028] __copy_tofrom_user_base+0x9c/0x5a4 LR [c000000000802978] copyout+0x68/0xc0 --- interrupt: 300 [c00000000a4f3af0] [c0000000008074b8] copy_page_to_iter+0x188/0x540 [c00000000a4f3b50] [c00000000035c678] generic_file_buffered_read+0x358/0xd80 [c00000000a4f3c40] [c0000000004c1e90] blkdev_read_iter+0x50/0x80 [c00000000a4f3c60] [c00000000045733c] new_sync_read+0x12c/0x1c0 [c00000000a4f3d00] [c00000000045a1f0] vfs_read+0x1d0/0x240 [c00000000a4f3d50] [c00000000045a7f4] ksys_read+0x84/0x140 [c00000000a4f3da0] [c000000000033a60] system_call_exception+0x100/0x280 [c00000000a4f3e10] [c00000000000c508] system_call_common+0xf8/0x2f8 Instruction dump: eae10078 3be0000b 4bfff890 60420000 792917e1 4182ff18 3c82ffab 3884a5e0 3c62ffab 3863a6e8 480ba891 60000000 <0fe00000> 3be0000b 4bfff860 e93c0938 Signed-off-by:
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Athira Rajeev authored
The power_pmu_event_init() callback access per-cpu variable (cpu_hw_events) to check for event constraints and Branch Stack (BHRB). Current usage is to disable preemption when accessing the per-cpu variable, but this does not prevent timer callback from interrupting event_init. Fix this by using 'local_irq_save/restore' to make sure the code path is invoked with disabled interrupts. This change is tested in mambo simulator to ensure that, if a timer interrupt comes in during the per-cpu access in event_init, it will be soft masked and replayed later. For testing purpose, introduced a udelay() in power_pmu_event_init() to make sure a timer interrupt arrives while in per-cpu variable access code between local_irq_save/resore. As expected the timer interrupt was replayed later during local_irq_restore called from power_pmu_event_init. This was confirmed by adding breakpoint in mambo and checking the backtrace when timer_interrupt was hit. Reported-by:
Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by:
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Harish authored
Patch fixes uninitialized variable warning in bad_accesses test which causes the selftests build to fail in older distibutions bad_accesses.c: In function ‘bad_access’: bad_accesses.c:52:9: error: ‘x’ may be used uninitialized in this function [-Werror=maybe-uninitialized] printf("Bad - no SEGV! (%c)\n", x); ^ cc1: all warnings being treated as errors Signed-off-by:Harish <harish@linux.ibm.com> Signed-off-by:
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