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path: root/arch/powerpc/kvm/book3s_hv.c
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2021-11-24KVM: PPC: Book3S HV P9: Improve mfmsr performance on entryNicholas 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 <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-46-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV Nested: Avoid extra mftb() in nested entryNicholas Piggin
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 HV timers. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-45-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Avoid tlbsync sequence on radix guest exitNicholas Piggin
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 currently just done on one thread, to be expanded to ensure the other threads execute a ptesync, because causing them to exit the guest will no longer cause a ptesync by itself. This results in more IPIs than the TLB flush logic requires, but it's a significant win for common case scheduling when the vCPU remains on the same physical CPU. This saves about 520 cycles (nearly 10%) on a guest entry+exit micro benchmark on a POWER9. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-44-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Don't restore PSSCR if not neededNicholas Piggin
This also moves the PSSCR update in nested entry to avoid a SPR scoreboard stall. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-42-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Use Linux SPR save/restore to manage some host SPRsNicholas Piggin
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 avoiding VRSAVE updates if they are not required. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-39-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Demand fault TM facility registersNicholas Piggin
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 guest is not frequently using them. When a guest does use them often, there will be some additional demand fault overhead, but these are not commonly used facilities. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-38-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Demand fault EBB facility registersNicholas Piggin
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 guest is not frequently using them. When a guest does use them often, there will be some additional demand fault overhead, but these are not commonly used facilities. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-37-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Restrict DSISR canary workaround to processors that ↵Nicholas Piggin
require it 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 <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-35-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Switch PMU to guest as late as possibleNicholas Piggin
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 is disabled there is no real difference. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-34-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Move remaining SPR and MSR access into low level entryNicholas Piggin
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 <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-32-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Move nested guest entry into its own functionNicholas Piggin
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 <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-31-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Move host OS save/restore functions to built-inNicholas Piggin
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: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-30-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Move vcpu register save/restore into functionsNicholas Piggin
This should be no functional difference but makes the caller easier to read. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-29-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Juggle SPR switching aroundNicholas Piggin
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 <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-28-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Only execute mtSPR if the value changedNicholas Piggin
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 <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-27-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Avoid SPR scoreboard stallsNicholas Piggin
Avoid interleaving mfSPR and mtSPR to reduce SPR scoreboard stalls. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-26-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Optimise timebase readsNicholas Piggin
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 <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-25-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV: Change dec_expires to be relative to guest timebaseNicholas Piggin
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 <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-23-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Add kvmppc_stop_thread to match kvmppc_start_threadNicholas Piggin
Small cleanup makes it a bit easier to match up entry and exit operations. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-22-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Improve mtmsrd scheduling by delaying MSR[EE] disableNicholas Piggin
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 facilities just below, but that is not done yet. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-21-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Reduce mtmsrd instructions required to save host SPRsNicholas Piggin
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. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-20-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Move SPRG restore to restore_p9_host_os_sprsNicholas Piggin
Move the SPR update into its relevant helper function. This will help with SPR scheduling improvements in later changes. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-19-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV: CTRL SPR does not require read-modify-writeNicholas Piggin
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 <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-18-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Factor out yield_count incrementNicholas Piggin
Factor duplicated code into a helper function. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-17-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Demand fault PMU SPRs when marked not inuseNicholas Piggin
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 the host to misbehave. So prevent guest access to the PMU with HFSCR[PM] if pmcregs_in_use is clear, and avoid the PMU SPR access on every partition switch. Guests that set pmcregs_in_use incorrectly or when first setting it and using the PMU will take a hypervisor facility unavailable interrupt that will bring in the PMU SPRs. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-16-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Factor PMU save/load into context switch functionsNicholas Piggin
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 requires mtSPR (to stop counters) and other difficulties, so there's less possibility to schedule those nicely. The SPR accesses also have side-effects if the PMU is running, and in later changes we keep the host PMU running as long as possible so this code can be better profiled, which also complicates scheduling. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-15-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Implement PMU save/restore in CNicholas Piggin
Implement the P9 path PMU save/restore code in C, and remove the POWER9/10 code from the P7/8 path assembly. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-14-npiggin@gmail.com
2021-11-24powerpc/64s: Always set PMU control registers to frozen/disabled when not in useNicholas Piggin
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 PMU switching to the perf subsystem. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-12-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV: Don't always save PMU for guest capable of nestingNicholas Piggin
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 178266389794 ("KVM: PPC: Book3S HV Nested: Reflect guest PMU in-use to L0 when guest SPRs are live") will now indicate the PMU in-use status of their guests, which means the parent does not need to unconditionally save the PMU for nested capable guests. After this latest round of performance optimisations, this option costs about 540 cycles or 10% entry/exit performance on a POWER9 nested-capable guest. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> References: 178266389794 ("KVM: PPC: Book3S HV Nested: Reflect guest PMU in-use to L0 when guest SPRs are live") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-11-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV: POWER10 enable HAIL when running radix guestsNicholas Piggin
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 disabled in the host will not have to be duplicated in KVM. This optimisation takes 1380 cycles off a NULL hcall entry+exit micro benchmark on a POWER10. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-9-npiggin@gmail.com
2021-11-24powerpc/time: add API for KVM to re-arm the host timer/decrementerNicholas Piggin
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 soft-pending if a timer has expired, rather than setting DEC to a -ve value, which tended to cause host timers to take two interrupts (first hdec to exit the guest, then the immediate dec). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-8-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Reduce mftb per guest entry/exitNicholas Piggin
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. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-7-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Use host timer accounting to avoid decrementer readNicholas Piggin
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 <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-5-npiggin@gmail.com
2021-11-24KMV: PPC: Book3S HV P9: Use set_dec to set decrementer to hostNicholas Piggin
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 makes the logic match and avoids this small extra change being brought into the next patch. Suggested-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-4-npiggin@gmail.com
2021-11-24powerpc/64s: guard optional TIDR SPR with CPU ftr testNicholas Piggin
The TIDR SPR only exists on POWER9. Avoid accessing it when the feature bit for it is not set. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-3-npiggin@gmail.com
2021-10-28KVM: PPC: Tick accounting should defer vtime accounting 'til after IRQ handlingLaurent Vivier
Commit 112665286d08 ("KVM: PPC: Book3S HV: Context tracking exit guest context before enabling irqs") moved guest_exit() into the interrupt protected area to avoid wrong context warning (or worse). The problem is that tick-based time accounting has not yet been updated at this point (because it depends on the timer interrupt firing), so the guest time gets incorrectly accounted to system time. To fix the problem, follow the x86 fix in commit 160457140187 ("Defer vtime accounting 'til after IRQ handling"), and allow host IRQs to run before accounting the guest exit time. In the case vtime accounting is enabled, this is not required because TB is used directly for accounting. Before this patch, with CONFIG_TICK_CPU_ACCOUNTING=y in the host and a guest running a kernel compile, the 'guest' fields of /proc/stat are stuck at zero. With the patch they can be observed increasing roughly as expected. Fixes: e233d54d4d97 ("KVM: booke: use __kvm_guest_exit") Fixes: 112665286d08 ("KVM: PPC: Book3S HV: Context tracking exit guest context before enabling irqs") Cc: stable@vger.kernel.org # 5.12+ Signed-off-by: Laurent Vivier <lvivier@redhat.com> [np: only required for tick accounting, add Book3E fix, tweak changelog] Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211027142150.3711582-1-npiggin@gmail.com
2021-09-07Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: "ARM: - Page ownership tracking between host EL1 and EL2 - Rely on userspace page tables to create large stage-2 mappings - Fix incompatibility between pKVM and kmemleak - Fix the PMU reset state, and improve the performance of the virtual PMU - Move over to the generic KVM entry code - Address PSCI reset issues w.r.t. save/restore - Preliminary rework for the upcoming pKVM fixed feature - A bunch of MM cleanups - a vGIC fix for timer spurious interrupts - Various cleanups s390: - enable interpretation of specification exceptions - fix a vcpu_idx vs vcpu_id mixup x86: - fast (lockless) page fault support for the new MMU - new MMU now the default - increased maximum allowed VCPU count - allow inhibit IRQs on KVM_RUN while debugging guests - let Hyper-V-enabled guests run with virtualized LAPIC as long as they do not enable the Hyper-V "AutoEOI" feature - fixes and optimizations for the toggling of AMD AVIC (virtualized LAPIC) - tuning for the case when two-dimensional paging (EPT/NPT) is disabled - bugfixes and cleanups, especially with respect to vCPU reset and choosing a paging mode based on CR0/CR4/EFER - support for 5-level page table on AMD processors Generic: - MMU notifier invalidation callbacks do not take mmu_lock unless necessary - improved caching of LRU kvm_memory_slot - support for histogram statistics - add statistics for halt polling and remote TLB flush requests" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (210 commits) KVM: Drop unused kvm_dirty_gfn_invalid() KVM: x86: Update vCPU's hv_clock before back to guest when tsc_offset is adjusted KVM: MMU: mark role_regs and role accessors as maybe unused KVM: MIPS: Remove a "set but not used" variable x86/kvm: Don't enable IRQ when IRQ enabled in kvm_wait KVM: stats: Add VM stat for remote tlb flush requests KVM: Remove unnecessary export of kvm_{inc,dec}_notifier_count() KVM: x86/mmu: Move lpage_disallowed_link further "down" in kvm_mmu_page KVM: x86/mmu: Relocate kvm_mmu_page.tdp_mmu_page for better cache locality Revert "KVM: x86: mmu: Add guest physical address check in translate_gpa()" KVM: x86/mmu: Remove unused field mmio_cached in struct kvm_mmu_page kvm: x86: Increase KVM_SOFT_MAX_VCPUS to 710 kvm: x86: Increase MAX_VCPUS to 1024 kvm: x86: Set KVM_MAX_VCPU_ID to 4*KVM_MAX_VCPUS KVM: VMX: avoid running vmx_handle_exit_irqoff in case of emulation KVM: x86/mmu: Don't freak out if pml5_root is NULL on 4-level host KVM: s390: index kvm->arch.idle_mask by vcpu_idx KVM: s390: Enable specification exception interpretation KVM: arm64: Trim guest debug exception handling KVM: SVM: Add 5-level page table support for SVM ...
2021-09-06Merge tag 'kvmarm-5.15' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for 5.15 - Page ownership tracking between host EL1 and EL2 - Rely on userspace page tables to create large stage-2 mappings - Fix incompatibility between pKVM and kmemleak - Fix the PMU reset state, and improve the performance of the virtual PMU - Move over to the generic KVM entry code - Address PSCI reset issues w.r.t. save/restore - Preliminary rework for the upcoming pKVM fixed feature - A bunch of MM cleanups - a vGIC fix for timer spurious interrupts - Various cleanups
2021-08-26Merge branch 'topic/ppc-kvm' into nextMichael Ellerman
Merge some KVM patches we are keeping in a topic branch in case there are any merge conflicts that need resolving.
2021-08-25powerpc/64s: Remove WORT SPR from POWER9/10Nicholas Piggin
This register is not architected and not implemented in POWER9 or 10, it just reads back zeroes for compatibility. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Link: https://lore.kernel.org/r/20210811160134.904987-11-npiggin@gmail.com
2021-08-25KVM: PPC: Book3S HV Nested: Reflect guest PMU in-use to L0 when guest SPRs ↵Nicholas Piggin
are live 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 indication between the L1 and L2 at the points where the registers are not live. This fixes the nested HV bug for which a workaround was added to the L0 HV by commit 63279eeb7f93a ("KVM: PPC: Book3S HV: Always save guest pmu for guest capable of nesting"), which explains the problem in detail. That workaround is no longer required for guests that include this bug fix. Fixes: 360cae313702 ("KVM: PPC: Book3S HV: Nested guest entry via hypercall") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Link: https://lore.kernel.org/r/20210811160134.904987-10-npiggin@gmail.com
2021-08-25KVM: PPC: Book3S HV Nested: Stop forwarding all HFUs to L1Fabiano 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 into a Hypervisor Emulation Assistance interrupt and forwards it to L1 for handling. The ones that happened because L1 explicitly disabled the facility for L2 are still let through, along with the corresponding Cause bits in the HFSCR. Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com> [np: move handling into kvmppc_handle_nested_exit] Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210811160134.904987-8-npiggin@gmail.com
2021-08-25KVM: PPC: Book3S HV Nested: Make nested HFSCR state accessibleNicholas Piggin
When the L0 runs a nested L2, there are several permutations of HFSCR that can be relevant. The HFSCR that the L1 vcpu L1 requested, the HFSCR that the L1 vcpu may use, and the HFSCR that is actually being used to run the L2. The L1 requested HFSCR is not accessible outside the nested hcall handler, so copy that into a new kvm_nested_guest.hfscr field. The permitted HFSCR is taken from the HFSCR that the L1 runs with, which is also not accessible while the hcall is being made. Move this into a new kvm_vcpu_arch.hfscr_permitted field. These will be used by the next patch to improve facility handling for nested guests, and later by facility demand faulting patches. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210811160134.904987-7-npiggin@gmail.com
2021-08-25KVM: PPC: Book3S HV Nested: Fix TM softpatch HFAC interrupt emulationNicholas Piggin
Have the TM softpatch emulation code set up the HFAC interrupt and return -1 in case an instruction was executed with HFSCR bits clear, and have the interrupt exit handler fall through to the HFAC handler. When the L0 is running a nested guest, this ensures the HFAC interrupt is correctly passed up to the L1. The "direct guest" exit handler will turn these into PROGILL program interrupts so functionality in practice will be unchanged. But it's possible an L1 would want to handle these in a different way. Also rearrange the FAC interrupt emulation code to match the HFAC format while here (mainly, adding the FSCR_INTR_CAUSE mask). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210811160134.904987-5-npiggin@gmail.com
2021-08-25KVM: PPC: Book3S HV: Initialise vcpu MSR with MSR_MENicholas Piggin
It is possible to create a VCPU without setting the MSR before running it, which results in a warning in kvmhv_vcpu_entry_p9() that MSR_ME is not set. This is pretty harmless because the MSR_ME bit is added to HSRR1 before HRFID to guest, and a normal qemu guest doesn't hit it. Initialise the vcpu MSR with MSR_ME set. Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210811160134.904987-2-npiggin@gmail.com
2021-08-20KVM: stats: Add halt polling related histogram statsJing Zhang
Add three log histogram stats to record the distribution of time spent on successful polling, failed polling and VCPU wait. halt_poll_success_hist: Distribution of spent time for a successful poll. halt_poll_fail_hist: Distribution of spent time for a failed poll. halt_wait_hist: Distribution of time a VCPU has spent on waiting. Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210802165633.1866976-6-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-08-20KVM: stats: Add halt_wait_ns stats for all architecturesJing Zhang
Add simple stats halt_wait_ns to record the time a VCPU has spent on waiting for all architectures (not just powerpc). Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210802165633.1866976-5-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-08-10KVM: PPC: Book3S HV: XICS: Fix mapping of passthrough interruptsCédric Le Goater
PCI MSIs now live in an MSI domain but the underlying calls, which will EOI the interrupt in real mode, need an HW IRQ number mapped in the XICS IRQ domain. Grab it there. Signed-off-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210701132750.1475580-31-clg@kaod.org
2021-08-10KVM: PPC: Book3S HV: XIVE: Change interface of passthrough interrupt routinesCédric Le Goater
The routine kvmppc_set_passthru_irq() calls kvmppc_xive_set_mapped() and kvmppc_xive_clr_mapped() with an IRQ descriptor. Use directly the host IRQ number to remove a useless conversion. Add some debug. Signed-off-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210701132750.1475580-15-clg@kaod.org
2021-08-10KVM: PPC: Book3S HV: Use the new IRQ chip to detect passthrough interruptsCédric Le Goater
Passthrough PCI MSI interrupts are detected in KVM with a check on a specific EOI handler (P8) or on XIVE (P9). We can now check the PCI-MSI IRQ chip which is cleaner. Signed-off-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210701132750.1475580-14-clg@kaod.org