linux.git/arch/powerpc/kvm, branch vsnprintf Linux kernel source tree Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2024-11-24T00:00:50+00:00 Linus Torvalds torvalds@linux-foundation.org 2024-11-24T00:00:50+00:00 9f16d5e6f220661f73b36a4be1b21575651d8833 Pull kvm updates from Paolo Bonzini: "The biggest change here is eliminating the awful idea that KVM had of essentially guessing which pfns are refcounted pages. The reason to do so was that KVM needs to map both non-refcounted pages (for example BARs of VFIO devices) and VM_PFNMAP/VM_MIXMEDMAP VMAs that contain refcounted pages. However, the result was security issues in the past, and more recently the inability to map VM_IO and VM_PFNMAP memory that _is_ backed by struct page but is not refcounted. In particular this broke virtio-gpu blob resources (which directly map host graphics buffers into the guest as "vram" for the virtio-gpu device) with the amdgpu driver, because amdgpu allocates non-compound higher order pages and the tail pages could not be mapped into KVM. This requires adjusting all uses of struct page in the per-architecture code, to always work on the pfn whenever possible. The large series that did this, from David Stevens and Sean Christopherson, also cleaned up substantially the set of functions that provided arch code with the pfn for a host virtual addresses. The previous maze of twisty little passages, all different, is replaced by five functions (__gfn_to_page, __kvm_faultin_pfn, the non-__ versions of these two, and kvm_prefetch_pages) saving almost 200 lines of code. ARM: - Support for stage-1 permission indirection (FEAT_S1PIE) and permission overlays (FEAT_S1POE), including nested virt + the emulated page table walker - Introduce PSCI SYSTEM_OFF2 support to KVM + client driver. This call was introduced in PSCIv1.3 as a mechanism to request hibernation, similar to the S4 state in ACPI - Explicitly trap + hide FEAT_MPAM (QoS controls) from KVM guests. As part of it, introduce trivial initialization of the host's MPAM context so KVM can use the corresponding traps - PMU support under nested virtualization, honoring the guest hypervisor's trap configuration and event filtering when running a nested guest - Fixes to vgic ITS serialization where stale device/interrupt table entries are not zeroed when the mapping is invalidated by the VM - Avoid emulated MMIO completion if userspace has requested synchronous external abort injection - Various fixes and cleanups affecting pKVM, vCPU initialization, and selftests LoongArch: - Add iocsr and mmio bus simulation in kernel. - Add in-kernel interrupt controller emulation. - Add support for virtualization extensions to the eiointc irqchip. PPC: - Drop lingering and utterly obsolete references to PPC970 KVM, which was removed 10 years ago. - Fix incorrect documentation references to non-existing ioctls RISC-V: - Accelerate KVM RISC-V when running as a guest - Perf support to collect KVM guest statistics from host side s390: - New selftests: more ucontrol selftests and CPU model sanity checks - Support for the gen17 CPU model - List registers supported by KVM_GET/SET_ONE_REG in the documentation x86: - Cleanup KVM's handling of Accessed and Dirty bits to dedup code, improve documentation, harden against unexpected changes. Even if the hardware A/D tracking is disabled, it is possible to use the hardware-defined A/D bits to track if a PFN is Accessed and/or Dirty, and that removes a lot of special cases. - Elide TLB flushes when aging secondary PTEs, as has been done in x86's primary MMU for over 10 years. - Recover huge pages in-place in the TDP MMU when dirty page logging is toggled off, instead of zapping them and waiting until the page is re-accessed to create a huge mapping. This reduces vCPU jitter. - Batch TLB flushes when dirty page logging is toggled off. This reduces the time it takes to disable dirty logging by ~3x. - Remove the shrinker that was (poorly) attempting to reclaim shadow page tables in low-memory situations. - Clean up and optimize KVM's handling of writes to MSR_IA32_APICBASE. - Advertise CPUIDs for new instructions in Clearwater Forest - Quirk KVM's misguided behavior of initialized certain feature MSRs to their maximum supported feature set, which can result in KVM creating invalid vCPU state. E.g. initializing PERF_CAPABILITIES to a non-zero value results in the vCPU having invalid state if userspace hides PDCM from the guest, which in turn can lead to save/restore failures. - Fix KVM's handling of non-canonical checks for vCPUs that support LA57 to better follow the "architecture", in quotes because the actual behavior is poorly documented. E.g. most MSR writes and descriptor table loads ignore CR4.LA57 and operate purely on whether the CPU supports LA57. - Bypass the register cache when querying CPL from kvm_sched_out(), as filling the cache from IRQ context is generally unsafe; harden the cache accessors to try to prevent similar issues from occuring in the future. The issue that triggered this change was already fixed in 6.12, but was still kinda latent. - Advertise AMD_IBPB_RET to userspace, and fix a related bug where KVM over-advertises SPEC_CTRL when trying to support cross-vendor VMs. - Minor cleanups - Switch hugepage recovery thread to use vhost_task. These kthreads can consume significant amounts of CPU time on behalf of a VM or in response to how the VM behaves (for example how it accesses its memory); therefore KVM tried to place the thread in the VM's cgroups and charge the CPU time consumed by that work to the VM's container. However the kthreads did not process SIGSTOP/SIGCONT, and therefore cgroups which had KVM instances inside could not complete freezing. Fix this by replacing the kthread with a PF_USER_WORKER thread, via the vhost_task abstraction. Another 100+ lines removed, with generally better behavior too like having these threads properly parented in the process tree. - Revert a workaround for an old CPU erratum (Nehalem/Westmere) that didn't really work; there was really nothing to work around anyway: the broken patch was meant to fix nested virtualization, but the PERF_GLOBAL_CTRL MSR is virtualized and therefore unaffected by the erratum. - Fix 6.12 regression where CONFIG_KVM will be built as a module even if asked to be builtin, as long as neither KVM_INTEL nor KVM_AMD is 'y'. x86 selftests: - x86 selftests can now use AVX. Documentation: - Use rST internal links - Reorganize the introduction to the API document Generic: - Protect vcpu->pid accesses outside of vcpu->mutex with a rwlock instead of RCU, so that running a vCPU on a different task doesn't encounter long due to having to wait for all CPUs become quiescent. In general both reads and writes are rare, but userspace that supports confidential computing is introducing the use of "helper" vCPUs that may jump from one host processor to another. Those will be very happy to trigger a synchronize_rcu(), and the effect on performance is quite the disaster" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (298 commits) KVM: x86: Break CONFIG_KVM_X86's direct dependency on KVM_INTEL || KVM_AMD KVM: x86: add back X86_LOCAL_APIC dependency Revert "KVM: VMX: Move LOAD_IA32_PERF_GLOBAL_CTRL errata handling out of setup_vmcs_config()" KVM: x86: switch hugepage recovery thread to vhost_task KVM: x86: expose MSR_PLATFORM_INFO as a feature MSR x86: KVM: Advertise CPUIDs for new instructions in Clearwater Forest Documentation: KVM: fix malformed table irqchip/loongson-eiointc: Add virt extension support LoongArch: KVM: Add irqfd support LoongArch: KVM: Add PCHPIC user mode read and write functions LoongArch: KVM: Add PCHPIC read and write functions LoongArch: KVM: Add PCHPIC device support LoongArch: KVM: Add EIOINTC user mode read and write functions LoongArch: KVM: Add EIOINTC read and write functions LoongArch: KVM: Add EIOINTC device support LoongArch: KVM: Add IPI user mode read and write function LoongArch: KVM: Add IPI read and write function LoongArch: KVM: Add IPI device support LoongArch: KVM: Add iocsr and mmio bus simulation in kernel KVM: arm64: Pass on SVE mapping failures ... 
Pull kvm updates from Paolo Bonzini:
 "The biggest change here is eliminating the awful idea that KVM had of
  essentially guessing which pfns are refcounted pages.

  The reason to do so was that KVM needs to map both non-refcounted
  pages (for example BARs of VFIO devices) and VM_PFNMAP/VM_MIXMEDMAP
  VMAs that contain refcounted pages.

  However, the result was security issues in the past, and more recently
  the inability to map VM_IO and VM_PFNMAP memory that _is_ backed by
  struct page but is not refcounted. In particular this broke virtio-gpu
  blob resources (which directly map host graphics buffers into the
  guest as "vram" for the virtio-gpu device) with the amdgpu driver,
  because amdgpu allocates non-compound higher order pages and the tail
  pages could not be mapped into KVM.

  This requires adjusting all uses of struct page in the
  per-architecture code, to always work on the pfn whenever possible.
  The large series that did this, from David Stevens and Sean
  Christopherson, also cleaned up substantially the set of functions
  that provided arch code with the pfn for a host virtual addresses.

  The previous maze of twisty little passages, all different, is
  replaced by five functions (__gfn_to_page, __kvm_faultin_pfn, the
  non-__ versions of these two, and kvm_prefetch_pages) saving almost
  200 lines of code.

  ARM:

   - Support for stage-1 permission indirection (FEAT_S1PIE) and
     permission overlays (FEAT_S1POE), including nested virt + the
     emulated page table walker

   - Introduce PSCI SYSTEM_OFF2 support to KVM + client driver. This
     call was introduced in PSCIv1.3 as a mechanism to request
     hibernation, similar to the S4 state in ACPI

   - Explicitly trap + hide FEAT_MPAM (QoS controls) from KVM guests. As
     part of it, introduce trivial initialization of the host's MPAM
     context so KVM can use the corresponding traps

   - PMU support under nested virtualization, honoring the guest
     hypervisor's trap configuration and event filtering when running a
     nested guest

   - Fixes to vgic ITS serialization where stale device/interrupt table
     entries are not zeroed when the mapping is invalidated by the VM

   - Avoid emulated MMIO completion if userspace has requested
     synchronous external abort injection

   - Various fixes and cleanups affecting pKVM, vCPU initialization, and
     selftests

  LoongArch:

   - Add iocsr and mmio bus simulation in kernel.

   - Add in-kernel interrupt controller emulation.

   - Add support for virtualization extensions to the eiointc irqchip.

  PPC:

   - Drop lingering and utterly obsolete references to PPC970 KVM, which
     was removed 10 years ago.

   - Fix incorrect documentation references to non-existing ioctls

  RISC-V:

   - Accelerate KVM RISC-V when running as a guest

   - Perf support to collect KVM guest statistics from host side

  s390:

   - New selftests: more ucontrol selftests and CPU model sanity checks

   - Support for the gen17 CPU model

   - List registers supported by KVM_GET/SET_ONE_REG in the
     documentation

  x86:

   - Cleanup KVM's handling of Accessed and Dirty bits to dedup code,
     improve documentation, harden against unexpected changes.

     Even if the hardware A/D tracking is disabled, it is possible to
     use the hardware-defined A/D bits to track if a PFN is Accessed
     and/or Dirty, and that removes a lot of special cases.

   - Elide TLB flushes when aging secondary PTEs, as has been done in
     x86's primary MMU for over 10 years.

   - Recover huge pages in-place in the TDP MMU when dirty page logging
     is toggled off, instead of zapping them and waiting until the page
     is re-accessed to create a huge mapping. This reduces vCPU jitter.

   - Batch TLB flushes when dirty page logging is toggled off. This
     reduces the time it takes to disable dirty logging by ~3x.

   - Remove the shrinker that was (poorly) attempting to reclaim shadow
     page tables in low-memory situations.

   - Clean up and optimize KVM's handling of writes to
     MSR_IA32_APICBASE.

   - Advertise CPUIDs for new instructions in Clearwater Forest

   - Quirk KVM's misguided behavior of initialized certain feature MSRs
     to their maximum supported feature set, which can result in KVM
     creating invalid vCPU state. E.g. initializing PERF_CAPABILITIES to
     a non-zero value results in the vCPU having invalid state if
     userspace hides PDCM from the guest, which in turn can lead to
     save/restore failures.

   - Fix KVM's handling of non-canonical checks for vCPUs that support
     LA57 to better follow the "architecture", in quotes because the
     actual behavior is poorly documented. E.g. most MSR writes and
     descriptor table loads ignore CR4.LA57 and operate purely on
     whether the CPU supports LA57.

   - Bypass the register cache when querying CPL from kvm_sched_out(),
     as filling the cache from IRQ context is generally unsafe; harden
     the cache accessors to try to prevent similar issues from occuring
     in the future. The issue that triggered this change was already
     fixed in 6.12, but was still kinda latent.

   - Advertise AMD_IBPB_RET to userspace, and fix a related bug where
     KVM over-advertises SPEC_CTRL when trying to support cross-vendor
     VMs.

   - Minor cleanups

   - Switch hugepage recovery thread to use vhost_task.

     These kthreads can consume significant amounts of CPU time on
     behalf of a VM or in response to how the VM behaves (for example
     how it accesses its memory); therefore KVM tried to place the
     thread in the VM's cgroups and charge the CPU time consumed by that
     work to the VM's container.

     However the kthreads did not process SIGSTOP/SIGCONT, and therefore
     cgroups which had KVM instances inside could not complete freezing.

     Fix this by replacing the kthread with a PF_USER_WORKER thread, via
     the vhost_task abstraction. Another 100+ lines removed, with
     generally better behavior too like having these threads properly
     parented in the process tree.

   - Revert a workaround for an old CPU erratum (Nehalem/Westmere) that
     didn't really work; there was really nothing to work around anyway:
     the broken patch was meant to fix nested virtualization, but the
     PERF_GLOBAL_CTRL MSR is virtualized and therefore unaffected by the
     erratum.

   - Fix 6.12 regression where CONFIG_KVM will be built as a module even
     if asked to be builtin, as long as neither KVM_INTEL nor KVM_AMD is
     'y'.

  x86 selftests:

   - x86 selftests can now use AVX.

  Documentation:

   - Use rST internal links

   - Reorganize the introduction to the API document

  Generic:

   - Protect vcpu->pid accesses outside of vcpu->mutex with a rwlock
     instead of RCU, so that running a vCPU on a different task doesn't
     encounter long due to having to wait for all CPUs become quiescent.

     In general both reads and writes are rare, but userspace that
     supports confidential computing is introducing the use of "helper"
     vCPUs that may jump from one host processor to another. Those will
     be very happy to trigger a synchronize_rcu(), and the effect on
     performance is quite the disaster"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (298 commits)
  KVM: x86: Break CONFIG_KVM_X86's direct dependency on KVM_INTEL || KVM_AMD
  KVM: x86: add back X86_LOCAL_APIC dependency
  Revert "KVM: VMX: Move LOAD_IA32_PERF_GLOBAL_CTRL errata handling out of setup_vmcs_config()"
  KVM: x86: switch hugepage recovery thread to vhost_task
  KVM: x86: expose MSR_PLATFORM_INFO as a feature MSR
  x86: KVM: Advertise CPUIDs for new instructions in Clearwater Forest
  Documentation: KVM: fix malformed table
  irqchip/loongson-eiointc: Add virt extension support
  LoongArch: KVM: Add irqfd support
  LoongArch: KVM: Add PCHPIC user mode read and write functions
  LoongArch: KVM: Add PCHPIC read and write functions
  LoongArch: KVM: Add PCHPIC device support
  LoongArch: KVM: Add EIOINTC user mode read and write functions
  LoongArch: KVM: Add EIOINTC read and write functions
  LoongArch: KVM: Add EIOINTC device support
  LoongArch: KVM: Add IPI user mode read and write function
  LoongArch: KVM: Add IPI read and write function
  LoongArch: KVM: Add IPI device support
  LoongArch: KVM: Add iocsr and mmio bus simulation in kernel
  KVM: arm64: Pass on SVE mapping failures
  ...
Merge tag 'powerpc-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux 2024-11-23T18:44:31+00:00 Linus Torvalds torvalds@linux-foundation.org 2024-11-23T18:44:31+00:00 42d9e8b7ccddee75989283cf7477305cfe3776ff Pull powerpc updates from Michael Ellerman: - Rework kfence support for the HPT MMU to work on systems with >= 16TB of RAM. - Remove the powerpc "maple" platform, used by the "Yellow Dog Powerstation". - Add support for DYNAMIC_FTRACE_WITH_CALL_OPS, DYNAMIC_FTRACE_WITH_DIRECT_CALLS & BPF Trampolines. - Add support for running KVM nested guests on Power11. - Other small features, cleanups and fixes. Thanks to Amit Machhiwal, Arnd Bergmann, Christophe Leroy, Costa Shulyupin, David Hunter, David Wang, Disha Goel, Gautam Menghani, Geert Uytterhoeven, Hari Bathini, Julia Lawall, Kajol Jain, Keith Packard, Lukas Bulwahn, Madhavan Srinivasan, Markus Elfring, Michal Suchanek, Ming Lei, Mukesh Kumar Chaurasiya, Nathan Chancellor, Naveen N Rao, Nicholas Piggin, Nysal Jan K.A, Paulo Miguel Almeida, Pavithra Prakash, Ritesh Harjani (IBM), Rob Herring (Arm), Sachin P Bappalige, Shen Lichuan, Simon Horman, Sourabh Jain, Thomas Weißschuh, Thorsten Blum, Thorsten Leemhuis, Venkat Rao Bagalkote, Zhang Zekun, and zhang jiao. * tag 'powerpc-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (89 commits) EDAC/powerpc: Remove PPC_MAPLE drivers powerpc/perf: Add per-task/process monitoring to vpa_pmu driver powerpc/kvm: Add vpa latency counters to kvm_vcpu_arch docs: ABI: sysfs-bus-event_source-devices-vpa-pmu: Document sysfs event format entries for vpa_pmu powerpc/perf: Add perf interface to expose vpa counters MAINTAINERS: powerpc: Mark Maddy as "M" powerpc/Makefile: Allow overriding CPP powerpc-km82xx.c: replace of_node_put() with __free ps3: Correct some typos in comments powerpc/kexec: Fix return of uninitialized variable macintosh: Use common error handling code in via_pmu_led_init() powerpc/powermac: Use of_property_match_string() in pmac_has_backlight_type() powerpc: remove dead config options for MPC85xx platform support powerpc/xive: Use cpumask_intersects() selftests/powerpc: Remove the path after initialization. powerpc/xmon: symbol lookup length fixed powerpc/ep8248e: Use %pa to format resource_size_t powerpc/ps3: Reorganize kerneldoc parameter names KVM: PPC: Book3S HV: Fix kmv -> kvm typo powerpc/sstep: make emulate_vsx_load and emulate_vsx_store static ... 
Pull powerpc updates from Michael Ellerman:

 - Rework kfence support for the HPT MMU to work on systems with >= 16TB
   of RAM.

 - Remove the powerpc "maple" platform, used by the "Yellow Dog
   Powerstation".

 - Add support for DYNAMIC_FTRACE_WITH_CALL_OPS,
   DYNAMIC_FTRACE_WITH_DIRECT_CALLS & BPF Trampolines.

 - Add support for running KVM nested guests on Power11.

 - Other small features, cleanups and fixes.

Thanks to Amit Machhiwal, Arnd Bergmann, Christophe Leroy, Costa
Shulyupin, David Hunter, David Wang, Disha Goel, Gautam Menghani, Geert
Uytterhoeven, Hari Bathini, Julia Lawall, Kajol Jain, Keith Packard,
Lukas Bulwahn, Madhavan Srinivasan, Markus Elfring, Michal Suchanek,
Ming Lei, Mukesh Kumar Chaurasiya, Nathan Chancellor, Naveen N Rao,
Nicholas Piggin, Nysal Jan K.A, Paulo Miguel Almeida, Pavithra Prakash,
Ritesh Harjani (IBM), Rob Herring (Arm), Sachin P Bappalige, Shen
Lichuan, Simon Horman, Sourabh Jain, Thomas Weißschuh, Thorsten Blum,
Thorsten Leemhuis, Venkat Rao Bagalkote, Zhang Zekun, and zhang jiao.

* tag 'powerpc-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (89 commits)
  EDAC/powerpc: Remove PPC_MAPLE drivers
  powerpc/perf: Add per-task/process monitoring to vpa_pmu driver
  powerpc/kvm: Add vpa latency counters to kvm_vcpu_arch
  docs: ABI: sysfs-bus-event_source-devices-vpa-pmu: Document sysfs event format entries for vpa_pmu
  powerpc/perf: Add perf interface to expose vpa counters
  MAINTAINERS: powerpc: Mark Maddy as "M"
  powerpc/Makefile: Allow overriding CPP
  powerpc-km82xx.c: replace of_node_put() with __free
  ps3: Correct some typos in comments
  powerpc/kexec: Fix return of uninitialized variable
  macintosh: Use common error handling code in via_pmu_led_init()
  powerpc/powermac: Use of_property_match_string() in pmac_has_backlight_type()
  powerpc: remove dead config options for MPC85xx platform support
  powerpc/xive: Use cpumask_intersects()
  selftests/powerpc: Remove the path after initialization.
  powerpc/xmon: symbol lookup length fixed
  powerpc/ep8248e: Use %pa to format resource_size_t
  powerpc/ps3: Reorganize kerneldoc parameter names
  KVM: PPC: Book3S HV: Fix kmv -> kvm typo
  powerpc/sstep: make emulate_vsx_load and emulate_vsx_store static
  ...
powerpc/perf: Add per-task/process monitoring to vpa_pmu driver 2024-11-19T03:11:30+00:00 Kajol Jain kjain@linux.ibm.com 2024-11-18T11:41:14+00:00 f26f9933e3e31b2117b804b6b8932388db88a131 Enhance the vpa_pmu driver with a feature to observe context switch latency event for both per-task (tid) and per-pid (pid) option. Couple of new helper functions are added to hide the abstraction of reading the context switch latency counter from kvm_vcpu_arch struct and these helper functions are defined in the "kvm/book3s_hv.c". "PERF_ATTACH_TASK" flag is used to decide whether to read the counter values from lppaca or kvm_vcpu_arch struct. Signed-off-by: Kajol Jain <kjain@linux.ibm.com> Co-developed-by: Madhavan Srinivasan <maddy@linux.ibm.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://patch.msgid.link/20241118114114.208964-4-kjain@linux.ibm.com 
Enhance the vpa_pmu driver with a feature to observe context switch
latency event for both per-task (tid) and per-pid (pid) option.
Couple of new helper functions are added to hide the abstraction of
reading the context switch latency counter from kvm_vcpu_arch struct
and these helper functions are defined in the "kvm/book3s_hv.c".

"PERF_ATTACH_TASK" flag is used to decide whether to read the counter
values from lppaca or kvm_vcpu_arch struct.

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Co-developed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241118114114.208964-4-kjain@linux.ibm.com
powerpc/kvm: Add vpa latency counters to kvm_vcpu_arch 2024-11-19T03:11:21+00:00 Kajol Jain kjain@linux.ibm.com 2024-11-18T11:41:13+00:00 5f0b48c6a168994cc09d02888c2d939eba2af193 Commit e1f288d2f9c69 ("KVM: PPC: Book3S HV nestedv2: Add support for reading VPA counters for pseries guests") introduced support for new Virtual Process Area(VPA) based software counters. These counters are useful when observing context switch latency of L1 <-> L2. It also added access to counters in lppaca, which is good enough to understand latency details per-cpu level. But to extend and aggregate per-process level(qemu) or per-pid/tid level(vcpu), these counters also needs to be added as part of kvm_vcpu_arch struct. Additional code added to update these new kvm_vcpu_arch variables in do_trace_nested_cs_time function. Signed-off-by: Kajol Jain <kjain@linux.ibm.com> Co-developed-by: Madhavan Srinivasan <maddy@linux.ibm.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://patch.msgid.link/20241118114114.208964-3-kjain@linux.ibm.com 
Commit e1f288d2f9c69 ("KVM: PPC: Book3S HV nestedv2: Add support
for reading VPA counters for pseries guests") introduced support for new
Virtual Process Area(VPA) based software counters. These counters are
useful when observing context switch latency of L1 <-> L2. It also
added access to counters in lppaca, which is good enough to understand
latency details per-cpu level. But to extend and aggregate
per-process level(qemu) or per-pid/tid level(vcpu), these
counters also needs to be added as part of kvm_vcpu_arch struct.
Additional code added to update these new kvm_vcpu_arch variables
in do_trace_nested_cs_time function.

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Co-developed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241118114114.208964-3-kjain@linux.ibm.com
powerpc/perf: Add perf interface to expose vpa counters 2024-11-19T03:11:06+00:00 Kajol Jain kjain@linux.ibm.com 2024-11-18T11:41:11+00:00 176cda0619b6c17a553625f6e2fcbc3981ad667d To support performance measurement for KVM on PowerVM(KoP) feature, PowerVM hypervisor has added couple of new software counters in Virtual Process Area(VPA) of the partition. Commit e1f288d2f9c69 ("KVM: PPC: Book3S HV nestedv2: Add support for reading VPA counters for pseries guests") have updated the paca fields with corresponding changes. Proposed perf interface is to expose these new software counters for monitoring of context switch latencies and runtime aggregate. Perf interface driver is called "vpa_pmu" and it has dependency on KVM and perf, hence added new config called "VPA_PMU" which depends on "CONFIG_KVM_BOOK3S_64_HV" and "CONFIG_HV_PERF_CTRS". Since, kvm and kvm_host are currently compiled as built-in modules, this perf interface takes the same path and registered as a module. vpa_pmu perf interface needs access to some of the kvm functions and structures like kvmhv_get_l2_counters_status(), hence kvm_book3s_64.h and kvm_ppc.h are included. Below are the events added to monitor KoP: vpa_pmu/l1_to_l2_lat/ vpa_pmu/l2_to_l1_lat/ vpa_pmu/l2_runtime_agg/ and vpa_pmu driver supports only per-cpu monitoring with this patch. Example usage: [command]# perf stat -e vpa_pmu/l1_to_l2_lat/ -a -I 1000 1.001017682 727,200 vpa_pmu/l1_to_l2_lat/ 2.003540491 1,118,824 vpa_pmu/l1_to_l2_lat/ 3.005699458 1,919,726 vpa_pmu/l1_to_l2_lat/ 4.007827011 2,364,630 vpa_pmu/l1_to_l2_lat/ Signed-off-by: Kajol Jain <kjain@linux.ibm.com> Co-developed-by: Madhavan Srinivasan <maddy@linux.ibm.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://patch.msgid.link/20241118114114.208964-1-kjain@linux.ibm.com 
To support performance measurement for KVM on PowerVM(KoP)
feature, PowerVM hypervisor has added couple of new software
counters in Virtual Process Area(VPA) of the partition.

Commit e1f288d2f9c69 ("KVM: PPC: Book3S HV nestedv2: Add
support for reading VPA counters for pseries guests")
have updated the paca fields with corresponding changes.

Proposed perf interface is to expose these new software
counters for monitoring of context switch latencies and
runtime aggregate. Perf interface driver is called
"vpa_pmu" and it has dependency on KVM and perf, hence
added new config called "VPA_PMU" which depends on
"CONFIG_KVM_BOOK3S_64_HV" and "CONFIG_HV_PERF_CTRS".
Since, kvm and kvm_host are currently compiled as built-in
modules, this perf interface takes the same path and
registered as a module.

vpa_pmu perf interface needs access to some of the kvm
functions and structures like kvmhv_get_l2_counters_status(),
hence kvm_book3s_64.h and kvm_ppc.h are included.
Below are the events added to monitor KoP:

  vpa_pmu/l1_to_l2_lat/
  vpa_pmu/l2_to_l1_lat/
  vpa_pmu/l2_runtime_agg/

and vpa_pmu driver supports only per-cpu monitoring with this patch.
Example usage:

[command]# perf stat -e vpa_pmu/l1_to_l2_lat/ -a -I 1000
     1.001017682            727,200      vpa_pmu/l1_to_l2_lat/
     2.003540491          1,118,824      vpa_pmu/l1_to_l2_lat/
     3.005699458          1,919,726      vpa_pmu/l1_to_l2_lat/
     4.007827011          2,364,630      vpa_pmu/l1_to_l2_lat/

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Co-developed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241118114114.208964-1-kjain@linux.ibm.com
Merge tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2024-11-18T20:24:06+00:00 Linus Torvalds torvalds@linux-foundation.org 2024-11-18T20:24:06+00:00 0f25f0e4efaeb68086f7e65c442f2d648b21736f Pull 'struct fd' class updates from Al Viro: "The bulk of struct fd memory safety stuff Making sure that struct fd instances are destroyed in the same scope where they'd been created, getting rid of reassignments and passing them by reference, converting to CLASS(fd{,_pos,_raw}). We are getting very close to having the memory safety of that stuff trivial to verify" * tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits) deal with the last remaing boolean uses of fd_file() css_set_fork(): switch to CLASS(fd_raw, ...) memcg_write_event_control(): switch to CLASS(fd) assorted variants of irqfd setup: convert to CLASS(fd) do_pollfd(): convert to CLASS(fd) convert do_select() convert vfs_dedupe_file_range(). convert cifs_ioctl_copychunk() convert media_request_get_by_fd() convert spu_run(2) switch spufs_calls_{get,put}() to CLASS() use convert cachestat(2) convert do_preadv()/do_pwritev() fdget(), more trivial conversions fdget(), trivial conversions privcmd_ioeventfd_assign(): don't open-code eventfd_ctx_fdget() o2hb_region_dev_store(): avoid goto around fdget()/fdput() introduce "fd_pos" class, convert fdget_pos() users to it. fdget_raw() users: switch to CLASS(fd_raw) convert vmsplice() to CLASS(fd) ... 
Pull 'struct fd' class updates from Al Viro:
 "The bulk of struct fd memory safety stuff

  Making sure that struct fd instances are destroyed in the same scope
  where they'd been created, getting rid of reassignments and passing
  them by reference, converting to CLASS(fd{,_pos,_raw}).

  We are getting very close to having the memory safety of that stuff
  trivial to verify"

* tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits)
  deal with the last remaing boolean uses of fd_file()
  css_set_fork(): switch to CLASS(fd_raw, ...)
  memcg_write_event_control(): switch to CLASS(fd)
  assorted variants of irqfd setup: convert to CLASS(fd)
  do_pollfd(): convert to CLASS(fd)
  convert do_select()
  convert vfs_dedupe_file_range().
  convert cifs_ioctl_copychunk()
  convert media_request_get_by_fd()
  convert spu_run(2)
  switch spufs_calls_{get,put}() to CLASS() use
  convert cachestat(2)
  convert do_preadv()/do_pwritev()
  fdget(), more trivial conversions
  fdget(), trivial conversions
  privcmd_ioeventfd_assign(): don't open-code eventfd_ctx_fdget()
  o2hb_region_dev_store(): avoid goto around fdget()/fdput()
  introduce "fd_pos" class, convert fdget_pos() users to it.
  fdget_raw() users: switch to CLASS(fd_raw)
  convert vmsplice() to CLASS(fd)
  ...
Merge tag 'loongarch-kvm-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson into HEAD 2024-11-14T12:06:24+00:00 Paolo Bonzini pbonzini@redhat.com 2024-11-14T12:06:24+00:00 0586ade9e7f9491ccbe1e00975978cb9c2093006 LoongArch KVM changes for v6.13 1. Add iocsr and mmio bus simulation in kernel. 2. Add in-kernel interrupt controller emulation. 3. Add virt extension support for eiointc irqchip. 
LoongArch KVM changes for v6.13

1. Add iocsr and mmio bus simulation in kernel.
2. Add in-kernel interrupt controller emulation.
3. Add virt extension support for eiointc irqchip.
KVM: PPC: Book3S HV: Fix kmv -> kvm typo 2024-11-14T11:22:30+00:00 Kajol Jain kjain@linux.ibm.com 2024-11-14T08:50:20+00:00 590d2f9347f7974d7954400e5d937672fd844a8b Fix typo in the following kvm function names from: kmvhv_counters_tracepoint_regfunc -> kvmhv_counters_tracepoint_regfunc kmvhv_counters_tracepoint_unregfunc -> kvmhv_counters_tracepoint_unregfunc Fixes: e1f288d2f9c6 ("KVM: PPC: Book3S HV nestedv2: Add support for reading VPA counters for pseries guests") Reported-by: Madhavan Srinivasan <maddy@linux.ibm.com> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Reviewed-by: Amit Machhiwal <amachhiw@linux.ibm.com> Signed-off-by: Kajol Jain <kjain@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://patch.msgid.link/20241114085020.1147912-1-kjain@linux.ibm.com 
Fix typo in the following kvm function names from:

 kmvhv_counters_tracepoint_regfunc -> kvmhv_counters_tracepoint_regfunc
 kmvhv_counters_tracepoint_unregfunc -> kvmhv_counters_tracepoint_unregfunc

Fixes: e1f288d2f9c6 ("KVM: PPC: Book3S HV nestedv2: Add support for reading VPA counters for pseries guests")
Reported-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241114085020.1147912-1-kjain@linux.ibm.com
KVM: PPC: Book3S HV: Avoid returning to nested hypervisor on pending doorbells 2024-11-14T02:04:29+00:00 Gautam Menghani gautam@linux.ibm.com 2024-11-09T06:32:57+00:00 26686db69917399fa30e3b3135360771e90f83ec Commit 6398326b9ba1 ("KVM: PPC: Book3S HV P9: Stop using vc->dpdes") dropped the use of vcore->dpdes for msgsndp / SMT emulation. Prior to that commit, the below code at L1 level (see [1] for terminology) was responsible for setting vc->dpdes for the respective L2 vCPU: if (!nested) { kvmppc_core_prepare_to_enter(vcpu); if (vcpu->arch.doorbell_request) { vc->dpdes = 1; smp_wmb(); vcpu->arch.doorbell_request = 0; } L1 then sent vc->dpdes to L0 via kvmhv_save_hv_regs(), and while servicing H_ENTER_NESTED at L0, the below condition at L0 level made sure to abort and go back to L1 if vcpu->arch.doorbell_request = 1 so that L1 sets vc->dpdes as per above if condition: } else if (vcpu->arch.pending_exceptions || vcpu->arch.doorbell_request || xive_interrupt_pending(vcpu)) { vcpu->arch.ret = RESUME_HOST; goto out; } This worked fine since vcpu->arch.doorbell_request was used more like a flag and vc->dpdes was used to pass around the doorbell state. But after Commit 6398326b9ba1 ("KVM: PPC: Book3S HV P9: Stop using vc->dpdes"), vcpu->arch.doorbell_request is the only variable used to pass around doorbell state. With the plumbing for handling doorbells for nested guests updated to use vcpu->arch.doorbell_request over vc->dpdes, the above "else if" stops doorbells from working correctly as L0 aborts execution of L2 and instead goes back to L1. Remove vcpu->arch.doorbell_request from the above "else if" condition as it is no longer needed for L0 to correctly handle the doorbell status while running L2. [1] Terminology 1. L0 : PowerNV linux running with HV privileges 2. L1 : Pseries KVM guest running on top of L0 2. L2 : Nested KVM guest running on top of L1 Fixes: 6398326b9ba1 ("KVM: PPC: Book3S HV P9: Stop using vc->dpdes") Signed-off-by: Gautam Menghani <gautam@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://patch.msgid.link/20241109063301.105289-4-gautam@linux.ibm.com 
Commit 6398326b9ba1 ("KVM: PPC: Book3S HV P9: Stop using vc->dpdes")
dropped the use of vcore->dpdes for msgsndp / SMT emulation. Prior to that
commit, the below code at L1 level (see [1] for terminology) was
responsible for setting vc->dpdes for the respective L2 vCPU:

if (!nested) {
	kvmppc_core_prepare_to_enter(vcpu);
	if (vcpu->arch.doorbell_request) {
		vc->dpdes = 1;
		smp_wmb();
		vcpu->arch.doorbell_request = 0;
	}

L1 then sent vc->dpdes to L0 via kvmhv_save_hv_regs(), and while
servicing H_ENTER_NESTED at L0, the below condition at L0 level made sure
to abort and go back to L1 if vcpu->arch.doorbell_request = 1 so that L1
sets vc->dpdes as per above if condition:

} else if (vcpu->arch.pending_exceptions ||
	   vcpu->arch.doorbell_request ||
	   xive_interrupt_pending(vcpu)) {
	vcpu->arch.ret = RESUME_HOST;
	goto out;
}

This worked fine since vcpu->arch.doorbell_request was used more like a
flag and vc->dpdes was used to pass around the doorbell state. But after
Commit 6398326b9ba1 ("KVM: PPC: Book3S HV P9: Stop using vc->dpdes"),
vcpu->arch.doorbell_request is the only variable used to pass around
doorbell state.
With the plumbing for handling doorbells for nested guests updated to use
vcpu->arch.doorbell_request over vc->dpdes, the above "else if" stops
doorbells from working correctly as L0 aborts execution of L2 and
instead goes back to L1.

Remove vcpu->arch.doorbell_request from the above "else if" condition as
it is no longer needed for L0 to correctly handle the doorbell status
while running L2.

[1] Terminology
1. L0 : PowerNV linux running with HV privileges
2. L1 : Pseries KVM guest running on top of L0
2. L2 : Nested KVM guest running on top of L1

Fixes: 6398326b9ba1 ("KVM: PPC: Book3S HV P9: Stop using vc->dpdes")
Signed-off-by: Gautam Menghani <gautam@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241109063301.105289-4-gautam@linux.ibm.com
KVM: PPC: Book3S HV: Stop using vc->dpdes for nested KVM guests 2024-11-14T02:04:23+00:00 Gautam Menghani gautam@linux.ibm.com 2024-11-09T06:32:56+00:00 0d3c6b28896f9889c8864dab469e0343a0ad1c0c commit 6398326b9ba1 ("KVM: PPC: Book3S HV P9: Stop using vc->dpdes") introduced an optimization to use only vcpu->doorbell_request for SMT emulation for Power9 and above guests, but the code for nested guests still relies on the old way of handling doorbells, due to which an L2 guest (see [1]) cannot be booted with XICS with SMT>1. The command to repro this issue is: // To be run in L1 qemu-system-ppc64 \ -drive file=rhel.qcow2,format=qcow2 \ -m 20G \ -smp 8,cores=1,threads=8 \ -cpu host \ -nographic \ -machine pseries,ic-mode=xics -accel kvm Fix the plumbing to utilize vcpu->doorbell_request instead of vcore->dpdes for nested KVM guests on P9 and above. [1] Terminology 1. L0 : PowerNV linux running with HV privileges 2. L1 : Pseries KVM guest running on top of L0 2. L2 : Nested KVM guest running on top of L1 Fixes: 6398326b9ba1 ("KVM: PPC: Book3S HV P9: Stop using vc->dpdes") Signed-off-by: Gautam Menghani <gautam@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://patch.msgid.link/20241109063301.105289-3-gautam@linux.ibm.com 
commit 6398326b9ba1 ("KVM: PPC: Book3S HV P9: Stop using vc->dpdes")
introduced an optimization to use only vcpu->doorbell_request for SMT
emulation for Power9 and above guests, but the code for nested guests
still relies on the old way of handling doorbells, due to which an L2
guest (see [1]) cannot be booted with XICS with SMT>1. The command to
repro this issue is:

// To be run in L1

qemu-system-ppc64 \
	-drive file=rhel.qcow2,format=qcow2 \
	-m 20G \
	-smp 8,cores=1,threads=8 \
	-cpu  host \
	-nographic \
	-machine pseries,ic-mode=xics -accel kvm

Fix the plumbing to utilize vcpu->doorbell_request instead of vcore->dpdes
for nested KVM guests on P9 and above.

[1] Terminology
1. L0 : PowerNV linux running with HV privileges
2. L1 : Pseries KVM guest running on top of L0
2. L2 : Nested KVM guest running on top of L1

Fixes: 6398326b9ba1 ("KVM: PPC: Book3S HV P9: Stop using vc->dpdes")
Signed-off-by: Gautam Menghani <gautam@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241109063301.105289-3-gautam@linux.ibm.com