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  • Linus Torvalds's avatar
    Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm · 4f712ee0
    Linus Torvalds authored
    Pull kvm updates from Paolo Bonzini:
     "S390:
    
       - Changes to FPU handling came in via the main s390 pull request
    
       - Only deliver to the guest the SCLP events that userspace has
         requested
    
       - More virtual vs physical address fixes (only a cleanup since
         virtual and physical address spaces are currently the same)
    
       - Fix selftests undefined behavior
    
      x86:
    
       - Fix a restriction that the guest can't program a PMU event whose
         encoding matches an architectural event that isn't included in the
         guest CPUID. The enumeration of an architectural event only says
         that if a CPU supports an architectural event, then the event can
         be programmed *using the architectural encoding*. The enumeration
         does NOT say anything about the encoding when the CPU doesn't
         report support the event *in general*. It might support it, and it
         might support it using the same encoding that made it into the
         architectural PMU spec
    
       - Fix a variety of bugs in KVM's emulation of RDPMC (more details on
         individual commits) and add a selftest to verify KVM correctly
         emulates RDMPC, counter availability, and a variety of other
         PMC-related behaviors that depend on guest CPUID and therefore are
         easier to validate with selftests than with custom guests (aka
         kvm-unit-tests)
    
       - Zero out PMU state on AMD if the virtual PMU is disabled, it does
         not cause any bug but it wastes time in various cases where KVM
         would check if a PMC event needs to be synthesized
    
       - Optimize triggering of emulated events, with a nice ~10%
         performance improvement in VM-Exit microbenchmarks when a vPMU is
         exposed to the guest
    
       - Tighten the check for "PMI in guest" to reduce false positives if
         an NMI arrives in the host while KVM is handling an IRQ VM-Exit
    
       - Fix a bug where KVM would report stale/bogus exit qualification
         information when exiting to userspace with an internal error exit
         code
    
       - Add a VMX flag in /proc/cpuinfo to report 5-level EPT support
    
       - Rework TDP MMU root unload, free, and alloc to run with mmu_lock
         held for read, e.g. to avoid serializing vCPUs when userspace
         deletes a memslot
    
       - Tear down TDP MMU page tables at 4KiB granularity (used to be
         1GiB). KVM doesn't support yielding in the middle of processing a
         zap, and 1GiB granularity resulted in multi-millisecond lags that
         are quite impolite for CONFIG_PREEMPT kernels
    
       - Allocate write-tracking metadata on-demand to avoid the memory
         overhead when a kernel is built with i915 virtualization support
         but the workloads use neither shadow paging nor i915 virtualization
    
       - Explicitly initialize a variety of on-stack variables in the
         emulator that triggered KMSAN false positives
    
       - Fix the debugregs ABI for 32-bit KVM
    
       - Rework the "force immediate exit" code so that vendor code
         ultimately decides how and when to force the exit, which allowed
         some optimization for both Intel and AMD
    
       - Fix a long-standing bug where kvm_has_noapic_vcpu could be left
         elevated if vCPU creation ultimately failed, causing extra
         unnecessary work
    
       - Cleanup the logic for checking if the currently loaded vCPU is
         in-kernel
    
       - Harden against underflowing the active mmu_notifier invalidation
         count, so that "bad" invalidations (usually due to bugs elsehwere
         in the kernel) are detected earlier and are less likely to hang the
         kernel
    
      x86 Xen emulation:
    
       - Overlay pages can now be cached based on host virtual address,
         instead of guest physical addresses. This removes the need to
         reconfigure and invalidate the cache if the guest changes the gpa
         but the underlying host virtual address remains the same
    
       - When possible, use a single host TSC value when computing the
         deadline for Xen timers in order to improve the accuracy of the
         timer emulation
    
       - Inject pending upcall events when the vCPU software-enables its
         APIC to fix a bug where an upcall can be lost (and to follow Xen's
         behavior)
    
       - Fall back to the slow path instead of warning if "fast" IRQ
         delivery of Xen events fails, e.g. if the guest has aliased xAPIC
         IDs
    
      RISC-V:
    
       - Support exception and interrupt handling in selftests
    
       - New self test for RISC-V architectural timer (Sstc extension)
    
       - New extension support (Ztso, Zacas)
    
       - Support userspace emulation of random number seed CSRs
    
      ARM:
    
       - Infrastructure for building KVM's trap configuration based on the
         architectural features (or lack thereof) advertised in the VM's ID
         registers
    
       - Support for mapping vfio-pci BARs as Normal-NC (vaguely similar to
         x86's WC) at stage-2, improving the performance of interacting with
         assigned devices that can tolerate it
    
       - Conversion of KVM's representation of LPIs to an xarray, utilized
         to address serialization some of the serialization on the LPI
         injection path
    
       - Support for _architectural_ VHE-only systems, advertised through
         the absence of FEAT_E2H0 in the CPU's ID register
    
       - Miscellaneous cleanups, fixes, and spelling corrections to KVM and
         selftests
    
      LoongArch:
    
       - Set reserved bits as zero in CPUCFG
    
       - Start SW timer only when vcpu is blocking
    
       - Do not restart SW timer when it is expired
    
       - Remove unnecessary CSR register saving during enter guest
    
       - Misc cleanups and fixes as usual
    
      Generic:
    
       - Clean up Kconfig by removing CONFIG_HAVE_KVM, which was basically
         always true on all architectures except MIPS (where Kconfig
         determines the available depending on CPU capabilities). It is
         replaced either by an architecture-dependent symbol for MIPS, and
         IS_ENABLED(CONFIG_KVM) everywhere else
    
       - Factor common "select" statements in common code instead of
         requiring each architecture to specify it
    
       - Remove thoroughly obsolete APIs from the uapi headers
    
       - Move architecture-dependent stuff to uapi/asm/kvm.h
    
       - Always flush the async page fault workqueue when a work item is
         being removed, especially during vCPU destruction, to ensure that
         there are no workers running in KVM code when all references to
         KVM-the-module are gone, i.e. to prevent a very unlikely
         use-after-free if kvm.ko is unloaded
    
       - Grab a reference to the VM's mm_struct in the async #PF worker
         itself instead of gifting the worker a reference, so that there's
         no need to remember to *conditionally* clean up after the worker
    
      Selftests:
    
       - Reduce boilerplate especially when utilize selftest TAP
         infrastructure
    
       - Add basic smoke tests for SEV and SEV-ES, along with a pile of
         library support for handling private/encrypted/protected memory
    
       - Fix benign bugs where tests neglect to close() guest_memfd files"
    
    * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (246 commits)
      selftests: kvm: remove meaningless assignments in Makefiles
      KVM: riscv: selftests: Add Zacas extension to get-reg-list test
      RISC-V: KVM: Allow Zacas extension for Guest/VM
      KVM: riscv: selftests: Add Ztso extension to get-reg-list test
      RISC-V: KVM: Allow Ztso extension for Guest/VM
      RISC-V: KVM: Forward SEED CSR access to user space
      KVM: riscv: selftests: Add sstc timer test
      KVM: riscv: selftests: Change vcpu_has_ext to a common function
      KVM: riscv: selftests: Add guest helper to get vcpu id
      KVM: riscv: selftests: Add exception handling support
      LoongArch: KVM: Remove unnecessary CSR register saving during enter guest
      LoongArch: KVM: Do not restart SW timer when it is expired
      LoongArch: KVM: Start SW timer only when vcpu is blocking
      LoongArch: KVM: Set reserved bits as zero in CPUCFG
      KVM: selftests: Explicitly close guest_memfd files in some gmem tests
      KVM: x86/xen: fix recursive deadlock in timer injection
      KVM: pfncache: simplify locking and make more self-contained
      KVM: x86/xen: remove WARN_ON_ONCE() with false positives in evtchn delivery
      KVM: x86/xen: inject vCPU upcall vector when local APIC is enabled
      KVM: x86/xen: improve accuracy of Xen timers
      ...
    4f712ee0