Commit ac354b5cb04d for kernel

commit ac354b5cb04d2077c3821a6cbfbc7981ad45f84a
Merge: b8a3bc856735 df8374607577
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Sun Mar 29 11:58:47 2026 -0700

    Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

    Pull kvm fixes from Paolo Bonzini:
     "s390:

       - Lots of small and not-so-small fixes for the newly rewritten gmap,
         mostly affecting the handling of nested guests.

      x86:

       - Fix an issue with shadow paging, which causes KVM to install an
         MMIO PTE in the shadow page tables without first zapping a non-MMIO
         SPTE if KVM didn't see the write that modified the shadowed guest
         PTE.

         While commit a54aa15c6bda3 ("KVM: x86/mmu: Handle MMIO SPTEs
         directly in mmu_set_spte()") was right about it being impossible to
         miss such a write if it was coming from the guest, it failed to
         account for writes to guest memory that are outside the scope of
         KVM: if userspace modifies the guest PTE, and then the guest hits a
         relevant page fault, KVM will get confused"

    * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
      KVM: x86/mmu: Only WARN in direct MMUs when overwriting shadow-present SPTE
      KVM: x86/mmu: Drop/zap existing present SPTE even when creating an MMIO SPTE
      KVM: s390: Fix KVM_S390_VCPU_FAULT ioctl
      KVM: s390: vsie: Fix guest page tables protection
      KVM: s390: vsie: Fix unshadowing while shadowing
      KVM: s390: vsie: Fix refcount overflow for shadow gmaps
      KVM: s390: vsie: Fix nested guest memory shadowing
      KVM: s390: Correctly handle guest mappings without struct page
      KVM: s390: Fix gmap_link()
      KVM: s390: vsie: Fix check for pre-existing shadow mapping
      KVM: s390: Remove non-atomic dat_crstep_xchg()
      KVM: s390: vsie: Fix dat_split_ste()