[PATCH v3 0/13] KVM: x86/xen: Bug fixes and long_mode cleanup

[David Woodhouse]

Clean up the handling of vcpu->arch.xen.long_mode to be consistent and
correctly handle 32-bit/64-bit alignment. And various other bug fixes
that have accumulated over the months since v1.

v3:
 - Rebase onto kvm/next (7.3 merge window).
 - Add poll_evtchn READ_ONCE/WRITE_ONCE annotation (Chengfeng Ye).
 - Add evtchn_ports IDR to XArray conversion (Furkan Caliskan).

v2: https://lore.kernel.org/all/20260811094829.98794-1-dwmw2@xxxxxxxxxxxxx/
 - Take kvm->srcu in __kvm_xen_has_interrupt().
 - Add dedicated invalidation sequence for HVA-based caches.
 - Take Sean's version of the 32-bit atomics patch, and his follow-up
   replacing the remaining asm blobs with atomic*() APIs.
 - Use GEN_BINARY_RMWcc() rather than open-coding the btsl.
 - Explain why the pending_bits access in kvm_xen_set_evtchn_fast() does
   not need the same treatment as the vcpu_info one (it is in the page
   aligned per-VM shared_info).
 - Don't require 8-byte alignment of vcpu_info in 64-bit mode; always
   accept 4-byte alignment, so as not to break migration of guests which
   registered while in 32-bit mode.
 - Add Closes: links for the reported issues.
 - Cast to u64 before the >> 32 in the unaligned evtchn_pending_sel
   handling; evtchn_pending_sel is unsigned long, so the shift was
   undefined on 32-bit even though the branch is unreachable there
   (kernel test robot).
 - Rebase onto kvm-x86/next; the mode-aware kvm_<reg>_read() helpers which
   landed in the meantime subsume most of what patch 1 was doing by hand.

v1: https://lore.kernel.org/all/20260605143034.3603-1-dwmw2@xxxxxxxxxxxxx/

Chengfeng Ye (1):
      KVM: x86/xen: Mark poll_evtchn accesses with READ_ONCE()/WRITE_ONCE()

David Woodhouse (8):
      KVM: x86/xen: Rename 'longmode' to 'is_64bit' in hypercall handling
      KVM: x86/xen: Introduce kvm_xen_has_64bit_shinfo() macro
      KVM: x86/xen: Rename max_evtchn_port() to kvm_max_evtchn_port()
      KVM: x86/xen: Latch shinfo mode in kvm_xen_schedop_poll()
      KVM: x86/xen: Enforce 4-byte alignment of vcpu_info registration
      KVM: x86/xen: Use 32-bit locked bts for vcpu_info evtchn_pending_sel
      KVM: x86/xen: Take kvm->srcu in __kvm_xen_has_interrupt()
      KVM: pfncache: use a dedicated invalidation sequence for cache refresh

Furkan Caliskan (1):
      KVM: x86/xen: Convert evtchn_ports from IDR to XArray

Hyunwoo Kim (1):
      KVM: x86/xen: Latch shinfo mode in kvm_xen_set_evtchn_fast()

Sean Christopherson (2):
      KVM: x86/xen: Use 32-bit atomics if vCPU's evtchn_pending_sel isn't aligned
      KVM: x86/xen: Use atomic*() APIs instead of open coded equivalents

 arch/x86/include/asm/kvm_host.h |   3 +-
 arch/x86/kvm/xen.c              | 212 ++++++++++++++++++++++++----------------
 arch/x86/kvm/xen.h              |   5 +
 include/linux/kvm_host.h        |   2 +
 virt/kvm/kvm_main.c             |  10 ++
 virt/kvm/pfncache.c             |  18 ++--
 6 files changed, 157 insertions(+), 93 deletions(-)