[PATCH v5 0/7] KVM: guest_memfd: reclaim()/convert() cleanups

[Sean Christopherson]

These are the cleanups from the SNP VMSA series.  I kept it as v5 to maintain
the paper trail.

Rework prepare()+invalidate() into convert()+reclaim(), and have the x86
backend use a single convert() flow for both (only SNP needs the hooks, and
for SNP, reclaim just means "make shared").  The goals are to eliminate the
misleading use of the term "invalidate", to drop a kvm_x86_ops callback, and to
prepare for in-place conversion, e.g. so that KVM ends up with something like:

	if (!to_private)
		kvm_gmem_make_shared(inode, start, end);

instead of a funky:

	if (!to_private)
		kvm_gmem_invalidate(inode, start, end);

v5
 - Drop the VMSA fixes (already applied).
 - Keep a dedicated reclaim() flow. [Fuad, Ackerley]
 - Pass a gfn, not a gpa, to convert() / reclaim(). [Ackerley]
 - Collect reviews. [Ackerley]
 - Align the gfn when folding __kvm_gmem_prepare_folio() into its caller. [Sashiko]
 
v4:
 - https://lore.kernel.org/all/20260709204948.1988414-1-seanjc@xxxxxxxxxx

 - Collect reviews. [Mike, Ackerley]
 - Rework prepare()+invalidate() into a common convert() instead of simply
   renaming invalidate() to reclaim_memory(). [Ackerley]
 - Fix several (mostly benign) issues in the "prepare" flow.

v3:
 - https://lore.kernel.org/all/20260630222607.497895-1-seanjc@xxxxxxxxxx
 - Ensure disabling quirks while the VM is live won't result in KVM skipping
   the back-half of "zap all fast". [Sashiko]
 - s/gmem_free_folio/gmem_reclaim_memory. [Ackerley]
 - Use {READ,WRITE}_ONCE() when accessing the guest's VMSA GPA outside of the
   per-vCPU mutex, and comment. [Sashiko]

v2:
 - https://lore.kernel.org/all/20260626231416.3943216-1-seanjc@xxxxxxxxxx
 - Invalidate VMSAs if the memslot is DELETED or MOVED. [Sashiko]
 - Limit stable@ patches without a Fixes to 6.12+.

v1: https://lore.kernel.org/all/20260625222229.3367197-2-seanjc@xxxxxxxxxx

Sean Christopherson (7):
  KVM: guest_memfd: Plumb the number of pages and max order into
    .invalidate()
  KVM: guest_memfd: Rename invalidate() arch hook to reclaim() and
    isolate it
  KVM: guest_memfd: Drop the redundant printk on arch gmem_prepare()
    failure
  KVM: guest_memfd: Fold __kvm_gmem_prepare_folio() into its sole caller
  KVM: guest_memfd: Explicitly pass number of pages to
    kvm_arch_gmem_prepare()
  KVM: x86: Combine .gmem_prepare()+.gmem_invalidate() into
    .gmem_convert()
  KVM: guest_memfd: Rework PREPARE config and hook into a more generic
    CONVERT

 arch/x86/include/asm/kvm-x86-ops.h |  5 ++--
 arch/x86/include/asm/kvm_host.h    |  6 ++--
 arch/x86/kvm/Kconfig               |  3 +-
 arch/x86/kvm/svm/sev.c             | 23 +++++++++++++--
 arch/x86/kvm/svm/svm.c             |  3 +-
 arch/x86/kvm/svm/svm.h             |  4 +--
 arch/x86/kvm/x86.c                 | 18 +++++++-----
 include/linux/kvm_host.h           | 10 +++++--
 virt/kvm/Kconfig                   |  6 +++-
 virt/kvm/guest_memfd.c             | 46 +++++++++++-------------------
 10 files changed, 70 insertions(+), 54 deletions(-)


base-commit: 6bc96b971766fbbbbdd9fb2642cedacaf02da957
-- 
2.55.0.141.g00534a21ce-goog