KVM: guest_memfd: Fix the in-place conversion documentation

Commit dcde2f853ff46 ("KVM: guest_memfd: Ensure pages are not in use
before conversion") added error_offset to struct kvm_memory_attributes2,
written back on failure, and a -EAGAIN return. The
KVM_SET_MEMORY_ATTRIBUTES2 section of api.rst still lists the old
struct, marks it input-only and leaves EAGAIN out of the Errors table.
It also refers to KVM_CAP_GUEST_MEMFD_MMAP, which had become
KVM_CAP_GUEST_MEMFD_FLAGS before this ioctl was added.

kvm.gmem_in_place_conversion's entry says in-place conversion is
unconditionally enabled without CONFIG_KVM_VM_MEMORY_ATTRIBUTES, but a
build without kvm_arch_has_private_mem has it disabled: arm64 always,
and x86 without CONFIG_KVM_SW_PROTECTED_VM, CONFIG_KVM_INTEL_TDX or
CONFIG_KVM_AMD_SEV.

Bring both in line with the code: replace the stale capability with
GUEST_MEMFD_FLAG_MMAP, and describe KVM_CAP_GUEST_MEMFD_MEMORY_ATTRIBUTES
the way the KVM_CREATE_GUEST_MEMFD section describes
KVM_CAP_GUEST_MEMFD_FLAGS.

Fixes: 799c9fadc6399 ("KVM: guest_memfd: Add base support for KVM_SET_MEMORY_ATTRIBUTES2")
Fixes: dcde2f853ff46 ("KVM: guest_memfd: Ensure pages are not in use before conversion")
Fixes: 537ec2b15fdd7 ("KVM: Let userspace disable per-VM mem attributes, enable per-gmem attributes")
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Link: https://patch.msgid.link/20260928180250.3075584-1-fuad.tabba@linux.dev
Signed-off-by: Sean Christopherson <seanjc@google.com>

0 files changed, 0 insertions, 0 deletions