[PATCH v2 7/7] Documentation: document the ABI changes for KVM_CAP_ARM_MTE

Peter Collingbourne
2022-07-22T01:51:21Z

Document both the restriction on VM_MTE_ALLOWED mappings and
the relaxation for shared mappings.

Signed-off-by: Peter Collingbourne <pcc@google.com>
---
Documentation/virt/kvm/api.rst | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index ebc5a519574f..5bb74b73bff3 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -7486,8 +7486,9 @@ hibernation of the host; however the VMM needs to manually save/restore the
tags as appropriate if the VM is migrated.

When this capability is enabled all memory in memslots must be mapped as
-not-shareable (no MAP_SHARED), attempts to create a memslot with a
-MAP_SHARED mmap will result in an -EINVAL return.
+``MAP_ANONYMOUS`` or with a RAM-based file mapping (``tmpfs``, ``memfd``),
+attempts to create a memslot with an invalid mmap will result in an
+-EINVAL return.

When enabled the VMM may make use of the ``KVM_ARM_MTE_COPY_TAGS`` ioctl to
perform a bulk copy of tags to/from the guest.
--
2.37.1.359.gd136c6c3e2-goog