From: Peter Collingbourne Date: Fri, 4 Nov 2022 01:10:41 +0000 (-0700) Subject: Documentation: document the ABI changes for KVM_CAP_ARM_MTE X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=a4baf8d2639f24d4d31983ff67c01878e7a5393f;p=linux.git Documentation: document the ABI changes for KVM_CAP_ARM_MTE Document both the restriction on VM_MTE_ALLOWED mappings and the relaxation for shared mappings. Signed-off-by: Peter Collingbourne Acked-by: Catalin Marinas Reviewed-by: Cornelia Huck Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20221104011041.290951-9-pcc@google.com --- diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index eee9f857a986f..b55f80dadcfeb 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -7385,8 +7385,9 @@ 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.