From a4baf8d2639f24d4d31983ff67c01878e7a5393f Mon Sep 17 00:00:00 2001 From: Peter Collingbourne Date: Thu, 3 Nov 2022 18:10:41 -0700 Subject: [PATCH] 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 --- 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 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.