summaryrefslogtreecommitdiffstats
path: root/Documentation
diff options
context:
space:
mode:
authorMarc Zyngier <maz@kernel.org>2021-01-21 12:08:15 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-02-03 23:25:57 +0100
commit632a7728da9bac175b88cab4151bfd535861bcfd (patch)
treefed69bb4a4098b1008a8f5d82bbeb08e7f1d7f19 /Documentation
parentba668a507788cf3036264fb509f4a0fbf9c332ad (diff)
downloadlinux-stable-632a7728da9bac175b88cab4151bfd535861bcfd.tar.gz
linux-stable-632a7728da9bac175b88cab4151bfd535861bcfd.tar.bz2
linux-stable-632a7728da9bac175b88cab4151bfd535861bcfd.zip
KVM: Forbid the use of tagged userspace addresses for memslots
commit 139bc8a6146d92822c866cf2fd410159c56b3648 upstream. The use of a tagged address could be pretty confusing for the whole memslot infrastructure as well as the MMU notifiers. Forbid it altogether, as it never quite worked the first place. Cc: stable@vger.kernel.org Reported-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/virt/kvm/api.txt3
1 files changed, 3 insertions, 0 deletions
diff --git a/Documentation/virt/kvm/api.txt b/Documentation/virt/kvm/api.txt
index a18e996fa54b..7064efd3b5ea 100644
--- a/Documentation/virt/kvm/api.txt
+++ b/Documentation/virt/kvm/api.txt
@@ -1132,6 +1132,9 @@ field userspace_addr, which must point at user addressable memory for
the entire memory slot size. Any object may back this memory, including
anonymous memory, ordinary files, and hugetlbfs.
+On architectures that support a form of address tagging, userspace_addr must
+be an untagged address.
+
It is recommended that the lower 21 bits of guest_phys_addr and userspace_addr
be identical. This allows large pages in the guest to be backed by large
pages in the host.