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| author | Marc Zyngier <maz@kernel.org> | 2021-01-21 12:08:15 +0000 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2021-01-21 14:17:36 +0000 |
| commit | 139bc8a6146d92822c866cf2fd410159c56b3648 (patch) | |
| tree | 47749e54b37ecdf138090403959ecd93c73a8ae6 /Documentation | |
| parent | 9529aaa056edc76b3a41df616c71117ebe11e049 (diff) | |
| download | lwn-139bc8a6146d92822c866cf2fd410159c56b3648.tar.gz lwn-139bc8a6146d92822c866cf2fd410159c56b3648.zip | |
KVM: Forbid the use of tagged userspace addresses for memslots
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>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/virt/kvm/api.rst | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 4e5316ed10e9..c347b7083abf 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -1269,6 +1269,9 @@ 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. |