diff options
| 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 | |
| parent | 9529aaa056edc76b3a41df616c71117ebe11e049 (diff) | |
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>
| -rw-r--r-- | Documentation/virt/kvm/api.rst | 3 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 1 |
2 files changed, 4 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. diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 2541a17ff1c4..a9abaf5f8e53 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1290,6 +1290,7 @@ int __kvm_set_memory_region(struct kvm *kvm, return -EINVAL; /* We can read the guest memory with __xxx_user() later on. */ if ((mem->userspace_addr & (PAGE_SIZE - 1)) || + (mem->userspace_addr != untagged_addr(mem->userspace_addr)) || !access_ok((void __user *)(unsigned long)mem->userspace_addr, mem->memory_size)) return -EINVAL; |