diff options
| author | Marc Zyngier <maz@kernel.org> | 2021-01-21 12:08:15 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-02-03 23:25:57 +0100 |
| commit | 632a7728da9bac175b88cab4151bfd535861bcfd (patch) | |
| tree | fed69bb4a4098b1008a8f5d82bbeb08e7f1d7f19 | |
| parent | ba668a507788cf3036264fb509f4a0fbf9c332ad (diff) | |
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>
| -rw-r--r-- | Documentation/virt/kvm/api.txt | 3 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 1 |
2 files changed, 4 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. diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 8f3b40ec02b7..f25b5043cbca 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1017,6 +1017,7 @@ int __kvm_set_memory_region(struct kvm *kvm, /* We can read the guest memory with __xxx_user() later on. */ if ((id < KVM_USER_MEM_SLOTS) && ((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))) goto out; |