kvm: add a memslot flag for incoherent memory regions

Memory regions may be incoherent with the caches, typically when the
guest has mapped a host system RAM backed memory region as uncached.
Add a flag KVM_MEMSLOT_INCOHERENT so that we can tag these memslots
and handle them appropriately when mapping them.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index a6059bd..e4d8f70 100644 (file)
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -43,6 +43,7 @@
  * include/linux/kvm_h.
  */
 #define KVM_MEMSLOT_INVALID    (1UL << 16)
+#define KVM_MEMSLOT_INCOHERENT (1UL << 17)
 
 /* Two fragments for cross MMIO pages. */
 #define KVM_MAX_MMIO_FRAGMENTS 2