On 4/16/21 8:40 AM, Kirill A. Shutemov wrote:

 	/*
-	 * If SME is active, the trampoline area will need to be in
-	 * decrypted memory in order to bring up other processors
+	 * If SME or KVM memory protection is active, the trampoline area will
+	 * need to be in decrypted memory in order to bring up other processors
 	 * successfully. This is not needed for SEV.
 	 */
-	if (sme_active())
+	if (sme_active() || kvm_mem_protected())
 		set_memory_decrypted((unsigned long)base, size >> PAGE_SHIFT);

Could you take a look at all the places you've added these:

	if (foo() || kvm_mem_protected())
		bar();

spots and see if some refactoring is in order?

I suspect that some thought about what the high-level commonalities are,
plus some thoughtful helper function names would go a long way to making
this whole thing understandable.


set_memory_decrypted() as a name needs to go.  It almost needs to be
something like:

	set_memory_sharing()

or something.  The "sharing" would be between the kernel and devices
(for SME), or the guest kernel and host kernel for protected memory.