On 7/29/2021 1:06 AM, Dave Hansen wrote:
On 7/28/21 7:52 AM, Tianyu Lan wrote:
@@ -1986,7 +1988,9 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
int ret;
/* Nothing to do if memory encryption is not active */
- if (!mem_encrypt_active())
+ if (hv_is_isolation_supported())
+ return hv_set_mem_enc(addr, numpages, enc);
+ else if (!mem_encrypt_active())
return 0;
One more thing. If you're going to be patching generic code, please
start using feature checks that can get optimized away at runtime.
hv_is_isolation_supported() doesn't look like the world's cheapest
check. It can't be inlined and costs at least a function call.
Yes, you are right. How about adding a static branch key for the check
of isolation VM? This may reduce the check cost.
