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;
__set_memory_enc_dec() is turning into a real mess. SEV, TDX and now
Hyper-V are messing around in here.
It doesn't help that these additions are totally uncommented. Even
worse is that hv_set_mem_enc() was intentionally named "enc" when it
presumably has nothing to do with encryption.
This needs to be refactored. The current __set_memory_enc_dec() can
become __set_memory_enc_pgtable(). It gets used for the hypervisors
that get informed about "encryption" status via page tables: SEV and TDX.
Then, rename hv_set_mem_enc() to hv_set_visible_hcall(). You'll end up
with:
int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
{
if (hv_is_isolation_supported())
return hv_set_visible_hcall(...);
if (mem_encrypt_active() || ...)
return __set_memory_enc_pgtable();
/* Nothing to do */
return 0;
}
That tells the story pretty effectively, in code.
> +int hv_set_mem_enc(unsigned long addr, int numpages, bool enc)
> +{
> + return hv_set_mem_host_visibility((void *)addr,
> + numpages * HV_HYP_PAGE_SIZE,
> + enc ? VMBUS_PAGE_NOT_VISIBLE
> + : VMBUS_PAGE_VISIBLE_READ_WRITE);
> +}
I know this is off in Hyper-V code, but this just makes my eyes bleed.
I'd much rather see something which is less compact but readable.
> +/* Hyper-V GPA map flags */
> +#define VMBUS_PAGE_NOT_VISIBLE 0
> +#define VMBUS_PAGE_VISIBLE_READ_ONLY 1
> +#define VMBUS_PAGE_VISIBLE_READ_WRITE 3
That looks suspiciously like an enum.
