On 09/06/2018 08:50 AM, Sean Christopherson wrote:
...
So are we going to be defining a decrypted section for every piece of
machinery now?
That's a bit too much in my book.
Why can't you simply free everything in .data..decrypted on !SVE guests?
That would prevent adding __decrypted to existing declarations, e.g.
hv_clock_boot, which would be ugly in its own right. A more generic
solution would be to add something like __decrypted_exclusive to mark
data that is used if and only if SEV is active, and then free the
SEV-only data when SEV is disabled.
Originally, my thought was that this would be a one-off case and the
array could be freed directly in kvmclock_init(), e.g.:
Please note that kvmclock_init() is called very early during the boot
process. We will not be able to use free_init_pages(...) so early.
Additionally, we also need to consider the bare-metal case -- which
will never call the kvmclock_init().
static struct pvclock_vsyscall_time_info
hv_clock_aux[HVC_AUX_ARRAY_SIZE] __decrypted __aligned(PAGE_SIZE);
...
void __init kvmclock_init(void)
{
u8 flags;
if (!sev_active())
free_init_pages("unused decrypted",
(unsigned long)hv_clock_aux,
(unsigned long)hv_clock_aux + sizeof(hv_clock_aux));
