On Sat, Sep 16, 2017 at 07:34:16AM -0500, Brijesh Singh wrote: > When SEV is active, memory is encrypted with guest-specific key, and if > guest OS wants to share the memory region with hypervisor then it must > clear the C-bit (i.e set unencrypted) before sharing it. > > DEFINE_PER_CPU_UNENCRYPTED can be used to define the per-cpu variables > which will be shared between guest and hypervisor. Currently, KVM defines > three variables (steal-time, apf_reason, and avic_eio) which are shared > with hypervisor. > > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Cc: Ingo Molnar <mingo@xxxxxxxxxx> > Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> > Cc: Borislav Petkov <bp@xxxxxxx> > Cc: Arnd Bergmann <arnd@xxxxxxxx> > Cc: Tejun Heo <tj@xxxxxxxxxx> > Cc: Christoph Lameter <cl@xxxxxxxxx> > Cc: linux-arch@xxxxxxxxxxxxxxx > Cc: x86@xxxxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx > Cc: Tom Lendacky <thomas.lendacky@xxxxxxx> > Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx> Acked-by: Tejun Heo <tj@xxxxxxxxxx> Thanks. -- tejun
