On Thu, Aug 27, 2020 at 06:48:10PM -0400, Arvind Sankar wrote: > On Mon, Aug 24, 2020 at 10:54:22AM +0200, Joerg Roedel wrote: > > From: Tom Lendacky <thomas.lendacky@xxxxxxx> > > > > Handle #VC exceptions caused by CPUID instructions. These happen in > > early boot code when the KASLR code checks for RDTSC. > > > > Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx> > > [ jroedel@xxxxxxx: Adapt to #VC handling framework ] > > Co-developed-by: Joerg Roedel <jroedel@xxxxxxx> > > Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> > > Link: https://lore.kernel.org/r/20200724160336.5435-27-joro@xxxxxxxxxx > > --- > > + > > +static enum es_result vc_handle_cpuid(struct ghcb *ghcb, > > + struct es_em_ctxt *ctxt) > > +{ > > + struct pt_regs *regs = ctxt->regs; > > + u32 cr4 = native_read_cr4(); > > + enum es_result ret; > > + > > + ghcb_set_rax(ghcb, regs->ax); > > + ghcb_set_rcx(ghcb, regs->cx); > > + > > + if (cr4 & X86_CR4_OSXSAVE) > > Will this ever happen? trampoline_32bit_src will clear CR4 except for > PAE and possibly LA57, no? This same code is later re-used in the runtime handler and there the check is needed :) Regards, Joerg
