-static int check_cr_write(struct x86_emulate_ctxt *ctxt)
-{
- u64 new_val = ctxt->src.val64;
- int cr = ctxt->modrm_reg;
- u64 efer = 0;
-
- static u64 cr_reserved_bits[] = {
- 0xffffffff00000000ULL,
- 0, 0, 0, /* CR3 checked later */
- CR4_RESERVED_BITS,
- 0, 0, 0,
- CR8_RESERVED_BITS,
- };
-
- if (!valid_cr(cr))
- return emulate_ud(ctxt);
-
- if (new_val & cr_reserved_bits[cr])
- return emulate_gp(ctxt, 0);
-
- switch (cr) {
- case 0: {
- u64 cr4;
- if (((new_val & X86_CR0_PG) && !(new_val & X86_CR0_PE)) ||
- ((new_val & X86_CR0_NW) && !(new_val & X86_CR0_CD)))
- return emulate_gp(ctxt, 0);
-
- cr4 = ctxt->ops->get_cr(ctxt, 4);
- ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
-
- if ((new_val & X86_CR0_PG) && (efer & EFER_LME) &&
- !(cr4 & X86_CR4_PAE))
- return emulate_gp(ctxt, 0);
-
- break;
- }
- case 3: {
- u64 rsvd = 0;
-
- ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
- if (efer & EFER_LMA) {
- u64 maxphyaddr;
- u32 eax, ebx, ecx, edx;
-
- eax = 0x80000008;
- ecx = 0;
- if (ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx,
- &edx, true))
- maxphyaddr = eax & 0xff;
- else
- maxphyaddr = 36;
- rsvd = rsvd_bits(maxphyaddr, 63);
- if (ctxt->ops->get_cr(ctxt, 4) & X86_CR4_PCIDE)
- rsvd &= ~X86_CR3_PCID_NOFLUSH;
- }
-
- if (new_val & rsvd)
- return emulate_gp(ctxt, 0);
-
- break;
- }
- case 4: {
- ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
-
- if ((efer & EFER_LMA) && !(new_val & X86_CR4_PAE))
- return emulate_gp(ctxt, 0);
-
- break;
- }
- }
-
- return X86EMUL_CONTINUE;
-}
-