}
-
-// TODO: this is a disaster we need to clean this up...
int v3_handle_efer_write(struct guest_info * core, uint_t msr, struct v3_msr src, void * priv_data) {
- //struct efer_64 * new_efer = (struct efer_64 *)&(src.value);
- struct efer_64 * shadow_efer = (struct efer_64 *)&(core->ctrl_regs.efer);
- struct v3_msr * guest_efer = &(core->shdw_pg_state.guest_efer);
+ struct v3_msr * vm_efer = &(core->shdw_pg_state.guest_efer);
+ struct efer_64 * hw_efer = (struct efer_64 *)&(core->ctrl_regs.efer);
+ struct efer_64 old_hw_efer = *((struct efer_64 *)&core->ctrl_regs.efer);
- PrintDebug("EFER Write\n");
- PrintDebug("EFER Write Values: HI=%x LO=%x\n", src.hi, src.lo);
+ PrintDebug("EFER Write HI=%x LO=%x\n", src.hi, src.lo);
- //PrintDebug("Old EFER=%p\n", (void *)*(addr_t*)(shadow_efer));
-
- // We virtualize the guests efer to hide the SVME and LMA bits
- guest_efer->value = src.value;
-
- if (core->shdw_pg_mode == SHADOW_PAGING) {
- // Enable/Disable Syscall
- shadow_efer->sce = src.value & 0x1;
- } else if (core->shdw_pg_mode == NESTED_PAGING) {
- *(uint64_t *)shadow_efer = src.value;
- shadow_efer->svme = 1;
+ // Set EFER value seen by guest if it reads EFER
+ vm_efer->value = src.value;
+
+ // Set EFER value seen by hardware while the guest is running
+ *(uint64_t *)hw_efer = src.value;
+
+ // Catch unsupported features
+ if ((old_hw_efer.lme == 1) && (hw_efer->lme == 0)) {
+ PrintError("Disabling long mode once it has been enabled is not supported\n");
+ return -1;
}
+
+ // Set LME and LMA bits seen by hardware
+ if (old_hw_efer.lme == 0) {
+ // Long mode was not previously enabled, so the lme bit cannot
+ // be set yet. It will be set later when the guest sets CR0.PG
+ // to enable paging.
+ hw_efer->lme = 0;
+ } else {
+ // Long mode was previously enabled. Ensure LMA bit is set.
+ // VMX does not automatically set LMA, and this should not affect SVM.
+ hw_efer->lma = 1;
+ }
+
return 0;
}
