palacios/src/geekos/svm_lowlevel.asm

   1 ;  -*- fundamental -*-
   2
   3
   4 %ifndef SVM_ASM
   5 %define SVM_ASM
   6
   7 %include "defs.asm"
   8 %include "symbol.asm"
   9
  10
  11
  12 EXTERN handle_svm_exit
  13
  14 EXPORT launch_svm
  15
  16
  17 [BITS 32]
  18
  19 %macro vmrun 0
  20         db      00fh, 001h, 0d8h
  21 %endmacro
  22
  23
  24 ;VMRUN  equ db 0Fh, 01h, D8h
  25 ;VMLOAD equ db 0x0F,0x01,0xDA
  26 ;VMSAVE equ db 0x0F,0x01,0xDB
  27 ;STGI   equ db 0x0F,0x01,0xDC
  28 ;CLGI   equ db 0x0F,0x01,0xDD
  29
  30
  31
  32
  33 ; I think its safe to say that there are some pretty serious register issues...
  34 launch_svm:
  35         push    ebp
  36         mov     ebp, esp
  37         pusha
  38
  39         mov     eax, [ebp + 8]
  40         vmrun
  41 ;       db      00fh, 001h, 0d8h
  42         popa
  43         pop     ebp
  44         ret
  45
  46 %endif
  47
  48
  49
  50
  51 ; eventual svm_launch
  52 ;   pusha
  53 ;   pushf
  54 ;
  55 ; .vmm_loop
  56 ;       vmrun
  57 ;       push guest GPRs
  58 ;       call handle_svm_exit
  59 ;       jz .vmm_loop
  60 ;  popf
  61 ;  popa
  62 ;  ret
  63 ;
  64 ;
  65 ;
  66
  67
  68
  69 ;; Need to check this..
  70 ;; Since RAX/EAX is saved in the VMCB, we should probably just
  71 ;;      do our own replacement for pusha/popa that excludes [e|r]ax
  72 safe_svm_launch:
  73         push    ebp
  74         mov     ebp, esp
  75         pushf
  76         pusha
  77
  78 .vmm_loop:
  79         mov     eax, [ebp + 8]
  80         vmrun
  81         pusha
  82         call    handle_svm_exit
  83         and     eax, eax
  84         popa                    ;; restore the guest GPRs, (DOES THIS AFFECT E/RFLAGS?)
  85         jz      .vmm_loop
  86
  87         ;; HOW DO WE GET THE RETURN VALUE OF HANDLE_SVM_EXIT BACK TO THE CALLER
  88         popf
  89         popa
  90         pop     ebp
  91         ret