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 EXPORT GetGDTR
  12 EXPORT GetIDTR
  13
  14
  15
  16 EXTERN handle_svm_exit
  17
  18 EXPORT launch_svm
  19
  20
  21 [BITS 32]
  22
  23 %macro vmrun 0
  24         db      00fh, 001h, 0d8h
  25 %endmacro
  26
  27
  28 ;VMRUN  equ db 0Fh, 01h, D8h
  29 ;VMLOAD equ db 0x0F,0x01,0xDA
  30 ;VMSAVE equ db 0x0F,0x01,0xDB
  31 ;STGI   equ db 0x0F,0x01,0xDC
  32 ;CLGI   equ db 0x0F,0x01,0xDD
  33
  34
  35
  36
  37 GetGDTR:
  38         push    ebp
  39         mov     ebp, esp
  40         pusha
  41         mov     ebx, [ebp + 8]
  42         sgdt    [ebx]
  43
  44         popa
  45         pop     ebp
  46         ret
  47
  48
  49
  50 GetIDTR:
  51         push    ebp
  52         mov     ebp, esp
  53         pusha
  54         mov     ebx, [ebp + 8]
  55         sgdt    [ebx]
  56
  57         popa
  58         pop     ebp
  59         ret
  60
  61
  62
  63 ; I think its safe to say that there are some pretty serious register issues...
  64 launch_svm:
  65         push    ebp
  66         mov     ebp, esp
  67         pusha
  68
  69         mov     eax, [ebp + 8]
  70         vmrun
  71 ;       db      00fh, 001h, 0d8h
  72         popa
  73         pop     ebp
  74         ret
  75
  76
  77
  78 ; eventual svm_launch
  79 ;   pusha
  80 ;   pushf
  81 ;
  82 ; .vmm_loop
  83 ;       vmrun
  84 ;       push guest GPRs
  85 ;       call handle_svm_exit
  86 ;       jz .vmm_loop
  87 ;  popf
  88 ;  popa
  89 ;  ret
  90 ;
  91 ;
  92 ;
  93
  94
  95
  96 ;; Need to check this..
  97 ;; Since RAX/EAX is saved in the VMCB, we should probably just
  98 ;;      do our own replacement for pusha/popa that excludes [e|r]ax
  99 safe_svm_launch:
 100         push    ebp
 101         mov     ebp, esp
 102         pushf
 103         pusha
 104
 105 .vmm_loop:
 106         mov     eax, [ebp + 8]
 107         vmrun
 108         pusha
 109         call    handle_svm_exit
 110         and     eax, eax
 111         popa                    ;; restore the guest GPRs, (DOES THIS AFFECT E/RFLAGS?)
 112         jz      .vmm_loop
 113
 114         ;; HOW DO WE GET THE RETURN VALUE OF HANDLE_SVM_EXIT BACK TO THE CALLER
 115         popf
 116         popa
 117         pop     ebp
 118         ret
 119
 120
 121 %endif
 122
 123