diff options
| author | mischief <mischief@offblast.org> | 2014-06-24 18:02:25 -0700 |
|---|---|---|
| committer | mischief <mischief@offblast.org> | 2014-06-24 18:02:25 -0700 |
| commit | 5ba95fdb07ddc2c32111a1b2f57f17aa27fcbbf5 (patch) | |
| tree | c1ec54cb9ecff85b0b820a26d26a10a32a118d0c /sys/src/9/xen/xen.s | |
| parent | fa03455b5057675b18d1c87aef2d1071b2088de0 (diff) | |
import xen 32 bit paravirtual kernel from /n/sources/xen.
Diffstat (limited to 'sys/src/9/xen/xen.s')
| -rw-r--r-- | sys/src/9/xen/xen.s | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/sys/src/9/xen/xen.s b/sys/src/9/xen/xen.s new file mode 100644 index 000000000..e409f70d9 --- /dev/null +++ b/sys/src/9/xen/xen.s @@ -0,0 +1,72 @@ +#include "xendefs.h" +#include "mem.h" + +#define ENTRY(X) TEXT X(SB), $0 + +/* + * XXX there's a race in here because we can get an upcall + * betwen the spllo() (in xenupcall) and the rti. This will make + * handlers stack, which could lead to a blown stack. Probably + * not worth fixing (but possibly worth detecting and panicing). + * + * For fun get some popcorn and turn off the lights and read the + * linux solution (search for scrit/ecrit). + */ +ENTRY(hypervisor_callback) + SUBL $8, SP /* space for ecode and trap type */ + PUSHL DS /* save DS */ + PUSHL $(KDSEL) + POPL DS /* fix up DS */ + PUSHL ES /* save ES */ + PUSHL $(KDSEL) + POPL ES /* fix up ES */ + + PUSHL FS /* save the rest of the Ureg struct */ + PUSHL GS + PUSHAL + + PUSHL SP /* Ureg* argument to trap */ + CALL xenupcall+0(SB) + POPL AX + + POPAL + POPL GS + POPL FS + POPL ES + POPL DS + ADDL $8, SP /* pop error code and trap type */ + IRETL + +/* Hypervisor uses this for application faults while it executes.*/ +ENTRY(failsafe_callback) + IRETL + PUSHL AX + CALL install_safe_pf_handler(SB) + MOVL 32(SP), BX + MOVW BX, DS + MOVL 36(SP), BX + MOVW BX, ES + MOVL 40(SP), BX + MOVW BX, FS + MOVL 44(SP), BX + MOVW BX, GS + CALL install_normal_pf_handler(SB) + POPL AX + ADDL $16, SP + IRETL + +/* xen traps with varying argument counts */ +TEXT xencall6(SB), $0 + MOVL VDI+20(FP), DI +TEXT xencall5(SB), $0 + MOVL VSI+16(FP), SI +TEXT xencall4(SB), $0 + MOVL VDX+12(FP), DX +TEXT xencall3(SB), $0 + MOVL VCX+8(FP), CX +TEXT xencall2(SB), $0 + MOVL VBX+4(FP), BX +TEXT xencall1(SB), $0 + MOVL op+0(FP), AX + INT $0x82 + RET |