diff --git a/sys/src/9/xen/archxen.c b/sys/src/9/xen/archxen.c
index c4f1b5607..6f3d1bfae 100644
--- a/sys/src/9/xen/archxen.c
+++ b/sys/src/9/xen/archxen.c
@@ -83,18 +83,3 @@ void	outl(int, ulong)	{}
 int	mtrrprint(char*, long) { return 0; }
 char*	mtrr(uvlong, uvlong, char *) { return nil; }
 void	mtrrsync(void) {}
-
-/*
- * XXX until fpsave is debugged
- */
-void
-fpssesave(FPsave* f)
-{
-	fpx87save(f);
-}
-
-void
-fpsserestore(FPsave* f)
-{
-	fpx87restore(f);
-}
diff --git a/sys/src/9/xen/fns.h b/sys/src/9/xen/fns.h
index f1e047654..bc87a60ef 100644
--- a/sys/src/9/xen/fns.h
+++ b/sys/src/9/xen/fns.h
@@ -17,18 +17,10 @@ void	(*cycles)(uvlong*);
 void	delay(int);
 #define	evenaddr(x)				/* x86 doesn't care */
 void	fpclear(void);
-void	fpenv(FPsave*);
 void	fpinit(void);
 void	fpoff(void);
 void	(*fprestore)(FPsave*);
 void	(*fpsave)(FPsave*);
-void	fpsserestore(FPsave*);
-void	fpsserestore0(FPsave*);
-void	fpssesave(FPsave*);
-void	fpssesave0(FPsave*);
-ulong	fpstatus(void);
-void	fpx87restore(FPsave*);
-void	fpx87save(FPsave*);
 ulong	getcr4(void);
 char*	getconf(char*);
 void	guesscpuhz(int);
diff --git a/sys/src/9/xen/l.s b/sys/src/9/xen/l.s
index 466b84d8c..af246e70a 100644
--- a/sys/src/9/xen/l.s
+++ b/sys/src/9/xen/l.s
@@ -163,34 +163,42 @@ TEXT fpinit(SB), $0				/* enable and init */
 	WAIT
 	RET
 
-TEXT fpx87save(SB), $0				/* save state and disable */
+TEXT fpx87save0(SB), $0				/* save state and disable */
 	MOVL	p+0(FP), AX
 	FSAVE	0(AX)				/* no WAIT */
 	FPOFF(l2)
 	RET
 
-TEXT fpx87restore(SB), $0				/* enable and restore state */
+TEXT fpx87restore0(SB), $0				/* enable and restore state */
 	FPON
 	MOVL	p+0(FP), AX
 	FRSTOR	0(AX)
 	WAIT
 	RET
 
-TEXT fpstatus(SB), $0				/* get floating point status */
-	FSTSW	AX
-	RET
-
-TEXT fpenv(SB), $0				/* save state without waiting */
-	MOVL	p+0(FP), AX
-	FSTENV	0(AX)
-	RET
-
 TEXT fpclear(SB), $0				/* clear pending exceptions */
 	FPON
 	FCLEX					/* no WAIT */
 	FPOFF(l3)
 	RET
 
+TEXT fpssesave(SB), $0				/* save state and disable */
+	MOVL	p+0(FP), AX
+	FXSAVE	0(AX)				/* no WAIT */
+	FPOFF(l4)
+	RET
+
+TEXT fpsserestore(SB), $0			/* enable and restore state */
+	FPON
+	MOVL	p+0(FP), AX
+	FXRSTOR	0(AX)
+	WAIT
+	RET
+
+TEXT ldmxcsr(SB), $0				/* Load MXCSR */
+	LDMXCSR	mxcsr+0(FP)
+	RET
+
 /*
  * Test-And-Set
  */
diff --git a/sys/src/9/xen/main.c b/sys/src/9/xen/main.c
index 19af3a820..76bdfe2f5 100644
--- a/sys/src/9/xen/main.c
+++ b/sys/src/9/xen/main.c
@@ -322,133 +322,6 @@ confinit(void)
 	}
 }
 
-static char* mathmsg[] =
-{
-	nil,	/* handled below */
-	"denormalized operand",
-	"division by zero",
-	"numeric overflow",
-	"numeric underflow",
-	"precision loss",
-};
-
-static void
-mathnote(void)
-{
-	int i;
-	ulong status;
-	char *msg, note[ERRMAX];
-
-	status = up->fpsave->status;
-
-	/*
-	 * Some attention should probably be paid here to the
-	 * exception masks and error summary.
-	 */
-	msg = "unknown exception";
-	for(i = 1; i <= 5; i++){
-		if(!((1<<i) & status))
-			continue;
-		msg = mathmsg[i];
-		break;
-	}
-	if(status & 0x01){
-		if(status & 0x40){
-			if(status & 0x200)
-				msg = "stack overflow";
-			else
-				msg = "stack underflow";
-		}else
-			msg = "invalid operation";
-	}
- 	snprint(note, sizeof note, "sys: fp: %s fppc=0x%lux status=0x%lux",
- 		msg, up->fpsave->pc, status);
-	postnote(up, 1, note, NDebug);
-}
-
-/*
- *  math coprocessor error
- */
-static void
-matherror(Ureg *ur, void*)
-{
-	/*
-	 *  a write cycle to port 0xF0 clears the interrupt latch attached
-	 *  to the error# line from the 387
-	 */
-	if(!(m->cpuiddx & 0x01))
-		outb(0xF0, 0xFF);
-
-	/*
-	 *  save floating point state to check out error
-	 */
-	fpenv(up->fpsave);
-	mathnote();
-
-	if(ur->pc & KZERO)
-		panic("fp: status %ux fppc=0x%lux pc=0x%lux",
-			up->fpsave->status, up->fpsave->pc, ur->pc);
-}
-
-/*
- *  math coprocessor emulation fault
- */
-static void
-mathemu(Ureg *ureg, void*)
-{
-	if(up->fpstate & FPillegal){
-		/* someone did floating point in a note handler */
-		postnote(up, 1, "sys: floating point in note handler", NDebug);
-		return;
-	}
-	switch(up->fpstate){
-	case FPinit:
-		fpinit();
-		while(up->fpsave == nil)
-			up->fpsave = mallocalign(sizeof(FPsave), FPalign, 0, 0);
-		up->fpstate = FPactive;
-		break;
-	case FPinactive:
-		/*
-		 * Before restoring the state, check for any pending
-		 * exceptions, there's no way to restore the state without
-		 * generating an unmasked exception.
-		 * More attention should probably be paid here to the
-		 * exception masks and error summary.
-		 */
-		if((up->fpsave->status & ~up->fpsave->control) & 0x07F){
-			mathnote();
-			break;
-		}
-		fprestore(up->fpsave);
-		up->fpstate = FPactive;
-		break;
-	case FPactive:
-		panic("math emu pid %ld %s pc 0x%lux", 
-			up->pid, up->text, ureg->pc);
-		break;
-	}
-}
-
-/*
- *  math coprocessor segment overrun
- */
-static void
-mathover(Ureg*, void*)
-{
-	pexit("math overrun", 0);
-}
-
-void
-mathinit(void)
-{
-	trapenable(VectorCERR, matherror, 0, "matherror");
-	//if(X86FAMILY(m->cpuidax) == 3)
-	//	intrenable(IrqIRQ13, matherror, 0, BUSUNKNOWN, "matherror");
-	trapenable(VectorCNA, mathemu, 0, "mathemu");
-	trapenable(VectorCSO, mathover, 0, "mathover");
-}
-
 /*
  *  set up floating point for a new process
  */