Index: head/lib/libc/sys/ptrace.2
===================================================================
--- head/lib/libc/sys/ptrace.2
+++ head/lib/libc/sys/ptrace.2
@@ -2,7 +2,7 @@
 .\"	$NetBSD: ptrace.2,v 1.2 1995/02/27 12:35:37 cgd Exp $
 .\"
 .\" This file is in the public domain.
-.Dd May 22, 2018
+.Dd June 2, 2018
 .Dt PTRACE 2
 .Os
 .Sh NAME
@@ -934,6 +934,24 @@
 Set the thread's
 .Dv ALTIVEC
 machine state from the buffer pointed to by
+.Fa addr .
+.Pp
+The
+.Fa data
+argument is ignored.
+.It Dv PT_GETVSRREGS
+Return doubleword 1 of the thread's
+.Dv VSX
+registers VSR0-VSR31 in the buffer pointed to by
+.Fa addr .
+.Pp
+The
+.Fa data
+argument is ignored.
+.It Dv PT_SETVSRREGS
+Set doubleword 1 of the thread's
+.Dv VSX
+registers VSR0-VSR31 from the buffer pointed to by
 .Fa addr .
 .Pp
 The
Index: head/sys/powerpc/include/fpu.h
===================================================================
--- head/sys/powerpc/include/fpu.h
+++ head/sys/powerpc/include/fpu.h
@@ -74,6 +74,7 @@
 
 void    enable_fpu(struct thread *);
 void    save_fpu(struct thread *);
+void    save_fpu_nodrop(struct thread *);
 
 #endif /* _KERNEL */
 
Index: head/sys/powerpc/include/ptrace.h
===================================================================
--- head/sys/powerpc/include/ptrace.h
+++ head/sys/powerpc/include/ptrace.h
@@ -39,5 +39,7 @@
 
 #define PT_GETVRREGS	(PT_FIRSTMACH + 0)
 #define PT_SETVRREGS	(PT_FIRSTMACH + 1)
+#define PT_GETVSRREGS	(PT_FIRSTMACH + 2)
+#define PT_SETVSRREGS	(PT_FIRSTMACH + 3)
 
 #endif
Index: head/sys/powerpc/powerpc/fpu.c
===================================================================
--- head/sys/powerpc/powerpc/fpu.c
+++ head/sys/powerpc/powerpc/fpu.c
@@ -45,6 +45,60 @@
 #include <machine/pcb.h>
 #include <machine/psl.h>
 
+static void
+save_fpu_int(struct thread *td)
+{
+	int	msr;
+	struct	pcb *pcb;
+
+	pcb = td->td_pcb;
+
+	/*
+	 * Temporarily re-enable floating-point during the save
+	 */
+	msr = mfmsr();
+	if (pcb->pcb_flags & PCB_VSX)
+		mtmsr(msr | PSL_FP | PSL_VSX);
+	else
+		mtmsr(msr | PSL_FP);
+
+	/*
+	 * Save the floating-point registers and FPSCR to the PCB
+	 */
+	if (pcb->pcb_flags & PCB_VSX) {
+	#define SFP(n)   __asm ("stxvw4x " #n ", 0,%0" \
+			:: "b"(&pcb->pcb_fpu.fpr[n]));
+		SFP(0);		SFP(1);		SFP(2);		SFP(3);
+		SFP(4);		SFP(5);		SFP(6);		SFP(7);
+		SFP(8);		SFP(9);		SFP(10);	SFP(11);
+		SFP(12);	SFP(13);	SFP(14);	SFP(15);
+		SFP(16);	SFP(17);	SFP(18);	SFP(19);
+		SFP(20);	SFP(21);	SFP(22);	SFP(23);
+		SFP(24);	SFP(25);	SFP(26);	SFP(27);
+		SFP(28);	SFP(29);	SFP(30);	SFP(31);
+	#undef SFP
+	} else {
+	#define SFP(n)   __asm ("stfd " #n ", 0(%0)" \
+			:: "b"(&pcb->pcb_fpu.fpr[n]));
+		SFP(0);		SFP(1);		SFP(2);		SFP(3);
+		SFP(4);		SFP(5);		SFP(6);		SFP(7);
+		SFP(8);		SFP(9);		SFP(10);	SFP(11);
+		SFP(12);	SFP(13);	SFP(14);	SFP(15);
+		SFP(16);	SFP(17);	SFP(18);	SFP(19);
+		SFP(20);	SFP(21);	SFP(22);	SFP(23);
+		SFP(24);	SFP(25);	SFP(26);	SFP(27);
+		SFP(28);	SFP(29);	SFP(30);	SFP(31);
+	#undef SFP
+	}
+	__asm __volatile ("mffs 0; stfd 0,0(%0)" :: "b"(&pcb->pcb_fpu.fpscr));
+
+	/*
+	 * Disable floating-point again
+	 */
+	isync();
+	mtmsr(msr);
+}
+
 void
 enable_fpu(struct thread *td)
 {
@@ -129,57 +183,13 @@
 void
 save_fpu(struct thread *td)
 {
-	int	msr;
 	struct	pcb *pcb;
 
 	pcb = td->td_pcb;
 
-	/*
-	 * Temporarily re-enable floating-point during the save
-	 */
-	msr = mfmsr();
-	if (pcb->pcb_flags & PCB_VSX)
-		mtmsr(msr | PSL_FP | PSL_VSX);
-	else
-		mtmsr(msr | PSL_FP);
+	save_fpu_int(td);
 
 	/*
-	 * Save the floating-point registers and FPSCR to the PCB
-	 */
-	if (pcb->pcb_flags & PCB_VSX) {
-	#define SFP(n)   __asm ("stxvw4x " #n ", 0,%0" \
-			:: "b"(&pcb->pcb_fpu.fpr[n]));
-		SFP(0);		SFP(1);		SFP(2);		SFP(3);
-		SFP(4);		SFP(5);		SFP(6);		SFP(7);
-		SFP(8);		SFP(9);		SFP(10);	SFP(11);
-		SFP(12);	SFP(13);	SFP(14);	SFP(15);
-		SFP(16);	SFP(17);	SFP(18);	SFP(19);
-		SFP(20);	SFP(21);	SFP(22);	SFP(23);
-		SFP(24);	SFP(25);	SFP(26);	SFP(27);
-		SFP(28);	SFP(29);	SFP(30);	SFP(31);
-	#undef SFP
-	} else {
-	#define SFP(n)   __asm ("stfd " #n ", 0(%0)" \
-			:: "b"(&pcb->pcb_fpu.fpr[n]));
-		SFP(0);		SFP(1);		SFP(2);		SFP(3);
-		SFP(4);		SFP(5);		SFP(6);		SFP(7);
-		SFP(8);		SFP(9);		SFP(10);	SFP(11);
-		SFP(12);	SFP(13);	SFP(14);	SFP(15);
-		SFP(16);	SFP(17);	SFP(18);	SFP(19);
-		SFP(20);	SFP(21);	SFP(22);	SFP(23);
-		SFP(24);	SFP(25);	SFP(26);	SFP(27);
-		SFP(28);	SFP(29);	SFP(30);	SFP(31);
-	#undef SFP
-	}
-	__asm __volatile ("mffs 0; stfd 0,0(%0)" :: "b"(&pcb->pcb_fpu.fpscr));
-
-	/*
-	 * Disable floating-point again
-	 */
-	isync();
-	mtmsr(msr);
-
-	/*
 	 * Clear the current fp thread and pcb's CPU id
 	 * XXX should this be left clear to allow lazy save/restore ?
 	 */
@@ -187,3 +197,19 @@
 	PCPU_SET(fputhread, NULL);
 }
 
+/*
+ * Save fpu state without dropping ownership.  This will only save state if
+ * the current fpu thread is `td'.
+ */
+void
+save_fpu_nodrop(struct thread *td)
+{
+	struct thread *ftd;
+
+	ftd = PCPU_GET(fputhread);
+	if (td != ftd) {
+		return;
+	}
+
+	save_fpu_int(td);
+}
Index: head/sys/powerpc/powerpc/ptrace_machdep.c
===================================================================
--- head/sys/powerpc/powerpc/ptrace_machdep.c
+++ head/sys/powerpc/powerpc/ptrace_machdep.c
@@ -35,6 +35,7 @@
 #include <sys/ptrace.h>
 #include <sys/sysent.h>
 #include <machine/altivec.h>
+#include <machine/fpu.h>
 #include <machine/cpu.h>
 #include <machine/md_var.h>
 #include <machine/pcb.h>
@@ -45,10 +46,14 @@
 	int error;
 	struct pcb *pcb;
 	struct vec vec;
+	uint64_t vsr[32];
+	uint64_t *vsr_dw1;
+	int vsr_idx;
 
 	pcb = td->td_pcb;
 
 	bzero(&vec, sizeof(vec));
+	bzero(vsr, sizeof(vsr));
 
 	error = EINVAL;
 	switch (req) {
@@ -69,6 +74,43 @@
 		if (error == 0) {
 			pcb->pcb_flags |= PCB_VEC;
 			memcpy(&pcb->pcb_vec, &vec, sizeof(vec));
+		}
+		break;
+	case PT_GETVSRREGS:
+		if (!(cpu_features & PPC_FEATURE_HAS_VSX))
+			break;
+
+		if (pcb->pcb_flags & PCB_VSX) {
+			save_fpu_nodrop(td);
+
+			/*
+			 * Doubleword 0 of VSR0-VSR31 overlap with FPR0-FPR31 and
+			 * VSR32-VSR63 overlap with VR0-VR31, so we only copy
+			 * the non-overlapping data, which is doubleword 1 of VSR0-VSR31.
+			 */
+			for (vsr_idx = 0; vsr_idx < nitems(vsr); vsr_idx++) {
+				vsr_dw1 = (uint64_t *)&pcb->pcb_fpu.fpr[vsr_idx].vsr[2];
+				vsr[vsr_idx] = *vsr_dw1;
+			}
+		}
+		error = copyout(&vsr, addr, sizeof(vsr));
+		break;
+	case PT_SETVSRREGS:
+		if (!(cpu_features & PPC_FEATURE_HAS_VSX))
+			break;
+		error = copyin(addr, &vsr, sizeof(vsr));
+		if (error == 0) {
+			pcb->pcb_flags |= PCB_VSX;
+
+			/*
+			 * Doubleword 0 of VSR0-VSR31 overlap with FPR0-FPR31 and
+			 * VSR32-VSR63 overlap with VR0-VR31, so we only copy
+			 * the non-overlapping data, which is doubleword 1 of VSR0-VSR31.
+			 */
+			for (vsr_idx = 0; vsr_idx < nitems(vsr); vsr_idx++) {
+				vsr_dw1 = (uint64_t *)&pcb->pcb_fpu.fpr[vsr_idx].vsr[2];
+				*vsr_dw1 = vsr[vsr_idx];
+			}
 		}
 		break;