xen: Add 64bit variant

* x86_64/xen_boothdr.S, x86_64/xen_locore.S: New files.

1 files changed, 146 insertions, 0 deletions

diff --git a/x86_64/xen_locore.S b/x86_64/xen_locore.S
new file mode 100644
index 00000000..967c8904
--- /dev/null
+++ b/x86_64/xen_locore.S
@@ -0,0 +1,146 @@
+/*
+ *  Copyright (C) 2006-2009 Free Software Foundation
+ *
+ * This program is free software ; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation ; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY ; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with the program ; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <mach/machine/asm.h>
+
+#include <i386/i386/i386asm.h>
+#include <i386/i386/cpu_number.h>
+#include <i386/i386/xen.h>
+
+	.data	2
+int_active:
+	.long	0
+	
+
+	.text
+	.globl	hyp_callback, hyp_failsafe_callback
+	P2ALIGN(TEXT_ALIGN)
+hyp_callback:
+	popq	%rcx
+	popq	%r11
+	pushq	%rax
+	jmp	EXT(all_intrs)
+
+ENTRY(interrupt)
+	incl	int_active		/* currently handling interrupts */
+	call	EXT(hyp_c_callback)	/* call generic interrupt routine */
+	decl	int_active		/* stopped handling interrupts */
+	sti
+	ret
+
+/* FIXME: if we're _very_ unlucky, we may be re-interrupted, filling stack
+ *
+ * Far from trivial, see mini-os. That said, maybe we could just, before poping
+ * everything (which is _not_ destructive), save sp into a known place and use
+ * it+jmp back?
+ *
+ * Mmm, there seems to be an iret hypcall that does exactly what we want:
+ * perform iret, and if IF is set, clear the interrupt mask.
+ */
+
+/* Pfff, we have to check pending interrupts ourselves. Some other DomUs just make an hypercall for retriggering the irq. Not sure it's really easier/faster */
+ENTRY(hyp_sti)
+	pushq	%rbp
+	movq	%rsp, %rbp
+_hyp_sti:
+	movb	$0,hyp_shared_info+CPU_CLI /* Enable interrupts */
+	cmpl	$0,int_active		/* Check whether we were already checking pending interrupts */
+	jz	0f
+	popq	%rbp
+	ret				/* Already active, just return */
+0:
+	/* Not active, check pending interrupts by hand */
+	/* no memory barrier needed on x86 */
+	cmpb	$0,hyp_shared_info+CPU_PENDING
+	jne	0f
+	popq	%rbp
+	ret
+0:
+	movb	$0xff,hyp_shared_info+CPU_CLI
+1:
+	pushq	%rax
+	pushq	%rcx
+	pushq	%rdx
+	pushq	%rdi
+	pushq	%rsi
+	pushq	%r8
+	pushq	%r9
+	pushq	%r10
+	pushq	%r11
+	incl	int_active		/* currently handling interrupts */
+
+	xorq	%rdi,%rdi
+	xorq	%rsi,%rsi
+	call	EXT(hyp_c_callback)
+
+	popq	%r11
+	popq	%r10
+	popq	%r9
+	popq	%r8
+	popq	%rsi
+	popq	%rdi
+	popq	%rdx
+	popq	%rcx
+	popq	%rax
+	decl	int_active		/* stopped handling interrupts */
+	cmpb	$0,hyp_shared_info+CPU_PENDING
+	jne	1b
+	jmp	_hyp_sti
+
+/* Hypervisor failed to reload segments. Dump them.  */
+hyp_failsafe_callback:
+ud2
+#if 1
+/* TODO: FIXME */
+	/* load sane segments */
+	mov	%ss, %ax
+#if 0
+	mov	%ax, %ds
+	mov	%ax, %es
+#endif
+	mov	%ax, %fs
+	mov	%ax, %gs
+	movq	%rsp, %rdi
+	call	EXT(hyp_failsafe_c_callback)
+#else
+	popq	%rdx
+	movq	%rdx,%ds
+	popq	%rdx
+	movq	%rdx,%es
+	popq	%fs
+	popq	%gs
+
+movq (%rsp),%rax
+ud2
+	iretq
+#endif
+
+#undef iretq
+ENTRY(hyp_iretq)
+	testb	$2,1*8(%rsp)
+	jnz	slow
+	/* There is no ring1 on x86_64, we have to force ring 3 */
+	orb	$3,1*8(%rsp)
+	orb	$3,4*8(%rsp)
+	iretq
+
+slow:
+/* There is no ring 1/2 on x86_64, so going back to user needs to go through
+ * hypervisor */
+	pushq	$0
+	jmp	__hyp_iret