Jan Beulich
2007-Mar-26 14:40 UTC
[Xen-devel] [PATCH] linx/x86-64: cleanup the Xen-specific macros in entry-xen.S
- SWITCH_TO_KERNEL is dead (and was broken)
- comments to HYPERVISOR_IRET were somewhat outdated
- updates of selecor RPLs shouldn''t be done with byte size to avoid
store-to-load forwarding issues
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Index: head-2007-03-19/arch/x86_64/kernel/entry-xen.S
==================================================================---
head-2007-03-19.orig/arch/x86_64/kernel/entry-xen.S 2007-03-21
12:29:15.000000000 +0100
+++ head-2007-03-19/arch/x86_64/kernel/entry-xen.S 2007-03-23 10:08:26.000000000
+0100
@@ -148,11 +148,11 @@ NMI_MASK = 0x80000000
.endm
/*
- * Must be consistent with the definition in arch-x86_64.h:
+ * Must be consistent with the definition in arch-x86/xen-x86_64.h:
* struct iret_context {
* u64 rax, r11, rcx, flags, rip, cs, rflags, rsp, ss;
* };
- * #define VGCF_IN_SYSCALL (1<<8)
+ * with rax, r11, and rcx being taken care of in the hypercall stub.
*/
.macro HYPERVISOR_IRET flag
testb $3,1*8(%rsp)
@@ -164,22 +164,16 @@ NMI_MASK = 0x80000000
jnz 1f
/* Direct iret to kernel space. Correct CS and SS. */
- orb $3,1*8(%rsp)
- orb $3,4*8(%rsp)
+ orl $3,1*8(%rsp)
+ orl $3,4*8(%rsp)
1: iretq
2: /* Slow iret via hypervisor. */
- andl $~NMI_MASK, 16(%rsp)
+ andl $~NMI_MASK, 2*8(%rsp)
pushq $\flag
jmp hypercall_page + (__HYPERVISOR_iret * 32)
.endm
- .macro SWITCH_TO_KERNEL ssoff,adjust=0
- jc 1f
- orb $1,\ssoff-\adjust+4(%rsp)
-1:
- .endm
-
/*
* A newly forked process directly context switches into this.
*/
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