[PATCH] i386: PARAVIRT: Use patch site IDs computed from offset in paravirt_ops structure
Use patch type identifiers derived from the offset of the operation in
the paravirt_ops structure. This avoids having to maintain a separate
enum for patch site types.
Also, since the identifier is derived from the offset into
paravirt_ops, the offset can be derived from the identifier. This is
used to remove replicated information in the various callsite macros,
which has been a source of bugs in the past.
This patch also drops the fused save_fl+cli operation, which doesn't
really add much and makes things more complex - specifically because
it breaks the 1:1 relationship between identifiers and offsets. If
this operation turns out to be particularly beneficial, then the right
answer is to define a new entrypoint for it.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Zachary Amsden <zach@vmware.com>
diff --git a/arch/i386/kernel/vmi.c b/arch/i386/kernel/vmi.c
index ea77d93..b8d01c3 100644
--- a/arch/i386/kernel/vmi.c
+++ b/arch/i386/kernel/vmi.c
@@ -83,11 +83,6 @@
#define MNEM_JMP 0xe9
#define MNEM_RET 0xc3
-static char irq_save_disable_callout[] = {
- MNEM_CALL, 0, 0, 0, 0,
- MNEM_CALL, 0, 0, 0, 0,
- MNEM_RET
-};
#define IRQ_PATCH_INT_MASK 0
#define IRQ_PATCH_DISABLE 5
@@ -135,33 +130,17 @@
static unsigned vmi_patch(u8 type, u16 clobbers, void *insns, unsigned len)
{
switch (type) {
- case PARAVIRT_IRQ_DISABLE:
+ case PARAVIRT_PATCH(irq_disable):
return patch_internal(VMI_CALL_DisableInterrupts, len, insns);
- case PARAVIRT_IRQ_ENABLE:
+ case PARAVIRT_PATCH(irq_enable):
return patch_internal(VMI_CALL_EnableInterrupts, len, insns);
- case PARAVIRT_RESTORE_FLAGS:
+ case PARAVIRT_PATCH(restore_fl):
return patch_internal(VMI_CALL_SetInterruptMask, len, insns);
- case PARAVIRT_SAVE_FLAGS:
+ case PARAVIRT_PATCH(save_fl):
return patch_internal(VMI_CALL_GetInterruptMask, len, insns);
- case PARAVIRT_SAVE_FLAGS_IRQ_DISABLE:
- if (len >= 10) {
- patch_internal(VMI_CALL_GetInterruptMask, len, insns);
- patch_internal(VMI_CALL_DisableInterrupts, len-5, insns+5);
- return 10;
- } else {
- /*
- * You bastards didn't leave enough room to
- * patch save_flags_irq_disable inline. Patch
- * to a helper
- */
- BUG_ON(len < 5);
- *(char *)insns = MNEM_CALL;
- patch_offset(insns, irq_save_disable_callout);
- return 5;
- }
- case PARAVIRT_INTERRUPT_RETURN:
+ case PARAVIRT_PATCH(iret):
return patch_internal(VMI_CALL_IRET, len, insns);
- case PARAVIRT_STI_SYSEXIT:
+ case PARAVIRT_PATCH(irq_enable_sysexit):
return patch_internal(VMI_CALL_SYSEXIT, len, insns);
default:
break;
@@ -796,12 +775,6 @@
para_fill(irq_disable, DisableInterrupts);
para_fill(irq_enable, EnableInterrupts);
- /* irq_save_disable !!! sheer pain */
- patch_offset(&irq_save_disable_callout[IRQ_PATCH_INT_MASK],
- (char *)paravirt_ops.save_fl);
- patch_offset(&irq_save_disable_callout[IRQ_PATCH_DISABLE],
- (char *)paravirt_ops.irq_disable);
-
para_fill(wbinvd, WBINVD);
para_fill(read_tsc, RDTSC);