mirror of
https://github.com/adulau/aha.git
synced 2024-12-28 03:36:19 +00:00
41edafdb78
Impact: Optimization Several paravirt ops implementations simply return their arguments, the most obvious being the make_pte/pte_val class of operations on native. On 32-bit, the identity function is literally a no-op, as the calling convention uses the same registers for the first argument and return. On 64-bit, it can be implemented with a single "mov". This patch adds special identity functions for 32 and 64 bit argument, and machinery to recognize them and replace them with either nops or a mov as appropriate. At the moment, the only users for the identity functions are the pagetable entry conversion functions. The result is a measureable improvement on pagetable-heavy benchmarks (2-3%, reducing the pvops overhead from 5 to 2%). Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
61 lines
1.7 KiB
C
61 lines
1.7 KiB
C
#include <asm/paravirt.h>
|
|
|
|
DEF_NATIVE(pv_irq_ops, irq_disable, "cli");
|
|
DEF_NATIVE(pv_irq_ops, irq_enable, "sti");
|
|
DEF_NATIVE(pv_irq_ops, restore_fl, "push %eax; popf");
|
|
DEF_NATIVE(pv_irq_ops, save_fl, "pushf; pop %eax");
|
|
DEF_NATIVE(pv_cpu_ops, iret, "iret");
|
|
DEF_NATIVE(pv_cpu_ops, irq_enable_sysexit, "sti; sysexit");
|
|
DEF_NATIVE(pv_mmu_ops, read_cr2, "mov %cr2, %eax");
|
|
DEF_NATIVE(pv_mmu_ops, write_cr3, "mov %eax, %cr3");
|
|
DEF_NATIVE(pv_mmu_ops, read_cr3, "mov %cr3, %eax");
|
|
DEF_NATIVE(pv_cpu_ops, clts, "clts");
|
|
DEF_NATIVE(pv_cpu_ops, read_tsc, "rdtsc");
|
|
|
|
unsigned paravirt_patch_ident_32(void *insnbuf, unsigned len)
|
|
{
|
|
/* arg in %eax, return in %eax */
|
|
return 0;
|
|
}
|
|
|
|
unsigned paravirt_patch_ident_64(void *insnbuf, unsigned len)
|
|
{
|
|
/* arg in %edx:%eax, return in %edx:%eax */
|
|
return 0;
|
|
}
|
|
|
|
unsigned native_patch(u8 type, u16 clobbers, void *ibuf,
|
|
unsigned long addr, unsigned len)
|
|
{
|
|
const unsigned char *start, *end;
|
|
unsigned ret;
|
|
|
|
#define PATCH_SITE(ops, x) \
|
|
case PARAVIRT_PATCH(ops.x): \
|
|
start = start_##ops##_##x; \
|
|
end = end_##ops##_##x; \
|
|
goto patch_site
|
|
switch (type) {
|
|
PATCH_SITE(pv_irq_ops, irq_disable);
|
|
PATCH_SITE(pv_irq_ops, irq_enable);
|
|
PATCH_SITE(pv_irq_ops, restore_fl);
|
|
PATCH_SITE(pv_irq_ops, save_fl);
|
|
PATCH_SITE(pv_cpu_ops, iret);
|
|
PATCH_SITE(pv_cpu_ops, irq_enable_sysexit);
|
|
PATCH_SITE(pv_mmu_ops, read_cr2);
|
|
PATCH_SITE(pv_mmu_ops, read_cr3);
|
|
PATCH_SITE(pv_mmu_ops, write_cr3);
|
|
PATCH_SITE(pv_cpu_ops, clts);
|
|
PATCH_SITE(pv_cpu_ops, read_tsc);
|
|
|
|
patch_site:
|
|
ret = paravirt_patch_insns(ibuf, len, start, end);
|
|
break;
|
|
|
|
default:
|
|
ret = paravirt_patch_default(type, clobbers, ibuf, addr, len);
|
|
break;
|
|
}
|
|
#undef PATCH_SITE
|
|
return ret;
|
|
}
|