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Re: [Qemu-devel] qemu softmmu inlined lookup sequence
From: |
陳韋任 |
Subject: |
Re: [Qemu-devel] qemu softmmu inlined lookup sequence |
Date: |
Tue, 17 Apr 2012 10:51:40 +0800 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
> what does the inline sequence look like ? what kind of things (other
> than refill tlb) performed in callout but not the inlined sequence ?
What do you mean by the inline sequence, the host binary? If so,
---
---- 0xe86c8
mov_i32 tmp2,edi
qemu_ld8u tmp0,tmp2,$0x0
ext8u_i32 tmp12,tmp0
movi_i32 tmp13,$0xffffff00
and_i32 edx,edx,tmp13
or_i32 edx,edx,tmp12
OUT: [size=172]
0x40000ce0: mov 0x1c(%r14),%ebp
0x40000ce4: mov %ebp,%esi <--- (a)
0x40000ce6: mov %ebp,%edi
0x40000ce8: shr $0x7,%esi
0x40000ceb: and $0xfffff000,%edi
0x40000cf1: and $0x1fe0,%esi
0x40000cf7: lea 0x348(%r14,%rsi,1),%rsi
0x40000cff: cmp (%rsi),%edi
0x40000d01: mov %ebp,%edi
0x40000d03: jne 0x40000d0e
0x40000d05: add 0x10(%rsi),%rdi
0x40000d09: movzbl (%rdi),%ebp
0x40000d0c: jmp 0x40000d18
0x40000d0e: xor %esi,%esi
0x40000d10: callq 0x54cf8e <--- (b)
0x40000d15: movzbl %al,%ebp
0x40000d18: movzbl %bpl,%ebp
0x40000d1c: mov 0x8(%r14),%ebx
---
The code between (a) and (b) is (almost) what TLB lookup hit/miss looks like.
If TLB miss, it will call something like __ldb_mmu (b). __ldb_mmu will try to
walk guest page table, then fill TLB entry if page table hit, or raise a guest
page fault exception if page table miss.
HTH,
chenwj
--
Wei-Ren Chen (陳韋任)
Computer Systems Lab, Institute of Information Science,
Academia Sinica, Taiwan (R.O.C.)
Tel:886-2-2788-3799 #1667
Homepage: http://people.cs.nctu.edu.tw/~chenwj
- [Qemu-devel] qemu softmmu inlined lookup sequence, Xin Tong, 2012/04/16
- Re: [Qemu-devel] qemu softmmu inlined lookup sequence,
陳韋任 <=
- Re: [Qemu-devel] qemu softmmu inlined lookup sequence, Xin Tong, 2012/04/16
- Re: [Qemu-devel] qemu softmmu inlined lookup sequence, 陳韋任, 2012/04/17
- Re: [Qemu-devel] qemu softmmu inlined lookup sequence, Xin Tong, 2012/04/17
- Re: [Qemu-devel] qemu softmmu inlined lookup sequence, Blue Swirl, 2012/04/17
- Re: [Qemu-devel] qemu softmmu inlined lookup sequence, 陳韋任, 2012/04/18
- Re: [Qemu-devel] qemu softmmu inlined lookup sequence, Blue Swirl, 2012/04/18
Re: [Qemu-devel] qemu softmmu inlined lookup sequence, Xin Tong, 2012/04/21