jcs.org
qemu with hax to log dma reads & writes
jcs.org/2018/11/12/vfio
1#
2# Copyright (c) 2018 Red Hat, Inc. and/or its affiliates
3#
4# Author:
5# Wei Huang <wei@redhat.com>
6#
7# This work is licensed under the terms of the GNU GPL, version 2 or later.
8# See the COPYING file in the top-level directory.
9#
10# Note: Please make sure the compiler compiles the assembly code below with
11# pc-relative address. Also the branch instructions should use relative
12# addresses only.
13
14#include "../migration-test.h"
15
16.section .text
17
18 .globl _start
19
20_start:
21 /* disable MMU to use phys mem address */
22 mrs x0, sctlr_el1
23 bic x0, x0, #(1<<0)
24 msr sctlr_el1, x0
25 isb
26
27 /* traverse test memory region */
28 mov x0, #ARM_TEST_MEM_START
29 mov x1, #ARM_TEST_MEM_END
30
31 /* output char 'A' to PL011 */
32 mov w3, 'A'
33 mov x2, #ARM_MACH_VIRT_UART
34 strb w3, [x2]
35
36 /* clean up memory */
37 mov w3, #0
38 mov x4, x0
39clean:
40 strb w3, [x4]
41 add x4, x4, #TEST_MEM_PAGE_SIZE
42 cmp x4, x1
43 ble clean
44
45 /* w5 keeps a counter so we can limit the output speed */
46 mov w5, #0
47
48 /* main body */
49mainloop:
50 mov x4, x0
51
52innerloop:
53 /* increment the first byte of each page by 1 */
54 ldrb w3, [x4]
55 add w3, w3, #1
56 and w3, w3, #0xff
57 strb w3, [x4]
58
59 /* make sure QEMU user space can see consistent data as MMU is off */
60 dc civac, x4
61
62 add x4, x4, #TEST_MEM_PAGE_SIZE
63 cmp x4, x1
64 blt innerloop
65
66 add w5, w5, #1
67 and w5, w5, #0xff
68 cmp w5, #0
69 bne mainloop
70
71 /* output char 'B' to PL011 */
72 mov w3, 'B'
73 strb w3, [x2]
74
75 b mainloop