>
> I see writes to fd 2 and 8:-
>
Oops, I was using the log backend - 2 is stderr of course.
With the ftrace backend build, I see this. It looks like qemu must be
run as root
[pid 15759] open("/sys/kernel/debug/tracing/tracing_on",
O_WRONLY) = -1 EACCES (Permission denied)
[pid 15759] open("/dev/null", O_WRONLY) = 10
[pid 15759] stat("/var/lib/libvirt/images/generic.qcow2",
{st_mode=S_IFREG|0644, st_size=21478375424, ...}) = 0
[pid 15759] write(10, "bdrv_open_common bs 0x7f77a19cfa"..., 116) = 116
[pid 15759] open("/dev/urandom", O_RDONLY) = 15
[pid 15759] read(15, "=S\202\372\17\17
\317\n\201G{\353\300\310\307", 16) = 16
[pid 15759] close(15) = 0
[pid 15759] futex(0x7f779f31d4a8, FUTEX_WAKE, 2147483647) = 0
[pid 15759] open("/var/lib/libvirt/images/generic.qcow2",
O_RDWR|O_CLOEXEC) = 15
[pid 15759] fstat(15, {st_mode=S_IFREG|0644,
st_size=21478375424, ...}) = 0
[pid 15759] lseek(15, 0, SEEK_END) = 21478375424
[pid 15759] fstat(15, {st_mode=S_IFREG|0644,
st_size=21478375424, ...}) = 0
[pid 15759] write(10, "bdrv_open_common bs 0x7f77a19c94"..., 117) = 117
With simple trace backend
[pid 27775] open("trace-27775", O_WRONLY|O_CREAT|O_TRUNC,
0666) = -1 EACCES (Permission denied)
I assume, these methods work best when launching qemu directly, as
compared to using libvirt.
-Prasun
