Re: [libvirt] [PATCH] docs: add a mention for start a vm with rawio = 'yes'
On Mon, Mar 02, 2015 at 06:04:44PM +0800, Luyao Huang wrote:
When we start a vm which have rawio = 'yes' settings without
any file caps settings for qemu, qemu process still cannot use
this caps (CAP_SYS_RAWIO) and the /proc/pidofqemu/status like
this:
CapInh: 0000000000020000
CapPrm: 0000000000000000
CapEff: 0000000000000000
CapBnd: 0000001fffffffff
this is because we do not set file caps for qemu (see man 7
capabilities), although laine have mentioned this in commit
e11451, i think it will be good if we add this in docs.
This is only true if you are starting the guest under the
qemu:///session URI. In such a case I think it is expected
that the QEMU lacks rawio capabilities, because the whole
point of qemu:///session is that the VM has no elevated
privileges.
In the case of qemu:///system libvirt should ensure that
it does the right thing with passing on raw io capability
flag. If it does not, then we must fix that in the code,
not the docs.
Regards,
Daniel
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