[libvirt] [PATCH v2] libxl: load on FreeBSD

[Roman Bogorodskiy]

  Martin Kletzander wrote:

> On Thu, May 28, 2015 at 11:11:06AM +0400, Roman Bogorodskiy wrote:
> >  Jim Fehlig wrote:
> >
> >> On 05/27/2015 09:06 AM, Martin Kletzander wrote:
> >> > On Sun, May 24, 2015 at 06:45:02PM +0300, Roman Bogorodskiy wrote:
> >> >> The libxl tries to check if it's running in dom0 by parsing
> >> >> /proc/xen/capabilities and if that fails it doesn't load.
> >> >>
> >> >> There's no procfs interface in Xen on FreeBSD, so this check always
> >> >> fails.
> >> >>
> >> >> In addition to checking procfs, check if /dev/xen/xenstored, that's enough to
> >> >> check if we're running in dom0 in FreeBSD case.
> >> >> ---
> >> >> src/libxl/libxl_driver.c | 42 ++++++++++++++++++++++--------------------
> >> >> 1 file changed, 22 insertions(+), 20 deletions(-)
> >> >>
> >> >> diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c
> >> >> index 12be816..fddafa1 100644
> >> >> --- a/src/libxl/libxl_driver.c
> >> >> +++ b/src/libxl/libxl_driver.c
> >> >> @@ -74,6 +74,7 @@ VIR_LOG_INIT("libxl.libxl_driver");
> >> >> #define LIBXL_CONFIG_FORMAT_SEXPR "xen-sxpr"
> >> >>
> >> >> #define HYPERVISOR_CAPABILITIES "/proc/xen/capabilities"
> >> >> +#define HYPERVISOR_XENSTORED "/dev/xen/xenstored"
> >> >>
> >> >> /* Number of Xen scheduler parameters */
> >> >> #define XEN_SCHED_CREDIT_NPARAM   2
> >> >> @@ -427,8 +428,6 @@ static bool
> >> >> libxlDriverShouldLoad(bool privileged)
> >> >> {
> >> >>     bool ret = false;
> >> >> -    int status;
> >> >> -    char *output = NULL;
> >> >>
> >> >>     /* Don't load if non-root */
> >> >>     if (!privileged) {
> >> >> @@ -436,24 +435,27 @@ libxlDriverShouldLoad(bool privileged)
> >> >>         return ret;
> >> >>     }
> >> >>
> >> >> -    if (!virFileExists(HYPERVISOR_CAPABILITIES)) {
> >> >> -        VIR_INFO("Disabling driver as " HYPERVISOR_CAPABILITIES
> >> >> -                 " does not exist");
> >> >> -        return ret;
> >> >> -    }
> >> >> -    /*
> >> >> -     * Don't load if not running on a Xen control domain (dom0). It is not
> >> >> -     * sufficient to check for the file to exist as any guest can mount
> >> >> -     * xenfs to /proc/xen.
> >> >> -     */
> >> >> -    status = virFileReadAll(HYPERVISOR_CAPABILITIES, 10, &output);
> >> >> -    if (status >= 0)
> >> >> -        status = strncmp(output, "control_d", 9);
> >> >> -    VIR_FREE(output);
> >> >> -    if (status) {
> >> >> -        VIR_INFO("No Xen capabilities detected, probably not running "
> >> >> -                 "in a Xen Dom0.  Disabling libxenlight driver");
> >> >> -
> >> >> +    if (virFileExists(HYPERVISOR_CAPABILITIES)) {
> >> >> +        int status;
> >> >> +        char *output = NULL;
> >> >> +        /*
> >> >> +         * Don't load if not running on a Xen control domain (dom0). It is not
> >> >> +         * sufficient to check for the file to exist as any guest can mount
> >> >> +         * xenfs to /proc/xen.
> >> >> +         */
> >> >> +        status = virFileReadAll(HYPERVISOR_CAPABILITIES, 10, &output);
> >> >> +        if (status >= 0)
> >> >> +            status = strncmp(output, "control_d", 9);
> >> >> +        VIR_FREE(output);
> >> >> +        if (status) {
> >> >> +            VIR_INFO("No Xen capabilities detected, probably not running "
> >> >> +                     "in a Xen Dom0.  Disabling libxenlight driver");
> >> >> +
> >> >> +            return ret;
> >> >> +        }
> >> >> +    } else if (!virFileExists(HYPERVISOR_XENSTORED)) {
> >> >> +        VIR_INFO("Disabling driver as neither " HYPERVISOR_CAPABILITIES
> >> >> +                 " nor " HYPERVISOR_CAPABILITIES " exist");
> >> >
> >> > s/HYPERVISOR_CAPABILITIES/HYPERVISOR_XENSTORED/
> >> >
> >> > ACK with that changed.
> >>
> >> For the record, I tested this on Linux.  Looks good with Martin's comment addressed.
> >>
> >> Regards,
> >> Jim
> >
> >Thanks for giving it a test!
> >
> >Is this safe to push during the freeze?
> >
> 
> I also tried it before ACKing on XEN-enabled linux (made sure there is
> no /dev/xen/xenstored so it doesn't collide), so I'd say it's fine
> with me.

Last few days were quite busy for me, so I didn't push this and
decided that it's too late now. I'll wait for the freeze to finish and
push that, there's no rush. Meanwhile, probably I'll be able to find
FreeBSD testers for libvirt/libxl to get it more tested for the next
release.

Thanks,

Roman Bogorodskiy
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 473 bytes
Desc: not available
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20150529/e22aab9d/attachment-0001.sig>