/dev/userfaultfd device is preferred over userfaultfd syscall for
post-copy migrations. Unless qemu driver is configured to disable mount
namespace or to forbid access to /dev/userfaultfd in cgroup_device_acl,
we will copy it to the limited /dev filesystem QEMU will have access to
and label it appropriately. So in the default configuration post-copy
migration will be allowed even without enabling
vm.unprivileged_userfaultfd sysctl.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Currently when we build with nbdkit support, libvirt will always try to
use nbdkit to access remote disk sources when it is available. But
without an up-to-date selinux policy allowing this, it will fail.
because the required selinux policies are not yet widely available, we
have disabled nbdkit support on rpm builds for all distributions before
Fedora 40.
Unfortunately, this makes it more difficult to test nbdkit support.
After someone updates to the necessary selinux policies, they would also
need to rebuild libvirt to enable nbdkit support. By introducing a
configure option (nbdkit_config_default), we can build packages with
nbdkit support but have it disabled by default.
Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
Suggested-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>
Reflect the new default value, and explain that a runtime
lookup will be performed if the value is not an absolute path.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Reflect the new default value, and explain that a runtime
lookup will be performed if the value is not an absolute path.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
Ideally, we would just pick the best default and users wouldn't
have to intervene at all. But in some cases it may be handy to
not bother with SCHED_CORE at all or place helper processes into
the same group as QEMU. Introduce a knob in qemu.conf to allow
users control this behaviour.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
The default values used by the library are determined at configure
time based on a number of factors, and we should reflect them in
the installed configuration file to make the comments it contains
more useful.
Resolves: https://gitlab.com/libvirt/libvirt/-/issues/263
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
