tst-fs-link.so: Use mktemp() for path names

Using hard-coded path names is problematic because other test cases may
use the same path names and forget to clean up after them.

Make tst-fs-link.so more robust by using mktemp() to generate unique
path names.

Reviewed-by: Tomasz Grabiec <tgrabiec@gmail.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
virtio-blk: Disable interrupts while irq handling is in progress

This reduces unnecessary interrupts that host could send to guest
while guest is in the progress of irq handling.

In virtio_driver::wait_for_queue, we will re-enable interrupts when
there is nothing to process.

Signed-off-by: Asias He <asias@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
Rename blacklisted tests

Rename blacklisted tests, from tst-wake.cc et al. to misc-wake.cc.

The different name will cause these tests not to be automatically run
by "make check" - without needing the separate blacklist in test.py
(which this patch deletes).
After this patch, testrunner.so will also only run tests called tst-*,
so will not run the misc-* tests.

The misc-* tests can still be run manually, e.g.,
  run.py -e tests/misc-mutex.so

In addition to the previously blacklisted tests, this patch "blacklists"
(renames) a few additional tests which fail quickly, but test.py didn't
know because they didn't use the word "fail". An example is tst-schedule.so,
which existed immediately when not run on 1 vcpu. So this patch also
renames it to misc-schedule.so, so "make check" or testrunner.so won't
run this test.

Note that after this patch, testrunner.so is a new way to run all tests,
but it isn't working well yet because it still exposes new bugs that do not
exist in the separate tests (depending on your view point, this might be
considered a feature, not a bug, in testrunner.so...).

Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>