Re: [Qemu-devel] [PATCH 2/2] virtio-blk-test.c: add hotplug subtest

[Michael S. Tsirkin]

On Thu, Jun 05, 2014 at 01:12:46PM +0800, Amos Kong wrote:
> On Wed, Jun 04, 2014 at 05:35:06PM +0200, Stefan Hajnoczi wrote:
> > On Tue, May 27, 2014 at 03:14:41PM +0800, Amos Kong wrote:
> > > This patch adds a new subtest, it hotplugs 29 * 8 = 232 virtio-blk
> > > devices to guest, and try to hot-unplug them.
> > > 
> > > Note: the hot-unplug can't work without cooperation of guest OS.
> > > 
> > > Signed-off-by: Amos Kong <address@hidden>
> > > ---
> > >  tests/virtio-blk-test.c | 55 
> > > +++++++++++++++++++++++++++++++++++++++++++++++++
> > >  1 file changed, 55 insertions(+)
> > > 
> > > diff --git a/tests/virtio-blk-test.c b/tests/virtio-blk-test.c
> > > index 0fdec01..54d1272 100644
> > > --- a/tests/virtio-blk-test.c
> > > +++ b/tests/virtio-blk-test.c
> > > @@ -7,11 +7,65 @@
> > >   * See the COPYING file in the top-level directory.
> > >   */
> > >  
> > > +#include <stdio.h>
> > >  #include <glib.h>
> > >  #include <string.h>
> > >  #include "libqtest.h"
> > >  #include "qemu/osdep.h"
> > >  
> > > +static void exec_hmp_cmd(const char *cmd, const char *expected_ret)
> > 
> > This is a generic function, should it be moved to libqtest.c?
> 
> OK
> 
> > 
> > > +{
> > > +    QDict *response;
> > > +    const char *response_return;
> > > +
> > > +    response = qmp("{\"execute\": \"human-monitor-command\","
> > > +                   " \"arguments\": {"
> > > +                   "   \"command-line\": \"%s\""
> > > +                   "}}", cmd);
>  
> > My only worry if we make this function generic is that cmd isn't escaped
> > so callers need to be careful.
> > Maybe something like g_strescape() should be used:
> > 
> > https://developer.gnome.org/glib/2.37/glib-String-Utility-Functions.html#g-strescape
> 
>  
> > > +    g_assert(response);
> > > +    response_return = qdict_get_try_str(response, "return");
> > > +    g_assert(response_return);
> > > +    g_assert(strcmp(response_return, expected_ret) == 0);
> > 
> > Please use g_assert_cmpstr() so the error message will be pretty-printed
> > with the values of response_return and expected_ret:
> > https://developer.gnome.org/glib/stable/glib-Testing.html#g-assert-cmpstr
>  
> OK
> 
> > > +    QDECREF(response);
> > > +}
> > 
> > > +static void test_blk_hotplug(void)
> > > +{
> > > +    char addr[6];
> > > +    char cmd[100];
> > > +    int i, j;
> > > +
> > > +    /* Start with no network/block device, slots 3~0x1f are free */
> > > +    qtest_start("-net none");
> > > +
> > > +    for (i = 3; i <= 0x1f; i++) {
> > > +        for (j = 7; j >= 0; j--) {
> > > +            sprintf(addr, "%x.%x", i, j);
> > > +            sprintf(cmd, "drive_add 0x%s 
> > > if=none,file=/dev/null,id=drv-%s",
> > > +                    addr, addr);
> > 
> > Does the address matter with if=none?  I think you can just do
> > "drive_add 0 if=none,...".
> 
> drive_add [[<domain>:]<bus>:]<slot>
> 
> multiple function is enabled, slot parameter is needed.
>  
> > > +            exec_hmp_cmd(cmd, "OK\r\n");
> > > +
> > > +            sprintf(cmd, "device_add 
> > > virtio-blk-pci,id=dev-%s,drive=drv-%s,"
> > > +                         "addr=0x%s,multifunction=on", addr, addr, addr);
> > > +            exec_hmp_cmd(cmd, "");
> > > +        }
> > > +    }
> > > +
> > > +    /* hot-unplug doesn't work without cooperation of guest OS */
> > 
> > We could implement hotplug/hotunplug in libqos, PCI support already
> > exists: tests/libqos/pci.h.
> > 
> > But I guess this test is useful too, it checks the case where the guest
> > is not cooperating?
> 
> OK, we can update and merge this test first, I will investigate and
> write a new subtest with PCI support.
> 
> -- 
>                       Amos.


Which tree should this go in through?