Re: [Xen-devel] [PATCH v3 COLOPre 12/26] tools/libxl: Update libxl_domain_unpause() to support qemu-xen

[Yang Hongyang <yanghy@xxxxxxxxxxxxxx>]

On 07/01/2015 06:38 PM, Ian Campbell wrote:
> On Wed, 2015-07-01 at 10:10 +0800, Yang Hongyang wrote:
> > On 06/30/2015 06:00 PM, Ian Campbell wrote:
> > > On Thu, 2015-06-25 at 14:25 +0800, Yang Hongyang wrote:
> > > > Currently, libxl__domain_unpause() only supports
> > > > qemu-xen-traditional. Update it to support qemu-xen.
> > > > We use libxl__domain_resume_device_model to unpause guest dm.
> > > There appears to be at least two significant semantic changes to the
> > > libxl__domain_resume_device_model function (namely it now deals
> > > internally with stubdom and checks the current status before doing
> > > anything). What is the impact on the existing callers of those changes?
> > This change was suggested by Wei on last round(v2), he thought it is an
> > enhancement to the existing callers.
> I don't think that contradicts what I've said. If multiple improvements
> are needed to make libxl__domain_resume_device_model suitable for your
> uses then there should be several patches. This will also give you an
> opportunity to explain in each commit message why there is no impact (or
> a positive impact) on the existing callers.
Yes, for this part, I agree with you, will separate it in the next version!
thank you!

> > > I think those changes should be two separate preparatory patches.
> > >
> > >
> > > > Signed-off-by: Yang Hongyang <yanghy@xxxxxxxxxxxxxx>
> > > > ---
> > > >    tools/libxl/libxl.c             | 15 +++++----------
> > > >    tools/libxl/libxl_dom_suspend.c | 15 ++++++++++++---
> > > >    tools/libxl/libxl_internal.h    |  1 +
> > > >    3 files changed, 18 insertions(+), 13 deletions(-)
> > > >
> > > > diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
> > > > index 2ca59ea..59e2dfe 100644
> > > > --- a/tools/libxl/libxl.c
> > > > +++ b/tools/libxl/libxl.c
> > > > @@ -938,8 +938,6 @@ out:
> > > >    int libxl_domain_unpause(libxl_ctx *ctx, uint32_t domid)
> > > >    {
> > > >        GC_INIT(ctx);
> > > > -    char *path;
> > > > -    char *state;
> > > >        int ret, rc = 0;
> > > >
> > > >        libxl_domain_type type = libxl__domain_type(gc, domid);
> > > > @@ -949,14 +947,11 @@ int libxl_domain_unpause(libxl_ctx *ctx, uint32_t domid)
> > > >        }
> > > >
> > > >        if (type == LIBXL_DOMAIN_TYPE_HVM) {
> > > > -        uint32_t dm_domid = libxl_get_stubdom_id(ctx, domid);
> > > > -
> > > > -        path = libxl__device_model_xs_path(gc, dm_domid, domid, "/state");
> > > > -        state = libxl__xs_read(gc, XBT_NULL, path);
> > > > -        if (state != NULL && !strcmp(state, "paused")) {
> > > > -            libxl__qemu_traditional_cmd(gc, domid, "continue");
> > > > -            libxl__wait_for_device_model_deprecated(gc, domid, "running",
> > > > -                                         NULL, NULL, NULL);
> > > > +        rc = libxl__domain_resume_device_model(gc, domid);
> > > > +        if (rc < 0) {
> > > > +            LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "failed to unpause device model "
> > > > +                       "for domain %u:%d", domid, rc);
> > > > +            goto out;
> > > >            }
> > > >        }
> > > >        ret = xc_domain_unpause(ctx->xch, domid);
> > > > diff --git a/tools/libxl/libxl_dom_suspend.c b/tools/libxl/libxl_dom_suspend.c
> > > > index 1c486c4..3edbd2e 100644
> > > > --- a/tools/libxl/libxl_dom_suspend.c
> > > > +++ b/tools/libxl/libxl_dom_suspend.c
> > > > @@ -376,13 +376,22 @@ static void 
> > > > domain_suspend_callback_common_done(libxl__egc *egc,
> > > >
> > > >    /*======================= Domain resume ========================*/
> > > >
> > > > -static int libxl__domain_resume_device_model(libxl__gc *gc, uint32_t domid)
> > > > +int libxl__domain_resume_device_model(libxl__gc *gc, uint32_t domid)
> > > >    {
> > > > +    char *path;
> > > > +    char *state;
> > > >
> > > >        switch (libxl__device_model_version_running(gc, domid)) {
> > > >        case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL: {
> > > > -        libxl__qemu_traditional_cmd(gc, domid, "continue");
> > > > -        libxl__wait_for_device_model_deprecated(gc, domid, "running", NULL, 
> > > > NULL, NULL);
> > > > +        uint32_t dm_domid = libxl_get_stubdom_id(CTX, domid);
> > > > +
> > > > +        path = libxl__device_model_xs_path(gc, dm_domid, domid, "/state");
> > > > +        state = libxl__xs_read(gc, XBT_NULL, path);
> > > > +        if (state != NULL && !strcmp(state, "paused")) {
> > > > +            libxl__qemu_traditional_cmd(gc, domid, "continue");
> > > > +            libxl__wait_for_device_model_deprecated(gc, domid, "running",
> > > > +                                                    NULL, NULL, NULL);
> > > > +        }
> > > >            break;
> > > >        }
> > > >        case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN:
> > > > diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
> > > > index 0adc9b4..6960280 100644
> > > > --- a/tools/libxl/libxl_internal.h
> > > > +++ b/tools/libxl/libxl_internal.h
> > > > @@ -3326,6 +3326,7 @@ static inline bool libxl__save_helper_inuse(const 
> > > > libxl__save_helper_state *shs)
> > > >    /* Each time the dm needs to be saved, we must call suspend and then save */
> > > >    _hidden int libxl__domain_suspend_device_model(libxl__gc *gc,
> > > >                                               libxl__domain_suspend_state 
> > > > *dsps);
> > > > +_hidden int libxl__domain_resume_device_model(libxl__gc *gc, uint32_t domid);
> > > >    _hidden void libxl__domain_save_device_model(libxl__egc *egc,
> > > >                                         libxl__domain_save_state *dss,
> > > >                                         libxl__save_device_model_cb *callback);
> > >
> > > .
>
> .
--
Thanks,
Yang.

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