Re: [Xen-devel] Upgrade from xen-4.1-testing to xen-unstable report

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Thu, 2012-04-12 at 15:42 +0100, Lin Ming wrote:
> On Thu, 2012-04-12 at 15:03 +0100, Ian Campbell wrote:
> > On Thu, 2012-04-12 at 13:50 +0100, Lin Ming wrote:
> > > On Thu, 2012-04-12 at 07:08 +0000, Ian Campbell wrote:
> > > > On Wed, 2012-04-11 at 22:23 +0100, Teck Choon Giam wrote:
> > > > > Hi,
> > > > > 
> > > > > This is just my experience about issues I encountered when upgrade
> > > > > from xen-4.1-testing changeset 23277:80130491806f to xen-unstable
> > > > > changeset 25191:a95fc7decc83.
> > > > > 
> > > > > 1. Immediately after upgrade, xl list show such error:
> > > > > 
> > > > > # xl list
> > > > > libxl: error: libxl.c:506:libxl_list_domain: geting domain info list:
> > > > > Permission denied
> > > > > libxl_domain_infolist failed.
> > > > > 
> > > > > After a reboot, it is fine.  Any idea why such behaviour?  Imagine if
> > > > > there are running domUs... this might cause issues to shutdown?  I
> > > > > will downgrade and repeat such test to confirm.  Might be worth a note
> > > > > in upgrading note about this if this is intended?
> > > > 
> > > > The tools and the hypervisor are a matched pair so you would need to
> > > > reboot the system in order to use the new tools. This has always been
> > > > the case with Xen upgrades.
> > > > 
> > > > > 2. localtime setting not working.  Set to localtime=1 doesn't seems to
> > > > > work whereby setting rtc_timeoffset works.  Any idea?
> > > > 
> > > > I've CC'd Lin Ming who implemented both of those.
> > > 
> > > Just did a quick gdb debug, seems libxl__domain_build_info_setdefault
> > > was called 3 times. So below statement was executed 3 times too.
> > > 
> > > b_info->rtc_timeoffset += tm->tm_gmtoff;
> > 
> > Oh, that sounds like the problem. The setdefault functions are supposed
> > to be idempotent, IOW calling it two or more times should give the same
> > result as calling it just once.
> > 
> > I think you need to move this logic from setdefault
> >     if (libxl_defbool_val(b_info->localtime)) {
> >         time_t t;
> >         struct tm *tm;
> > 
> >         t = time(NULL);
> >         tm = localtime(&t);
> > 
> >         b_info->rtc_timeoffset += tm->tm_gmtoff;
> >     }
> > 
> > into libxl__build_pre and do that calculation on a temporary variable
> > whjich you pass to xc_domain_set_time_offset rather than modifying
> > b_info.
> 
> How about below patch?
> 
> From e06589cb5f1efd885f9589405d0f4ecc97427ad6 Mon Sep 17 00:00:00 2001
> From: Lin Ming <mlin@xxxxxxxxxxxxx>
> Date: Thu, 12 Apr 2012 22:36:24 +0800
> Subject: [PATCH] libxl: fix rtc_timeoffset setting
> 
> libxl__domain_build_info_setdefault may be called several times, so
> rtc_timeoffset can't be set in it.
> 
> Move rtc_timeoffset setting logic to libxl__build_pre.
> 
> Reported-by: Teck Choon Giam <giamteckchoon@xxxxxxxxx>
> Signed-off-by: Lin Ming <mlin@xxxxxxxxxxxxx>

Looks good to me.

Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>

> ---
>  tools/libxl/libxl_create.c |    9 ---------
>  tools/libxl/libxl_dom.c    |   17 +++++++++++++++--
>  2 files changed, 15 insertions(+), 11 deletions(-)
> 
> diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
> index e63c7bd..e706124 100644
> --- a/tools/libxl/libxl_create.c
> +++ b/tools/libxl/libxl_create.c
> @@ -127,15 +127,6 @@ int libxl__domain_build_info_setdefault(libxl__gc *gc,
>          b_info->target_memkb = b_info->max_memkb;
>  
>      libxl_defbool_setdefault(&b_info->localtime, false);
> -    if (libxl_defbool_val(b_info->localtime)) {
> -        time_t t;
> -        struct tm *tm;
> -
> -        t = time(NULL);
> -        tm = localtime(&t);
> -
> -        b_info->rtc_timeoffset += tm->tm_gmtoff;
> -    }
>  
>      libxl_defbool_setdefault(&b_info->disable_migrate, false);
>  
> diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
> index 0bdd654..91c4bd8 100644
> --- a/tools/libxl/libxl_dom.c
> +++ b/tools/libxl/libxl_dom.c
> @@ -65,6 +65,8 @@ int libxl__build_pre(libxl__gc *gc, uint32_t domid,
>      libxl_ctx *ctx = libxl__gc_owner(gc);
>      int tsc_mode;
>      char *xs_domid, *con_domid;
> +    uint32_t rtc_timeoffset;
> +
>      xc_domain_max_vcpus(ctx->xch, domid, info->max_vcpus);
>      libxl_set_vcpuaffinity_all(ctx, domid, info->max_vcpus, &info->cpumap);
>      xc_domain_setmaxmem(ctx->xch, domid, info->target_memkb + 
> LIBXL_MAXMEM_CONSTANT);
> @@ -91,8 +93,19 @@ int libxl__build_pre(libxl__gc *gc, uint32_t domid,
>      if (libxl_defbool_val(info->disable_migrate))
>          xc_domain_disable_migrate(ctx->xch, domid);
>  
> -    if (info->rtc_timeoffset)
> -        xc_domain_set_time_offset(ctx->xch, domid, info->rtc_timeoffset);
> +    rtc_timeoffset = info->rtc_timeoffset;
> +    if (libxl_defbool_val(info->localtime)) {
> +        time_t t;
> +        struct tm *tm;
> +
> +        t = time(NULL);
> +        tm = localtime(&t);
> +
> +        rtc_timeoffset += tm->tm_gmtoff;
> +    }
> +
> +    if (rtc_timeoffset)
> +        xc_domain_set_time_offset(ctx->xch, domid, rtc_timeoffset);
>  
>      if (info->type == LIBXL_DOMAIN_TYPE_HVM) {
>          unsigned long shadow;



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