Re: [PATCH] libxc: Introduce xc_domain_nr_gpfns as a cousin of xc_domain_maximum_gpfn.

[Ian Campbell <ian.campbell@citrix.com>]

On Mon, 2015-03-30 at 15:52 +0100, Andrew Cooper wrote:
> On 30/03/15 15:46, Konrad Rzeszutek Wilk wrote:
> > The commit a8f8a590e02d2d2b717257c0bd9a8b396103bdf4
> > "libxc: Check xc_domain_maximum_gpfn for negative return values"
> > introduced an regression in tools outside libxc (migrate v2)
> > which wanted the unfiltered GPFN value. Said commit added
> > a wrapper which added +1 if there were no errors.
> >
> > To make it work pre-commit a8f8a59 we add an xc_domain_nr_gpfns
> > which will add +1 if there are no errors (and change all in-tree
> > callers to use it). The xc_domain_maximum_gpfn will return the
> > unfiltered GPFN value.
> >
> > Suggested-by: Ian Campbell <ian.campbell@citrix.com>
> > Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
> > Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> 
> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

Applied.

> 
> > ---
> >  tools/libxc/include/xenctrl.h |  2 ++
> >  tools/libxc/xc_core_arm.c     |  2 +-
> >  tools/libxc/xc_core_x86.c     |  6 +++---
> >  tools/libxc/xc_domain.c       | 12 +++++++++++-
> >  tools/libxc/xc_domain_save.c  |  2 +-
> >  5 files changed, 18 insertions(+), 6 deletions(-)
> >
> > diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
> > index 4e9537e..552ace8 100644
> > --- a/tools/libxc/include/xenctrl.h
> > +++ b/tools/libxc/include/xenctrl.h
> > @@ -1317,6 +1317,8 @@ int xc_domain_disable_migrate(xc_interface *xch, uint32_t domid);
> >  
> >  int xc_domain_maximum_gpfn(xc_interface *xch, domid_t domid, xen_pfn_t *gpfns);
> >  
> > +int xc_domain_nr_gpfns(xc_interface *xch, domid_t domid, xen_pfn_t *gpfns);
> > +
> >  int xc_domain_increase_reservation(xc_interface *xch,
> >                                     uint32_t domid,
> >                                     unsigned long nr_extents,
> > diff --git a/tools/libxc/xc_core_arm.c b/tools/libxc/xc_core_arm.c
> > index c3f5868..57d4715 100644
> > --- a/tools/libxc/xc_core_arm.c
> > +++ b/tools/libxc/xc_core_arm.c
> > @@ -45,7 +45,7 @@ xc_core_arch_memory_map_get(xc_interface *xch, struct xc_core_arch_context *unus
> >      xen_pfn_t p2m_size = 0;
> >      xc_core_memory_map_t *map;
> >  
> > -    if ( xc_domain_maximum_gpfn(xch, info->domid, &p2m_size) < 0 )
> > +    if ( xc_domain_nr_gpfns(xch, info->domid, &p2m_size) < 0 )
> >          return -1;
> >  
> >      map = malloc(sizeof(*map));
> > diff --git a/tools/libxc/xc_core_x86.c b/tools/libxc/xc_core_x86.c
> > index 4552e43..93ebcbb 100644
> > --- a/tools/libxc/xc_core_x86.c
> > +++ b/tools/libxc/xc_core_x86.c
> > @@ -50,7 +50,7 @@ xc_core_arch_memory_map_get(xc_interface *xch, struct xc_core_arch_context *unus
> >      xen_pfn_t p2m_size = 0;
> >      xc_core_memory_map_t *map;
> >  
> > -    if ( xc_domain_maximum_gpfn(xch, info->domid, &p2m_size) < 0 )
> > +    if ( xc_domain_nr_gpfns(xch, info->domid, &p2m_size) < 0 )
> >          return -1;
> >  
> >      map = malloc(sizeof(*map));
> > @@ -85,7 +85,7 @@ xc_core_arch_map_p2m_rw(xc_interface *xch, struct domain_info_context *dinfo, xc
> >      int err;
> >      int i;
> >  
> > -    if ( xc_domain_maximum_gpfn(xch, info->domid, &dinfo->p2m_size) < 0 )
> > +    if ( xc_domain_nr_gpfns(xch, info->domid, &dinfo->p2m_size) < 0 )
> >      {
> >          ERROR("Could not get maximum GPFN!");
> >          goto out;
> > @@ -212,7 +212,7 @@ int
> >  xc_core_arch_get_scratch_gpfn(xc_interface *xch, domid_t domid,
> >                                xen_pfn_t *gpfn)
> >  {
> > -    return xc_domain_maximum_gpfn(xch, domid, gpfn);
> > +    return xc_domain_nr_gpfns(xch, domid, gpfn);
> >  }
> >  
> >  /*
> > diff --git a/tools/libxc/xc_domain.c b/tools/libxc/xc_domain.c
> > index da88e08..dc62eff 100644
> > --- a/tools/libxc/xc_domain.c
> > +++ b/tools/libxc/xc_domain.c
> > @@ -795,12 +795,22 @@ int xc_domain_maximum_gpfn(xc_interface *xch, domid_t domid, xen_pfn_t *gpfns)
> >  
> >      if ( rc >= 0 )
> >      {
> > -        *gpfns = rc + 1;
> > +        *gpfns = rc;
> >          rc = 0;
> >      }
> >      return rc;
> >  }
> >  
> > +int xc_domain_nr_gpfns(xc_interface *xch, domid_t domid, xen_pfn_t *gpfns)
> > +{
> > +    int rc = xc_domain_maximum_gpfn(xch, domid, gpfns);
> > +
> > +    if ( rc >= 0 )
> > +        *gpfns += 1;
> > +
> > +    return rc;
> > +}
> > +
> >  int xc_domain_increase_reservation(xc_interface *xch,
> >                                     uint32_t domid,
> >                                     unsigned long nr_extents,
> > diff --git a/tools/libxc/xc_domain_save.c b/tools/libxc/xc_domain_save.c
> > index b611c07..cef6995 100644
> > --- a/tools/libxc/xc_domain_save.c
> > +++ b/tools/libxc/xc_domain_save.c
> > @@ -939,7 +939,7 @@ int xc_domain_save(xc_interface *xch, int io_fd, uint32_t dom, uint32_t max_iter
> >      }
> >  
> >      /* Get the size of the P2M table */
> > -    if ( xc_domain_maximum_gpfn(xch, dom, &dinfo->p2m_size) < 0 )
> > +    if ( xc_domain_nr_gpfns(xch, dom, &dinfo->p2m_size) < 0 )
> >      {
> >          ERROR("Could not get maximum GPFN!");
> >          goto out;
>