Xen devel - Nov 2013 - [PATCH] xen/gnttab: leave lazy MMU mode in the case of a m2p override failure

From: Matt Wilson <msw@amazon.com>

Commit f62805f1 introduced a bug where lazy MMU mode isn''t exited if a
m2p_add/remove_override call fails.

Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Anthony Liguori <aliguori@amazon.com>
Cc: xen-devel@lists.xenproject.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Matt Wilson <msw@amazon.com>
---
 drivers/xen/grant-table.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 62ccf54..0283871 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -930,9 +930,10 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
 		ret = m2p_add_override(mfn, pages[i], kmap_ops ?
 				       &kmap_ops[i] : NULL);
 		if (ret)
-			return ret;
+			goto out;
 	}
 
+ out:
 	if (lazy)
 		arch_leave_lazy_mmu_mode();
 
@@ -969,9 +970,10 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref
*unmap_ops,
 		ret = m2p_remove_override(pages[i], kmap_ops ?
 				       &kmap_ops[i] : NULL);
 		if (ret)
-			return ret;
+			goto out;
 	}
 
+ out:
 	if (lazy)
 		arch_leave_lazy_mmu_mode();
 
-- 
1.7.9.5

On Wed, Nov 20, 2013 at 12:11 PM, Matt Wilson <msw@linux.com>
wrote:
> From: Matt Wilson <msw@amazon.com>
>
> Commit f62805f1 introduced a bug where lazy MMU mode isn''t exited
if a
> m2p_add/remove_override call fails.
>
> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> Cc: David Vrabel <david.vrabel@citrix.com>
> Cc: Anthony Liguori <aliguori@amazon.com>
> Cc: xen-devel@lists.xenproject.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Matt Wilson <msw@amazon.com>
Reviewed-by: Anthony Liguori <aliguori@amazon.com>

Regards,

Anthony Liguori
> ---
>  drivers/xen/grant-table.c |    6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
> index 62ccf54..0283871 100644
> --- a/drivers/xen/grant-table.c
> +++ b/drivers/xen/grant-table.c
> @@ -930,9 +930,10 @@ int gnttab_map_refs(struct gnttab_map_grant_ref
*map_ops,
>                 ret = m2p_add_override(mfn, pages[i], kmap_ops ?
>                                        &kmap_ops[i] : NULL);
>                 if (ret)
> -                       return ret;
> +                       goto out;
>         }
>
> + out:
>         if (lazy)
>                 arch_leave_lazy_mmu_mode();
>
> @@ -969,9 +970,10 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref
*unmap_ops,
>                 ret = m2p_remove_override(pages[i], kmap_ops ?
>                                        &kmap_ops[i] : NULL);
>                 if (ret)
> -                       return ret;
> +                       goto out;
>         }
>
> + out:
>         if (lazy)
>                 arch_leave_lazy_mmu_mode();
>
> --
> 1.7.9.5
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel

On 20/11/13 20:11, Matt Wilson wrote:
> From: Matt Wilson <msw@amazon.com>
> 
> Commit f62805f1 introduced a bug where lazy MMU mode isn''t exited
if a
> m2p_add/remove_override call fails.
Reviewed-by: David Vrabel <david.vrabel@citrix.com>

Should be tagged for stable.

David

On Wed, 20 Nov 2013, Matt Wilson wrote:
> From: Matt Wilson <msw@amazon.com>
> 
> Commit f62805f1 introduced a bug where lazy MMU mode isn''t exited
if a
> m2p_add/remove_override call fails.
> 
> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> Cc: David Vrabel <david.vrabel@citrix.com>
> Cc: Anthony Liguori <aliguori@amazon.com>
> Cc: xen-devel@lists.xenproject.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Matt Wilson <msw@amazon.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

>  drivers/xen/grant-table.c |    6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
> index 62ccf54..0283871 100644
> --- a/drivers/xen/grant-table.c
> +++ b/drivers/xen/grant-table.c
> @@ -930,9 +930,10 @@ int gnttab_map_refs(struct gnttab_map_grant_ref
*map_ops,
>  		ret = m2p_add_override(mfn, pages[i], kmap_ops ?
>  				       &kmap_ops[i] : NULL);
>  		if (ret)
> -			return ret;
> +			goto out;
>  	}
>  
> + out:
>  	if (lazy)
>  		arch_leave_lazy_mmu_mode();
>  
> @@ -969,9 +970,10 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref
*unmap_ops,
>  		ret = m2p_remove_override(pages[i], kmap_ops ?
>  				       &kmap_ops[i] : NULL);
>  		if (ret)
> -			return ret;
> +			goto out;
>  	}
>  
> + out:
>  	if (lazy)
>  		arch_leave_lazy_mmu_mode();
>  
> -- 
> 1.7.9.5
>

On Wed, Nov 20, 2013 at 12:11:35PM -0800, Matt Wilson
wrote:
> From: Matt Wilson <msw@amazon.com>
> 
> Commit f62805f1 introduced a bug where lazy MMU mode isn''t exited
if a
> m2p_add/remove_override call fails.
Stefano?
> 
> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> Cc: David Vrabel <david.vrabel@citrix.com>
> Cc: Anthony Liguori <aliguori@amazon.com>
> Cc: xen-devel@lists.xenproject.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Matt Wilson <msw@amazon.com>
> ---
>  drivers/xen/grant-table.c |    6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
> index 62ccf54..0283871 100644
> --- a/drivers/xen/grant-table.c
> +++ b/drivers/xen/grant-table.c
> @@ -930,9 +930,10 @@ int gnttab_map_refs(struct gnttab_map_grant_ref
*map_ops,
>  		ret = m2p_add_override(mfn, pages[i], kmap_ops ?
>  				       &kmap_ops[i] : NULL);
>  		if (ret)
> -			return ret;
> +			goto out;
>  	}
>  
> + out:
>  	if (lazy)
>  		arch_leave_lazy_mmu_mode();
>  
> @@ -969,9 +970,10 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref
*unmap_ops,
>  		ret = m2p_remove_override(pages[i], kmap_ops ?
>  				       &kmap_ops[i] : NULL);
>  		if (ret)
> -			return ret;
> +			goto out;
>  	}
>  
> + out:
>  	if (lazy)
>  		arch_leave_lazy_mmu_mode();
>  
> -- 
> 1.7.9.5
>

On Fri, 22 Nov 2013, Konrad Rzeszutek Wilk wrote:
> On Wed, Nov 20, 2013 at 12:11:35PM -0800, Matt Wilson wrote:
> > From: Matt Wilson <msw@amazon.com>
> > 
> > Commit f62805f1 introduced a bug where lazy MMU mode isn''t
exited if a
> > m2p_add/remove_override call fails.
> 
> Stefano?
> 
Already acked here:

http://marc.info/?l=linux-kernel&m=138505917602905&w=2


> > Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> > Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> > Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> > Cc: David Vrabel <david.vrabel@citrix.com>
> > Cc: Anthony Liguori <aliguori@amazon.com>
> > Cc: xen-devel@lists.xenproject.org
> > Cc: linux-kernel@vger.kernel.org
> > Signed-off-by: Matt Wilson <msw@amazon.com>
> > ---
> >  drivers/xen/grant-table.c |    6 ++++--
> >  1 file changed, 4 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
> > index 62ccf54..0283871 100644
> > --- a/drivers/xen/grant-table.c
> > +++ b/drivers/xen/grant-table.c
> > @@ -930,9 +930,10 @@ int gnttab_map_refs(struct gnttab_map_grant_ref
*map_ops,
> >  		ret = m2p_add_override(mfn, pages[i], kmap_ops ?
> >  				       &kmap_ops[i] : NULL);
> >  		if (ret)
> > -			return ret;
> > +			goto out;
> >  	}
> >  
> > + out:
> >  	if (lazy)
> >  		arch_leave_lazy_mmu_mode();
> >  
> > @@ -969,9 +970,10 @@ int gnttab_unmap_refs(struct
gnttab_unmap_grant_ref *unmap_ops,
> >  		ret = m2p_remove_override(pages[i], kmap_ops ?
> >  				       &kmap_ops[i] : NULL);
> >  		if (ret)
> > -			return ret;
> > +			goto out;
> >  	}
> >  
> > + out:
> >  	if (lazy)
> >  		arch_leave_lazy_mmu_mode();
> >  
> > -- 
> > 1.7.9.5
> > 
>

On Fri, Nov 29, 2013 at 12:22:40PM +0000, Stefano Stabellini
wrote:
> On Fri, 22 Nov 2013, Konrad Rzeszutek Wilk wrote:
> > On Wed, Nov 20, 2013 at 12:11:35PM -0800, Matt Wilson wrote:
> > > From: Matt Wilson <msw@amazon.com>
> > > 
> > > Commit f62805f1 introduced a bug where lazy MMU mode
isn''t exited if a
> > > m2p_add/remove_override call fails.
> > 
> > Stefano?
> > 
> 
> Already acked here:
> 
> http://marc.info/?l=linux-kernel&m=138505917602905&w=2
Sent to Linus today.

Thank you!
> 
> 
> 
> > > Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> > > Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> > > Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> > > Cc: David Vrabel <david.vrabel@citrix.com>
> > > Cc: Anthony Liguori <aliguori@amazon.com>
> > > Cc: xen-devel@lists.xenproject.org
> > > Cc: linux-kernel@vger.kernel.org
> > > Signed-off-by: Matt Wilson <msw@amazon.com>
> > > ---
> > >  drivers/xen/grant-table.c |    6 ++++--
> > >  1 file changed, 4 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/drivers/xen/grant-table.c
b/drivers/xen/grant-table.c
> > > index 62ccf54..0283871 100644
> > > --- a/drivers/xen/grant-table.c
> > > +++ b/drivers/xen/grant-table.c
> > > @@ -930,9 +930,10 @@ int gnttab_map_refs(struct
gnttab_map_grant_ref *map_ops,
> > >  		ret = m2p_add_override(mfn, pages[i], kmap_ops ?
> > >  				       &kmap_ops[i] : NULL);
> > >  		if (ret)
> > > -			return ret;
> > > +			goto out;
> > >  	}
> > >  
> > > + out:
> > >  	if (lazy)
> > >  		arch_leave_lazy_mmu_mode();
> > >  
> > > @@ -969,9 +970,10 @@ int gnttab_unmap_refs(struct
gnttab_unmap_grant_ref *unmap_ops,
> > >  		ret = m2p_remove_override(pages[i], kmap_ops ?
> > >  				       &kmap_ops[i] : NULL);
> > >  		if (ret)
> > > -			return ret;
> > > +			goto out;
> > >  	}
> > >  
> > > + out:
> > >  	if (lazy)
> > >  		arch_leave_lazy_mmu_mode();
> > >  
> > > -- 
> > > 1.7.9.5
> > > 
> >