[PATCH] libxl: create pci backend only when there are pci devices

[PATCH] libxl: create pci backend only when there are pci devices

[Roger Pau Monne]

# HG changeset patch
# User Roger Pau Monne <roger.pau@entel.upc.edu>
# Date 1316002720 -7200
# Node ID 63e254468d6e8d81baeafaed68f05791dc21eb4e
# Parent  ac33d68e89767d49113824e5661c49a5465a18e7
libxl: create pci backend only when there are pci devices.

Signed-off-by: Roger Pau Monne <roger.pau@entel.upc.edu>

diff -r ac33d68e8976 -r 63e254468d6e tools/libxl/libxl_create.c
--- a/tools/libxl/libxl_create.c	Thu Sep 08 15:13:06 2011 +0100
+++ b/tools/libxl/libxl_create.c	Wed Sep 14 14:18:40 2011 +0200
@@ -584,12 +584,14 @@ static int do_domain_create(libxl__gc *g
     for (i = 0; i < d_config->num_pcidevs; i++)
         libxl__device_pci_add(gc, domid, &d_config->pcidevs[i], 1);
 
-    ret = libxl__create_pci_backend(gc, domid, d_config->pcidevs,
-                                    d_config->num_pcidevs);
-    if (ret < 0) {
-        LIBXL__LOG(ctx, LIBXL__LOG_ERROR,
-                   "libxl_create_pci_backend failed: %d", ret);
-        goto error_out;
+    if (d_config->num_pcidevs > 0) {
+        ret = libxl__create_pci_backend(gc, domid, d_config->pcidevs,
+                                        d_config->num_pcidevs);
+        if (ret < 0) {
+            LIBXL__LOG(ctx, LIBXL__LOG_ERROR,
+                "libxl_create_pci_backend failed: %d", ret);
+            goto error_out;
+        }
     }
 
     if (d_config->c_info.type == LIBXL_DOMAIN_TYPE_PV &&

Re: [PATCH] libxl: create pci backend only when there are pci devices

[Ian Campbell]

On Wed, 2011-09-14 at 08:19 -0400, Roger Pau Monne wrote:
> # HG changeset patch
> # User Roger Pau Monne <roger.pau@entel.upc.edu>
> # Date 1316002720 -7200
> # Node ID 63e254468d6e8d81baeafaed68f05791dc21eb4e
> # Parent  ac33d68e89767d49113824e5661c49a5465a18e7
> libxl: create pci backend only when there are pci devices.

I think I recall discussing this a way back but I don't recall the
specific rationale, can you add something to the commit message please?

Also does this continue to allow a subsequent pci hotplug to work? I
expect it does but it would be useful to check.

Ian.

> 
> Signed-off-by: Roger Pau Monne <roger.pau@entel.upc.edu>
> 
> diff -r ac33d68e8976 -r 63e254468d6e tools/libxl/libxl_create.c
> --- a/tools/libxl/libxl_create.c	Thu Sep 08 15:13:06 2011 +0100
> +++ b/tools/libxl/libxl_create.c	Wed Sep 14 14:18:40 2011 +0200
> @@ -584,12 +584,14 @@ static int do_domain_create(libxl__gc *g
>      for (i = 0; i < d_config->num_pcidevs; i++)
>          libxl__device_pci_add(gc, domid, &d_config->pcidevs[i], 1);
>  
> -    ret = libxl__create_pci_backend(gc, domid, d_config->pcidevs,
> -                                    d_config->num_pcidevs);
> -    if (ret < 0) {
> -        LIBXL__LOG(ctx, LIBXL__LOG_ERROR,
> -                   "libxl_create_pci_backend failed: %d", ret);
> -        goto error_out;
> +    if (d_config->num_pcidevs > 0) {
> +        ret = libxl__create_pci_backend(gc, domid, d_config->pcidevs,
> +                                        d_config->num_pcidevs);
> +        if (ret < 0) {
> +            LIBXL__LOG(ctx, LIBXL__LOG_ERROR,
> +                "libxl_create_pci_backend failed: %d", ret);
> +            goto error_out;
> +        }
>      }
>  
>      if (d_config->c_info.type == LIBXL_DOMAIN_TYPE_PV &&
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel

Re: [PATCH] libxl: create pci backend only when there are pci devices

[Christoph Egger]

If you want to have this patch applied to xen-4.1 then please
mention this explicitely.

Christoph

On 09/14/11 14:19, Roger Pau Monne wrote:
> # HG changeset patch
> # User Roger Pau Monne<roger.pau@entel.upc.edu>
> # Date 1316002720 -7200
> # Node ID 63e254468d6e8d81baeafaed68f05791dc21eb4e
> # Parent  ac33d68e89767d49113824e5661c49a5465a18e7
> libxl: create pci backend only when there are pci devices.
>
> Signed-off-by: Roger Pau Monne<roger.pau@entel.upc.edu>
>
> diff -r ac33d68e8976 -r 63e254468d6e tools/libxl/libxl_create.c
> --- a/tools/libxl/libxl_create.c	Thu Sep 08 15:13:06 2011 +0100
> +++ b/tools/libxl/libxl_create.c	Wed Sep 14 14:18:40 2011 +0200
> @@ -584,12 +584,14 @@ static int do_domain_create(libxl__gc *g
>       for (i = 0; i<  d_config->num_pcidevs; i++)
>           libxl__device_pci_add(gc, domid,&d_config->pcidevs[i], 1);
>
> -    ret = libxl__create_pci_backend(gc, domid, d_config->pcidevs,
> -                                    d_config->num_pcidevs);
> -    if (ret<  0) {
> -        LIBXL__LOG(ctx, LIBXL__LOG_ERROR,
> -                   "libxl_create_pci_backend failed: %d", ret);
> -        goto error_out;
> +    if (d_config->num_pcidevs>  0) {
> +        ret = libxl__create_pci_backend(gc, domid, d_config->pcidevs,
> +                                        d_config->num_pcidevs);
> +        if (ret<  0) {
> +            LIBXL__LOG(ctx, LIBXL__LOG_ERROR,
> +                "libxl_create_pci_backend failed: %d", ret);
> +            goto error_out;
> +        }
>       }
>
>       if (d_config->c_info.type == LIBXL_DOMAIN_TYPE_PV&&


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Re: [PATCH] libxl: create pci backend only when there are pci devices

[Roger Pau Monné]

This was commited as a part of another patch, and I've decided to
submit it alone. This solves a problem with NetBSD Dom0 and at least
Linux DomU, the DomU kernel waited a very long time at XENBUS init,
because it was unable to attach the PCI devices (although there were
no PCI devices, only an empty pci entry in xenstore). This prevents
libxl from adding the pci entries to xenstore if there are no PCI
devices and solves the problem. I don't have any Linux boxes, but I
think this should not break anything.

If the patch is correct, please add it to xen-4.1 too.

Regards, Roger.

Re: [PATCH] libxl: create pci backend only when there are pci devices

[Roger Pau Monné]

Can this patch be applied?

Thanks, Roger.