[PATCH] libxl: check nesthvm and altp2m in libxl level

[PATCH] libxl: check nesthvm and altp2m in libxl level

[Wei Liu]

In ea214001 ("x86/altp2m: add altp2mhvm HVM domain parameter"), a
check was added to ensure nestedhvm and altp2m cannot be enabled at
the same time. That check was added in xl, but in fact it should be in
libxl because it should be the entity that decides whether
the provided configuration is valid.

This patch moves the check to libxl. The code snippet is moved after
calling libxl__domain_build_info_setdefault so that we can:
1. remove libxl_defbool_is_default in `if()';
2. detect mistake in libxl__domain_build_info_setdefault.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
Cc: Ed White <edmund.h.white@intel.com>
Cc: "Sahita, Ravi" <ravi.sahita@intel.com>

I said I discovered an issue during review but also volunteered to fix
it after the series is merged. Here is the patch to do that.
---
 tools/libxl/libxl_create.c | 6 ++++++
 tools/libxl/xl_cmdimpl.c   | 8 --------
 2 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
index 855b42c..de536ba 100644
--- a/tools/libxl/libxl_create.c
+++ b/tools/libxl/libxl_create.c
@@ -883,6 +883,12 @@ static void initiate_domain_create(libxl__egc *egc,
         goto error_out;
     }
 
+    if (libxl_defbool_val(d_config->b_info.u.hvm.nested_hvm) &&
+        libxl_defbool_val(d_config->b_info.u.hvm.altp2m)) {
+        LOG(ERROR, "nestedhvm and altp2mhvm cannot be used together");
+        goto error_out;
+    }
+
     for (i = 0; i < d_config->num_disks; i++) {
         ret = libxl__device_disk_setdefault(gc, &d_config->disks[i]);
         if (ret) {
diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
index d0bf0cb..9755d55 100644
--- a/tools/libxl/xl_cmdimpl.c
+++ b/tools/libxl/xl_cmdimpl.c
@@ -1568,14 +1568,6 @@ static void parse_config_data(const char *config_source,
 
         xlu_cfg_get_defbool(config, "altp2mhvm", &b_info->u.hvm.altp2m, 0);
 
-        if (!libxl_defbool_is_default(b_info->u.hvm.nested_hvm) &&
-            libxl_defbool_val(b_info->u.hvm.nested_hvm) &&
-            !libxl_defbool_is_default(b_info->u.hvm.altp2m) &&
-            libxl_defbool_val(b_info->u.hvm.altp2m)) {
-            fprintf(stderr, "ERROR: nestedhvm and altp2mhvm cannot be used together\n");
-            exit(1);
-        }
-
         xlu_cfg_replace_string(config, "smbios_firmware",
                                &b_info->u.hvm.smbios_firmware, 0);
         xlu_cfg_replace_string(config, "acpi_firmware",
-- 
2.1.4

Re: [PATCH] libxl: check nesthvm and altp2m in libxl level

[Sahita, Ravi]

>From: Wei Liu [mailto:wei.liu2@citrix.com]
>Sent: Friday, July 24, 2015 8:40 AM
>
>In ea214001 ("x86/altp2m: add altp2mhvm HVM domain parameter"), a check
>was added to ensure nestedhvm and altp2m cannot be enabled at the same
>time. That check was added in xl, but in fact it should be in libxl because it
>should be the entity that decides whether the provided configuration is valid.
>
>This patch moves the check to libxl. The code snippet is moved after calling
>libxl__domain_build_info_setdefault so that we can:
>1. remove libxl_defbool_is_default in `if()'; 2. detect mistake in
>libxl__domain_build_info_setdefault.
>
>Signed-off-by: Wei Liu <wei.liu2@citrix.com>
>---
>Cc: Ed White <edmund.h.white@intel.com>
>Cc: "Sahita, Ravi" <ravi.sahita@intel.com>
>
>I said I discovered an issue during review but also volunteered to fix it after
>the series is merged. Here is the patch to do that.
>---
> tools/libxl/libxl_create.c | 6 ++++++
> tools/libxl/xl_cmdimpl.c   | 8 --------
> 2 files changed, 6 insertions(+), 8 deletions(-)
>
>diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c index
>855b42c..de536ba 100644
>--- a/tools/libxl/libxl_create.c
>+++ b/tools/libxl/libxl_create.c
>@@ -883,6 +883,12 @@ static void initiate_domain_create(libxl__egc *egc,
>         goto error_out;
>     }
>
>+    if (libxl_defbool_val(d_config->b_info.u.hvm.nested_hvm) &&
>+        libxl_defbool_val(d_config->b_info.u.hvm.altp2m)) {
>+        LOG(ERROR, "nestedhvm and altp2mhvm cannot be used together");
>+        goto error_out;
>+    }
>+
>     for (i = 0; i < d_config->num_disks; i++) {
>         ret = libxl__device_disk_setdefault(gc, &d_config->disks[i]);
>         if (ret) {
>diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c index
>d0bf0cb..9755d55 100644
>--- a/tools/libxl/xl_cmdimpl.c
>+++ b/tools/libxl/xl_cmdimpl.c
>@@ -1568,14 +1568,6 @@ static void parse_config_data(const char
>*config_source,
>
>         xlu_cfg_get_defbool(config, "altp2mhvm", &b_info->u.hvm.altp2m, 0);
>
>-        if (!libxl_defbool_is_default(b_info->u.hvm.nested_hvm) &&
>-            libxl_defbool_val(b_info->u.hvm.nested_hvm) &&
>-            !libxl_defbool_is_default(b_info->u.hvm.altp2m) &&
>-            libxl_defbool_val(b_info->u.hvm.altp2m)) {
>-            fprintf(stderr, "ERROR: nestedhvm and altp2mhvm cannot be used
>together\n");
>-            exit(1);
>-        }
>-
>         xlu_cfg_replace_string(config, "smbios_firmware",
>                                &b_info->u.hvm.smbios_firmware, 0);
>         xlu_cfg_replace_string(config, "acpi_firmware",
>--
>2.1.4

Thanks Wei

Ravi

Re: [PATCH] libxl: check nesthvm and altp2m in libxl level

[Julien Grall]

Hi Wei,

On 24/07/15 16:39, Wei Liu wrote:
> In ea214001 ("x86/altp2m: add altp2mhvm HVM domain parameter"), a
> check was added to ensure nestedhvm and altp2m cannot be enabled at
> the same time. That check was added in xl, but in fact it should be in
> libxl because it should be the entity that decides whether
> the provided configuration is valid.
> 
> This patch moves the check to libxl. The code snippet is moved after
> calling libxl__domain_build_info_setdefault so that we can:
> 1. remove libxl_defbool_is_default in `if()';
> 2. detect mistake in libxl__domain_build_info_setdefault.
> 
> Signed-off-by: Wei Liu <wei.liu2@citrix.com>
> ---
> Cc: Ed White <edmund.h.white@intel.com>
> Cc: "Sahita, Ravi" <ravi.sahita@intel.com>
> 
> I said I discovered an issue during review but also volunteered to fix
> it after the series is merged. Here is the patch to do that.
> ---
>  tools/libxl/libxl_create.c | 6 ++++++
>  tools/libxl/xl_cmdimpl.c   | 8 --------
>  2 files changed, 6 insertions(+), 8 deletions(-)
> 
> diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
> index 855b42c..de536ba 100644
> --- a/tools/libxl/libxl_create.c
> +++ b/tools/libxl/libxl_create.c
> @@ -883,6 +883,12 @@ static void initiate_domain_create(libxl__egc *egc,
>          goto error_out;
>      }
>  
> +    if (libxl_defbool_val(d_config->b_info.u.hvm.nested_hvm) &&
> +        libxl_defbool_val(d_config->b_info.u.hvm.altp2m)) {
> +        LOG(ERROR, "nestedhvm and altp2mhvm cannot be used together");
> +        goto error_out;
> +    }
> +

The u.hvm.{nested_hvm,altp2m} can only be checked when the created
domain is an HVM.

But initiate_domain_create is called with either a PV or HVM domain. So
you may need to check if we are creating a HVM one.

Regards,

-- 
Julien Grall

Re: [PATCH] libxl: check nesthvm and altp2m in libxl level

[Wei Liu]

On Mon, Jul 27, 2015 at 01:34:04PM +0100, Julien Grall wrote:
> Hi Wei,
> 
> On 24/07/15 16:39, Wei Liu wrote:
> > In ea214001 ("x86/altp2m: add altp2mhvm HVM domain parameter"), a
> > check was added to ensure nestedhvm and altp2m cannot be enabled at
> > the same time. That check was added in xl, but in fact it should be in
> > libxl because it should be the entity that decides whether
> > the provided configuration is valid.
> > 
> > This patch moves the check to libxl. The code snippet is moved after
> > calling libxl__domain_build_info_setdefault so that we can:
> > 1. remove libxl_defbool_is_default in `if()';
> > 2. detect mistake in libxl__domain_build_info_setdefault.
> > 
> > Signed-off-by: Wei Liu <wei.liu2@citrix.com>
> > ---
> > Cc: Ed White <edmund.h.white@intel.com>
> > Cc: "Sahita, Ravi" <ravi.sahita@intel.com>
> > 
> > I said I discovered an issue during review but also volunteered to fix
> > it after the series is merged. Here is the patch to do that.
> > ---
> >  tools/libxl/libxl_create.c | 6 ++++++
> >  tools/libxl/xl_cmdimpl.c   | 8 --------
> >  2 files changed, 6 insertions(+), 8 deletions(-)
> > 
> > diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
> > index 855b42c..de536ba 100644
> > --- a/tools/libxl/libxl_create.c
> > +++ b/tools/libxl/libxl_create.c
> > @@ -883,6 +883,12 @@ static void initiate_domain_create(libxl__egc *egc,
> >          goto error_out;
> >      }
> >  
> > +    if (libxl_defbool_val(d_config->b_info.u.hvm.nested_hvm) &&
> > +        libxl_defbool_val(d_config->b_info.u.hvm.altp2m)) {
> > +        LOG(ERROR, "nestedhvm and altp2mhvm cannot be used together");
> > +        goto error_out;
> > +    }
> > +
> 
> The u.hvm.{nested_hvm,altp2m} can only be checked when the created
> domain is an HVM.
> 
> But initiate_domain_create is called with either a PV or HVM domain. So
> you may need to check if we are creating a HVM one.
> 

Good point. I will respin.

Wei.

> Regards,
> 
> -- 
> Julien Grall