diff mbox

[2/2] x86/xen/efi: Init only efi struct members used by Xen

Message ID 1497989668-6238-3-git-send-email-daniel.kiper@oracle.com (mailing list archive)
State New, archived
Headers show

Commit Message

Daniel Kiper June 20, 2017, 8:14 p.m. UTC 
Current approach, wholesale efi struct initialization from efi_xen, is not
good. Usually if new member is defined then it is properly initialized in
drivers/firmware/efi/efi.c but not in arch/x86/xen/efi.c. As I saw it happened
a few times until now. So, let's initialize only efi struct members used by
Xen to avoid such issues in the future.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
---
 arch/x86/xen/efi.c |   45 ++++++++++++---------------------------------
 1 file changed, 12 insertions(+), 33 deletions(-)

Comments

Ard Biesheuvel June 21, 2017, 7:53 a.m. UTC | #1 
On 20 June 2017 at 22:14, Daniel Kiper <daniel.kiper@oracle.com> wrote:
> Current approach, wholesale efi struct initialization from efi_xen, is not
> good. Usually if new member is defined then it is properly initialized in
> drivers/firmware/efi/efi.c but not in arch/x86/xen/efi.c. As I saw it happened
> a few times until now. So, let's initialize only efi struct members used by
> Xen to avoid such issues in the future.
>
> Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>

Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

> ---
>  arch/x86/xen/efi.c |   45 ++++++++++++---------------------------------
>  1 file changed, 12 insertions(+), 33 deletions(-)
>
> diff --git a/arch/x86/xen/efi.c b/arch/x86/xen/efi.c
> index 30bb2e8..01b9faf 100644
> --- a/arch/x86/xen/efi.c
> +++ b/arch/x86/xen/efi.c
> @@ -54,38 +54,6 @@
>         .tables         = EFI_INVALID_TABLE_ADDR  /* Initialized later. */
>  };
>
> -static const struct efi efi_xen __initconst = {
> -       .systab                   = NULL, /* Initialized later. */
> -       .runtime_version          = 0,    /* Initialized later. */
> -       .mps                      = EFI_INVALID_TABLE_ADDR,
> -       .acpi                     = EFI_INVALID_TABLE_ADDR,
> -       .acpi20                   = EFI_INVALID_TABLE_ADDR,
> -       .smbios                   = EFI_INVALID_TABLE_ADDR,
> -       .smbios3                  = EFI_INVALID_TABLE_ADDR,
> -       .sal_systab               = EFI_INVALID_TABLE_ADDR,
> -       .boot_info                = EFI_INVALID_TABLE_ADDR,
> -       .hcdp                     = EFI_INVALID_TABLE_ADDR,
> -       .uga                      = EFI_INVALID_TABLE_ADDR,
> -       .uv_systab                = EFI_INVALID_TABLE_ADDR,
> -       .fw_vendor                = EFI_INVALID_TABLE_ADDR,
> -       .runtime                  = EFI_INVALID_TABLE_ADDR,
> -       .config_table             = EFI_INVALID_TABLE_ADDR,
> -       .get_time                 = xen_efi_get_time,
> -       .set_time                 = xen_efi_set_time,
> -       .get_wakeup_time          = xen_efi_get_wakeup_time,
> -       .set_wakeup_time          = xen_efi_set_wakeup_time,
> -       .get_variable             = xen_efi_get_variable,
> -       .get_next_variable        = xen_efi_get_next_variable,
> -       .set_variable             = xen_efi_set_variable,
> -       .query_variable_info      = xen_efi_query_variable_info,
> -       .update_capsule           = xen_efi_update_capsule,
> -       .query_capsule_caps       = xen_efi_query_capsule_caps,
> -       .get_next_high_mono_count = xen_efi_get_next_high_mono_count,
> -       .reset_system             = xen_efi_reset_system,
> -       .set_virtual_address_map  = NULL, /* Not used under Xen. */
> -       .flags                    = 0     /* Initialized later. */
> -};
> -
>  static efi_system_table_t __init *xen_efi_probe(void)
>  {
>         struct xen_platform_op op = {
> @@ -102,7 +70,18 @@ static efi_system_table_t __init *xen_efi_probe(void)
>
>         /* Here we know that Xen runs on EFI platform. */
>
> -       efi = efi_xen;
> +       efi.get_time = xen_efi_get_time;
> +       efi.set_time = xen_efi_set_time;
> +       efi.get_wakeup_time = xen_efi_get_wakeup_time;
> +       efi.set_wakeup_time = xen_efi_set_wakeup_time;
> +       efi.get_variable = xen_efi_get_variable;
> +       efi.get_next_variable = xen_efi_get_next_variable;
> +       efi.set_variable = xen_efi_set_variable;
> +       efi.query_variable_info = xen_efi_query_variable_info;
> +       efi.update_capsule = xen_efi_update_capsule;
> +       efi.query_capsule_caps = xen_efi_query_capsule_caps;
> +       efi.get_next_high_mono_count = xen_efi_get_next_high_mono_count;
> +       efi.reset_system = xen_efi_reset_system;
>
>         efi_systab_xen.tables = info->cfg.addr;
>         efi_systab_xen.nr_tables = info->cfg.nent;
> --
> 1.7.10.4
>
Andrew Cooper June 21, 2017, 8:10 a.m. UTC | #2 
On 20/06/2017 21:14, Daniel Kiper wrote:
> Current approach, wholesale efi struct initialization from efi_xen, is not
> good. Usually if new member is defined then it is properly initialized in
> drivers/firmware/efi/efi.c but not in arch/x86/xen/efi.c. As I saw it happened
> a few times until now. So, let's initialize only efi struct members used by
> Xen to avoid such issues in the future.
>
> Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
> ---
>  arch/x86/xen/efi.c |   45 ++++++++++++---------------------------------
>  1 file changed, 12 insertions(+), 33 deletions(-)
>
> diff --git a/arch/x86/xen/efi.c b/arch/x86/xen/efi.c
> index 30bb2e8..01b9faf 100644
> --- a/arch/x86/xen/efi.c
> +++ b/arch/x86/xen/efi.c
> @@ -54,38 +54,6 @@
>  	.tables		= EFI_INVALID_TABLE_ADDR  /* Initialized later. */
>  };
>  
> -static const struct efi efi_xen __initconst = {
> -	.systab                   = NULL, /* Initialized later. */
> -	.runtime_version	  = 0,    /* Initialized later. */
> -	.mps                      = EFI_INVALID_TABLE_ADDR,
> -	.acpi                     = EFI_INVALID_TABLE_ADDR,
> -	.acpi20                   = EFI_INVALID_TABLE_ADDR,
> -	.smbios                   = EFI_INVALID_TABLE_ADDR,
> -	.smbios3                  = EFI_INVALID_TABLE_ADDR,
> -	.sal_systab               = EFI_INVALID_TABLE_ADDR,
> -	.boot_info                = EFI_INVALID_TABLE_ADDR,
> -	.hcdp                     = EFI_INVALID_TABLE_ADDR,
> -	.uga                      = EFI_INVALID_TABLE_ADDR,
> -	.uv_systab                = EFI_INVALID_TABLE_ADDR,
> -	.fw_vendor                = EFI_INVALID_TABLE_ADDR,
> -	.runtime                  = EFI_INVALID_TABLE_ADDR,
> -	.config_table             = EFI_INVALID_TABLE_ADDR,
> -	.get_time                 = xen_efi_get_time,
> -	.set_time                 = xen_efi_set_time,
> -	.get_wakeup_time          = xen_efi_get_wakeup_time,
> -	.set_wakeup_time          = xen_efi_set_wakeup_time,
> -	.get_variable             = xen_efi_get_variable,
> -	.get_next_variable        = xen_efi_get_next_variable,
> -	.set_variable             = xen_efi_set_variable,
> -	.query_variable_info      = xen_efi_query_variable_info,
> -	.update_capsule           = xen_efi_update_capsule,
> -	.query_capsule_caps       = xen_efi_query_capsule_caps,
> -	.get_next_high_mono_count = xen_efi_get_next_high_mono_count,
> -	.reset_system             = xen_efi_reset_system,
> -	.set_virtual_address_map  = NULL, /* Not used under Xen. */
> -	.flags			  = 0     /* Initialized later. */
> -};
> -
>  static efi_system_table_t __init *xen_efi_probe(void)
>  {
>  	struct xen_platform_op op = {
> @@ -102,7 +70,18 @@ static efi_system_table_t __init *xen_efi_probe(void)
>  
>  	/* Here we know that Xen runs on EFI platform. */
>  
> -	efi = efi_xen;
> +	efi.get_time = xen_efi_get_time;
> +	efi.set_time = xen_efi_set_time;
> +	efi.get_wakeup_time = xen_efi_get_wakeup_time;
> +	efi.set_wakeup_time = xen_efi_set_wakeup_time;
> +	efi.get_variable = xen_efi_get_variable;
> +	efi.get_next_variable = xen_efi_get_next_variable;
> +	efi.set_variable = xen_efi_set_variable;
> +	efi.query_variable_info = xen_efi_query_variable_info;
> +	efi.update_capsule = xen_efi_update_capsule;
> +	efi.query_capsule_caps = xen_efi_query_capsule_caps;
> +	efi.get_next_high_mono_count = xen_efi_get_next_high_mono_count;
> +	efi.reset_system = xen_efi_reset_system;

This presumably means that the system default values are already present
in efi at the point that we overwrite some Xen specifics?

If so, surely you need to retain the clobbering of set_virtual_address_map ?

~Andrew
Ingo Molnar June 21, 2017, 9:24 a.m. UTC | #3 
* Daniel Kiper <daniel.kiper@oracle.com> wrote:

> -static const struct efi efi_xen __initconst = {
> -	.systab                   = NULL, /* Initialized later. */
> -	.runtime_version	  = 0,    /* Initialized later. */
> -	.mps                      = EFI_INVALID_TABLE_ADDR,
> -	.acpi                     = EFI_INVALID_TABLE_ADDR,
> -	.acpi20                   = EFI_INVALID_TABLE_ADDR,
> -	.smbios                   = EFI_INVALID_TABLE_ADDR,
> -	.smbios3                  = EFI_INVALID_TABLE_ADDR,
> -	.sal_systab               = EFI_INVALID_TABLE_ADDR,
> -	.boot_info                = EFI_INVALID_TABLE_ADDR,
> -	.hcdp                     = EFI_INVALID_TABLE_ADDR,
> -	.uga                      = EFI_INVALID_TABLE_ADDR,
> -	.uv_systab                = EFI_INVALID_TABLE_ADDR,
> -	.fw_vendor                = EFI_INVALID_TABLE_ADDR,
> -	.runtime                  = EFI_INVALID_TABLE_ADDR,
> -	.config_table             = EFI_INVALID_TABLE_ADDR,
> -	.get_time                 = xen_efi_get_time,
> -	.set_time                 = xen_efi_set_time,
> -	.get_wakeup_time          = xen_efi_get_wakeup_time,
> -	.set_wakeup_time          = xen_efi_set_wakeup_time,
> -	.get_variable             = xen_efi_get_variable,
> -	.get_next_variable        = xen_efi_get_next_variable,
> -	.set_variable             = xen_efi_set_variable,
> -	.query_variable_info      = xen_efi_query_variable_info,
> -	.update_capsule           = xen_efi_update_capsule,
> -	.query_capsule_caps       = xen_efi_query_capsule_caps,
> -	.get_next_high_mono_count = xen_efi_get_next_high_mono_count,
> -	.reset_system             = xen_efi_reset_system,
> -	.set_virtual_address_map  = NULL, /* Not used under Xen. */
> -	.flags			  = 0     /* Initialized later. */
> -};
> -
>  static efi_system_table_t __init *xen_efi_probe(void)
>  {
>  	struct xen_platform_op op = {
> @@ -102,7 +70,18 @@ static efi_system_table_t __init *xen_efi_probe(void)
>  
>  	/* Here we know that Xen runs on EFI platform. */
>  
> -	efi = efi_xen;
> +	efi.get_time = xen_efi_get_time;
> +	efi.set_time = xen_efi_set_time;
> +	efi.get_wakeup_time = xen_efi_get_wakeup_time;
> +	efi.set_wakeup_time = xen_efi_set_wakeup_time;
> +	efi.get_variable = xen_efi_get_variable;
> +	efi.get_next_variable = xen_efi_get_next_variable;
> +	efi.set_variable = xen_efi_set_variable;
> +	efi.query_variable_info = xen_efi_query_variable_info;
> +	efi.update_capsule = xen_efi_update_capsule;
> +	efi.query_capsule_caps = xen_efi_query_capsule_caps;
> +	efi.get_next_high_mono_count = xen_efi_get_next_high_mono_count;
> +	efi.reset_system = xen_efi_reset_system;

This is a step back stylistically, as you lost the nice vertical tabulation of the 
original initializer ...

Thanks,

	Ingo
Daniel Kiper June 21, 2017, 9:29 a.m. UTC | #4 
On Wed, Jun 21, 2017 at 09:10:51AM +0100, Andrew Cooper wrote:
> On 20/06/2017 21:14, Daniel Kiper wrote:
> > Current approach, wholesale efi struct initialization from efi_xen, is not
> > good. Usually if new member is defined then it is properly initialized in
> > drivers/firmware/efi/efi.c but not in arch/x86/xen/efi.c. As I saw it happened
> > a few times until now. So, let's initialize only efi struct members used by
> > Xen to avoid such issues in the future.
> >
> > Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
> > ---
> >  arch/x86/xen/efi.c |   45 ++++++++++++---------------------------------
> >  1 file changed, 12 insertions(+), 33 deletions(-)
> >
> > diff --git a/arch/x86/xen/efi.c b/arch/x86/xen/efi.c
> > index 30bb2e8..01b9faf 100644
> > --- a/arch/x86/xen/efi.c
> > +++ b/arch/x86/xen/efi.c
> > @@ -54,38 +54,6 @@
> >  	.tables		= EFI_INVALID_TABLE_ADDR  /* Initialized later. */
> >  };
> >
> > -static const struct efi efi_xen __initconst = {
> > -	.systab                   = NULL, /* Initialized later. */
> > -	.runtime_version	  = 0,    /* Initialized later. */
> > -	.mps                      = EFI_INVALID_TABLE_ADDR,
> > -	.acpi                     = EFI_INVALID_TABLE_ADDR,
> > -	.acpi20                   = EFI_INVALID_TABLE_ADDR,
> > -	.smbios                   = EFI_INVALID_TABLE_ADDR,
> > -	.smbios3                  = EFI_INVALID_TABLE_ADDR,
> > -	.sal_systab               = EFI_INVALID_TABLE_ADDR,
> > -	.boot_info                = EFI_INVALID_TABLE_ADDR,
> > -	.hcdp                     = EFI_INVALID_TABLE_ADDR,
> > -	.uga                      = EFI_INVALID_TABLE_ADDR,
> > -	.uv_systab                = EFI_INVALID_TABLE_ADDR,
> > -	.fw_vendor                = EFI_INVALID_TABLE_ADDR,
> > -	.runtime                  = EFI_INVALID_TABLE_ADDR,
> > -	.config_table             = EFI_INVALID_TABLE_ADDR,
> > -	.get_time                 = xen_efi_get_time,
> > -	.set_time                 = xen_efi_set_time,
> > -	.get_wakeup_time          = xen_efi_get_wakeup_time,
> > -	.set_wakeup_time          = xen_efi_set_wakeup_time,
> > -	.get_variable             = xen_efi_get_variable,
> > -	.get_next_variable        = xen_efi_get_next_variable,
> > -	.set_variable             = xen_efi_set_variable,
> > -	.query_variable_info      = xen_efi_query_variable_info,
> > -	.update_capsule           = xen_efi_update_capsule,
> > -	.query_capsule_caps       = xen_efi_query_capsule_caps,
> > -	.get_next_high_mono_count = xen_efi_get_next_high_mono_count,
> > -	.reset_system             = xen_efi_reset_system,
> > -	.set_virtual_address_map  = NULL, /* Not used under Xen. */
> > -	.flags			  = 0     /* Initialized later. */
> > -};
> > -
> >  static efi_system_table_t __init *xen_efi_probe(void)
> >  {
> >  	struct xen_platform_op op = {
> > @@ -102,7 +70,18 @@ static efi_system_table_t __init *xen_efi_probe(void)
> >
> >  	/* Here we know that Xen runs on EFI platform. */
> >
> > -	efi = efi_xen;
> > +	efi.get_time = xen_efi_get_time;
> > +	efi.set_time = xen_efi_set_time;
> > +	efi.get_wakeup_time = xen_efi_get_wakeup_time;
> > +	efi.set_wakeup_time = xen_efi_set_wakeup_time;
> > +	efi.get_variable = xen_efi_get_variable;
> > +	efi.get_next_variable = xen_efi_get_next_variable;
> > +	efi.set_variable = xen_efi_set_variable;
> > +	efi.query_variable_info = xen_efi_query_variable_info;
> > +	efi.update_capsule = xen_efi_update_capsule;
> > +	efi.query_capsule_caps = xen_efi_query_capsule_caps;
> > +	efi.get_next_high_mono_count = xen_efi_get_next_high_mono_count;
> > +	efi.reset_system = xen_efi_reset_system;
>
> This presumably means that the system default values are already present
> in efi at the point that we overwrite some Xen specifics?

More or less.

> If so, surely you need to retain the clobbering of set_virtual_address_map ?

Nope, by default efi.set_virtual_address_map is NULL (please take a look
at efi struct initialization in drivers/firmware/efi/efi.c). And it is
not touched if efi_enabled(EFI_PARAVIRT).

Daniel
Daniel Kiper June 21, 2017, 9:32 a.m. UTC | #5 
On Wed, Jun 21, 2017 at 11:24:06AM +0200, Ingo Molnar wrote:
>
> * Daniel Kiper <daniel.kiper@oracle.com> wrote:
>
> > -static const struct efi efi_xen __initconst = {
> > -	.systab                   = NULL, /* Initialized later. */
> > -	.runtime_version	  = 0,    /* Initialized later. */
> > -	.mps                      = EFI_INVALID_TABLE_ADDR,
> > -	.acpi                     = EFI_INVALID_TABLE_ADDR,
> > -	.acpi20                   = EFI_INVALID_TABLE_ADDR,
> > -	.smbios                   = EFI_INVALID_TABLE_ADDR,
> > -	.smbios3                  = EFI_INVALID_TABLE_ADDR,
> > -	.sal_systab               = EFI_INVALID_TABLE_ADDR,
> > -	.boot_info                = EFI_INVALID_TABLE_ADDR,
> > -	.hcdp                     = EFI_INVALID_TABLE_ADDR,
> > -	.uga                      = EFI_INVALID_TABLE_ADDR,
> > -	.uv_systab                = EFI_INVALID_TABLE_ADDR,
> > -	.fw_vendor                = EFI_INVALID_TABLE_ADDR,
> > -	.runtime                  = EFI_INVALID_TABLE_ADDR,
> > -	.config_table             = EFI_INVALID_TABLE_ADDR,
> > -	.get_time                 = xen_efi_get_time,
> > -	.set_time                 = xen_efi_set_time,
> > -	.get_wakeup_time          = xen_efi_get_wakeup_time,
> > -	.set_wakeup_time          = xen_efi_set_wakeup_time,
> > -	.get_variable             = xen_efi_get_variable,
> > -	.get_next_variable        = xen_efi_get_next_variable,
> > -	.set_variable             = xen_efi_set_variable,
> > -	.query_variable_info      = xen_efi_query_variable_info,
> > -	.update_capsule           = xen_efi_update_capsule,
> > -	.query_capsule_caps       = xen_efi_query_capsule_caps,
> > -	.get_next_high_mono_count = xen_efi_get_next_high_mono_count,
> > -	.reset_system             = xen_efi_reset_system,
> > -	.set_virtual_address_map  = NULL, /* Not used under Xen. */
> > -	.flags			  = 0     /* Initialized later. */
> > -};
> > -
> >  static efi_system_table_t __init *xen_efi_probe(void)
> >  {
> >  	struct xen_platform_op op = {
> > @@ -102,7 +70,18 @@ static efi_system_table_t __init *xen_efi_probe(void)
> >
> >  	/* Here we know that Xen runs on EFI platform. */
> >
> > -	efi = efi_xen;
> > +	efi.get_time = xen_efi_get_time;
> > +	efi.set_time = xen_efi_set_time;
> > +	efi.get_wakeup_time = xen_efi_get_wakeup_time;
> > +	efi.set_wakeup_time = xen_efi_set_wakeup_time;
> > +	efi.get_variable = xen_efi_get_variable;
> > +	efi.get_next_variable = xen_efi_get_next_variable;
> > +	efi.set_variable = xen_efi_set_variable;
> > +	efi.query_variable_info = xen_efi_query_variable_info;
> > +	efi.update_capsule = xen_efi_update_capsule;
> > +	efi.query_capsule_caps = xen_efi_query_capsule_caps;
> > +	efi.get_next_high_mono_count = xen_efi_get_next_high_mono_count;
> > +	efi.reset_system = xen_efi_reset_system;
>
> This is a step back stylistically, as you lost the nice vertical tabulation of the
> original initializer ...

If you wish and others do not object I can realign it back.

Daniel
diff mbox

Patch

diff --git a/arch/x86/xen/efi.c b/arch/x86/xen/efi.c
index 30bb2e8..01b9faf 100644
--- a/arch/x86/xen/efi.c
+++ b/arch/x86/xen/efi.c
@@ -54,38 +54,6 @@ 
 	.tables		= EFI_INVALID_TABLE_ADDR  /* Initialized later. */
 };
 
-static const struct efi efi_xen __initconst = {
-	.systab                   = NULL, /* Initialized later. */
-	.runtime_version	  = 0,    /* Initialized later. */
-	.mps                      = EFI_INVALID_TABLE_ADDR,
-	.acpi                     = EFI_INVALID_TABLE_ADDR,
-	.acpi20                   = EFI_INVALID_TABLE_ADDR,
-	.smbios                   = EFI_INVALID_TABLE_ADDR,
-	.smbios3                  = EFI_INVALID_TABLE_ADDR,
-	.sal_systab               = EFI_INVALID_TABLE_ADDR,
-	.boot_info                = EFI_INVALID_TABLE_ADDR,
-	.hcdp                     = EFI_INVALID_TABLE_ADDR,
-	.uga                      = EFI_INVALID_TABLE_ADDR,
-	.uv_systab                = EFI_INVALID_TABLE_ADDR,
-	.fw_vendor                = EFI_INVALID_TABLE_ADDR,
-	.runtime                  = EFI_INVALID_TABLE_ADDR,
-	.config_table             = EFI_INVALID_TABLE_ADDR,
-	.get_time                 = xen_efi_get_time,
-	.set_time                 = xen_efi_set_time,
-	.get_wakeup_time          = xen_efi_get_wakeup_time,
-	.set_wakeup_time          = xen_efi_set_wakeup_time,
-	.get_variable             = xen_efi_get_variable,
-	.get_next_variable        = xen_efi_get_next_variable,
-	.set_variable             = xen_efi_set_variable,
-	.query_variable_info      = xen_efi_query_variable_info,
-	.update_capsule           = xen_efi_update_capsule,
-	.query_capsule_caps       = xen_efi_query_capsule_caps,
-	.get_next_high_mono_count = xen_efi_get_next_high_mono_count,
-	.reset_system             = xen_efi_reset_system,
-	.set_virtual_address_map  = NULL, /* Not used under Xen. */
-	.flags			  = 0     /* Initialized later. */
-};
-
 static efi_system_table_t __init *xen_efi_probe(void)
 {
 	struct xen_platform_op op = {
@@ -102,7 +70,18 @@  static efi_system_table_t __init *xen_efi_probe(void)
 
 	/* Here we know that Xen runs on EFI platform. */
 
-	efi = efi_xen;
+	efi.get_time = xen_efi_get_time;
+	efi.set_time = xen_efi_set_time;
+	efi.get_wakeup_time = xen_efi_get_wakeup_time;
+	efi.set_wakeup_time = xen_efi_set_wakeup_time;
+	efi.get_variable = xen_efi_get_variable;
+	efi.get_next_variable = xen_efi_get_next_variable;
+	efi.set_variable = xen_efi_set_variable;
+	efi.query_variable_info = xen_efi_query_variable_info;
+	efi.update_capsule = xen_efi_update_capsule;
+	efi.query_capsule_caps = xen_efi_query_capsule_caps;
+	efi.get_next_high_mono_count = xen_efi_get_next_high_mono_count;
+	efi.reset_system = xen_efi_reset_system;
 
 	efi_systab_xen.tables = info->cfg.addr;
 	efi_systab_xen.nr_tables = info->cfg.nent;