Instead of using a private macro for an invalid grant reference use
the common one.
Signed-off-by: Juergen Gross <[email protected]>
---
drivers/xen/xen-front-pgdir-shbuf.c | 17 ++++-------------
1 file changed, 4 insertions(+), 13 deletions(-)
diff --git a/drivers/xen/xen-front-pgdir-shbuf.c b/drivers/xen/xen-front-pgdir-shbuf.c
index a959dee21134..fa2921d4fbfc 100644
--- a/drivers/xen/xen-front-pgdir-shbuf.c
+++ b/drivers/xen/xen-front-pgdir-shbuf.c
@@ -21,15 +21,6 @@
#include <xen/xen-front-pgdir-shbuf.h>
-#ifndef GRANT_INVALID_REF
-/*
- * FIXME: usage of grant reference 0 as invalid grant reference:
- * grant reference 0 is valid, but never exposed to a PV driver,
- * because of the fact it is already in use/reserved by the PV console.
- */
-#define GRANT_INVALID_REF 0
-#endif
-
/**
* This structure represents the structure of a shared page
* that contains grant references to the pages of the shared
@@ -83,7 +74,7 @@ grant_ref_t
xen_front_pgdir_shbuf_get_dir_start(struct xen_front_pgdir_shbuf *buf)
{
if (!buf->grefs)
- return GRANT_INVALID_REF;
+ return INVALID_GRANT_REF;
return buf->grefs[0];
}
@@ -142,7 +133,7 @@ void xen_front_pgdir_shbuf_free(struct xen_front_pgdir_shbuf *buf)
int i;
for (i = 0; i < buf->num_grefs; i++)
- if (buf->grefs[i] != GRANT_INVALID_REF)
+ if (buf->grefs[i] != INVALID_GRANT_REF)
gnttab_end_foreign_access(buf->grefs[i], 0UL);
}
kfree(buf->grefs);
@@ -355,7 +346,7 @@ static void backend_fill_page_dir(struct xen_front_pgdir_shbuf *buf)
}
/* Last page must say there is no more pages. */
page_dir = (struct xen_page_directory *)ptr;
- page_dir->gref_dir_next_page = GRANT_INVALID_REF;
+ page_dir->gref_dir_next_page = INVALID_GRANT_REF;
}
/**
@@ -384,7 +375,7 @@ static void guest_fill_page_dir(struct xen_front_pgdir_shbuf *buf)
if (grefs_left <= XEN_NUM_GREFS_PER_PAGE) {
to_copy = grefs_left;
- page_dir->gref_dir_next_page = GRANT_INVALID_REF;
+ page_dir->gref_dir_next_page = INVALID_GRANT_REF;
} else {
to_copy = XEN_NUM_GREFS_PER_PAGE;
page_dir->gref_dir_next_page = buf->grefs[i + 1];
--
2.34.1
Hello Juergen
On 28.04.22 21:03, Oleksandr Tyshchenko wrote:
>
>
> On Thu, Apr 28, 2022 at 11:28 AM Juergen Gross <[email protected]
> <mailto:[email protected]>> wrote:
>
> Hello Juergen
>
> [sorry for the possible format issue]
>
> Instead of using a private macro for an invalid grant reference use
> the common one.
>
> Signed-off-by: Juergen Gross <[email protected]
> <mailto:[email protected]>>
> ---
> drivers/xen/xen-front-pgdir-shbuf.c | 17 ++++-------------
> 1 file changed, 4 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/xen/xen-front-pgdir-shbuf.c
> b/drivers/xen/xen-front-pgdir-shbuf.c
> index a959dee21134..fa2921d4fbfc 100644
> --- a/drivers/xen/xen-front-pgdir-shbuf.c
> +++ b/drivers/xen/xen-front-pgdir-shbuf.c
> @@ -21,15 +21,6 @@
>
> #include <xen/xen-front-pgdir-shbuf.h>
>
> -#ifndef GRANT_INVALID_REF
> -/*
> - * FIXME: usage of grant reference 0 as invalid grant reference:
> - * grant reference 0 is valid, but never exposed to a PV driver,
> - * because of the fact it is already in use/reserved by the PV
> console.
> - */
> -#define GRANT_INVALID_REF 0
> -#endif
> -
> /**
> * This structure represents the structure of a shared page
> * that contains grant references to the pages of the shared
> @@ -83,7 +74,7 @@ grant_ref_t
> xen_front_pgdir_shbuf_get_dir_start(struct xen_front_pgdir_shbuf
> *buf)
> {
> if (!buf->grefs)
> - return GRANT_INVALID_REF;
> + return INVALID_GRANT_REF;
>
> return buf->grefs[0];
> }
> @@ -142,7 +133,7 @@ void xen_front_pgdir_shbuf_free(struct
> xen_front_pgdir_shbuf *buf)
> int i;
>
> for (i = 0; i < buf->num_grefs; i++)
> - if (buf->grefs[i] != GRANT_INVALID_REF)
> + if (buf->grefs[i] != INVALID_GRANT_REF)
> gnttab_end_foreign_access(buf->grefs[i], 0UL);
> }
> kfree(buf->grefs);
> @@ -355,7 +346,7 @@ static void backend_fill_page_dir(struct
> xen_front_pgdir_shbuf *buf)
> }
> /* Last page must say there is no more pages. */
> page_dir = (struct xen_page_directory *)ptr;
> - page_dir->gref_dir_next_page = GRANT_INVALID_REF;
> + page_dir->gref_dir_next_page = INVALID_GRANT_REF;
> }
>
> /**
> @@ -384,7 +375,7 @@ static void guest_fill_page_dir(struct
> xen_front_pgdir_shbuf *buf)
>
> if (grefs_left <= XEN_NUM_GREFS_PER_PAGE) {
> to_copy = grefs_left;
> - page_dir->gref_dir_next_page =
> GRANT_INVALID_REF;
> + page_dir->gref_dir_next_page =
> INVALID_GRANT_REF;
>
>
> I faced an issue with testing PV Sound with the current series.
>
> root@salvator-x-h3-4x2g-xt-domu:~# aplay /media/MoodyLoop.wav
> Playing WAVE '/media/MoodyLoop.wav' : Signed 16 bit Little Endian,
> Rate 44100 Hz, Stereo
> (XEN) common/grant_table.c:1053:d1v2 Bad ref 0xffffffff for d6
>
> Here we have an interesting situation. PV Sound frontend uses this
> xen-front-pgdir-shbuf framework. Technically, this patch changes
> page_dir->gref_dir_next_page (reference to the next page describing
> page directory) from 0 to 0xffffffff here.
> #define INVALID_GRANT_REF ((grant_ref_t)-1)
>
> But according to the protocol (sndif.h), "0" means that there are no
> more pages in the list and the user space backend expects only that
> value. So receiving 0xffffffff it assumes there are pages in the list
> and trying to process...
> https://elixir.bootlin.com/linux/v5.18-rc4/source/include/xen/interface/io/sndif.h#L650
>
>
> I think, the same is relevant to backend_fill_page_dir() as well.
In addition to what I said yesterday:
PV Display also uses this xen-front-pgdir-shbuf framework. It's protocol
(displif.h) also mentions the same as sndif.h if the context of
gref_dir_next_page:
* gref_dir_next_page - grant_ref_t, reference to the next page describing
* page directory. Must be 0 if there are no more pages in the list.
With that local change both PV devices work in my environment.
diff --git a/drivers/xen/xen-front-pgdir-shbuf.c
b/drivers/xen/xen-front-pgdir-shbuf.c
index fa2921d..ad4a88e 100644
--- a/drivers/xen/xen-front-pgdir-shbuf.c
+++ b/drivers/xen/xen-front-pgdir-shbuf.c
@@ -346,7 +346,7 @@ static void backend_fill_page_dir(struct
xen_front_pgdir_shbuf *buf)
}
/* Last page must say there is no more pages. */
page_dir = (struct xen_page_directory *)ptr;
- page_dir->gref_dir_next_page = INVALID_GRANT_REF;
+ page_dir->gref_dir_next_page = 0;
}
/**
@@ -375,7 +375,7 @@ static void guest_fill_page_dir(struct
xen_front_pgdir_shbuf *buf)
if (grefs_left <= XEN_NUM_GREFS_PER_PAGE) {
to_copy = grefs_left;
- page_dir->gref_dir_next_page = INVALID_GRANT_REF;
+ page_dir->gref_dir_next_page = 0;
} else {
to_copy = XEN_NUM_GREFS_PER_PAGE;
page_dir->gref_dir_next_page = buf->grefs[i + 1];
(END)
>
> } else {
> to_copy = XEN_NUM_GREFS_PER_PAGE;
> page_dir->gref_dir_next_page =
> buf->grefs[i + 1];
> --
> 2.34.1
>
>
>
>
> --
> Regards,
>
> Oleksandr Tyshchenko
--
Regards,
Oleksandr Tyshchenko
On 28.04.22 20:03, Oleksandr Tyshchenko wrote:
>
>
> On Thu, Apr 28, 2022 at 11:28 AM Juergen Gross <[email protected]
> <mailto:[email protected]>> wrote:
>
> Hello Juergen
>
> [sorry for the possible format issue]
>
> Instead of using a private macro for an invalid grant reference use
> the common one.
>
> Signed-off-by: Juergen Gross <[email protected] <mailto:[email protected]>>
> ---
> drivers/xen/xen-front-pgdir-shbuf.c | 17 ++++-------------
> 1 file changed, 4 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/xen/xen-front-pgdir-shbuf.c
> b/drivers/xen/xen-front-pgdir-shbuf.c
> index a959dee21134..fa2921d4fbfc 100644
> --- a/drivers/xen/xen-front-pgdir-shbuf.c
> +++ b/drivers/xen/xen-front-pgdir-shbuf.c
> @@ -21,15 +21,6 @@
>
> #include <xen/xen-front-pgdir-shbuf.h>
>
> -#ifndef GRANT_INVALID_REF
> -/*
> - * FIXME: usage of grant reference 0 as invalid grant reference:
> - * grant reference 0 is valid, but never exposed to a PV driver,
> - * because of the fact it is already in use/reserved by the PV console.
> - */
> -#define GRANT_INVALID_REF 0
> -#endif
> -
> /**
> * This structure represents the structure of a shared page
> * that contains grant references to the pages of the shared
> @@ -83,7 +74,7 @@ grant_ref_t
> xen_front_pgdir_shbuf_get_dir_start(struct xen_front_pgdir_shbuf *buf)
> {
> if (!buf->grefs)
> - return GRANT_INVALID_REF;
> + return INVALID_GRANT_REF;
>
> return buf->grefs[0];
> }
> @@ -142,7 +133,7 @@ void xen_front_pgdir_shbuf_free(struct
> xen_front_pgdir_shbuf *buf)
> int i;
>
> for (i = 0; i < buf->num_grefs; i++)
> - if (buf->grefs[i] != GRANT_INVALID_REF)
> + if (buf->grefs[i] != INVALID_GRANT_REF)
> gnttab_end_foreign_access(buf->grefs[i], 0UL);
> }
> kfree(buf->grefs);
> @@ -355,7 +346,7 @@ static void backend_fill_page_dir(struct
> xen_front_pgdir_shbuf *buf)
> }
> /* Last page must say there is no more pages. */
> page_dir = (struct xen_page_directory *)ptr;
> - page_dir->gref_dir_next_page = GRANT_INVALID_REF;
> + page_dir->gref_dir_next_page = INVALID_GRANT_REF;
> }
>
> /**
> @@ -384,7 +375,7 @@ static void guest_fill_page_dir(struct
> xen_front_pgdir_shbuf *buf)
>
> if (grefs_left <= XEN_NUM_GREFS_PER_PAGE) {
> to_copy = grefs_left;
> - page_dir->gref_dir_next_page = GRANT_INVALID_REF;
> + page_dir->gref_dir_next_page = INVALID_GRANT_REF;
>
>
> I faced an issue with testing PV Sound with the current series.
>
> root@salvator-x-h3-4x2g-xt-domu:~# aplay /media/MoodyLoop.wav
> Playing WAVE '/media/MoodyLoop.wav' : Signed 16 bit Little Endian, Rate 44100
> Hz, Stereo
> (XEN) common/grant_table.c:1053:d1v2 Bad ref 0xffffffff for d6
>
> Here we have an interesting situation. PV Sound frontend uses this
> xen-front-pgdir-shbuf framework. Technically, this patch changes
> page_dir->gref_dir_next_page (reference to the next page describing page
> directory) from 0 to 0xffffffff here.
> #define INVALID_GRANT_REF ((grant_ref_t)-1)
>
> But according to the protocol (sndif.h), "0" means that there are no more pages
> in the list and the user space backend expects only that value. So
> receiving 0xffffffff it assumes there are pages in the list and trying to
> process...
Hmm, that's unfortunate.
> https://elixir.bootlin.com/linux/v5.18-rc4/source/include/xen/interface/io/sndif.h#L650
> <https://elixir.bootlin.com/linux/v5.18-rc4/source/include/xen/interface/io/sndif.h#L650>
>
>
> I think, the same is relevant to backend_fill_page_dir() as well.
Thanks for finding this.
Juergen
On 02.05.22 16:31, Juergen Gross wrote:
Hello Juergen
> On 29.04.22 17:28, Oleksandr wrote:
>>
>> Hello Juergen
>>
>>
>> On 28.04.22 21:03, Oleksandr Tyshchenko wrote:
>>>
>>>
>>> On Thu, Apr 28, 2022 at 11:28 AM Juergen Gross <[email protected]
>>> <mailto:[email protected]>> wrote:
>>>
>>> Hello Juergen
>>>
>>> [sorry for the possible format issue]
>>>
>>> Instead of using a private macro for an invalid grant reference use
>>> the common one.
>>>
>>> Signed-off-by: Juergen Gross <[email protected]
>>> <mailto:[email protected]>>
>>> ---
>>> drivers/xen/xen-front-pgdir-shbuf.c | 17 ++++-------------
>>> 1 file changed, 4 insertions(+), 13 deletions(-)
>>>
>>> diff --git a/drivers/xen/xen-front-pgdir-shbuf.c
>>> b/drivers/xen/xen-front-pgdir-shbuf.c
>>> index a959dee21134..fa2921d4fbfc 100644
>>> --- a/drivers/xen/xen-front-pgdir-shbuf.c
>>> +++ b/drivers/xen/xen-front-pgdir-shbuf.c
>>> @@ -21,15 +21,6 @@
>>>
>>> #include <xen/xen-front-pgdir-shbuf.h>
>>>
>>> -#ifndef GRANT_INVALID_REF
>>> -/*
>>> - * FIXME: usage of grant reference 0 as invalid grant reference:
>>> - * grant reference 0 is valid, but never exposed to a PV driver,
>>> - * because of the fact it is already in use/reserved by the PV
>>> console.
>>> - */
>>> -#define GRANT_INVALID_REF 0
>>> -#endif
>>> -
>>> /**
>>> * This structure represents the structure of a shared page
>>> * that contains grant references to the pages of the shared
>>> @@ -83,7 +74,7 @@ grant_ref_t
>>> xen_front_pgdir_shbuf_get_dir_start(struct xen_front_pgdir_shbuf
>>> *buf)
>>> {
>>> if (!buf->grefs)
>>> - return GRANT_INVALID_REF;
>>> + return INVALID_GRANT_REF;
>>>
>>> return buf->grefs[0];
>>> }
>>> @@ -142,7 +133,7 @@ void xen_front_pgdir_shbuf_free(struct
>>> xen_front_pgdir_shbuf *buf)
>>> int i;
>>>
>>> for (i = 0; i < buf->num_grefs; i++)
>>> - if (buf->grefs[i] != GRANT_INVALID_REF)
>>> + if (buf->grefs[i] != INVALID_GRANT_REF)
>>> gnttab_end_foreign_access(buf->grefs[i], 0UL);
>>> }
>>> kfree(buf->grefs);
>>> @@ -355,7 +346,7 @@ static void backend_fill_page_dir(struct
>>> xen_front_pgdir_shbuf *buf)
>>> }
>>> /* Last page must say there is no more pages. */
>>> page_dir = (struct xen_page_directory *)ptr;
>>> - page_dir->gref_dir_next_page = GRANT_INVALID_REF;
>>> + page_dir->gref_dir_next_page = INVALID_GRANT_REF;
>>> }
>>>
>>> /**
>>> @@ -384,7 +375,7 @@ static void guest_fill_page_dir(struct
>>> xen_front_pgdir_shbuf *buf)
>>>
>>> if (grefs_left <= XEN_NUM_GREFS_PER_PAGE) {
>>> to_copy = grefs_left;
>>> - page_dir->gref_dir_next_page =
>>> GRANT_INVALID_REF;
>>> + page_dir->gref_dir_next_page =
>>> INVALID_GRANT_REF;
>>>
>>>
>>> I faced an issue with testing PV Sound with the current series.
>>>
>>> root@salvator-x-h3-4x2g-xt-domu:~# aplay /media/MoodyLoop.wav
>>> Playing WAVE '/media/MoodyLoop.wav' : Signed 16 bit Little Endian,
>>> Rate 44100 Hz, Stereo
>>> (XEN) common/grant_table.c:1053:d1v2 Bad ref 0xffffffff for d6
>>>
>>> Here we have an interesting situation. PV Sound frontend uses this
>>> xen-front-pgdir-shbuf framework. Technically, this patch changes
>>> page_dir->gref_dir_next_page (reference to the next page describing
>>> page directory) from 0 to 0xffffffff here.
>>> #define INVALID_GRANT_REF ((grant_ref_t)-1)
>>>
>>> But according to the protocol (sndif.h), "0" means that there are no
>>> more pages in the list and the user space backend expects only that
>>> value. So receiving 0xffffffff it assumes there are pages in the
>>> list and trying to process...
>>> https://elixir.bootlin.com/linux/v5.18-rc4/source/include/xen/interface/io/sndif.h#L650
>>>
>>>
>>>
>>> I think, the same is relevant to backend_fill_page_dir() as well.
>>
>>
>> In addition to what I said yesterday:
>>
>> PV Display also uses this xen-front-pgdir-shbuf framework. It's
>> protocol (displif.h) also mentions the same as sndif.h if the context
>> of gref_dir_next_page:
>>
>> * gref_dir_next_page - grant_ref_t, reference to the next page
>> describing
>> * page directory. Must be 0 if there are no more pages in the list.
>>
>>
>> With that local change both PV devices work in my environment.
>>
>> diff --git a/drivers/xen/xen-front-pgdir-shbuf.c
>> b/drivers/xen/xen-front-pgdir-shbuf.c
>> index fa2921d..ad4a88e 100644
>> --- a/drivers/xen/xen-front-pgdir-shbuf.c
>> +++ b/drivers/xen/xen-front-pgdir-shbuf.c
>> @@ -346,7 +346,7 @@ static void backend_fill_page_dir(struct
>> xen_front_pgdir_shbuf *buf)
>> }
>> /* Last page must say there is no more pages. */
>> page_dir = (struct xen_page_directory *)ptr;
>> - page_dir->gref_dir_next_page = INVALID_GRANT_REF;
>> + page_dir->gref_dir_next_page = 0;
>> }
>>
>> /**
>> @@ -375,7 +375,7 @@ static void guest_fill_page_dir(struct
>> xen_front_pgdir_shbuf *buf)
>>
>> if (grefs_left <= XEN_NUM_GREFS_PER_PAGE) {
>> to_copy = grefs_left;
>> - page_dir->gref_dir_next_page =
>> INVALID_GRANT_REF;
>> + page_dir->gref_dir_next_page = 0;
>> } else {
>> to_copy = XEN_NUM_GREFS_PER_PAGE;
>> page_dir->gref_dir_next_page = buf->grefs[i
>> + 1];
>
> I think I'll introduce a proper define for that purpose.
I think it would be the best option.
>
>
>
> Juergen
--
Regards,
Oleksandr Tyshchenko
On 29.04.22 17:28, Oleksandr wrote:
>
> Hello Juergen
>
>
> On 28.04.22 21:03, Oleksandr Tyshchenko wrote:
>>
>>
>> On Thu, Apr 28, 2022 at 11:28 AM Juergen Gross <[email protected]
>> <mailto:[email protected]>> wrote:
>>
>> Hello Juergen
>>
>> [sorry for the possible format issue]
>>
>> Instead of using a private macro for an invalid grant reference use
>> the common one.
>>
>> Signed-off-by: Juergen Gross <[email protected]
>> <mailto:[email protected]>>
>> ---
>> drivers/xen/xen-front-pgdir-shbuf.c | 17 ++++-------------
>> 1 file changed, 4 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/xen/xen-front-pgdir-shbuf.c
>> b/drivers/xen/xen-front-pgdir-shbuf.c
>> index a959dee21134..fa2921d4fbfc 100644
>> --- a/drivers/xen/xen-front-pgdir-shbuf.c
>> +++ b/drivers/xen/xen-front-pgdir-shbuf.c
>> @@ -21,15 +21,6 @@
>>
>> #include <xen/xen-front-pgdir-shbuf.h>
>>
>> -#ifndef GRANT_INVALID_REF
>> -/*
>> - * FIXME: usage of grant reference 0 as invalid grant reference:
>> - * grant reference 0 is valid, but never exposed to a PV driver,
>> - * because of the fact it is already in use/reserved by the PV
>> console.
>> - */
>> -#define GRANT_INVALID_REF 0
>> -#endif
>> -
>> /**
>> * This structure represents the structure of a shared page
>> * that contains grant references to the pages of the shared
>> @@ -83,7 +74,7 @@ grant_ref_t
>> xen_front_pgdir_shbuf_get_dir_start(struct xen_front_pgdir_shbuf
>> *buf)
>> {
>> if (!buf->grefs)
>> - return GRANT_INVALID_REF;
>> + return INVALID_GRANT_REF;
>>
>> return buf->grefs[0];
>> }
>> @@ -142,7 +133,7 @@ void xen_front_pgdir_shbuf_free(struct
>> xen_front_pgdir_shbuf *buf)
>> int i;
>>
>> for (i = 0; i < buf->num_grefs; i++)
>> - if (buf->grefs[i] != GRANT_INVALID_REF)
>> + if (buf->grefs[i] != INVALID_GRANT_REF)
>> gnttab_end_foreign_access(buf->grefs[i], 0UL);
>> }
>> kfree(buf->grefs);
>> @@ -355,7 +346,7 @@ static void backend_fill_page_dir(struct
>> xen_front_pgdir_shbuf *buf)
>> }
>> /* Last page must say there is no more pages. */
>> page_dir = (struct xen_page_directory *)ptr;
>> - page_dir->gref_dir_next_page = GRANT_INVALID_REF;
>> + page_dir->gref_dir_next_page = INVALID_GRANT_REF;
>> }
>>
>> /**
>> @@ -384,7 +375,7 @@ static void guest_fill_page_dir(struct
>> xen_front_pgdir_shbuf *buf)
>>
>> if (grefs_left <= XEN_NUM_GREFS_PER_PAGE) {
>> to_copy = grefs_left;
>> - page_dir->gref_dir_next_page =
>> GRANT_INVALID_REF;
>> + page_dir->gref_dir_next_page =
>> INVALID_GRANT_REF;
>>
>>
>> I faced an issue with testing PV Sound with the current series.
>>
>> root@salvator-x-h3-4x2g-xt-domu:~# aplay /media/MoodyLoop.wav
>> Playing WAVE '/media/MoodyLoop.wav' : Signed 16 bit Little Endian, Rate 44100
>> Hz, Stereo
>> (XEN) common/grant_table.c:1053:d1v2 Bad ref 0xffffffff for d6
>>
>> Here we have an interesting situation. PV Sound frontend uses this
>> xen-front-pgdir-shbuf framework. Technically, this patch changes
>> page_dir->gref_dir_next_page (reference to the next page describing page
>> directory) from 0 to 0xffffffff here.
>> #define INVALID_GRANT_REF ((grant_ref_t)-1)
>>
>> But according to the protocol (sndif.h), "0" means that there are no more
>> pages in the list and the user space backend expects only that value. So
>> receiving 0xffffffff it assumes there are pages in the list and trying to
>> process...
>> https://elixir.bootlin.com/linux/v5.18-rc4/source/include/xen/interface/io/sndif.h#L650
>>
>>
>>
>> I think, the same is relevant to backend_fill_page_dir() as well.
>
>
> In addition to what I said yesterday:
>
> PV Display also uses this xen-front-pgdir-shbuf framework. It's protocol
> (displif.h) also mentions the same as sndif.h if the context of gref_dir_next_page:
>
> * gref_dir_next_page - grant_ref_t, reference to the next page describing
> * page directory. Must be 0 if there are no more pages in the list.
>
>
> With that local change both PV devices work in my environment.
>
> diff --git a/drivers/xen/xen-front-pgdir-shbuf.c
> b/drivers/xen/xen-front-pgdir-shbuf.c
> index fa2921d..ad4a88e 100644
> --- a/drivers/xen/xen-front-pgdir-shbuf.c
> +++ b/drivers/xen/xen-front-pgdir-shbuf.c
> @@ -346,7 +346,7 @@ static void backend_fill_page_dir(struct
> xen_front_pgdir_shbuf *buf)
> }
> /* Last page must say there is no more pages. */
> page_dir = (struct xen_page_directory *)ptr;
> - page_dir->gref_dir_next_page = INVALID_GRANT_REF;
> + page_dir->gref_dir_next_page = 0;
> }
>
> /**
> @@ -375,7 +375,7 @@ static void guest_fill_page_dir(struct xen_front_pgdir_shbuf
> *buf)
>
> if (grefs_left <= XEN_NUM_GREFS_PER_PAGE) {
> to_copy = grefs_left;
> - page_dir->gref_dir_next_page = INVALID_GRANT_REF;
> + page_dir->gref_dir_next_page = 0;
> } else {
> to_copy = XEN_NUM_GREFS_PER_PAGE;
> page_dir->gref_dir_next_page = buf->grefs[i + 1];
I think I'll introduce a proper define for that purpose.
Juergen