Re: [Xen-devel] [PATCH v3 08/10] xen: add capability to load initrd outside of initial mapping
On Thu, Feb 18, 2016 at 01:43:33PM +0100, Juergen Gross wrote:
> On 18/02/16 12:18, Daniel Kiper wrote:
> > On Wed, Feb 17, 2016 at 06:19:35PM +0100, Juergen Gross wrote:
> >> Modern pvops linux kernels support an initrd not covered by the initial
> >> mapping. This capability is flagged by an elf-note.
> >>
> >> In case the elf-note is set by the kernel don't place the initrd into
> >> the initial mapping. This will allow to load larger initrds and/or
> >> support domains with larger memory, as the initial mapping is limited
> >> to 2GB and it is containing the p2m list.
> >>
> >> Signed-off-by: Juergen Gross
> >
> > One nitpick.
> >
> > Reviewed-by: Daniel Kiper
> >
> >> ---
> >> grub-core/loader/i386/xen.c| 61
> >> ++
> >> grub-core/loader/i386/xen_fileXX.c | 3 ++
> >> include/grub/xen_file.h| 1 +
> >> 3 files changed, 52 insertions(+), 13 deletions(-)
> >>
> >> diff --git a/grub-core/loader/i386/xen.c b/grub-core/loader/i386/xen.c
> >> index 3bcf4c8..7ac74f6 100644
> >> --- a/grub-core/loader/i386/xen.c
> >> +++ b/grub-core/loader/i386/xen.c
> >> @@ -58,6 +58,7 @@ struct xen_loader_state {
> >>grub_uint64_t modules_target_start;
> >>grub_size_t n_modules;
> >>int loaded;
> >> + int alloc_end_called;
> >> };
> >>
> >> static struct xen_loader_state xen_state;
> >> @@ -320,6 +321,28 @@ grub_xen_pt_alloc (void)
> >> }
> >>
> >> static grub_err_t
> >> +grub_xen_alloc_end (void)
> >
> > Why is it called grub_xen_alloc_end()?
> > Could we use just grub_xen_alloc()?
>
> We could, of course. I just wanted to make clear that this function will
> do the allocations needed to be at the end of the allocation process.
> Naming it grub_xen_alloc() would make it occur to be a very basic
> allocation function, which just isn't true. What about
> grub_xen_alloc_rest()?
My order of preference is: grub_xen_alloc_final() or grub_xen_alloc_last() or
grub_xen_alloc_end() or grub_xen_alloc_rest().
Choose one which is best for you.
Daniel
___
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel
Re: [Xen-devel] [PATCH v3 08/10] xen: add capability to load initrd outside of initial mapping
On 18/02/16 12:18, Daniel Kiper wrote:
> On Wed, Feb 17, 2016 at 06:19:35PM +0100, Juergen Gross wrote:
>> Modern pvops linux kernels support an initrd not covered by the initial
>> mapping. This capability is flagged by an elf-note.
>>
>> In case the elf-note is set by the kernel don't place the initrd into
>> the initial mapping. This will allow to load larger initrds and/or
>> support domains with larger memory, as the initial mapping is limited
>> to 2GB and it is containing the p2m list.
>>
>> Signed-off-by: Juergen Gross
>
> One nitpick.
>
> Reviewed-by: Daniel Kiper
>
>> ---
>> grub-core/loader/i386/xen.c| 61
>> ++
>> grub-core/loader/i386/xen_fileXX.c | 3 ++
>> include/grub/xen_file.h| 1 +
>> 3 files changed, 52 insertions(+), 13 deletions(-)
>>
>> diff --git a/grub-core/loader/i386/xen.c b/grub-core/loader/i386/xen.c
>> index 3bcf4c8..7ac74f6 100644
>> --- a/grub-core/loader/i386/xen.c
>> +++ b/grub-core/loader/i386/xen.c
>> @@ -58,6 +58,7 @@ struct xen_loader_state {
>>grub_uint64_t modules_target_start;
>>grub_size_t n_modules;
>>int loaded;
>> + int alloc_end_called;
>> };
>>
>> static struct xen_loader_state xen_state;
>> @@ -320,6 +321,28 @@ grub_xen_pt_alloc (void)
>> }
>>
>> static grub_err_t
>> +grub_xen_alloc_end (void)
>
> Why is it called grub_xen_alloc_end()?
> Could we use just grub_xen_alloc()?
We could, of course. I just wanted to make clear that this function will
do the allocations needed to be at the end of the allocation process.
Naming it grub_xen_alloc() would make it occur to be a very basic
allocation function, which just isn't true. What about
grub_xen_alloc_rest()?
Juergen
___
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel
Re: [Xen-devel] [PATCH v3 08/10] xen: add capability to load initrd outside of initial mapping
On Wed, Feb 17, 2016 at 06:19:35PM +0100, Juergen Gross wrote:
> Modern pvops linux kernels support an initrd not covered by the initial
> mapping. This capability is flagged by an elf-note.
>
> In case the elf-note is set by the kernel don't place the initrd into
> the initial mapping. This will allow to load larger initrds and/or
> support domains with larger memory, as the initial mapping is limited
> to 2GB and it is containing the p2m list.
>
> Signed-off-by: Juergen Gross
One nitpick.
Reviewed-by: Daniel Kiper
> ---
> grub-core/loader/i386/xen.c| 61
> ++
> grub-core/loader/i386/xen_fileXX.c | 3 ++
> include/grub/xen_file.h| 1 +
> 3 files changed, 52 insertions(+), 13 deletions(-)
>
> diff --git a/grub-core/loader/i386/xen.c b/grub-core/loader/i386/xen.c
> index 3bcf4c8..7ac74f6 100644
> --- a/grub-core/loader/i386/xen.c
> +++ b/grub-core/loader/i386/xen.c
> @@ -58,6 +58,7 @@ struct xen_loader_state {
>grub_uint64_t modules_target_start;
>grub_size_t n_modules;
>int loaded;
> + int alloc_end_called;
> };
>
> static struct xen_loader_state xen_state;
> @@ -320,6 +321,28 @@ grub_xen_pt_alloc (void)
> }
>
> static grub_err_t
> +grub_xen_alloc_end (void)
Why is it called grub_xen_alloc_end()?
Could we use just grub_xen_alloc()?
Daniel
___
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel
[Xen-devel] [PATCH v3 08/10] xen: add capability to load initrd outside of initial mapping
Modern pvops linux kernels support an initrd not covered by the initial
mapping. This capability is flagged by an elf-note.
In case the elf-note is set by the kernel don't place the initrd into
the initial mapping. This will allow to load larger initrds and/or
support domains with larger memory, as the initial mapping is limited
to 2GB and it is containing the p2m list.
Signed-off-by: Juergen Gross
---
grub-core/loader/i386/xen.c| 61 ++
grub-core/loader/i386/xen_fileXX.c | 3 ++
include/grub/xen_file.h| 1 +
3 files changed, 52 insertions(+), 13 deletions(-)
diff --git a/grub-core/loader/i386/xen.c b/grub-core/loader/i386/xen.c
index 3bcf4c8..7ac74f6 100644
--- a/grub-core/loader/i386/xen.c
+++ b/grub-core/loader/i386/xen.c
@@ -58,6 +58,7 @@ struct xen_loader_state {
grub_uint64_t modules_target_start;
grub_size_t n_modules;
int loaded;
+ int alloc_end_called;
};
static struct xen_loader_state xen_state;
@@ -320,6 +321,28 @@ grub_xen_pt_alloc (void)
}
static grub_err_t
+grub_xen_alloc_end (void)
+{
+ grub_err_t err;
+
+ if (xen_state.alloc_end_called)
+return GRUB_ERR_NONE;
+ xen_state.alloc_end_called = 1;
+
+ err = grub_xen_p2m_alloc ();
+ if (err)
+return err;
+ err = grub_xen_special_alloc ();
+ if (err)
+return err;
+ err = grub_xen_pt_alloc ();
+ if (err)
+return err;
+
+ return GRUB_ERR_NONE;
+}
+
+static grub_err_t
grub_xen_boot (void)
{
grub_err_t err;
@@ -330,13 +353,7 @@ grub_xen_boot (void)
if (grub_xen_n_allocated_shared_pages)
return grub_error (GRUB_ERR_BUG, "active grants");
- err = grub_xen_p2m_alloc ();
- if (err)
-return err;
- err = grub_xen_special_alloc ();
- if (err)
-return err;
- err = grub_xen_pt_alloc ();
+ err = grub_xen_alloc_end ();
if (err)
return err;
@@ -609,6 +626,13 @@ grub_cmd_initrd (grub_command_t cmd __attribute__
((unused)),
goto fail;
}
+ if (xen_state.xen_inf.unmapped_initrd)
+{
+ err = grub_xen_alloc_end ();
+ if (err)
+ goto fail;
+}
+
if (grub_initrd_init (argc, argv, &initrd_ctx))
goto fail;
@@ -626,14 +650,24 @@ grub_cmd_initrd (grub_command_t cmd __attribute__
((unused)),
goto fail;
}
- xen_state.next_start.mod_start =
-xen_state.max_addr + xen_state.xen_inf.virt_base;
- xen_state.next_start.mod_len = size;
-
- xen_state.max_addr = ALIGN_UP (xen_state.max_addr + size, PAGE_SIZE);
+ if (xen_state.xen_inf.unmapped_initrd)
+{
+ xen_state.next_start.flags |= SIF_MOD_START_PFN;
+ xen_state.next_start.mod_start = xen_state.max_addr >> PAGE_SHIFT;
+ xen_state.next_start.mod_len = size;
+}
+ else
+{
+ xen_state.next_start.mod_start =
+ xen_state.max_addr + xen_state.xen_inf.virt_base;
+ xen_state.next_start.mod_len = size;
+}
grub_dprintf ("xen", "Initrd, addr=0x%x, size=0x%x\n",
- (unsigned) xen_state.next_start.mod_start, (unsigned) size);
+ (unsigned) (xen_state.max_addr + xen_state.xen_inf.virt_base),
+ (unsigned) size);
+
+ xen_state.max_addr = ALIGN_UP (xen_state.max_addr + size, PAGE_SIZE);
fail:
grub_initrd_close (&initrd_ctx);
@@ -685,6 +719,7 @@ grub_cmd_module (grub_command_t cmd __attribute__
((unused)),
if (!xen_state.module_info_page)
{
+ xen_state.xen_inf.unmapped_initrd = 0;
xen_state.n_modules = 0;
xen_state.max_addr = ALIGN_UP (xen_state.max_addr, PAGE_SIZE);
xen_state.modules_target_start = xen_state.max_addr;
diff --git a/grub-core/loader/i386/xen_fileXX.c
b/grub-core/loader/i386/xen_fileXX.c
index 1f7f71d..d68634d 100644
--- a/grub-core/loader/i386/xen_fileXX.c
+++ b/grub-core/loader/i386/xen_fileXX.c
@@ -259,6 +259,9 @@ parse_note (grub_elf_t elf, struct grub_xen_file_info *xi,
descsz == 2 ? 2 : 3) == 0)
xi->arch = GRUB_XEN_FILE_I386;
break;
+ case XEN_ELFNOTE_MOD_START_PFN:
+ xi->unmapped_initrd = !!grub_le_to_cpu32(*(grub_uint32_t *) desc);
+ break;
default:
grub_dprintf ("xen", "unknown note type %d\n", nh->n_type);
break;
diff --git a/include/grub/xen_file.h b/include/grub/xen_file.h
index 4b2ccba..ed749fa 100644
--- a/include/grub/xen_file.h
+++ b/include/grub/xen_file.h
@@ -36,6 +36,7 @@ struct grub_xen_file_info
int has_note;
int has_xen_guest;
int extended_cr3;
+ int unmapped_initrd;
enum
{
GRUB_XEN_FILE_I386 = 1,
--
2.6.2
___
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel
