[PATCH v6 08/44] x86/boot: convert mod refs to boot_module mod

Daniel P. Smith posted 44 patches 1 month ago
There is a newer version of this series
[PATCH v6 08/44] x86/boot: convert mod refs to boot_module mod
Posted by Daniel P. Smith 1 month ago
To allow a slow conversion of x86 over to struct boot_module, start with
replacing all references to module_t mod, only in setup.c, to the mod element
of struct boot_module. These serves twofold, first to allow the incremental
transition from module_t fields to struct boot_module fields. The second is to
allow the conversion of function definitions from taking module_t parameters to
accepting struct boot_module as needed when a transitioned field will be
accessed.

Signed-off-by: Daniel P. Smith <dpsmith@apertussolutions.com>
---
Changes since v5:
- rewrote commit message
- coding style changes
- added comment for initial_images assignment
---
 xen/arch/x86/setup.c | 64 +++++++++++++++++++++++++-------------------
 1 file changed, 37 insertions(+), 27 deletions(-)

diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index 11e1027d72dd..1b56eaf26efe 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -1341,15 +1341,19 @@ void asmlinkage __init noreturn __start_xen(unsigned long mbi_p)
     set_kexec_crash_area_size((u64)nr_pages << PAGE_SHIFT);
     kexec_reserve_area();
 
-    initial_images = mod;
+    /*
+     * The field bi->mods[0].mod points to the first element of the module_t
+     * array.
+     */
+    initial_images = bi->mods[0].mod;
 
     for ( i = 0; !efi_enabled(EFI_LOADER) && i < bi->nr_modules; i++ )
     {
-        if ( mod[i].mod_start & (PAGE_SIZE - 1) )
+        if ( bi->mods[i].mod->mod_start & (PAGE_SIZE - 1) )
             panic("Bootloader didn't honor module alignment request\n");
-        mod[i].mod_end -= mod[i].mod_start;
-        mod[i].mod_start >>= PAGE_SHIFT;
-        mod[i].reserved = 0;
+        bi->mods[i].mod->mod_end -= bi->mods[i].mod->mod_start;
+        bi->mods[i].mod->mod_start >>= PAGE_SHIFT;
+        bi->mods[i].mod->reserved = 0;
     }
 
     /*
@@ -1360,6 +1364,7 @@ void asmlinkage __init noreturn __start_xen(unsigned long mbi_p)
 
     if ( xen_phys_start )
     {
+        unsigned int xen = bi->nr_modules;
         relocated = true;
 
         /*
@@ -1367,8 +1372,8 @@ void asmlinkage __init noreturn __start_xen(unsigned long mbi_p)
          * respective reserve_e820_ram() invocation below. No need to
          * query efi_boot_mem_unused() here, though.
          */
-        mod[bi->nr_modules].mod_start = virt_to_mfn(_stext);
-        mod[bi->nr_modules].mod_end = __2M_rwdata_end - _stext;
+        bi->mods[xen].mod->mod_start = virt_to_mfn(_stext);
+        bi->mods[xen].mod->mod_end = __2M_rwdata_end - _stext;
     }
 
     bi->mods[0].headroom =
@@ -1460,9 +1465,9 @@ void asmlinkage __init noreturn __start_xen(unsigned long mbi_p)
              * move mod[0], we incorporate this as extra space at the start.
              */
             struct boot_module *bm = &bi->mods[j];
-            unsigned long size = PAGE_ALIGN(bm->headroom + mod[j].mod_end);
+            unsigned long size = PAGE_ALIGN(bm->headroom + bm->mod->mod_end);
 
-            if ( mod[j].reserved )
+            if ( bi->mods[j].mod->reserved )
                 continue;
 
             /* Don't overlap with other modules (or Xen itself). */
@@ -1474,14 +1479,14 @@ void asmlinkage __init noreturn __start_xen(unsigned long mbi_p)
 
             if ( s < end &&
                  (bm->headroom ||
-                  ((end - size) >> PAGE_SHIFT) > mod[j].mod_start) )
+                  ((end - size) >> PAGE_SHIFT) > bm->mod->mod_start) )
             {
                 move_memory(end - size + bm->headroom,
-                            (uint64_t)mod[j].mod_start << PAGE_SHIFT,
-                            mod[j].mod_end);
-                mod[j].mod_start = (end - size) >> PAGE_SHIFT;
-                mod[j].mod_end += bm->headroom;
-                mod[j].reserved = 1;
+                            (uint64_t)bm->mod->mod_start << PAGE_SHIFT,
+                            bm->mod->mod_end);
+                bm->mod->mod_start = (end - size) >> PAGE_SHIFT;
+                bm->mod->mod_end += bm->headroom;
+                bm->mod->reserved = 1;
             }
         }
 
@@ -1507,13 +1512,15 @@ void asmlinkage __init noreturn __start_xen(unsigned long mbi_p)
 #endif
     }
 
-    if ( bi->mods[0].headroom && !mod->reserved )
+    if ( bi->mods[0].headroom && !bi->mods[0].mod->reserved )
         panic("Not enough memory to relocate the dom0 kernel image\n");
     for ( i = 0; i < bi->nr_modules; ++i )
     {
-        uint64_t s = (uint64_t)mod[i].mod_start << PAGE_SHIFT;
+        uint64_t s = (uint64_t)bi->mods[i].mod->mod_start
+                        << PAGE_SHIFT;
 
-        reserve_e820_ram(&boot_e820, s, s + PAGE_ALIGN(mod[i].mod_end));
+        reserve_e820_ram(&boot_e820, s,
+                         s + PAGE_ALIGN(bi->mods[i].mod->mod_end));
     }
 
     if ( !xen_phys_start )
@@ -1591,8 +1598,9 @@ void asmlinkage __init noreturn __start_xen(unsigned long mbi_p)
                 map_e = boot_e820.map[j].addr + boot_e820.map[j].size;
                 for ( j = 0; j < bi->nr_modules; ++j )
                 {
-                    uint64_t end = pfn_to_paddr(mod[j].mod_start) +
-                                   mod[j].mod_end;
+                    uint64_t end = pfn_to_paddr(
+                                   bi->mods[j].mod->mod_start) +
+                                   bi->mods[j].mod->mod_end;
 
                     if ( map_e < end )
                         map_e = end;
@@ -1666,11 +1674,12 @@ void asmlinkage __init noreturn __start_xen(unsigned long mbi_p)
 
     for ( i = 0; i < bi->nr_modules; ++i )
     {
-        set_pdx_range(mod[i].mod_start,
-                      mod[i].mod_start + PFN_UP(mod[i].mod_end));
-        map_pages_to_xen((unsigned long)mfn_to_virt(mod[i].mod_start),
-                         _mfn(mod[i].mod_start),
-                         PFN_UP(mod[i].mod_end), PAGE_HYPERVISOR);
+        set_pdx_range(bi->mods[i].mod->mod_start,
+                      bi->mods[i].mod->mod_start +
+                      PFN_UP(bi->mods[i].mod->mod_end));
+        map_pages_to_xen((unsigned long)mfn_to_virt(bi->mods[i].mod->mod_start),
+            _mfn(bi->mods[i].mod->mod_start),
+            PFN_UP(bi->mods[i].mod->mod_end), PAGE_HYPERVISOR);
     }
 
 #ifdef CONFIG_KEXEC
@@ -2059,8 +2068,9 @@ void asmlinkage __init noreturn __start_xen(unsigned long mbi_p)
      * We're going to setup domain0 using the module(s) that we stashed safely
      * above our heap. The second module, if present, is an initrd ramdisk.
      */
-    dom0 = create_dom0(mod, bi->mods[0].headroom,
-                       initrdidx < bi->nr_modules ? mod + initrdidx : NULL,
+    dom0 = create_dom0(bi->mods[0].mod, bi->mods[0].headroom,
+                       initrdidx < bi->nr_modules ? bi->mods[initrdidx].mod
+                                                  : NULL,
                        kextra, bi->loader);
     if ( !dom0 )
         panic("Could not set up DOM0 guest OS\n");
-- 
2.30.2
Re: [PATCH v6 08/44] x86/boot: convert mod refs to boot_module mod
Posted by Jason Andryuk 1 month ago
On 2024-10-17 13:02, Daniel P. Smith wrote:
> To allow a slow conversion of x86 over to struct boot_module, start with
> replacing all references to module_t mod, only in setup.c, to the mod element
> of struct boot_module. These serves twofold, first to allow the incremental
> transition from module_t fields to struct boot_module fields. The second is to
> allow the conversion of function definitions from taking module_t parameters to
> accepting struct boot_module as needed when a transitioned field will be
> accessed.
> 
> Signed-off-by: Daniel P. Smith <dpsmith@apertussolutions.com>
> ---
> Changes since v5:
> - rewrote commit message
> - coding style changes
> - added comment for initial_images assignment
> ---
>   xen/arch/x86/setup.c | 64 +++++++++++++++++++++++++-------------------
>   1 file changed, 37 insertions(+), 27 deletions(-)
> 
> diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
> index 11e1027d72dd..1b56eaf26efe 100644
> --- a/xen/arch/x86/setup.c
> +++ b/xen/arch/x86/setup.c

> @@ -1460,9 +1465,9 @@ void asmlinkage __init noreturn __start_xen(unsigned long mbi_p)
>                * move mod[0], we incorporate this as extra space at the start.
>                */
>               struct boot_module *bm = &bi->mods[j];
> -            unsigned long size = PAGE_ALIGN(bm->headroom + mod[j].mod_end);
> +            unsigned long size = PAGE_ALIGN(bm->headroom + bm->mod->mod_end);
>   
> -            if ( mod[j].reserved )
> +            if ( bi->mods[j].mod->reserved )

Use bm->mod->reserved here?

>                   continue;
>   
>               /* Don't overlap with other modules (or Xen itself). */

> @@ -1591,8 +1598,9 @@ void asmlinkage __init noreturn __start_xen(unsigned long mbi_p)
>                   map_e = boot_e820.map[j].addr + boot_e820.map[j].size;
>                   for ( j = 0; j < bi->nr_modules; ++j )
>                   {
> -                    uint64_t end = pfn_to_paddr(mod[j].mod_start) +
> -                                   mod[j].mod_end;
> +                    uint64_t end = pfn_to_paddr(
> +                                   bi->mods[j].mod->mod_start) +

pfn_to_paddr and mod_start can fit on one line

> +                                   bi->mods[j].mod->mod_end;
>   
>                       if ( map_e < end )
>                           map_e = end;
> @@ -1666,11 +1674,12 @@ void asmlinkage __init noreturn __start_xen(unsigned long mbi_p)
>   
>       for ( i = 0; i < bi->nr_modules; ++i )
>       {
> -        set_pdx_range(mod[i].mod_start,
> -                      mod[i].mod_start + PFN_UP(mod[i].mod_end));
> -        map_pages_to_xen((unsigned long)mfn_to_virt(mod[i].mod_start),
> -                         _mfn(mod[i].mod_start),
> -                         PFN_UP(mod[i].mod_end), PAGE_HYPERVISOR);
> +        set_pdx_range(bi->mods[i].mod->mod_start,
> +                      bi->mods[i].mod->mod_start +
> +                      PFN_UP(bi->mods[i].mod->mod_end));

Indent PFN_UP since it's a continuation of the previous argument?

> +        map_pages_to_xen((unsigned long)mfn_to_virt(bi->mods[i].mod->mod_start),
> +            _mfn(bi->mods[i].mod->mod_start),
> +            PFN_UP(bi->mods[i].mod->mod_end), PAGE_HYPERVISOR);
>       }
>   
>   #ifdef CONFIG_KEXEC

Regards,
Jason
Re: [PATCH v6 08/44] x86/boot: convert mod refs to boot_module mod
Posted by Daniel P. Smith 1 month ago
On 10/17/24 19:02, Jason Andryuk wrote:
> On 2024-10-17 13:02, Daniel P. Smith wrote:
>> To allow a slow conversion of x86 over to struct boot_module, start with
>> replacing all references to module_t mod, only in setup.c, to the mod 
>> element
>> of struct boot_module. These serves twofold, first to allow the 
>> incremental
>> transition from module_t fields to struct boot_module fields. The 
>> second is to
>> allow the conversion of function definitions from taking module_t 
>> parameters to
>> accepting struct boot_module as needed when a transitioned field will be
>> accessed.
>>
>> Signed-off-by: Daniel P. Smith <dpsmith@apertussolutions.com>
>> ---
>> Changes since v5:
>> - rewrote commit message
>> - coding style changes
>> - added comment for initial_images assignment
>> ---
>>   xen/arch/x86/setup.c | 64 +++++++++++++++++++++++++-------------------
>>   1 file changed, 37 insertions(+), 27 deletions(-)
>>
>> diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
>> index 11e1027d72dd..1b56eaf26efe 100644
>> --- a/xen/arch/x86/setup.c
>> +++ b/xen/arch/x86/setup.c
> 
>> @@ -1460,9 +1465,9 @@ void asmlinkage __init noreturn 
>> __start_xen(unsigned long mbi_p)
>>                * move mod[0], we incorporate this as extra space at 
>> the start.
>>                */
>>               struct boot_module *bm = &bi->mods[j];
>> -            unsigned long size = PAGE_ALIGN(bm->headroom + 
>> mod[j].mod_end);
>> +            unsigned long size = PAGE_ALIGN(bm->headroom + 
>> bm->mod->mod_end);
>> -            if ( mod[j].reserved )
>> +            if ( bi->mods[j].mod->reserved )
> 
> Use bm->mod->reserved here?

Yah, that would be better.

>>                   continue;
>>               /* Don't overlap with other modules (or Xen itself). */
> 
>> @@ -1591,8 +1598,9 @@ void asmlinkage __init noreturn 
>> __start_xen(unsigned long mbi_p)
>>                   map_e = boot_e820.map[j].addr + boot_e820.map[j].size;
>>                   for ( j = 0; j < bi->nr_modules; ++j )
>>                   {
>> -                    uint64_t end = pfn_to_paddr(mod[j].mod_start) +
>> -                                   mod[j].mod_end;
>> +                    uint64_t end = pfn_to_paddr(
>> +                                   bi->mods[j].mod->mod_start) +
> 
> pfn_to_paddr and mod_start can fit on one line

I will check but you have to also account for the '+' as generally it 
should stay with the LHS.

>> +                                   bi->mods[j].mod->mod_end;
>>                       if ( map_e < end )
>>                           map_e = end;
>> @@ -1666,11 +1674,12 @@ void asmlinkage __init noreturn 
>> __start_xen(unsigned long mbi_p)
>>       for ( i = 0; i < bi->nr_modules; ++i )
>>       {
>> -        set_pdx_range(mod[i].mod_start,
>> -                      mod[i].mod_start + PFN_UP(mod[i].mod_end));
>> -        map_pages_to_xen((unsigned long)mfn_to_virt(mod[i].mod_start),
>> -                         _mfn(mod[i].mod_start),
>> -                         PFN_UP(mod[i].mod_end), PAGE_HYPERVISOR);
>> +        set_pdx_range(bi->mods[i].mod->mod_start,
>> +                      bi->mods[i].mod->mod_start +
>> +                      PFN_UP(bi->mods[i].mod->mod_end));
> 
> Indent PFN_UP since it's a continuation of the previous argument?

Ack.


v/r,
dps