Transition Xen's command line to being held in struct boot_info.

No functional change intended.

Signed-off-by: Daniel P. Smith <dpsmith@apertussolutions.com>
---
 xen/arch/x86/include/asm/bootinfo.h |  1 +
 xen/arch/x86/setup.c                | 21 +++++++++++++--------
 2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/xen/arch/x86/include/asm/bootinfo.h b/xen/arch/x86/include/asm/bootinfo.h
index e69feb1bb8be..d2ca077d2356 100644
--- a/xen/arch/x86/include/asm/bootinfo.h
+++ b/xen/arch/x86/include/asm/bootinfo.h
@@ -12,6 +12,7 @@ struct boot_info {
     unsigned int nr_mods;
 
     const char *boot_loader_name;
+    const char *cmdline;
 };
 
 #endif
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index 432b7d1701e4..a945fa10555f 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -276,6 +276,8 @@ static int __init cf_check parse_acpi_param(const char *s)
 }
 custom_param("acpi", parse_acpi_param);
 
+static const char *cmdline_cook(const char *p, const char *loader_name);
+
 static const module_t *__initdata initial_images;
 static struct boot_info __initdata *boot_info;
 
@@ -288,6 +290,13 @@ static void __init multiboot_to_bootinfo(multiboot_info_t *mbi)
     info.boot_loader_name = (mbi->flags & MBI_LOADERNAME) ?
                             __va(mbi->boot_loader_name) : "unknown";
 
+    /* Parse the command-line options. */
+    if ( mbi->flags & MBI_CMDLINE )
+        info.cmdline = cmdline_cook(__va(mbi->cmdline),
+                                    info.boot_loader_name);
+    else
+        info.cmdline = "";
+
     boot_info = &info;
 }
 
@@ -996,7 +1005,7 @@ static struct domain *__init create_dom0(const module_t *image,
 
 void asmlinkage __init noreturn __start_xen(unsigned long mbi_p)
 {
-    const char *memmap_type = NULL, *cmdline = "";
+    const char *memmap_type = NULL;
     char *kextra;
     void *bsp_stack;
     struct cpu_info *info = get_cpu_info(), *bsp_info;
@@ -1049,11 +1058,7 @@ void asmlinkage __init noreturn __start_xen(unsigned long mbi_p)
 
     multiboot_to_bootinfo(mbi);
 
-    /* Parse the command-line options. */
-    if ( mbi->flags & MBI_CMDLINE )
-        cmdline = cmdline_cook(__va(mbi->cmdline), boot_info->boot_loader_name);
-
-    if ( (kextra = strstr(cmdline, " -- ")) != NULL )
+    if ( (kextra = strstr(boot_info->cmdline, " -- ")) != NULL )
     {
         /*
          * Options after ' -- ' separator belong to dom0.
@@ -1064,7 +1069,7 @@ void asmlinkage __init noreturn __start_xen(unsigned long mbi_p)
         kextra += 3;
         while ( kextra[1] == ' ' ) kextra++;
     }
-    cmdline_parse(cmdline);
+    cmdline_parse(boot_info->cmdline);
 
     /* Must be after command line argument parsing and before
      * allocing any xenheap structures wanted in lower memory. */
@@ -1094,7 +1099,7 @@ void asmlinkage __init noreturn __start_xen(unsigned long mbi_p)
 
     printk("Bootloader: %s\n", boot_info->boot_loader_name);
 
-    printk("Command line: %s\n", cmdline);
+    printk("Command line: %s\n", boot_info->cmdline);
 
     printk("Xen image load base address: %#lx\n", xen_phys_start);
     if ( hypervisor_name )
-- 
2.30.2

On 30/08/2024 10:46 pm, Daniel P. Smith wrote:
> Transition Xen's command line to being held in struct boot_info.
>
> No functional change intended.
>
> Signed-off-by: Daniel P. Smith <dpsmith@apertussolutions.com>

Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>

> diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
> index 432b7d1701e4..a945fa10555f 100644
> --- a/xen/arch/x86/setup.c
> +++ b/xen/arch/x86/setup.c
> @@ -1049,11 +1058,7 @@ void asmlinkage __init noreturn __start_xen(unsigned long mbi_p)
>  
>      multiboot_to_bootinfo(mbi);
>  
> -    /* Parse the command-line options. */
> -    if ( mbi->flags & MBI_CMDLINE )
> -        cmdline = cmdline_cook(__va(mbi->cmdline), boot_info->boot_loader_name);
> -
> -    if ( (kextra = strstr(cmdline, " -- ")) != NULL )
> +    if ( (kextra = strstr(boot_info->cmdline, " -- ")) != NULL )
>      {
>          /*
>           * Options after ' -- ' separator belong to dom0.
> @@ -1064,7 +1069,7 @@ void asmlinkage __init noreturn __start_xen(unsigned long mbi_p)
>          kextra += 3;
>          while ( kextra[1] == ' ' ) kextra++;
>      }
> -    cmdline_parse(cmdline);
> +    cmdline_parse(boot_info->cmdline);

It would be nice to get this kextra handling out of __start_xen(), but
I'm not entirely sure how.

It shouldn't live in multiboot_fill_boot_info() if that's going to be
split for pvh, yet it really ought to live with the other editing of
bi->cmdline.

Something that is very subtle is that the *kextra = '\0' between these
two hunks ends up truncating bi->cmdline.

Perhaps best to leave it alone until inspiration strikes.

~Andrew

On 9/3/24 19:04, Andrew Cooper wrote:
> On 30/08/2024 10:46 pm, Daniel P. Smith wrote:
>> Transition Xen's command line to being held in struct boot_info.
>>
>> No functional change intended.
>>
>> Signed-off-by: Daniel P. Smith <dpsmith@apertussolutions.com>
> 
> Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>

Thank you.

>> diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
>> index 432b7d1701e4..a945fa10555f 100644
>> --- a/xen/arch/x86/setup.c
>> +++ b/xen/arch/x86/setup.c
>> @@ -1049,11 +1058,7 @@ void asmlinkage __init noreturn __start_xen(unsigned long mbi_p)
>>   
>>       multiboot_to_bootinfo(mbi);
>>   
>> -    /* Parse the command-line options. */
>> -    if ( mbi->flags & MBI_CMDLINE )
>> -        cmdline = cmdline_cook(__va(mbi->cmdline), boot_info->boot_loader_name);
>> -
>> -    if ( (kextra = strstr(cmdline, " -- ")) != NULL )
>> +    if ( (kextra = strstr(boot_info->cmdline, " -- ")) != NULL )
>>       {
>>           /*
>>            * Options after ' -- ' separator belong to dom0.
>> @@ -1064,7 +1069,7 @@ void asmlinkage __init noreturn __start_xen(unsigned long mbi_p)
>>           kextra += 3;
>>           while ( kextra[1] == ' ' ) kextra++;
>>       }
>> -    cmdline_parse(cmdline);
>> +    cmdline_parse(boot_info->cmdline);
> 
> It would be nice to get this kextra handling out of __start_xen(), but
> I'm not entirely sure how.
> 
> It shouldn't live in multiboot_fill_boot_info() if that's going to be
> split for pvh, yet it really ought to live with the other editing of
> bi->cmdline.
> 
> Something that is very subtle is that the *kextra = '\0' between these
> two hunks ends up truncating bi->cmdline.
> 
> Perhaps best to leave it alone until inspiration strikes.

One thought is to move all the logic into a function and make it the 
responsibility of fill function(s) to call it, since each entry point 
has its own unique way for the xen command line to be passed in.

v/r,
dps