Re: [PATCH] x86, add hypervisor name to dump_stack() [v4]

[Gleb Natapov <gleb@redhat.com>]

On Tue, Oct 30, 2012 at 04:26:33PM -0400, Prarit Bhargava wrote:
> Debugging crash, panics, stack trace WARN_ONs, etc., from both virtual and
> bare-metal boots can get difficult very quickly.  While there are ways to
> decipher the output and determine if the output is from a virtual guest,
> the in-kernel hypervisors now have a single registration point
> and set x86_hyper.  We can use this to output additional debug
> information during a panic/oops/stack trace.
> 
> Signed-off-by: Prarit Bhargava <prarit@redhat.com>
> Cc: Avi Kivity <avi@redhat.com>
> Cc: Gleb Natapov <gleb@redhat.com>
> Cc: Alex Williamson <alex.williamson@redhat.com>
> Cc: Marcelo Tostatti <mtosatti@redhat.com>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: kvm@vger.kernel.org
> Cc: x86@kernel.org
> 
Acked-by: Gleb Natapov <gleb@redhat.com>

> [v2]: Modifications suggested by Ingo and added changes for similar output
>       from process.c
> 
> [v3]: Unify common code and move output to end of line
> ---
>  arch/x86/kernel/dumpstack.c |    6 +-----
>  arch/x86/kernel/process.c   |   14 ++++++++++++--
>  2 files changed, 13 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
> index ae42418b..96d40ed 100644
> --- a/arch/x86/kernel/dumpstack.c
> +++ b/arch/x86/kernel/dumpstack.c
> @@ -188,11 +188,7 @@ void dump_stack(void)
>  	unsigned long stack;
>  
>  	bp = stack_frame(current, NULL);
> -	printk("Pid: %d, comm: %.20s %s %s %.*s\n",
> -		current->pid, current->comm, print_tainted(),
> -		init_utsname()->release,
> -		(int)strcspn(init_utsname()->version, " "),
> -		init_utsname()->version);
> +	show_regs_common();
>  	show_trace(NULL, NULL, &stack, bp);
>  }
>  EXPORT_SYMBOL(dump_stack);
> diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
> index b644e1c..7ea4692 100644
> --- a/arch/x86/kernel/process.c
> +++ b/arch/x86/kernel/process.c
> @@ -28,6 +28,7 @@
>  #include <asm/fpu-internal.h>
>  #include <asm/debugreg.h>
>  #include <asm/nmi.h>
> +#include <asm/hypervisor.h>
>  
>  /*
>   * per-CPU TSS segments. Threads are completely 'soft' on Linux,
> @@ -124,6 +125,13 @@ void exit_thread(void)
>  void show_regs_common(void)
>  {
>  	const char *vendor, *product, *board;
> +	const char *machine_name = "x86";
> +	const char *kernel_type = "native";
> +
> +	if (x86_hyper) {
> +		machine_name = x86_hyper->name;
> +		kernel_type = "guest";
> +	}
>  
>  	vendor = dmi_get_system_info(DMI_SYS_VENDOR);
>  	if (!vendor)
> @@ -135,14 +143,16 @@ void show_regs_common(void)
>  	/* Board Name is optional */
>  	board = dmi_get_system_info(DMI_BOARD_NAME);
>  
> -	printk(KERN_DEFAULT "Pid: %d, comm: %.20s %s %s %.*s %s %s%s%s\n",
> +	printk(KERN_DEFAULT
> +	       "Pid: %d, comm: %.20s %s %s %.*s %s %s%s%s [%s %s kernel]\n",
>  	       current->pid, current->comm, print_tainted(),
>  	       init_utsname()->release,
>  	       (int)strcspn(init_utsname()->version, " "),
>  	       init_utsname()->version,
>  	       vendor, product,
>  	       board ? "/" : "",
> -	       board ? board : "");
> +	       board ? board : "",
> +	       machine_name, kernel_type);
>  }
>  
>  void flush_thread(void)
> -- 
> 1.7.9.3

--
			Gleb.