Re: [Xen-devel] [PATCH v9 04/19] amd64: introduce hook for custom preload metadata parsers

On Thu, Jan 02, 2014 at 04:43:38PM +0100, Roger Pau Monne wrote:
> ---
>  sys/amd64/amd64/machdep.c   |   41 ++++++++++++++++------
>  sys/amd64/include/sysarch.h |   12 ++++++
>  sys/x86/xen/pv.c            |   82 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 124 insertions(+), 11 deletions(-)
> 
> diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c
> index eae657b..e073eea 100644
> --- a/sys/amd64/amd64/machdep.c
> +++ b/sys/amd64/amd64/machdep.c
> _at__at_ -126,6 +126,7 _at__at_ __FBSDID("$FreeBSD$");
>  #include <machine/reg.h>
>  #include <machine/sigframe.h>
>  #include <machine/specialreg.h>
> +#include <machine/sysarch.h>
>  #ifdef PERFMON
>  #include <machine/perfmon.h>
>  #endif
> _at__at_ -165,6 +166,14 _at__at_ static int  set_fpcontext(struct thread *td, const mcontext_t *mcp,
>      char *xfpustate, size_t xfpustate_len);
>  SYSINIT(cpu, SI_SUB_CPU, SI_ORDER_FIRST, cpu_startup, NULL);
>  
> +/* Preload data parse function */
> +static caddr_t native_parse_preload_data(u_int64_t);
> +
> +/* Default init_ops implementation. */
> +struct init_ops init_ops = {
> +	.parse_preload_data =	native_parse_preload_data,

Extra space there.

> +};
> +
>  /*
>   * The file "conf/ldscript.amd64" defines the symbol "kernphys".  Its value is
>   * the physical address at which the kernel is loaded.
> _at__at_ -1683,6 +1692,26 _at__at_ do_next:
>  	msgbufp = (struct msgbuf *)PHYS_TO_DMAP(phys_avail[pa_indx]);
>  }
>  
> +static caddr_t
> +native_parse_preload_data(u_int64_t modulep)
> +{
> +	caddr_t kmdp;
> +
> +	preload_metadata = (caddr_t)(uintptr_t)(modulep + KERNBASE);

Two casts? Could it be done via one?

> +	preload_bootstrap_relocate(KERNBASE);
> +	kmdp = preload_search_by_type("elf kernel");
> +	if (kmdp == NULL)
> +		kmdp = preload_search_by_type("elf64 kernel");
> +	boothowto = MD_FETCH(kmdp, MODINFOMD_HOWTO, int);
> +	kern_envp = MD_FETCH(kmdp, MODINFOMD_ENVP, char *) + KERNBASE;
> +#ifdef DDB
> +	ksym_start = MD_FETCH(kmdp, MODINFOMD_SSYM, uintptr_t);
> +	ksym_end = MD_FETCH(kmdp, MODINFOMD_ESYM, uintptr_t);
> +#endif
> +
> +	return (kmdp);
> +}
> +
>  u_int64_t
>  hammer_time(u_int64_t modulep, u_int64_t physfree)
>  {
> _at__at_ -1707,17 +1736,7 _at__at_ hammer_time(u_int64_t modulep, u_int64_t physfree)
>  	 */
>  	proc_linkup0(&proc0, &thread0);
>  
> -	preload_metadata = (caddr_t)(uintptr_t)(modulep + KERNBASE);

Oh, you just moved the code - right, lets not modify it in this patch.

> -	preload_bootstrap_relocate(KERNBASE);
> -	kmdp = preload_search_by_type("elf kernel");
> -	if (kmdp == NULL)
> -		kmdp = preload_search_by_type("elf64 kernel");
> -	boothowto = MD_FETCH(kmdp, MODINFOMD_HOWTO, int);
> -	kern_envp = MD_FETCH(kmdp, MODINFOMD_ENVP, char *) + KERNBASE;
> -#ifdef DDB
> -	ksym_start = MD_FETCH(kmdp, MODINFOMD_SSYM, uintptr_t);
> -	ksym_end = MD_FETCH(kmdp, MODINFOMD_ESYM, uintptr_t);
> -#endif
> +	kmdp = init_ops.parse_preload_data(modulep);
>  
>  	/* Init basic tunables, hz etc */
>  	init_param1();
> diff --git a/sys/amd64/include/sysarch.h b/sys/amd64/include/sysarch.h
> index cd380d4..58ac8cd 100644
> --- a/sys/amd64/include/sysarch.h
> +++ b/sys/amd64/include/sysarch.h
> _at__at_ -4,3 +4,15 _at__at_
>  /* $FreeBSD$ */
>  
>  #include <x86/sysarch.h>
> +
> +/*
> + * Struct containing pointers to init functions whose
> + * implementation is run time selectable.  Selection can be made,
> + * for example, based on detection of a BIOS variant or
> + * hypervisor environment.
> + */
> +struct init_ops {
> +	caddr_t	(*parse_preload_data)(u_int64_t);
> +};
> +
> +extern struct init_ops init_ops;
> diff --git a/sys/x86/xen/pv.c b/sys/x86/xen/pv.c
> index db3b7a3..908b50b 100644
> --- a/sys/x86/xen/pv.c
> +++ b/sys/x86/xen/pv.c
> _at__at_ -46,6 +46,8 _at__at_ __FBSDID("$FreeBSD$");
>  #include <vm/vm_pager.h>
>  #include <vm/vm_param.h>
>  
> +#include <machine/sysarch.h>
> +
>  #include <xen/xen-os.h>
>  #include <xen/hypervisor.h>
>  
> _at__at_ -54,6 +56,36 _at__at_ extern u_int64_t hammer_time(u_int64_t, u_int64_t);
>  /* Xen initial function */
>  extern u_int64_t hammer_time_xen(start_info_t *, u_int64_t);
>  
> +/*--------------------------- Forward Declarations ---------------------------*/
> +static caddr_t xen_pv_parse_preload_data(u_int64_t);
> +
> +static void xen_pv_set_init_ops(void);
> +
> +/*-------------------------------- Global Data -------------------------------*/
> +/* Xen init_ops implementation. */
> +struct init_ops xen_init_ops = {
> +	.parse_preload_data =	xen_pv_parse_preload_data,
> +};
> +
> +static struct
> +{
> +	const char	*ev;
> +	int		mask;
> +} howto_names[] = {
> +	{"boot_askname",	RB_ASKNAME},
> +	{"boot_single",		RB_SINGLE},
> +	{"boot_nosync",		RB_NOSYNC},
> +	{"boot_halt",		RB_ASKNAME},
> +	{"boot_serial",		RB_SERIAL},
> +	{"boot_cdrom",		RB_CDROM},
> +	{"boot_gdb",		RB_GDB},
> +	{"boot_gdb_pause",	RB_RESERVED1},
> +	{"boot_verbose",	RB_VERBOSE},
> +	{"boot_multicons",	RB_MULTIPLE},
> +	{NULL,	0}
> +};
> +
> +/*-------------------------------- Xen PV init -------------------------------*/
>  /*
>   * First function called by the Xen PVH boot sequence.
>   *
> _at__at_ -118,6 +150,56 _at__at_ hammer_time_xen(start_info_t *si, u_int64_t xenstack)
>  	}
>  	load_cr3(((u_int64_t)&PT4[0]) - KERNBASE);
>  
> +	/* Set the hooks for early functions that diverge from bare metal */
> +	xen_pv_set_init_ops();
> +
>  	/* Now we can jump into the native init function */
>  	return (hammer_time(0, physfree));
>  }
> +
> +/*-------------------------------- PV specific -------------------------------*/
> +/*
> + * Functions to convert the "extra" parameters passed by Xen
> + * into FreeBSD boot options (from the i386 Xen port).
> + */
> +static char *
> +xen_setbootenv(char *cmd_line)
> +{
> +	char *cmd_line_next;
> +
> +        /* Skip leading spaces */
> +        for (; *cmd_line == ' '; cmd_line++);

Spaces?

> +
> +	for (cmd_line_next = cmd_line; strsep(&cmd_line_next, ",") != NULL;);
> +	return (cmd_line);
> +}
> +
> +static int
> +xen_boothowto(char *envp)
> +{
> +	int i, howto = 0;
> +
> +	/* get equivalents from the environment */
> +	for (i = 0; howto_names[i].ev != NULL; i++)
> +		if (getenv(howto_names[i].ev) != NULL)
> +			howto |= howto_names[i].mask;

You don't believe in '{}' do you ? :-)

> +	return (howto);
> +}
> +
> +static caddr_t
> +xen_pv_parse_preload_data(u_int64_t modulep)
> +{
> +	/* Parse the extra boot information given by Xen */
> +	if (HYPERVISOR_start_info->cmd_line)
> +		kern_envp = xen_setbootenv(HYPERVISOR_start_info->cmd_line);
> +	boothowto |= xen_boothowto(kern_envp);
> +
> +	return (NULL);
> +}
> +
> +static void
> +xen_pv_set_init_ops(void)
> +{
> +	/* Init ops for Xen PV */
> +	init_ops = xen_init_ops;
> +}
> -- 
> 1.7.7.5 (Apple Git-26)
> 
> 
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