From mboxrd@z Thu Jan  1 00:00:00 1970
From: Wei Liu <wei.liu2@citrix.com>
Subject: Re: [v4][PATCH 15/19] tools: introduce a new parameter
 to set a predefined rdm boundary
Date: Thu, 25 Jun 2015 12:27:47 +0100
Message-ID: <20150625112747.GK6545@zion.uk.xensource.com>
References: <1435053450-25131-1-git-send-email-tiejun.chen@intel.com>
	<1435053450-25131-16-git-send-email-tiejun.chen@intel.com>
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To: Tiejun Chen <tiejun.chen@intel.com>
Cc: Wei Liu <wei.liu2@citrix.com>, Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Ian Jackson <ian.jackson@eu.citrix.com>, Ian Campbell <ian.campbell@citrix.com>, xen-devel@lists.xen.org
List-Id: xen-devel@lists.xenproject.org

On Tue, Jun 23, 2015 at 05:57:26PM +0800, Tiejun Chen wrote:
> Previously we always fix that predefined boundary as 2G to handle
> conflict between memory and rdm, but now this predefined boundar
> can be changes with the parameter "rdm_mem_boundary" in .cfg file.
> 
> CC: Ian Jackson <ian.jackson@eu.citrix.com>
> CC: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> CC: Ian Campbell <ian.campbell@citrix.com>
> CC: Wei Liu <wei.liu2@citrix.com>
> Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
> ---
> v4:
> 
> * Separated from the previous patch to provide a parameter to set that
>   predefined boundary dynamically.
> 
>  docs/man/xl.cfg.pod.5       | 21 +++++++++++++++++++++
>  tools/libxl/libxl.h         |  6 ++++++
>  tools/libxl/libxl_create.c  |  4 ++++
>  tools/libxl/libxl_dom.c     |  8 +-------
>  tools/libxl/libxl_types.idl |  1 +
>  tools/libxl/xl_cmdimpl.c    |  3 +++
>  6 files changed, 36 insertions(+), 7 deletions(-)
> 
> diff --git a/docs/man/xl.cfg.pod.5 b/docs/man/xl.cfg.pod.5
> index 638b350..079465f 100644
> --- a/docs/man/xl.cfg.pod.5
> +++ b/docs/man/xl.cfg.pod.5
> @@ -767,6 +767,27 @@ to a given device, and "strict" is default here.
>  
>  Note this would override global B<rdm> option.
>  
> +=item B<rdm_mem_boundary=MBYTES>
> +
> +Number of megabytes to set a boundary for checking rdm conflict.
> +
> +When RDM conflicts with RAM, RDM probably scatter the whole RAM space.
> +Especially multiple RDM entries would worsen this to lead a complicated
> +memory layout. So here we're trying to figure out a simple solution to
> +avoid breaking existing layout. So when a conflict occurs,
> +
> +    #1. Above a predefined boundary
> +        - move lowmem_end below reserved region to solve conflict;
> +
> +    #2. Below a predefined boundary
> +        - Check strict/relaxed policy.
> +        "strict" policy leads to fail libxl. Note when both policies
> +        are specified on a given region, 'strict' is always preferred.
> +        "relaxed" policy issue a warning message and also mask this entry INVALID
> +        to indicate we shouldn't expose this entry to hvmloader.
> +

Can you check the generated manpage to see if the format is correct?

> +Here the default is 2G.
> +
>  =back
>  
>  =back
> diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h
> index 0a7913b..a6212fb 100644
> --- a/tools/libxl/libxl.h
> +++ b/tools/libxl/libxl.h
> @@ -858,6 +858,12 @@ const char *libxl_defbool_to_string(libxl_defbool b);
>  #define LIBXL_TIMER_MODE_DEFAULT -1
>  #define LIBXL_MEMKB_DEFAULT ~0ULL
>  
> +/*
> + * We'd like to set a memory boundary to determine if we need to check
> + * any overlap with reserved device memory.
> + */
> +#define LIBXL_RDM_MEM_BOUNDARY_MEMKB_DEFAULT (2048 * 1024)
> +
>  #define LIBXL_MS_VM_GENID_LEN 16
>  typedef struct {
>      uint8_t bytes[LIBXL_MS_VM_GENID_LEN];
> diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
> index 30e6593..0438731 100644
> --- a/tools/libxl/libxl_create.c
> +++ b/tools/libxl/libxl_create.c
> @@ -109,6 +109,10 @@ void libxl__rdm_setdefault(libxl__gc *gc, libxl_domain_build_info *b_info)
>  {
>      if (b_info->rdm.reserve == LIBXL_RDM_RESERVE_FLAG_INVALID)
>          b_info->rdm.reserve = LIBXL_RDM_RESERVE_FLAG_RELAXED;
> +
> +    if (b_info->rdm_mem_boundary_memkb == LIBXL_MEMKB_DEFAULT)
> +        b_info->rdm_mem_boundary_memkb =
> +                            LIBXL_RDM_MEM_BOUNDARY_MEMKB_DEFAULT;
>  }
>  
>  int libxl__domain_build_info_setdefault(libxl__gc *gc,
> diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
> index 34bd466..0987991 100644
> --- a/tools/libxl/libxl_dom.c
> +++ b/tools/libxl/libxl_dom.c
> @@ -922,12 +922,6 @@ int libxl__build_hvm(libxl__gc *gc, uint32_t domid,
>      int ret, rc = ERROR_FAIL;
>      uint64_t mmio_start, lowmem_end, highmem_end;
>      libxl_domain_build_info *const info = &d_config->b_info;
> -    /*
> -     * Currently we fix this as 2G to guarantte how to handle
> -     * our rdm policy. But we'll provide a parameter to set
> -     * this dynamically.
> -     */
> -    uint64_t rdm_mem_boundary = 0x80000000;
>  
>      memset(&args, 0, sizeof(struct xc_hvm_build_args));
>      /* The params from the configuration file are in Mb, which are then
> @@ -966,7 +960,7 @@ int libxl__build_hvm(libxl__gc *gc, uint32_t domid,
>      args.mmio_start = mmio_start;
>  
>      ret = libxl__domain_device_construct_rdm(gc, d_config,
> -                                             rdm_mem_boundary,
> +                                             info->rdm_mem_boundary_memkb*1024,
>                                               &args);
>      if (ret) {
>          LOG(ERROR, "checking reserved device memory failed");
> diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
> index 5ba075d..d130d48 100644
> --- a/tools/libxl/libxl_types.idl
> +++ b/tools/libxl/libxl_types.idl
> @@ -395,6 +395,7 @@ libxl_domain_build_info = Struct("domain_build_info",[
>      ("target_memkb",    MemKB),
>      ("video_memkb",     MemKB),
>      ("shadow_memkb",    MemKB),
> +    ("rdm_mem_boundary_memkb",    MemKB),

Should this be restricted to .hvm? This is HVM only feature after all.

Wei.

>      ("rtc_timeoffset",  uint32),
>      ("exec_ssidref",    uint32),
>      ("exec_ssid_label", string),
> diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
> index 5637c30..c7a12b1 100644
> --- a/tools/libxl/xl_cmdimpl.c
> +++ b/tools/libxl/xl_cmdimpl.c
> @@ -1374,6 +1374,9 @@ static void parse_config_data(const char *config_source,
>      if (!xlu_cfg_get_long (config, "videoram", &l, 0))
>          b_info->video_memkb = l * 1024;
>  
> +    if (!xlu_cfg_get_long (config, "rdm_mem_boundary", &l, 0))
> +        b_info->rdm_mem_boundary_memkb = l * 1024;
> +
>      if (!xlu_cfg_get_long(config, "max_event_channels", &l, 0))
>          b_info->event_channels = l;
>  
> -- 
> 1.9.1