From patchwork Fri Mar 20 01:04:07 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tiejun Chen X-Patchwork-Id: 452409 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 87D5314007F for ; Fri, 20 Mar 2015 12:04:38 +1100 (AEDT) Received: from localhost ([::1]:41904 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YYlMY-0001OJ-KN for incoming@patchwork.ozlabs.org; Thu, 19 Mar 2015 21:04:34 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37870) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YYlMH-00017q-MR for qemu-devel@nongnu.org; Thu, 19 Mar 2015 21:04:18 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YYlMC-0007O4-MJ for qemu-devel@nongnu.org; Thu, 19 Mar 2015 21:04:17 -0400 Received: from mga02.intel.com ([134.134.136.20]:60285) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YYlMC-0007Ny-B1 for qemu-devel@nongnu.org; Thu, 19 Mar 2015 21:04:12 -0400 Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga101.jf.intel.com with ESMTP; 19 Mar 2015 18:04:09 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.11,433,1422950400"; d="scan'208";a="682857593" Received: from tiejunch-mobl.ccr.corp.intel.com (HELO [10.238.128.175]) ([10.238.128.175]) by fmsmga001.fm.intel.com with ESMTP; 19 Mar 2015 18:04:07 -0700 Message-ID: <550B7207.6020503@intel.com> Date: Fri, 20 Mar 2015 09:04:07 +0800 From: "Chen, Tiejun" User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Ian Campbell References: <1425980538-5508-1-git-send-email-tiejun.chen@intel.com> <1425980538-5508-3-git-send-email-tiejun.chen@intel.com> <1426073641.21353.192.camel@citrix.com> <55010596.2030106@intel.com> <1426163186.21353.409.camel@citrix.com> <55023FDA.7030204@intel.com> <1426241479.32572.94.camel@citrix.com> <55062CD2.8050305@intel.com> <1426508400.18247.33.camel@citrix.com> <5507DBD6.8030401@intel.com> <1426584396.18247.136.camel@citrix.com> <55092A24.8010409@intel.com> <1426674310.18247.318.camel@citrix.com> <550A2F6A.4060508@intel.com> <1426761860.610.22.camel@citrix.com> In-Reply-To: <1426761860.610.22.camel@citrix.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 134.134.136.20 Cc: Ian.Jackson@eu.citrix.com, wei.liu2@citrix.com, qemu-devel@nongnu.org, stefano.stabellini@citrix.com, xen-devel@lists.xen.org Subject: Re: [Qemu-devel] [v2][PATCH 2/2] libxl: introduce gfx_passthru_kind X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org On 2015/3/19 18:44, Ian Campbell wrote: > On Thu, 2015-03-19 at 10:07 +0800, Chen, Tiejun wrote: >>> This duplicates the code from above. I think this would be best done as: >>> >>> static int libxl__detect_gfx_passthru_kind(libxl__gc *gc, guest_config) >>> { >>> if (b_info->u.hvm.gfx_passthru_kind != LIBXL_GFX_PASSTHRU_KIND_DEFAULT) >>> return 0; >>> >>> if (libxl__is_igd_vga_passthru(gc, guest_config)) { >>> b_info->u.hvm.gfx_passthru_kind = LIBXL_GFX_PASSTHRU_KIND_IGD; >>> return 0; >>> } >>> >>> LOG(ERROR, "Unable to detect graphics passthru kind"); >>> return 1; >>> } >>> >>> Then for the code in libxl__build_device_model_args_new: >>> >>> if (libxl_defbool_val(b_info->u.hvm.gfx_passthru)) { >>> if (!libxl__detect_gfx_passthru_kind(gc, guest_config)) >>> return NULL >>> switch (b_info->u.hvm.gfx_passthru_kind) { >>> case LIBXL_GFX_PASSTHRU_KIND_IGD: >>> machinearg = GCSPRINTF("%s,igd-passthru=on", machinearg); >>> break; >>> default: >>> LOG(ERROR, "unknown gfx_passthru_kind\n"); >>> return NULL; >>> } >>> } >>> >>> That is, a helper to try and autodetect kind if it is default and then a >>> single switch entry for each kind. >>> >>>> + default: >>>> + LOG(WARN, "gfx_passthru_kind is invalid so ignored.\n"); >>> >>> Please return an error here, as I've shown above. >> >> Looks good and thanks, but here 'guest_config' is a const so we >> shouldn't/can't reset b_info->u.hvm.gfx_passthru_kind like this, >> >> b_info->u.hvm.gfx_passthru_kind = LIBXL_GFX_PASSTHRU_KIND_IGD; >> >> So I tried to refactor a little bit to follow up yours, >> >> diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c >> index 8599a6a..605b17c 100644 >> --- a/tools/libxl/libxl_dm.c >> +++ b/tools/libxl/libxl_dm.c >> @@ -409,6 +409,23 @@ static char *dm_spice_options(libxl__gc *gc, >> return opt; >> } >> >> +static int >> +libxl__detect_gfx_passthru_kind(libxl__gc *gc, >> + const libxl_domain_config *guest_config) >> +{ >> + const libxl_domain_build_info *b_info = &guest_config->b_info; >> + >> + if (b_info->u.hvm.gfx_passthru_kind != LIBXL_GFX_PASSTHRU_KIND_DEFAULT) >> + return b_info->u.hvm.gfx_passthru_kind; >> + >> + if (libxl__is_igd_vga_passthru(gc, guest_config)) { >> + return LIBXL_GFX_PASSTHRU_KIND_IGD; >> + } >> + >> + LOG(ERROR, "Unable to detect graphics passthru kind"); >> + return -1; > > I think you can make this function return enum > libxl_gfx_passthrough_kind and then return > LIBXL_GFX_PASSTHRU_KIND_DEFAULT in this case. > >> +} >> + >> static char ** libxl__build_device_model_args_new(libxl__gc *gc, >> const char *dm, int guest_domid, >> const libxl_domain_config >> *guest_config, >> @@ -427,7 +444,7 @@ static char ** >> libxl__build_device_model_args_new(libxl__gc *gc, >> const char *keymap = dm_keymap(guest_config); >> char *machinearg; >> flexarray_t *dm_args; >> - int i, connection, devid; >> + int i, connection, devid, gfx_passthru_kind; > > Please declare this in the smallest necessary scope... > [...] >> + if (libxl_defbool_val(b_info->u.hvm.gfx_passthru)) { >> + gfx_passthru_kind = libxl__detect_gfx_passthru_kind(gc, > > i.e. here. > >> + >> guest_config); >> + switch (gfx_passthru_kind) { >> + case LIBXL_GFX_PASSTHRU_KIND_IGD: >> + machinearg = GCSPRINTF("%s,igd-passthru=on", machinearg); >> + break; >> + default: > > With the suggestion to return KIND_DEFAULT if detection fails then I > think an extra case should be added: > case LIBXL_GFX_PASSTHRU_KIND_DEFAULT: > LOG(ERROR, "unable to detect required > gfx_passthru_kind"); > return NULL; > >> + LOG(ERROR, "unknown gfx_passthru_kind\n"); > > I think LOG is supposed to not include the final \n. > Refactor again, *guest_config, @@ -757,6 +771,21 @@ static char ** libxl__build_device_model_args_new(libxl__gc *gc, machinearg, max_ram_below_4g); } } + + if (libxl_defbool_val(b_info->u.hvm.gfx_passthru)) { + enum libxl_gfx_passthru_kind gfx_passthru_kind = + libxl__detect_gfx_passthru_kind(gc, guest_config); + switch (gfx_passthru_kind) { + case LIBXL_GFX_PASSTHRU_KIND_IGD: + machinearg = GCSPRINTF("%s,igd-passthru=on", machinearg); + break; + case LIBXL_GFX_PASSTHRU_KIND_DEFAULT: + LOG(ERROR, "unable to detect required gfx_passthru_kind"); + default: + return NULL; + } + } + flexarray_append(dm_args, machinearg); for (i = 0; b_info->extra_hvm && b_info->extra_hvm[i] != NULL; i++) flexarray_append(dm_args, b_info->extra_hvm[i]); Thanks Tiejun diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c index 8599a6a..05c8916 100644 --- a/tools/libxl/libxl_dm.c +++ b/tools/libxl/libxl_dm.c @@ -409,6 +409,23 @@ static char *dm_spice_options(libxl__gc *gc, return opt; } +static enum libxl_gfx_passthru_kind +libxl__detect_gfx_passthru_kind(libxl__gc *gc, + const libxl_domain_config *guest_config) +{ + const libxl_domain_build_info *b_info = &guest_config->b_info; + + if (b_info->u.hvm.gfx_passthru_kind != LIBXL_GFX_PASSTHRU_KIND_DEFAULT) + return b_info->u.hvm.gfx_passthru_kind; + + if (libxl__is_igd_vga_passthru(gc, guest_config)) { + return LIBXL_GFX_PASSTHRU_KIND_IGD; + } + + LOG(ERROR, "Unable to detect graphics passthru kind"); + return LIBXL_GFX_PASSTHRU_KIND_DEFAULT; +} + static char ** libxl__build_device_model_args_new(libxl__gc *gc, const char *dm, int guest_domid, const libxl_domain_config