From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Jy5nb-00035J-2H for qemu-devel@nongnu.org; Mon, 19 May 2008 09:53:11 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1Jy5na-00032i-4m for qemu-devel@nongnu.org; Mon, 19 May 2008 09:53:10 -0400 Received: from [199.232.76.173] (port=51056 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Jy5na-00032E-19 for qemu-devel@nongnu.org; Mon, 19 May 2008 09:53:10 -0400 Received: from gecko.sbs.de ([194.138.37.40]:17237) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1Jy5nZ-0006pb-E8 for qemu-devel@nongnu.org; Mon, 19 May 2008 09:53:09 -0400 Received: from mail1.sbs.de (localhost [127.0.0.1]) by gecko.sbs.de (8.12.11.20060308/8.12.11) with ESMTP id m4JDr5F9004579 for ; Mon, 19 May 2008 15:53:05 +0200 Received: from [139.25.109.167] (mchn012c.mchp.siemens.de [139.25.109.167] (may be forged)) by mail1.sbs.de (8.12.11.20060308/8.12.11) with ESMTP id m4JDr5KX010818 for ; Mon, 19 May 2008 15:53:05 +0200 Message-ID: <48318641.800@siemens.com> Date: Mon, 19 May 2008 15:53:05 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <482EDEF8.7030309@web.de> <5d6222a80805190618l59f2e312mfedd96c9ce343652@mail.gmail.com> In-Reply-To: <5d6222a80805190618l59f2e312mfedd96c9ce343652@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] Re: [RFC][PATCH 1/2] machine-specific command line switches Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Glauber Costa wrote: > On Sat, May 17, 2008 at 10:34 AM, Jan Kiszka wrote: >> For a different project, I once wrote a patch to organize purely >> machine-specific command line switches under the hood of the respective >> machine implementations. Now the MusicPal has precisely that need as >> well. So I reanimated the patch, and here we go: >> >> The idea is to add two fields to QEMUMachine and process them: >> o options_help - a string that is inserted under a separate section of >> the "qemu -h" output. >> o parse_option - a callback invoked if a given option was not handled >> by the generic code. It returns -1 if the option is unkown, 0 if it >> is know but comes without an argument, and 1 when the argument was >> consumed. > > This would be quite useful for QEMUAccel too. > > So... > >> +typedef int QEMUMachineParseOption(const char *optname, const char *optarg); >> + >> typedef struct QEMUMachine { >> const char *name; >> const char *desc; >> QEMUMachineInitFunc *init; >> #define RAMSIZE_FIXED (1 << 0) >> ram_addr_t ram_require; >> + const char *options_help; >> + QEMUMachineParseOption *parse_option; >> struct QEMUMachine *next; >> } QEMUMachine; > > Why don't turn the naming into a more generic one? Maybe QEMUOpts, or > smth like this. > >> Index: b/vl.c >> =================================================================== >> --- a/vl.c >> +++ b/vl.c >> @@ -7141,6 +7141,8 @@ static int main_loop(void) >> >> static void help(int exitcode) >> { >> + QEMUMachine *m; >> + >> printf("QEMU PC emulator version " QEMU_VERSION ", Copyright (c) 2003-2008 Fabrice Bellard\n" >> "usage: %s [options] [disk_image]\n" >> "\n" >> @@ -7275,14 +7277,7 @@ static void help(int exitcode) >> "-clock force the use of the given methods for timer alarm.\n" >> " To see what timers are available use -clock ?\n" >> "-startdate select initial date of the clock\n" >> - "\n" >> - "During emulation, the following keys are useful:\n" >> - "ctrl-alt-f toggle full screen\n" >> - "ctrl-alt-n switch to virtual console 'n'\n" >> - "ctrl-alt toggle mouse and keyboard grab\n" >> - "\n" >> - "When using -nographic, press 'ctrl-a h' to get some help.\n" >> - , >> + "\n", >> "qemu", >> DEFAULT_RAM_SIZE, >> #ifndef _WIN32 >> @@ -7291,6 +7286,17 @@ static void help(int exitcode) >> #endif >> DEFAULT_GDBSTUB_PORT, >> "/tmp/qemu.log"); >> + for (m = first_machine; m != NULL; m = m->next) { >> + if (m->options_help) >> + printf("Options specific to %s machine:\n%s\n", >> + m->name, m->options_help); >> + } > So, If I understand correctly what you mean here, This will print out > specific options for every registered machine, right? Right. > It does not sound correct, since we won't have support for more than > one in the same binary anyway. It looks correct, tough, if we think I was thinking of such examples: $ arm-softmmu/qemu-system-arm -M ? Supported machines are: integratorcp ARM Integrator/CP (ARM926EJ-S) (default) versatilepb ARM Versatile/PB (ARM926EJ-S) versatileab ARM Versatile/AB (ARM926EJ-S) realview ARM RealView Emulation Baseboard (ARM926EJ-S) akita Akita PDA (PXA270) spitz Spitz PDA (PXA270) borzoi Borzoi PDA (PXA270) terrier Terrier PDA (PXA270) cheetah Palm Tungsten|E aka. Cheetah PDA (OMAP310) n800 Nokia N800 tablet aka. RX-34 (OMAP2420) n810 Nokia N810 tablet aka. RX-44 (OMAP2420) lm3s811evb Stellaris LM3S811EVB lm3s6965evb Stellaris LM3S6965EVB connex Gumstix Connex (PXA255) verdex Gumstix Verdex (PXA270) mainstone Mainstone II (PXA27x) musicpal Marvell 88w8618 / MusicPal (ARM926EJ-S) And only the latter one needs a special switch here. Thus the user should know that this switch is not interpreted if some other machine is picked. > that we're not representing 'machines', but anything dumping specific > options here. But in this case, wouldn't it be better to leave the > whole help string > to the user of the interface, instead of just using m->name and m->help? Nevertheless, I do agree that a non-machine oriented abstraction would be even nicer in order to organize all those specific options without the help of increasing #ifdef'ery. However, yet no smart idea came to my mind to handle all cases (per-arch, per-machine, per-accelerator, per-whatever - and all this combined). > >> @@ -7673,7 +7679,7 @@ int main(int argc, char **argv) >> const char *gdbstub_port; >> #endif >> uint32_t boot_devices_bitmap = 0; >> - int i; >> + int i, result; >> int snapshot, linux_boot, net_boot; >> const char *initrd_filename; >> const char *kernel_filename, *kernel_cmdline; >> @@ -7692,7 +7698,7 @@ int main(int argc, char **argv) >> const char *parallel_devices[MAX_PARALLEL_PORTS]; >> int parallel_device_index; >> const char *loadvm = NULL; >> - QEMUMachine *machine; >> + QEMUMachine *machine, *m; >> const char *cpu_model; >> const char *usb_devices[MAX_USB_CMDLINE]; >> int usb_devices_index; >> @@ -7784,6 +7790,21 @@ int main(int argc, char **argv) >> /* Treat --foo the same as -foo. */ >> if (r[1] == '-') >> r++; >> + >> + result = -1; >> + for (m = first_machine; m != NULL; m = m->next) { >> + if (m->parse_option) { > I don't like this very much. There's no point in having specific > options without this parse_option anyway. So it would be better to > check for it before displaying the options at all, and simplify the > code here. Don't understand your concern yet. If machine provides options_help, it is supposed to provide parse_options and vice versa. Thus you don't dump help about non-existent services - unless someone messes up the machine definition. > >> + result = m->parse_option(r, >> + (optind < argc) ? argv[optind] : NULL); >> + if (result >= 0) >> + break; >> + } >> + } >> + if (result >= 0) { >> + optind += result; >> + continue; >> + } >> + > > Other than the commented, it all looks very good. OK, let's try again and do some brainstorming about more flexible option handling. My initial idea was machine focused (both for the MusicPal and here @work), thus I stuffed the information into the machine descriptor. However, my scenario would be fine as well when the machines register some additional options (in what ever form). The same could be done by arch-common initialization functions for per-arch options or by an accelerator initializer for its special switches. Sounds feasible? Jan -- Siemens AG, Corporate Technology, CT SE 2 Corporate Competence Center Embedded Linux