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[2001:4830:134:3::11]) by mx.google.com with ESMTPS id x65si3235101qke.229.2017.01.27.02.42.37 for (version=TLS1 cipher=AES128-SHA bits=128/128); Fri, 27 Jan 2017 02:42:38 -0800 (PST) Received-SPF: pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) client-ip=2001:4830:134:3::11; Authentication-Results: mx.google.com; dkim=fail header.i=@linaro.org; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) smtp.mailfrom=qemu-devel-bounces+patch=linaro.org@nongnu.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: from localhost ([::1]:44247 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cX3zH-00054o-4N for patch@linaro.org; Fri, 27 Jan 2017 05:42:35 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47903) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cX3sC-0007qS-Hz for qemu-devel@nongnu.org; Fri, 27 Jan 2017 05:35:19 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cX3sA-00029u-Rz for qemu-devel@nongnu.org; Fri, 27 Jan 2017 05:35:16 -0500 Received: from mail-wm0-x236.google.com ([2a00:1450:400c:c09::236]:38457) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cX3sA-00029W-Il for qemu-devel@nongnu.org; Fri, 27 Jan 2017 05:35:14 -0500 Received: by mail-wm0-x236.google.com with SMTP id r144so129828323wme.1 for ; Fri, 27 Jan 2017 02:35:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=8jg6RZj0CTHSYLn9yq0CoQ7TigGXymIvPOsBoLSL1Rg=; b=cADirWdPfnv/OwgiqwoP7ysQXXaOnPHxT8evmQ/7zrWiQIDAyVdFNV0B0Fr53lXCIS A2H4/YM9pXJZrQiihoyij/SVCm0HlDRSWbssMO3xQGuOwhTfFcwUW2gBQOLzO98rJwjH zo6frxJD9ocRTtvLJucCodxEBTCkExvriVQtQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=8jg6RZj0CTHSYLn9yq0CoQ7TigGXymIvPOsBoLSL1Rg=; b=qmZPdWfyicUpuQzSKraZ7EiXUeE0yr01Kd0ciDsjfSgQz+/u+APGqQdw9kY6dVNz9P Y7hAkvshLgGynP6L9oVwM5efO7v5t2QWleARL23Ie4nCOSSdIm+h8OLVu7fAIGk0lSFT 1JXsBHum+EDcA9tWkf1erHhb3rsVQ20o2Xbg6f5WIMrwAVRA4s3GACjDv8BoZoNUUJ36 qT6xIS5/kOo+vYlSG1XekKsjaxhft9GRDQmEg0eyOdLIC/m06ZpDSp2eFDl/AXQ+O9jI f+EAM0bF0JmFdBmRiG6BwVW2/HlsanOyWsxNsPh/sRbCNzBP2OEgAprhn7kSm+sRTY1e qaoA== X-Gm-Message-State: AIkVDXKc1+Ewc24cpYwqSTbu9ObjcP8J/5MTx5F5CbRmyIQEBFoBC8Q+sewFrszLfeBpZeza X-Received: by 10.28.144.66 with SMTP id s63mr2589467wmd.134.1485513313209; Fri, 27 Jan 2017 02:35:13 -0800 (PST) Received: from zen.linaro.local ([81.128.185.34]) by smtp.gmail.com with ESMTPSA id 123sm3147520wml.6.2017.01.27.02.35.07 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 27 Jan 2017 02:35:09 -0800 (PST) Received: from zen.linaroharston (localhost [127.0.0.1]) by zen.linaro.local (Postfix) with ESMTP id DF95D3E3744; Fri, 27 Jan 2017 10:35:05 +0000 (GMT) From: =?utf-8?q?Alex_Benn=C3=A9e?= To: Date: Fri, 27 Jan 2017 10:34:45 +0000 Message-Id: <20170127103505.18606-6-alex.bennee@linaro.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170127103505.18606-1-alex.bennee@linaro.org> References: <20170127103505.18606-1-alex.bennee@linaro.org> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2a00:1450:400c:c09::236 Subject: [Qemu-devel] [PATCH v8 05/25] tcg: add options for enabling MTTCG X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Crosthwaite , "open list:Overall" , Paolo Bonzini , KONRAD Frederic , =?utf-8?q?Alex_Benn=C3=A9e?= , Richard Henderson Errors-To: qemu-devel-bounces+patch=linaro.org@nongnu.org Sender: "Qemu-devel" From: KONRAD Frederic We know there will be cases where MTTCG won't work until additional work is done in the front/back ends to support. It will however be useful to be able to turn it on. As a result MTTCG will default to off unless the combination is supported. However the user can turn it on for the sake of testing. Signed-off-by: KONRAD Frederic [AJB: move to -accel tcg,thread=multi|single, defaults] Signed-off-by: Alex Bennée Reviewed-by: Richard Henderson --- v1: - merge with add mttcg option. - update commit message v2: - machine_init->opts_init v3: - moved from -tcg to -accel tcg,thread=single|multi - fix checkpatch warnings v4: - make mttcg_enabled extern, qemu_tcg_mttcg_enabled() now just macro - qemu_tcg_configure now propagates Error instead of exiting - better error checking of thread=foo - use CONFIG flags for default_mttcg_enabled() - disable mttcg with icount, error if both forced on v7 - explicitly disable MTTCG for TCG_OVERSIZED_GUEST - use check_tcg_memory_orders_compatible() instead of CONFIG_MTTCG_HOST - change CONFIG_MTTCG_TARGET to TARGET_SUPPORTS_MTTCG v8 - fix missing include tcg.h - change mismatched MOs to a warning instead of error --- cpus.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++ include/qom/cpu.h | 9 +++++++ include/sysemu/cpus.h | 2 ++ qemu-options.hx | 20 ++++++++++++++ tcg/tcg.h | 9 +++++++ vl.c | 49 ++++++++++++++++++++++++++++++++++- 6 files changed, 160 insertions(+), 1 deletion(-) -- 2.11.0 diff --git a/cpus.c b/cpus.c index 71a82e5004..76b6e04332 100644 --- a/cpus.c +++ b/cpus.c @@ -25,6 +25,7 @@ /* Needed early for CONFIG_BSD etc. */ #include "qemu/osdep.h" #include "qemu-common.h" +#include "qemu/config-file.h" #include "cpu.h" #include "monitor/monitor.h" #include "qapi/qmp/qerror.h" @@ -45,6 +46,7 @@ #include "qemu/main-loop.h" #include "qemu/bitmap.h" #include "qemu/seqlock.h" +#include "tcg.h" #include "qapi-event.h" #include "hw/nmi.h" #include "sysemu/replay.h" @@ -150,6 +152,76 @@ typedef struct TimersState { } TimersState; static TimersState timers_state; +bool mttcg_enabled; + +/* + * We default to false if we know other options have been enabled + * which are currently incompatible with MTTCG. Otherwise when each + * guest (target) has been updated to support: + * - atomic instructions + * - memory ordering primitives (barriers) + * they can set the appropriate CONFIG flags in ${target}-softmmu.mak + * + * Once a guest architecture has been converted to the new primitives + * there are two remaining limitations to check. + * + * - The guest can't be oversized (e.g. 64 bit guest on 32 bit host) + * - The host must have a stronger memory order than the guest + * + * It may be possible in future to support strong guests on weak hosts + * but that will require tagging all load/stores in a guest with their + * implicit memory order requirements which would likely slow things + * down a lot. + */ + +static bool check_tcg_memory_orders_compatible(void) +{ +#if defined(TCG_DEFAULT_MO) && defined(TCG_TARGET_DEFAULT_MO) + return (TCG_DEFAULT_MO & ~TCG_TARGET_DEFAULT_MO) == 0; +#else + return false; +#endif +} + +static bool default_mttcg_enabled(void) +{ + QemuOpts *icount_opts = qemu_find_opts_singleton("icount"); + const char *rr = qemu_opt_get(icount_opts, "rr"); + + if (rr || TCG_OVERSIZED_GUEST) { + return false; + } else { +#ifdef TARGET_SUPPORTS_MTTCG + return check_tcg_memory_orders_compatible(); +#else + return false; +#endif + } +} + +void qemu_tcg_configure(QemuOpts *opts, Error **errp) +{ + const char *t = qemu_opt_get(opts, "thread"); + if (t) { + if (strcmp(t, "multi") == 0) { + if (TCG_OVERSIZED_GUEST) { + error_setg(errp, "No MTTCG when guest word size > hosts"); + } else { + if (!check_tcg_memory_orders_compatible()) { + error_report("Guest requires stronger MO that host"); + error_printf("Results will likely be unpredictable"); + } + mttcg_enabled = true; + } + } else if (strcmp(t, "single") == 0) { + mttcg_enabled = false; + } else { + error_setg(errp, "Invalid 'thread' setting %s", t); + } + } else { + mttcg_enabled = default_mttcg_enabled(); + } +} int64_t cpu_get_icount_raw(void) { diff --git a/include/qom/cpu.h b/include/qom/cpu.h index ca4d0fb1b4..11db2015a4 100644 --- a/include/qom/cpu.h +++ b/include/qom/cpu.h @@ -412,6 +412,15 @@ extern struct CPUTailQ cpus; extern __thread CPUState *current_cpu; /** + * qemu_tcg_mttcg_enabled: + * Check whether we are running MultiThread TCG or not. + * + * Returns: %true if we are in MTTCG mode %false otherwise. + */ +extern bool mttcg_enabled; +#define qemu_tcg_mttcg_enabled() (mttcg_enabled) + +/** * cpu_paging_enabled: * @cpu: The CPU whose state is to be inspected. * diff --git a/include/sysemu/cpus.h b/include/sysemu/cpus.h index 3728a1ea7e..a73b5d4bce 100644 --- a/include/sysemu/cpus.h +++ b/include/sysemu/cpus.h @@ -36,4 +36,6 @@ extern int smp_threads; void list_cpus(FILE *f, fprintf_function cpu_fprintf, const char *optarg); +void qemu_tcg_configure(QemuOpts *opts, Error **errp); + #endif diff --git a/qemu-options.hx b/qemu-options.hx index 588e5beab3..47ac537285 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -95,6 +95,26 @@ STEXI Select CPU model (@code{-cpu help} for list and additional feature selection) ETEXI +DEF("accel", HAS_ARG, QEMU_OPTION_accel, + "-accel [accel=]accelerator[,thread=single|multi]\n" + " select accelerator ('-accel help for list')\n" + " thread=single|multi (enable multi-threaded TCG)", QEMU_ARCH_ALL) +STEXI +@item -accel @var{name}[,prop=@var{value}[,...]] +@findex -accel +This is used to enable an accelerator. Depending on the target architecture, +kvm, xen, or tcg can be available. By default, tcg is used. If there is more +than one accelerator specified, the next one is used if the previous one fails +to initialize. +@table @option +@item thread=single|multi +Controls number of TCG threads. When the TCG is multi-threaded there will be one +thread per vCPU therefor taking advantage of additional host cores. The default +is to enable multi-threading where both the back-end and front-ends support it and +no incompatible TCG features have been enabled (e.g. icount/replay). +@end table +ETEXI + DEF("smp", HAS_ARG, QEMU_OPTION_smp, "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n" " set the number of CPUs to 'n' [default=1]\n" diff --git a/tcg/tcg.h b/tcg/tcg.h index f946452049..4c7f258220 100644 --- a/tcg/tcg.h +++ b/tcg/tcg.h @@ -80,6 +80,15 @@ typedef uint64_t tcg_target_ulong; #error unsupported #endif +/* Oversized TCG guests make things like MTTCG hard + * as we can't use atomics for cputlb updates. + */ +#if TARGET_LONG_BITS > TCG_TARGET_REG_BITS +#define TCG_OVERSIZED_GUEST 1 +#else +#define TCG_OVERSIZED_GUEST 0 +#endif + #if TCG_TARGET_NB_REGS <= 32 typedef uint32_t TCGRegSet; #elif TCG_TARGET_NB_REGS <= 64 diff --git a/vl.c b/vl.c index 68e8c003d1..eabd7e04f8 100644 --- a/vl.c +++ b/vl.c @@ -299,6 +299,26 @@ static QemuOptsList qemu_machine_opts = { }, }; +static QemuOptsList qemu_accel_opts = { + .name = "accel", + .implied_opt_name = "accel", + .head = QTAILQ_HEAD_INITIALIZER(qemu_accel_opts.head), + .merge_lists = true, + .desc = { + { + .name = "accel", + .type = QEMU_OPT_STRING, + .help = "Select the type of accelerator", + }, + { + .name = "thread", + .type = QEMU_OPT_STRING, + .help = "Enable/disable multi-threaded TCG", + }, + { /* end of list */ } + }, +}; + static QemuOptsList qemu_boot_opts = { .name = "boot-opts", .implied_opt_name = "order", @@ -2973,7 +2993,8 @@ int main(int argc, char **argv, char **envp) const char *boot_once = NULL; DisplayState *ds; int cyls, heads, secs, translation; - QemuOpts *hda_opts = NULL, *opts, *machine_opts, *icount_opts = NULL; + QemuOpts *opts, *machine_opts; + QemuOpts *hda_opts = NULL, *icount_opts = NULL, *accel_opts = NULL; QemuOptsList *olist; int optind; const char *optarg; @@ -3028,6 +3049,7 @@ int main(int argc, char **argv, char **envp) qemu_add_opts(&qemu_trace_opts); qemu_add_opts(&qemu_option_rom_opts); qemu_add_opts(&qemu_machine_opts); + qemu_add_opts(&qemu_accel_opts); qemu_add_opts(&qemu_mem_opts); qemu_add_opts(&qemu_smp_opts); qemu_add_opts(&qemu_boot_opts); @@ -3723,6 +3745,26 @@ int main(int argc, char **argv, char **envp) qdev_prop_register_global(&kvm_pit_lost_tick_policy); break; } + case QEMU_OPTION_accel: + accel_opts = qemu_opts_parse_noisily(qemu_find_opts("accel"), + optarg, true); + optarg = qemu_opt_get(accel_opts, "accel"); + + olist = qemu_find_opts("machine"); + if (strcmp("kvm", optarg) == 0) { + qemu_opts_parse_noisily(olist, "accel=kvm", false); + } else if (strcmp("xen", optarg) == 0) { + qemu_opts_parse_noisily(olist, "accel=xen", false); + } else if (strcmp("tcg", optarg) == 0) { + qemu_opts_parse_noisily(olist, "accel=tcg", false); + } else { + if (!is_help_option(optarg)) { + error_printf("Unknown accelerator: %s", optarg); + } + error_printf("Supported accelerators: kvm, xen, tcg\n"); + exit(1); + } + break; case QEMU_OPTION_usb: olist = qemu_find_opts("machine"); qemu_opts_parse_noisily(olist, "usb=on", false); @@ -4031,6 +4073,8 @@ int main(int argc, char **argv, char **envp) replay_configure(icount_opts); + qemu_tcg_configure(accel_opts, &error_fatal); + machine_class = select_machine(); set_memory_options(&ram_slots, &maxram_size, machine_class); @@ -4395,6 +4439,9 @@ int main(int argc, char **argv, char **envp) if (!tcg_enabled()) { error_report("-icount is not allowed with hardware virtualization"); exit(1); + } else if (qemu_tcg_mttcg_enabled()) { + error_report("-icount does not currently work with MTTCG"); + exit(1); } configure_icount(icount_opts, &error_abort); qemu_opts_del(icount_opts);