From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.90_1) id 1mb2RD-00068f-RY for mharc-qemu-riscv@gnu.org; Thu, 14 Oct 2021 11:14:31 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:44916) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mb2RA-00067c-Vy for qemu-riscv@nongnu.org; Thu, 14 Oct 2021 11:14:30 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:39669) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mb2R6-0004JA-99 for qemu-riscv@nongnu.org; Thu, 14 Oct 2021 11:14:26 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1634224461; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=VGf40n6rnuRvz/W2E7iIH24GzDEeB0FtWbXbC+hXd3I=; b=R1/bFEe1I3zk8nZOVH29cKqDdEis/nbMWV6ImrRuAc3xReG8FCjZcGr3femmKq+AwVpQpr 51n5P4Nu6RVz2KFdlYReieOtDxu+Pn2Mw/qJ4+UtB6qEeXG4lR4n3XLLoRJ285VwMX0Ref RaS0ywzpdPRej0nRgBot3wA4WO4JWqE= Received: from mail-ed1-f72.google.com (mail-ed1-f72.google.com [209.85.208.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-404-1LKqdhbDPrmRDHdHFiQVMQ-1; Thu, 14 Oct 2021 11:14:20 -0400 X-MC-Unique: 1LKqdhbDPrmRDHdHFiQVMQ-1 Received: by mail-ed1-f72.google.com with SMTP id c25-20020a056402143900b003dc19782ea8so1933061edx.3 for ; Thu, 14 Oct 2021 08:14:20 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=VGf40n6rnuRvz/W2E7iIH24GzDEeB0FtWbXbC+hXd3I=; b=ZyqtuAUbNhPzr36KKxyYXIYQNdtVEjFFwBSKs5aFattL0WY9E5DFOn6Bw9MM56EP8Y KW+AXzqOb7gRWbp3AG5XrSwsi4hqfRSlajI10bC/FXzqDTkooefZIeGhm4e4I7/BeElx x9PQzgBo5adHxcKouWqSL45dec/GSiGdEK652GsG3djtSKbuyk5NfuWG0F0ZhrPq73qQ tVbTpBxDqwKwG3FOZc2+Y8JSoSZ3EhOHsgUMN4zdm0FT7zKl2IuvViR+d9OhlgGBvtP/ 95/IU3TCTwIdixEpSFNS4n3+qCvu5us5MFV94D/ww4wDsDzw/y4NAoUvlHGVVCtEqAL1 1Zow== X-Gm-Message-State: AOAM533OkZNsLRzhO0HkkNYbGKgc6w38pvBnNQTtmHzNtITKrBQhmR6c xUGYcARSsSw+t4+dw7ovByNPacMdfsOj+jH94Q0w5bddIvaxRtBiH+OaRd9Nu7Nw2WBtBg/N4b1 cgjbn3biYhcg3cnc= X-Received: by 2002:a05:6402:1e88:: with SMTP id f8mr9555372edf.86.1634224459166; Thu, 14 Oct 2021 08:14:19 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyQJXkZ0aOrV89xy765yWT5hzAV3Evgy6ityhqOEkedIS2ZZGnk+EvBRT0tSAWF/ZAz6OUUPw== X-Received: by 2002:a05:6402:1e88:: with SMTP id f8mr9555329edf.86.1634224458816; Thu, 14 Oct 2021 08:14:18 -0700 (PDT) Received: from localhost (nat-pool-brq-t.redhat.com. [213.175.37.10]) by smtp.gmail.com with ESMTPSA id c6sm2124324ejb.41.2021.10.14.08.14.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 14 Oct 2021 08:14:18 -0700 (PDT) Date: Thu, 14 Oct 2021 17:14:17 +0200 From: Igor Mammedov To: Andrew Jones Cc: peter.maydell@linaro.org, Gavin Shan , ehabkost@redhat.com, robh@kernel.org, qemu-devel@nongnu.org, qemu-arm@nongnu.org, shan.gavin@gmail.com, qemu-riscv@nongnu.org Subject: Re: [PATCH v3 1/2] numa: Require distance map when empty node exists Message-ID: <20211014171417.541c9bee@redhat.com> In-Reply-To: <20211013122840.fi4ufle4czyzegtb@gator.home> References: <20211013045805.192165-1-gshan@redhat.com> <20211013045805.192165-2-gshan@redhat.com> <20211013133011.62b8812d@redhat.com> <20211013113544.4xrfagduw4nlbvou@gator.home> <20211013135346.3a8f6c9a@redhat.com> <20211013121125.sdewyrxcipsi3o22@gator.home> <20211013122840.fi4ufle4czyzegtb@gator.home> X-Mailer: Claws Mail 3.18.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=imammedo@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=imammedo@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.049, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-riscv@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 14 Oct 2021 15:14:30 -0000 On Wed, 13 Oct 2021 14:28:40 +0200 Andrew Jones wrote: > On Wed, Oct 13, 2021 at 02:11:25PM +0200, Andrew Jones wrote: > > On Wed, Oct 13, 2021 at 01:53:46PM +0200, Igor Mammedov wrote: > > > On Wed, 13 Oct 2021 13:35:44 +0200 > > > Andrew Jones wrote: > > > > > > > On Wed, Oct 13, 2021 at 01:30:11PM +0200, Igor Mammedov wrote: > > > > > On Wed, 13 Oct 2021 12:58:04 +0800 > > > > > Gavin Shan wrote: > > > > > > > > > > > The following option is used to specify the distance map. It's > > > > > > possible the option isn't provided by user. In this case, the > > > > > > distance map isn't populated and exposed to platform. On the > > > > > > other hand, the empty NUMA node, where no memory resides, is > > > > > > allowed on platforms like ARM64 virt. For these empty NUMA > > > > > > nodes, their corresponding device-tree nodes aren't populated, > > > > > > but their NUMA IDs should be included in the "/distance-map" > > > > > > device-tree node, so that kernel can probe them properly if > > > > > > device-tree is used. > > > > > > > > > > > > -numa,dist,src=,dst=,val= > > > > > > > > > > > > This adds extra check after the machine is initialized, to > > > > > > ask for the distance map from user when empty nodes exist in > > > > > > device-tree. > > > > > > > > > > > > Signed-off-by: Gavin Shan > > > > > > --- > > > > > > hw/core/machine.c | 4 ++++ > > > > > > hw/core/numa.c | 24 ++++++++++++++++++++++++ > > > > > > include/sysemu/numa.h | 1 + > > > > > > 3 files changed, 29 insertions(+) > > > > > > > > > > > > diff --git a/hw/core/machine.c b/hw/core/machine.c > > > > > > index b8d95eec32..c0765ad973 100644 > > > > > > --- a/hw/core/machine.c > > > > > > +++ b/hw/core/machine.c > > > > > > @@ -1355,6 +1355,10 @@ void machine_run_board_init(MachineState *machine) > > > > > > accel_init_interfaces(ACCEL_GET_CLASS(machine->accelerator)); > > > > > > machine_class->init(machine); > > > > > > phase_advance(PHASE_MACHINE_INITIALIZED); > > > > > > + > > > > > > + if (machine->numa_state) { > > > > > > + numa_complete_validation(machine); > > > > > > + } > > > > > > } > > > > > > > > > > > > static NotifierList machine_init_done_notifiers = > > > > > > diff --git a/hw/core/numa.c b/hw/core/numa.c > > > > > > index 510d096a88..7404b7dd38 100644 > > > > > > --- a/hw/core/numa.c > > > > > > +++ b/hw/core/numa.c > > > > > > @@ -727,6 +727,30 @@ void numa_complete_configuration(MachineState *ms) > > > > > > } > > > > > > } > > > > > > > > > > > > +/* > > > > > > + * When device-tree is used by the machine, the empty node IDs should > > > > > > + * be included in the distance map. So we need provide pairs of distances > > > > > > + * in this case. > > > > > > + */ > > > > > > +void numa_complete_validation(MachineState *ms) > > > > > > +{ > > > > > > + NodeInfo *numa_info = ms->numa_state->nodes; > > > > > > + int nb_numa_nodes = ms->numa_state->num_nodes; > > > > > > + int i; > > > > > > + > > > > > > + if (!ms->fdt || ms->numa_state->have_numa_distance) { > > > > > > > > > > also skip check/limitation when VM is launched with ACPI enabled? > > On second thought, I guess it's a good idea to not error out when ACPI is > enabled. There's no point in burdening the ACPI user. > > > > > > > > > Even with ACPI enabled we generate a DT and would like that DT to be as > > > > complete as possible. Of course we should generate a SLIT table with > > > > > > Guest will work just fine without distance map as SRAT describes > > > all numa nodes. > > > You are forcing VM to have SLIT just for the sake of 'completeness' > > > that's practically unused. > > > > > > I'm still unsure about pushing all of this in generic numa code, > > > as this will be used only by ARM for now. It's better to keep it > > > ARM specific, and when RISCV machine will start using this, it > > > could be moved to generic code. > > I think RISCV could start using it now. Linux shares the mem/numa DT > parsing code between Arm and RISCV. If RISCV QEMU wanted to start > exposing NUMA nodes, then they might as well support empty ones from > the start. When RISCV will start using memory-less nodes, we can move this check to generic code. So far 2/2 takes care of ARM only, as result I don't see a good reason to generalize it now. (CCing RISCV folks to see if there is any plans to impl. that) > > I don't see a problem in providing this DT node / ACPI table to guests > > with empty NUMA nodes. I don't even see a problem with providing the > > distance information unconditionally. Can you explain why we should > > prefer not to provide optional HW descriptions? > > I'm still curious why we should be so reluctant to add HW descriptions. > I agree we should be reluctant to error out, though. If distance map were the only way to figure out present node-ids, I wouldn't mind making it non-optional. However guest can already get node-ids from mem/cpu/pci nodes with current device-tree that QEMU generates and forcing optional distance-map (with duplicate info) on user creates non must-have CLI requirements/inconvenience that will eventually propagate to higher layers, I'd rather avoid that if possible. So question is if an idea of fetching numa-ids from cpu nodes in addition to memory nodes (which should cover QEMU needs) have been considered and why it didn't work out? > So, when ACPI is > enabled, let's skip the enforcement of the SLIT table generation, even > if there are empty nodes, as you suggest. > > Thanks, > drew > > > > > Thanks, > > drew > > > > > > > > > the distance information the user provides on the command line in order > > > > to satisfy the check, and we will, since we already have that code in > > > > place. > > > > > > > > > > > > > > Thanks, > > > > drew > > > > > > > > > > > > > > > + return; > > > > > > + } > > > > > > + > > > > > > + for (i = 0; i < nb_numa_nodes; i++) { > > > > > > + if (numa_info[i].present && !numa_info[i].node_mem) { > > > > > > + error_report("Empty node %d found, please provide " > > > > > > + "distance map.", i); > > > > > > + exit(EXIT_FAILURE); > > > > > > + } > > > > > > + } > > > > > > +} > > > > > > + > > > > > > void parse_numa_opts(MachineState *ms) > > > > > > { > > > > > > qemu_opts_foreach(qemu_find_opts("numa"), parse_numa, ms, &error_fatal); > > > > > > diff --git a/include/sysemu/numa.h b/include/sysemu/numa.h > > > > > > index 4173ef2afa..80f25ab830 100644 > > > > > > --- a/include/sysemu/numa.h > > > > > > +++ b/include/sysemu/numa.h > > > > > > @@ -104,6 +104,7 @@ void parse_numa_hmat_lb(NumaState *numa_state, NumaHmatLBOptions *node, > > > > > > void parse_numa_hmat_cache(MachineState *ms, NumaHmatCacheOptions *node, > > > > > > Error **errp); > > > > > > void numa_complete_configuration(MachineState *ms); > > > > > > +void numa_complete_validation(MachineState *ms); > > > > > > void query_numa_node_mem(NumaNodeMem node_mem[], MachineState *ms); > > > > > > extern QemuOptsList qemu_numa_opts; > > > > > > void numa_cpu_pre_plug(const struct CPUArchId *slot, DeviceState *dev, > > > > > > > > > > > > > >