From patchwork Tue Dec 10 16:39:44 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Igor Mammedov X-Patchwork-Id: 13901752 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8997CE77182 for ; Tue, 10 Dec 2024 16:40:43 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tL3HI-0003gt-W7; Tue, 10 Dec 2024 11:40:05 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tL3HG-0003ei-Ed for qemu-devel@nongnu.org; Tue, 10 Dec 2024 11:40:02 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tL3HE-00029L-QW for qemu-devel@nongnu.org; Tue, 10 Dec 2024 11:40:02 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1733848800; 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=F+Pfc7rn2iLs0BkcvqcbQ1BgYvYFW9KRmaWnTbFjiyE=; b=YhAI4WtU0S8bDqlFpnqHwuWZpdLos+QmmpY8D6hJ0whVa7mP7ovCK+5lsRMFLXz72kMEOJ cKzzOniYhf2OHUK2IgAkTAag23DEwpe9aBFTrUAs0CgM13pPOgMEYYUrJK265g7euWQzGr 7Lns60oDxw5M7vLH5bac4TFMAbQl80M= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-523-dqb6VGQEPsaTppXpV1CHlA-1; Tue, 10 Dec 2024 11:39:57 -0500 X-MC-Unique: dqb6VGQEPsaTppXpV1CHlA-1 X-Mimecast-MFC-AGG-ID: dqb6VGQEPsaTppXpV1CHlA Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id B4F071954B3B; Tue, 10 Dec 2024 16:39:56 +0000 (UTC) Received: from dell-r430-03.lab.eng.brq2.redhat.com (dell-r430-03.lab.eng.brq2.redhat.com [10.37.153.18]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 759B2300019F; Tue, 10 Dec 2024 16:39:53 +0000 (UTC) From: Igor Mammedov To: qemu-devel@nongnu.org Cc: mst@redhat.com, imammedo@redhat.com, eric.mackay@oracle.com, anisinha@redhat.com Subject: [PATCH 2/3] cpuhp: make sure that remove events are handled within the same SCI Date: Tue, 10 Dec 2024 17:39:44 +0100 Message-ID: <20241210163945.3422623-3-imammedo@redhat.com> In-Reply-To: <20241210163945.3422623-1-imammedo@redhat.com> References: <20241210163945.3422623-1-imammedo@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Received-SPF: pass client-ip=170.10.129.124; envelope-from=imammedo@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -25 X-Spam_score: -2.6 X-Spam_bar: -- X-Spam_report: (-2.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.52, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org CPU_SCAN_METHOD was processing insert events first and only if insert event was not present then it would check remove event. Normally it's not an issue as it doesn't make much sense tho hotplug and immediately unplug it. In this corner case, which can be reproduced with: qemu -smp 1,maxcpus=2 -cpu host -monitor stdio \ -drive if=pflash,format=raw,readonly,file=edk2-x86_64-code.fd * boot till GRUB prompt and pause guest (either via monitor or stop GRUB from automatic boot) * at monitor prompt add CPU: device_add host-x86_64-cpu,socket-id=0,core-id=1,thread-id=0,id=foo * let guest OS boot completely, and unplug CPU from monitor prompt: device_del foo which triggers GPE event that leads to CPU_SCAN_METHOD on guest side as result of above cpu 'foo' will not be hotunplugged, since QEMU sees insert event and ignores remove event (leaving it in pending state) for the GPE event. Any follow up CPU hotplug/unplug action from QEMU side will handle previously ignored event, so as workaround user can repeat device_del. Fix this corner-case by queuing remove events independently from insert events, aka the same way as we do with insert events. And then go over remove queue to send eject notify events to OSPM within the same GPE event. PS: Process remove queue after the cpu add queue has been processed 1st to ensure that OSPM gets hotadd evets after hotremove ones. PS2: Case where it's still borken happens when guest OS is Linux and device_del happens before guest OS initializes ACPI subsystem. Culprit in this case though is the guest kernel, which mangles GPE.sts (by clearing them up) and thus pending SCI turns to NOP leaving insert/remove events in pending state. That is the guest bug and should be fixed there. Signed-off-by: Igor Mammedov Reported-by: Eric Mackay --- hw/acpi/cpu.c | 43 ++++++++++++++++++++++++++++++++++--------- 1 file changed, 34 insertions(+), 9 deletions(-) diff --git a/hw/acpi/cpu.c b/hw/acpi/cpu.c index 5cb60ca8bc..f6a5680b4d 100644 --- a/hw/acpi/cpu.c +++ b/hw/acpi/cpu.c @@ -327,6 +327,7 @@ const VMStateDescription vmstate_cpu_hotplug = { #define CPU_EJECT_METHOD "CEJ0" #define CPU_OST_METHOD "COST" #define CPU_ADDED_LIST "CNEW" +#define CPU_EJ_LIST "CEJL" #define CPU_ENABLED "CPEN" #define CPU_SELECTOR "CSEL" @@ -488,7 +489,6 @@ void build_cpus_aml(Aml *table, MachineState *machine, CPUHotplugFeatures opts, method = aml_method(CPU_SCAN_METHOD, 0, AML_SERIALIZED); { const uint8_t max_cpus_per_pass = 255; - Aml *else_ctx; Aml *while_ctx, *while_ctx2; Aml *has_event = aml_local(0); Aml *dev_chk = aml_int(1); @@ -499,6 +499,8 @@ void build_cpus_aml(Aml *table, MachineState *machine, CPUHotplugFeatures opts, Aml *uid = aml_local(3); Aml *has_job = aml_local(4); Aml *new_cpus = aml_name(CPU_ADDED_LIST); + Aml *ej_cpus = aml_name(CPU_EJ_LIST); + Aml *num_ej_cpus = aml_local(5); aml_append(method, aml_acquire(ctrl_lock, 0xFFFF)); @@ -513,6 +515,8 @@ void build_cpus_aml(Aml *table, MachineState *machine, CPUHotplugFeatures opts, */ aml_append(method, aml_name_decl(CPU_ADDED_LIST, aml_package(max_cpus_per_pass))); + aml_append(method, aml_name_decl(CPU_EJ_LIST, + aml_package(max_cpus_per_pass))); aml_append(method, aml_store(zero, uid)); aml_append(method, aml_store(one, has_job)); @@ -527,6 +531,7 @@ void build_cpus_aml(Aml *table, MachineState *machine, CPUHotplugFeatures opts, aml_append(while_ctx2, aml_store(one, has_event)); aml_append(while_ctx2, aml_store(zero, num_added_cpus)); + aml_append(while_ctx2, aml_store(zero, num_ej_cpus)); /* * Scan CPUs, till there are CPUs with events or @@ -559,8 +564,10 @@ void build_cpus_aml(Aml *table, MachineState *machine, CPUHotplugFeatures opts, * if CPU_ADDED_LIST is full, exit inner loop and process * collected CPUs */ - ifctx = aml_if( - aml_equal(num_added_cpus, aml_int(max_cpus_per_pass))); + ifctx = aml_if(aml_lor( + aml_equal(num_added_cpus, aml_int(max_cpus_per_pass)), + aml_equal(num_ej_cpus, aml_int(max_cpus_per_pass)) + )); { aml_append(ifctx, aml_store(one, has_job)); aml_append(ifctx, aml_break()); @@ -577,16 +584,16 @@ void build_cpus_aml(Aml *table, MachineState *machine, CPUHotplugFeatures opts, aml_append(ifctx, aml_store(one, has_event)); } aml_append(while_ctx, ifctx); - else_ctx = aml_else(); + ifctx = aml_if(aml_equal(rm_evt, one)); { - aml_append(ifctx, - aml_call2(CPU_NOTIFY_METHOD, uid, eject_req)); - aml_append(ifctx, aml_store(one, rm_evt)); + /* cache to be removed CPUs to Notify later */ + aml_append(ifctx, aml_store(uid, + aml_index(ej_cpus, num_ej_cpus))); + aml_append(ifctx, aml_increment(num_ej_cpus)); aml_append(ifctx, aml_store(one, has_event)); } - aml_append(else_ctx, ifctx); - aml_append(while_ctx, else_ctx); + aml_append(while_ctx, ifctx); aml_append(while_ctx, aml_increment(uid)); } aml_append(while_ctx2, while_ctx); @@ -620,6 +627,24 @@ void build_cpus_aml(Aml *table, MachineState *machine, CPUHotplugFeatures opts, aml_append(while_ctx, aml_increment(cpu_idx)); } aml_append(while_ctx2, while_ctx); + + /* + * Notify OSPM about to be removed CPUs and clear remove flag + */ + aml_append(while_ctx2, aml_store(zero, cpu_idx)); + while_ctx = aml_while(aml_lless(cpu_idx, num_ej_cpus)); + { + aml_append(while_ctx, + aml_store(aml_derefof(aml_index(ej_cpus, cpu_idx)), + uid)); + aml_append(while_ctx, + aml_call2(CPU_NOTIFY_METHOD, uid, eject_req)); + aml_append(while_ctx, aml_store(uid, cpu_selector)); + aml_append(while_ctx, aml_store(one, rm_evt)); + aml_append(while_ctx, aml_increment(cpu_idx)); + } + aml_append(while_ctx2, while_ctx); + /* * If another batch is needed, then it will resume scanning * exactly at -- and not after -- the last CPU that's currently