From patchwork Mon May 2 12:33:26 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Igor Mammedov X-Patchwork-Id: 8992001 Return-Path: X-Original-To: patchwork-qemu-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 3DA4EBF29F for ; Mon, 2 May 2016 12:41:31 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 7E81E201FE for ; Mon, 2 May 2016 12:41:30 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9E39D201FA for ; Mon, 2 May 2016 12:41:29 +0000 (UTC) Received: from localhost ([::1]:36407 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1axDAD-000060-Q6 for patchwork-qemu-devel@patchwork.kernel.org; Mon, 02 May 2016 08:41:25 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35504) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1axD3n-0006Pz-4r for qemu-devel@nongnu.org; Mon, 02 May 2016 08:34:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1axD3b-0008So-5r for qemu-devel@nongnu.org; Mon, 02 May 2016 08:34:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33875) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1axD3a-0008PA-UN for qemu-devel@nongnu.org; Mon, 02 May 2016 08:34:35 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D1F56C049D7F for ; Mon, 2 May 2016 12:34:23 +0000 (UTC) Received: from dell-r430-03.lab.eng.brq.redhat.com (dell-r430-03.lab.eng.brq.redhat.com [10.34.112.60]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u42CXqc4000450; Mon, 2 May 2016 08:34:22 -0400 From: Igor Mammedov To: qemu-devel@nongnu.org Date: Mon, 2 May 2016 14:33:26 +0200 Message-Id: <1462192431-146342-18-git-send-email-imammedo@redhat.com> In-Reply-To: <1462192431-146342-1-git-send-email-imammedo@redhat.com> References: <1462192431-146342-1-git-send-email-imammedo@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [RFC 17/42] docs: update ACPI CPU hotplug spec with new protocol 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: drjones@redhat.com, ehabkost@redhat.com, mst@redhat.com, armbru@redhat.com, marcel@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Signed-off-by: Igor Mammedov --- docs/specs/acpi_cpu_hotplug.txt | 88 +++++++++++++++++++++++++++++++++++------ 1 file changed, 76 insertions(+), 12 deletions(-) diff --git a/docs/specs/acpi_cpu_hotplug.txt b/docs/specs/acpi_cpu_hotplug.txt index 340b751..c5bce6a 100644 --- a/docs/specs/acpi_cpu_hotplug.txt +++ b/docs/specs/acpi_cpu_hotplug.txt @@ -4,21 +4,85 @@ QEMU<->ACPI BIOS CPU hotplug interface QEMU supports CPU hotplug via ACPI. This document describes the interface between QEMU and the ACPI BIOS. -ACPI GPE block (IO ports 0xafe0-0xafe3, byte access): ------------------------------------------ - -Generic ACPI GPE block. Bit 2 (GPE.2) used to notify CPU -hot-add/remove event to ACPI BIOS, via SCI interrupt. +ACPI BIOS GPE.2 handler is dedicated for notifying OS about CPU hot-add +and hot-remove events. +============================================ +Legacy ACPI CPU hotplug interface registers: +-------------------------------------------- CPU present bitmap for: + One bit per CPU. Bit position reflects corresponding CPU APIC ID. Read-only. ICH9-LPC (IO port 0x0cd8-0xcf7, 1-byte access) PIIX-PM (IO port 0xaf00-0xaf1f, 1-byte access) --------------------------------------------------------------- -One bit per CPU. Bit position reflects corresponding CPU APIC ID. -Read-only. +QEMU sets corresponding CPU bit on hot-add event and issues SCI +with GPE.2 event set. CPU present map read by ACPI BIOS GPE.2 handler +to notify OS about CPU hot-add events. CPU hot-remove isn't supported. + +===================================== +ACPI CPU hotplug interface registers: +------------------------------------- +Register block base address: + ICH9-LPC IO port 0x0cd8 + PIIX-PM IO port 0xaf00 +Register block size: + ACPI_CPU_HOTPLUG_REG_LEN = 12 + +read access: + offset: + [0x0-0x3] reserved + [0x4] CPU device status fields: (1 byte access) + bits: + 0: Device is enabled and may be used by guest + 1: Device insert event, used to distinguish device for which + no device check event to OSPM was issued. + It's valid only when bit 0 is set. + 2: Device remove event, used to distinguish device for which + no device eject request to OSPM was issued. + 3-7: reserved and should be ignored by OSPM + [0x5-0x7] reserved + [0x8] Command data: (DWORD access) + in case of error or unsupported command reads is 0xFFFFFFFF + current 'Command field' value: + 0: returns PXM value corresponding to device + +write access: + offset: + [0x0-0x3] CPU selector: (DWORD access) + selects active CPU device. All following accesses to other + registers will read/store data from/to selected CPU. + [0x4] CPU device control fields: (1 byte access) + bits: + 0: reserved, OSPM must clear it before writing to register. + 1: if set to 1 clears device insert event, set by OSPM + after it has emitted device check event for the + selected CPU device + 2: if set to 1 clears device remove event, set by OSPM + after it has emitted device eject request for the + selected CPU device + 3: if set to 1 initiates device eject, set by OSPM when it + triggers CPU device removal and calls _EJ0 method + 4-7: reserved, OSPM must clear them before writing to register + [0x5] Command field: (1 byte access) + value: + 0: following reads from 'Command data' register returns PXM + value of device + 1: following writes to 'Command data' register set OST event + register in QEMU + 2: following writes to 'Command data' register set OST status + register in QEMU + other values: reserved + [0x6-0x7] reserved + [0x8] Command data: (DWORD access) + current 'Command field' value: + 1: stores value into OST event register + 2: stores value into OST status register, triggers + ACPI_DEVICE_OST QMP event from QEMU to external applications + with current values of OST event and status registers. + other values: reserved -CPU hot-add/remove notification: ------------------------------------------------------ -QEMU sets/clears corresponding CPU bit on hot-add/remove event. -CPU present map read by ACPI BIOS GPE.2 handler to notify OS of CPU -hot-(un)plug events. +Selecting CPU device beyond possible range has no effect on platform: + - write accesses to CPU hot-plug registers not documented above are + ignored + - read accesses to CPU hot-plug registers not documented above return + all bits set to 1.