From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from refb01.tmes.trendmicro.eu (refb01.tmes.trendmicro.eu [18.185.115.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C0C3515B0EE for ; Thu, 20 Jun 2024 12:06:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=18.185.115.54 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718885207; cv=fail; b=n/fhBgSpj2w0EVDfqqnHGB8vRRAb0wGHf7t/+JTeN8n/Khv4FmaRdI6iaiSizuzdryzLmDtiNPbnuCtu7HL38I73uutcKwz9Bc48LS0iN1tGZWDyFzgLH4kI+7BfXC4GVBK0HmBxKBJy34IiPVxTOzrY+RL4JJ6hS0YQbrjksgo= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718885207; c=relaxed/simple; bh=O0GMQ9dOhVakRCX8D0CnxQRmxu0Ue/8ECkjt1UD/ANk=; h=Message-ID:Date:From:Subject:To:Cc:References:In-Reply-To: Content-Type:MIME-Version; b=ACpaDrYMiaBC6GoRRgJxhOIlBymUlGcn76iu1S5ufUWvvwuCMroH0IA12igB9oGMh9HAZcXZau/5DVMe+xxJQRmEo9EHH1fACSMbXxdSSSjaQTzg786lZGteY+iJs4pgLQ0RWOszNon5LUrAjpvKOdwaLUARVcdzU7hJZrhnhfU= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=opensynergy.com; spf=pass smtp.mailfrom=opensynergy.com; dkim=pass (2048-bit key) header.d=opensynergy.com header.i=@opensynergy.com header.b=vN1QuG8l; arc=fail smtp.client-ip=18.185.115.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=opensynergy.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=opensynergy.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=opensynergy.com header.i=@opensynergy.com header.b="vN1QuG8l" Received: from 104.47.11.168_.trendmicro.com (unknown [172.21.10.134]) by refb01.tmes.trendmicro.eu (Postfix) with ESMTPS id 6182A10056E61 for ; Thu, 20 Jun 2024 12:06:44 +0000 (UTC) Received: from 104.47.11.168_.trendmicro.com (unknown [172.21.191.80]) by repost01.tmes.trendmicro.eu (Postfix) with SMTP id 6ECB510001FBC; Thu, 20 Jun 2024 12:06:37 +0000 (UTC) X-TM-MAIL-RECEIVED-TIME: 1718885195.787000 X-TM-MAIL-UUID: d2e37d00-fef0-49b7-aec9-70d137e25fd1 Received: from DEU01-FR2-obe.outbound.protection.outlook.com (unknown [104.47.11.168]) by repre01.tmes.trendmicro.eu (Trend Micro Email Security) with ESMTPS id C0672100058E4; Thu, 20 Jun 2024 12:06:35 +0000 (UTC) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=FY4oPwPstlIyOwGkpFqr5npjuq435VnyMAjrtwCiyZ6b8zF636t3Le94UtSab9RpUba4miz6sdyddCovmcgCAaGeChOgYBV9E75nMjNRxbpO8X+4BM5FgJSBYlIGO634hiydmmAnKCOiwvFvD7oPqGGcEcEUEu6XoxZ0OLzK8REEapARcvjd7aBgx74R7MZDv66Y199FiuYzSz9wmQCZgHzesFqLkhx7BTlUqaVP5r/svXQlzcKQlKE491KziZV1qdaNMHgMGuguHhAKFeCE1rQo2yY60BBx6KCMCRqQfzT0p/wZX63DxZuUSWp2o5Ujpm1PMPLKk8ZW421Nk/LDDg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=VbN30poB3tCwfYn66GoIIo56ast/jE9yfXeLEQFi7ho=; b=hDdIRtjJdLSfr7sKo4jsW+9ZTwRuBxzT4xXPZ0F0+RvQod9zvk6X5N1VBiDXCkwRGOwnuTohUduHm6sKKi+n+qeeWgPT3mpttkSAFSdYPs86ApcdVTvHlt1dfPqo0ucvOYtuCNf4L1OIe4sJLUGPBm2TfvvVWbO79hUKYou9WAMc4zqRiNNDb0BCEKfI0R1lgIeeXFvXvfOvInV0bazyMp6EHbJ1PN6qCbQ1+7kvYsUYKr9dpnESW1vEcy3xvyQ3dhs0YVfoN2QKfOjw2WOQzbRHwzcVNaTcpbRMWsaRlDh6t6gse6A0CqkHMc/pqWfn5dx95Z6WtmtNFlSMv119EQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=opensynergy.com; dmarc=pass action=none header.from=opensynergy.com; dkim=pass header.d=opensynergy.com; arc=none Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=opensynergy.com; Message-ID: Date: Thu, 20 Jun 2024 14:06:32 +0200 From: Peter Hilber Subject: Re: [RFC PATCH v3 6/7] virtio_rtc: Add Arm Generic Timer cross-timestamping To: David Woodhouse , linux-kernel@vger.kernel.org, virtualization@lists.linux.dev, linux-arm-kernel@lists.infradead.org, virtio-dev@lists.linux.dev Cc: "Michael S. Tsirkin" , Jason Wang , Xuan Zhuo , Marc Zyngier , Mark Rutland , Daniel Lezcano , Thomas Gleixner References: <20231218073849.35294-1-peter.hilber@opensynergy.com> <20231218073849.35294-7-peter.hilber@opensynergy.com> Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-ClientProxiedBy: BE1P281CA0337.DEUP281.PROD.OUTLOOK.COM (2603:10a6:b10:7d::14) To BE1P281MB1906.DEUP281.PROD.OUTLOOK.COM (2603:10a6:b10:3d::8) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BE1P281MB1906:EE_|FR2P281MB0105:EE_ X-MS-Office365-Filtering-Correlation-Id: e48352d9-79ec-4faf-2a8c-08dc91216ddc X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230037|366013|376011|7416011|1800799021; X-Microsoft-Antispam-Message-Info: =?utf-8?B?dGJwSkhjZHNmak9BSG1HdlUxcXI3ODZKYXBjUUE2em0zZTY1WFpacTg2aU8y?= =?utf-8?B?bkd4bVBEcGpWNGFyZUVoYVJwNlpSQ2xkeVhjZHdJNkRmdW1VWWVlaU5uOG9y?= =?utf-8?B?ZVpHKzNvWlBkTzRvZStWSGlLeGMrWTN2U2RNS3NEU2ZnQ1V6dWxLNEgxQ0ZG?= =?utf-8?B?dlBRWTZydjh5Mm4zRVZIM2c5ZDFyVmY1NzRleXI2amFCelN4QXA2NllFU2VL?= =?utf-8?B?ZUpxd3FzcjB2SnY0N1gxQ0NHUGdidGZjeWdvMGVpU3RTT0dlemFwS0JjZWV6?= =?utf-8?B?RmxzMm9BcFBTNW1GQURoSlZQNjl4c3BjQzhBSjJYRkVlK2s3UnVRTS9Zd0t4?= =?utf-8?B?Tm5RMzVxZ1BsaDdtVi95SVhkd2V6SENteGE1YWVkMFcyY2p6ajZaWkhuSTZI?= =?utf-8?B?U1dvWmlSQmxOQ3h1TFRXdmR6TzU1T2ZnYU91Znk2UVc3eUFCenVYZ2lvZXBh?= =?utf-8?B?UWg2YWZORlRHK2Fua0ZYSlRaZlZCRWR0SDQ1UG9hejU4eEErelZuYWZjQmFG?= =?utf-8?B?SllOdENFTG1zampaZSsrcUNWL2ozaS9BWTNTYm5TelJEUFpZNVo2OW14TGpW?= =?utf-8?B?WDdYRllkVEpRaG5wTFEzbXJyUnhFTmN5T1ZZZlpMUVFkeStBczI0d3VwRml0?= =?utf-8?B?OGovVkJsVzJEbzlPK2lzSXpBc1FwVDJwZVc1bmtmZ1VpSkhLN1ErZm9LZlVp?= =?utf-8?B?djB3T0hHdjRMN0Rwcmd0K1VnY1djZ1NSdHNvSStBSnRjWHVYRWRtdlQ0VGxw?= =?utf-8?B?V3RRd285dlAySXovVW11UVlyc2lzOHplMkNuaERqNW1UbG1SS0RkaCs1VHg4?= =?utf-8?B?ZXZQWGhkeHdnT2RHQ3lPMWMyYVZyeE40WW05OWJJSjlVREdsaG5kRlFaN3lS?= =?utf-8?B?bXdkaTFGdThEMDNyZ1pXeVhVcGNKVGJlN2hUaWJaT0Z2M0V6c2E5cjkyTDZ1?= =?utf-8?B?c3pJQ3JMc0Z1K2txenVrdlFVbGhNbHkxanlDbEFnckdGMVBWVzFEc2JnMWVD?= =?utf-8?B?NWNzTjkzc2ZYdUUxbENyVm1BaGZubys1UGNQczJYRkRUOWN1WEplalFIMGda?= =?utf-8?B?NlphVzEzTjhUZVAxRjhZMlA3ckRtYnlOYTdZcVd6YXZ0WXRFTXZzUUlmUkIz?= =?utf-8?B?R1BpMkdkMnBPVGRHQzlXVUlrc0cybDhHTVZjblQzRWtFQW52RXUwYW5ESFBM?= =?utf-8?B?c2lDcUM5MlkwMkNveGRwYUUzTHFyelQ0YlpNaEtoZVdyYXBpbmtJWEpLaWJo?= =?utf-8?B?KytzOGJaVlRsVVpZQU8wRlp0aEk4RFJINm1PZ1lXYUVqQW1wbkN3OGdoMFlr?= =?utf-8?B?YUFyZTAxSUV0cllpMktvdHRRRlR5SE4xSDd0dlFPaGN1bnpmTmRCaGxESTFH?= =?utf-8?B?YUZkbGFFUEpnRlUwRlphaEtoOWlZeVdwZ0REMzAwUTgwYVNNQUNxakdCWWNT?= =?utf-8?B?T1RxRDZSbUZZeXZsaFBHTmlrR1h4dkdoYjNsOG5oRGpCSXY3Tkoxa2tYbW9G?= =?utf-8?B?emJSdGxodUhBYlNMdjdKeS8wOHBwSWVyNFVMRkVxR1MvMENLNjRZYVBGYzl4?= =?utf-8?B?MTlrS1dHa2Q5UlNMcFhpY243aWZUb21WdjE3bUlPTTRKcnhRVldFVlBVaVM3?= =?utf-8?B?K1N4Vmx6RFdQbWhZdm92a2hGNFl6cVp6MndBbUlhdUFsOHVFYVhHNjlHWURY?= =?utf-8?B?WW80MUdSK3RQMFhsUkxLKy9wKzlEZUtwS255cnRJQ3Y0OVhhazJrUzBnPT0=?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BE1P281MB1906.DEUP281.PROD.OUTLOOK.COM;PTR:;CAT:NONE;SFS:(13230037)(366013)(376011)(7416011)(1800799021);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?VXVDVE5jRVNoeVRGNy9nK1M1TGt3elVSK2paL1VmNk01MmtNM0Y5QjR2Z2M5?= =?utf-8?B?S3M3YTEyQ1laeW1ielNrWXNkZE9IR0k5YUhXdEhRSVk3WGFhNWh1SStUTGIx?= =?utf-8?B?V1BSeE5hRFFQNXRZdk1BVVFoWllqbDU2Z2Noa0F0bkJDbVNxM0dJUkFlRFVZ?= =?utf-8?B?dTh6S0ZTTTdIWXRCZUNTbk1kb1ZKaVdlVk1ZQ1JBZ2hlR3h1M0QwOUQ5MmdY?= =?utf-8?B?ZE1uK1dNSkhtdVJUcmovZEN6MW9xUDVaZXFjTXk3RUNrYnhhUWlxb200aG1S?= =?utf-8?B?ckdZaWtCR0p3blZIUWNqUTNmbnpWV1ZlTjNFZDVIUjBuV043Wkx2RjVCWDBI?= =?utf-8?B?Nm0wZUhxZ1FBK0ZHTHhia09nT0ZRcGpCK2dCUklReFFuZG9HdGxnaWJ3V3lv?= =?utf-8?B?aE5iRTdpbW11ZU1MZGt2QXNMTjU3R2lwZysyMGhYMFF3aFZ6cURZWS9HaTZW?= =?utf-8?B?L0IzeForWXhvSEpZdTVNc2Zkd1gvQmxJb1JnWGgybXY3cjNwQTl1akZacGFx?= =?utf-8?B?QlF3aXRHMjVzREJXblFDR0JYay9jN2pHcks1bllRNXFqRDR6Tm1md1A2bi9u?= =?utf-8?B?dTZkS0J5VFcyU2wvSW1PVzkzSHBTUXEvOHdSZHArUUF3K1JTaXk3ZWNCazhx?= =?utf-8?B?bnpQSUg5cmFnd29YTyt0Q2Vna3ZaR1FERHpGRmI5b2xubG9FWmlsV0RTV0I1?= =?utf-8?B?d2RYaW5ycGN6STlQd0k3NndzekUxRGdKSlVNSTZpTWZpemF0VWZnOHloWTNH?= =?utf-8?B?VjVqUTI0VzhuYzFDaXlHaHp5Vm9TYnlIMFAxbWhkNnpybkFJOVZJWGdQZ2tJ?= =?utf-8?B?OTZZWEZDWkRPN0phQ0xFS0FTRFg0L00wVnFXcnFnaDhkSUloS1orNU1yaGdv?= =?utf-8?B?aU41ZWNHOFhNRC9iUVNtQ2NWVzZuT1ZsM3FocHF5OXVSMnBRdVFic0JzOFNR?= =?utf-8?B?SVBYaHBWbkR1UVFoQWV3V09MRVNMbGo0YzVFTDllSDhmT29OVDVTTGd4NDFB?= =?utf-8?B?aUpCR3hIQndBRjVqNmdiUEI0WHBLL3hoTXlqcFlXWWJ1bEV0em9OdXBjTHZY?= =?utf-8?B?OVlBcVBNUTNQdnE2dG03SlpJeHE2MUsra2h0N1ljcDIrbmowbkFCbFh1Rmoy?= =?utf-8?B?Nzd1Nm4rWnpQOVkxcjdHR2hLbEsrNGdyMmNzU2Y4VkRZSDdHZDdoQnNtT1VZ?= =?utf-8?B?SUVCTG9NTUlzd3hNdFRsbUNKcmJvU2ZPZU0rUkQ0bVl6TlhNdC9FTTRsSlpC?= =?utf-8?B?dEF5NFlBNElMWVBkMmQxY3RXQ2sxcGhpR09UdkVBQUZvZmViR0kyVXo3bnFk?= =?utf-8?B?ZU1KQnNab3BHTUJmQ05BSEhld3B1WmlFb1pQK0tBTURTL0tjNlNGelFDMHgy?= =?utf-8?B?Z1JUbDVuek9MR3F0ek1lK1B4bzhoVW05NzhVbGM3VVZlbEpscitsYkFzd24y?= =?utf-8?B?c09JT0EwdkliV0F6QWlIYXF2aUY1WnJvQnp1ek9UclFpVXBJTjZ3anl6WTVN?= =?utf-8?B?VzY4Y1hnSUYrWFRVdmtNejZPZ3Z1TzNKY3R5YURzT21ua0lhUVBxQm1ta1Bt?= =?utf-8?B?U21oZVFHYzBPdjJadHBlT2RvaUZwT0E2eHBiNlVKNEVkUmZjN0FIVXB1d2Zl?= =?utf-8?B?UENZNkdKWkNubnNKdEVVOFJEV0NVOGg2VkNmSm8wTVpsRUVpWFR0RG9YY2xF?= =?utf-8?B?ZzBEVGZybUpVSDRGaHI0bTNFSFloRUlOUWtXKzN4amxjVFJIdlpzS0hPd2pH?= =?utf-8?B?NXNZMkx4eHBIaGlXMURFc3hZOG9lOUh4TnptZEtiNjlHeXpzMnQxdW94ZGZN?= =?utf-8?B?MUd5dFlET084SjBWUDhyaFhmSlBmbHpaTDJKUlZwVmJmbnpkWnEzWnVNWlVF?= =?utf-8?B?VHp1V1lHTkdUUXBjN3p0YVBnS1ZEM3EvUlNKOEZKYU8rWW1SR3FtbnZhRkdn?= =?utf-8?B?Z214MVNla1pCeVFqN0tTam1xVzU2STcwd1NvNmxqSzVQb01pT3ZUTWF0ME52?= =?utf-8?B?ZTRDRjVZMFNSVXk2ZFhGOHBQQ28yL3BuSUpYYWYvU2ZUdzlaUnJ1d2FyOTg0?= =?utf-8?B?YW9tSEVJNFRMYTZET3BiUXBpeUFuUVdYQkJyRWFTSGpqbnZKbXFGN014RWUr?= =?utf-8?B?N3F2V1FKYzNRdzZHVWZqYU1FWURZZ3dIamxlTHRGRnUwQS9reXdubEVRb05u?= =?utf-8?Q?sCT7r24a9u1wW4ewdizXDVR+szd9hW/umHbcY27JoYFk?= X-OriginatorOrg: opensynergy.com X-MS-Exchange-CrossTenant-Network-Message-Id: e48352d9-79ec-4faf-2a8c-08dc91216ddc X-MS-Exchange-CrossTenant-AuthSource: BE1P281MB1906.DEUP281.PROD.OUTLOOK.COM X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 20 Jun 2024 12:06:34.4817 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 800fae25-9b1b-4edc-993d-c939c4e84a64 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: EadJRaunBpgc4oiNMX7DKeJdBr65AHUZFQKeDYRlsphJGTCgid+wQ1zVYiFzH8mAsoGtPaia2rtWmdTi10NOJQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: FR2P281MB0105 X-TM-AS-ERS: 104.47.11.168-0.0.0.0 X-TMASE-Version: StarCloud-1.3-9.1.1026-28464.007 X-TMASE-Result: 10--15.569800-4.000000 X-TMASE-MatchedRID: byfwvk+IcRn5ETspAEX/ni5SIQSguq+gGfP6Q7XnYoeRnjfvXVSKt689 5HEdohSr6lROzfyovSM3TavLrREKnHAHTluwxdGFybaMhlRNDfDrlkvw0pZ13DZF3fXwq22PXeA eGekCohIr+qWDpaTpageG9+7JmpwrJjpgX+qGOZEJ9830SX03Azsagavr4+KJImJmy502lS0NDH XdWeqRGrwY8epx+4ywhH0rjqaZPdIyrV2ubzbrNZ0UyaWO1QCnF1k2re42Ig0hkL0gCMh6DsJi3 JKzHbmk1mh3V2G9QO8aqShqHxesm0Fp7EpJVf2uOagwGSua5/+YJgzgxqgVT3vBA9C/1eiFSJap XYJQvpPYeXOEzfM22dEoO5p+Ouf5muMpo5XKw29WPx536TZMQBomt7e+ksQhJpK4F9wnIiZiyuQ OZndK/bpcTKsMs1ZR+gsSeW2jNCfz06lohXENhP08piqRFMnZ40pnJqOe/RX84SWtFYp7wAkrYw rjkf4Y X-TMASE-XGENCLOUD: 26535871-38dd-44cd-b188-7de1eb07b9d1-0-0-200-0 X-TM-Deliver-Signature: 499231C7649B77F7641C2652589B65A8 X-TM-Addin-Auth: QZNHK0YGoM9+6fAtK51X0TLG6DY2VmPM/0/ew2N1HhPjL9FIoZSgDoLXusj ylK43Gh2LsvWUy3UsIy02bxw8f2BswD2jTogQam+XGx27kYLeXHkBxFUoyUctSWYPighAdN349g NH1u5XfL2eADLAwQY4BP42t6z1dsX1Sp+XWnKPS68qai2kY6G5tyTA2Q4Jwa/MluXyGJD3OyfdN kyzAnTHOcYz54mngt1SRf5D2xiKhpvpqn5/UXzkM4k+c0xDGgz/qjnyinqNTqIFz81Uaag6iHx4 zfT677GY/he1MW8=.GyIAX4l/MAtcJymbQv3IS4avFP0xlmcbB/9TFO1gtbdTMeAeYN5LTx23dR NMt0/v1n4Vs0DxMNyq7OAc1E5oktisD/GAhaQb5M3sQxRJDqvdfbI0I9okRJeGdL27y31r7oLhp ziO5dEHC1v+aeE/b4dJDK/yGgWgsWrGqgiQ+qusbqnn7odyRuD2aHmjmw/vb9PQ2dyNUaAndebQ Td8X5XUckvOIS9tTzxN/wCGD0EDpDho1465I/8cnxd6S1AJljHR+A7ahvHvm86+04A5Fc4OkBIO 1yaIaVIvvIDgxmnDcduivvy9SxkuGDYjchtxOS3wCaP0EUFk1Sxsb/ukSzg== X-TM-Addin-ProductCode: EMS DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=opensynergy.com; s=TM-DKIM-20210503141657; t=1718885197; bh=O0GMQ9dOhVakRCX8D0CnxQRmxu0Ue/8ECkjt1UD/ANk=; l=2433; h=Date:From:To; b=vN1QuG8lEc7Slb1lLFjabqgL6FO1yNrOM8VDVAg0tft3o4YklD8d3vViWixjBCa9P eKv+3IbrjuZKO4JX+SoaKrjWXRKRNHbrFJ7xhriTuNv9mL9YCym507NlWCf0BpWgmg Z0x7tjb4F5ga0gQbSKYuDPyBur3YGK4PWE9pZdomLuxxbsLcZYmyZHL0TXvCIJC5Zk lcP/VHrLe7DfD/cTTqg8t2JcHNjhzFUkNAOa+vdOpCapehzKfaG+uiQclwbjtbJFV0 /DwqngAUVdBTRteGB7mt7lW5rZ5HyIp4i181pgiKMQA1/eI+n8NLaksQhxyolZqxDS 7QXo/8KLZgKkA== Changing virtio-dev address to the new one. On 15.06.24 09:50, David Woodhouse wrote: > On Mon, 2023-12-18 at 08:38 +0100, Peter Hilber wrote: >> >> +int viortc_hw_xtstamp_params(u16 *hw_counter, enum clocksource_ids *cs_id) >> +{ >> + *hw_counter = VIRTIO_RTC_COUNTER_ARM_VIRT; > > Hm, but what if it isn't? I think you need to put this in > drivers/clocksource/arm_arch_timer.c where it can do something like > kvm_arch_ptp_get_crosststamp() does to decide: > > if (arch_timer_uses_ppi == ARCH_TIMER_VIRT_PPI) > ptp_counter = KVM_PTP_VIRT_COUNTER; > else > ptp_counter = KVM_PTP_PHYS_COUNTER; > > >> + *cs_id = CSID_ARM_ARCH_COUNTER; >> + >> + return 0; >> +} > I had such a check in v1, but Marc Zyngier didn't like the distinction [1, 2] - maybe also exposing the timer through a generic helper was not desired. Quoting from [2]: >> This was the rationale to come up with the physical/virtual counter >> distinction for the Virtio RTC device. Looking at extensions such as >> FEAT_ECV, where the CNTPCT_EL0 value can depend on the EL, or FEAT_NV*, >> it might be a bit simplistic. > > Not just simplistic. It doesn't make sense. For this to work, you'd > need to know the global offset that KVM applies to the global counter, > plus the *virtualised* CNTPOFF/CNTVOFF values that the guest can > change at any time on a *per-CPU* basis. None of that is available > outside of KVM, nor would it make any sense anyway. > >> Does this physical/virtual counter distinction sound like a good idea? >> Otherwise I would drop the arch_timer_counter_get_type() in the next >> iteration. > > My take on this is that only the global counter value makes any sense. > That value is already available from the host as the virtual counter, > because we guarantee that CNTVOFF is 0 when outside of the guest > (well, technically, outside of the vcpu_load/vcpu_put section). So I put the assumption that the virtual counter will always be the right choice for current Linux kernels, from the Virtio device POV. Thanks for the comment, Peter [1] https://lore.kernel.org/lkml/20230630171052.985577-1-peter.hilber@opensynergy.com/T/#ma8d596de1cbc8f4a78a18b2aa995db18423494a7 [2] https://lore.kernel.org/lkml/20230630171052.985577-1-peter.hilber@opensynergy.com/T/#m65fa1d715933360498c4e33d7225e4220215a9d6