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b=eRPsQYuXaXoIq+qOFZzrJcgb3g25OEzV2ptk0b2JKePgOsiV6n+Wnc1R1ca4kkuUr/Uxg9vw1L8ue0oSv2VjsOAw6/4vMVAJ+C8m78kcs5AvvSVG/QjTEArMYW7jTOkvwou3gzPfGXAaoJtvuvykIJQvqG3v+saXN+Ayh27x/tY= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from DS7PR12MB5766.namprd12.prod.outlook.com (2603:10b6:8:75::12) by CY3PR12MB9680.namprd12.prod.outlook.com (2603:10b6:930:100::10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.48.17; Fri, 29 May 2026 04:13:42 +0000 Received: from DS7PR12MB5766.namprd12.prod.outlook.com ([fe80::222:966a:d65d:d08e]) by DS7PR12MB5766.namprd12.prod.outlook.com ([fe80::222:966a:d65d:d08e%3]) with mapi id 15.21.0071.010; Fri, 29 May 2026 04:13:42 +0000 Message-ID: Date: Fri, 29 May 2026 09:43:34 +0530 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1 1/3] iommu/amd: Prevent SB IOAPIC from overriding IVRS validation errors To: Wei Wang , joro@8bytes.org, suravee.suthikulpanit@amd.com, will@kernel.org, robin.murphy@arm.com, thomas.lendacky@amd.com, aik@amd.com, jgg@nvidia.com, kevin.tian@intel.com, xuyongwei@open-hieco.net Cc: iommu@lists.linux.dev, linux-kernel@vger.kernel.org References: Content-Language: en-US From: Vasant Hegde In-Reply-To: Content-Type: text/plain; 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But if the Southbridge (SB) > IOAPIC is enumerated after it in the MADT, the loop overwrites 'ret' to > true. > > This bypasses the validation failure and leaves IR enabled. When devices > attached to the unmapped secondary IOAPIC fire interrupts, the IOMMU drops > them due to the missing Requestor ID, leading to localized device hangs. > > Fix this by initializing 'ret' to true and only toggling it to false > upon encountering a validation error, ensuring failures are never erased. > > Fixes: c2ff5cf5294b ("iommu/amd: Work around wrong IOAPIC device-id in IVRS table") > Signed-off-by: Wei Wang Thanks for the fix. Reviewed-by: Vasant Hegde -Vasant