From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f175.google.com (mail-pl1-f175.google.com [209.85.214.175]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 218FD1A238A for ; Tue, 25 Feb 2025 16:47:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.175 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740502080; cv=none; b=GSm1FHMGsWkcuKNDl6NbGniEvhtt4lWQKNgwZMOWfSP/5Reb4gI4LA6GqijzO5jqe/bGH3TVpLGSkw2/jxZKvjEUAZ7ZiDDBGbfMJ8sjwOcb7CR0Ake7+yUEKpmvlYN0KedA6FHZGpGvtiv6o/Qb0DYX3QXrMMSAYnUbuhKdoVA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740502080; c=relaxed/simple; bh=6iPgSZh+iO33nHQzseddwrKUrNhaFUNY8ua+PPksf0A=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=DhoHKXlN4Gr0WhPzvGEGMgSXbbYz2Q3MZJ234h8Ajji8KxpYMkQDm4Egtflzx+ns7x1QYMht3X6epB9elGTYA7yYcsgmdcGTa7U3LrYrc3gtoxgGsl5eH3a/RTKwDWAQ5UMs4Au7eGgxLkm3OJujsNnkSWFCF64JwXJKXzs01QE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=HyLnmGI5; arc=none smtp.client-ip=209.85.214.175 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="HyLnmGI5" Received: by mail-pl1-f175.google.com with SMTP id d9443c01a7336-220e0575f5bso216775ad.0 for ; Tue, 25 Feb 2025 08:47:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1740502078; x=1741106878; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=6TXPG1g3tHBq7F0JV2QmBmMxnoyZNN73F2qMEQ/D5jc=; b=HyLnmGI5H4N2oXfYeACgsRbk6UslRc3vF9u87tf2wF5YS9nmKpLCeeu9ZExlk/194a vr+4BDxkPsG/WQgC6FGFkYXXeQseyunoIkWLBao60GTY7g+hzfhpGK+p0nJ9W+16BMUY n8wIG9DZnUgsFH/F38O3no+vqn81YfDsNSp1Nh+CNPgiiRda0VFeT48EWiYJIUFYNyDp pJzVXxegLyq3dUWSrTQtn0FOoG4higfGBUu91y6SEwPBOp/Tdqjf6uAYfQO5UU23KhRc E7+oqvXgo0A0TfSLilItGoL/v/o2sKcpcd/ELRz+so8korttVGahuex7slTkVjEKAyHf 4Uew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740502078; x=1741106878; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=6TXPG1g3tHBq7F0JV2QmBmMxnoyZNN73F2qMEQ/D5jc=; b=X8UDMTl48TOOBfES9UtQB4pb4cAt8fx9L4uvzab0XRbi3gb4NdSuSK0nfV7zvQPZuF 9KCBTI4+Fj0gkxPrDcQSjGtudr4TFkADOhlIwJ0F4wkDQc73jNx0t7zn/4Sj0gtN6eOm UCNd8g1O54bFzRooj3l06FgTKxCbKs3MxYON1ubyqiX8qbs/z25OltYdXxWmcaffO99o ucTWVzbfSnBJns4oFgosQBzPyg6nrM/fnx2Q6tL4ODJbpW3grM/KJqsxBlVZy+LqYlML a19v6ypXulH2akj0+mh++Mcm+l1N0DnZxERBJDNbjGWnDjBGh/4vquKYrjCfZYVgTyGs U6Ww== X-Forwarded-Encrypted: i=1; AJvYcCUFnJIBIpj4xmEs9yInjtJJXFE9NEgZEJ3p165YXrQqaSlWpXNbgQmoQgz7Ozm+1Vk1tdl/wUbFeyo=@vger.kernel.org X-Gm-Message-State: AOJu0YzxqQpiclIO6deuqPWh+03MSq7axlFDdQIErAWlc1hnfWVyRbse /CCyo4qR2cT9MaYcEgZeWclzDby3f/bijv6w5bdJXNyTy40lFn1f1Ubmx1F9ow== X-Gm-Gg: ASbGncv2zlJvsE8zUNWRE3X5YI5XiQQJN1zSTVdbp4O3fayFHdgddEhIKk/1hzNi0WL PtROjfThHenlWKqmkYZZYi7yeaUI1rEuCBfioyPgi+2Hp1tyikuOo3Me9L+x/QemDnFeRv7uNw1 SEpqmebiCCuQLftFv44zBr5e53ne41fbzHeDouajncFb40Sb1/QJb4iGO1zB2TBBFFrbJkVkmUX kPXo6Bb/HYRLiMaL+CpsF43qKDcHlWyRa4y2DN/ptTiSSAERLw5O3jS7sMFxf7AeHZMDxzSY+qs TdVO8Exps9z0m137LcmDKAZAZDAsbVF11PS7O2ZrVp3ZuLBUqMTkF/kyY/RTIz0= X-Google-Smtp-Source: AGHT+IFvXw+OvC4N/IKxwnR5Ayk0dG/Aagp8HSvp5fGkA6z7Brsy0CGy7v+QNECgYTSPzGrZqtSVWw== X-Received: by 2002:a17:902:ce91:b0:21f:465d:c588 with SMTP id d9443c01a7336-22307a60c47mr3818095ad.14.1740502078043; Tue, 25 Feb 2025 08:47:58 -0800 (PST) Received: from google.com (169.224.198.35.bc.googleusercontent.com. [35.198.224.169]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2230a095f02sm16558235ad.152.2025.02.25.08.47.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 25 Feb 2025 08:47:57 -0800 (PST) Date: Tue, 25 Feb 2025 16:47:47 +0000 From: Pranjal Shrivastava To: Nicolin Chen Cc: jgg@nvidia.com, kevin.tian@intel.com, corbet@lwn.net, will@kernel.org, joro@8bytes.org, suravee.suthikulpanit@amd.com, robin.murphy@arm.com, dwmw2@infradead.org, baolu.lu@linux.intel.com, shuah@kernel.org, linux-kernel@vger.kernel.org, iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kselftest@vger.kernel.org, linux-doc@vger.kernel.org, eric.auger@redhat.com, jean-philippe@linaro.org, mdf@kernel.org, mshavit@google.com, shameerali.kolothum.thodi@huawei.com, smostafa@google.com, ddutile@redhat.com, yi.l.liu@intel.com, patches@lists.linux.dev Subject: Re: [PATCH v7 13/14] iommu/arm-smmu-v3: Report events that belong to devices attached to vIOMMU Message-ID: References: Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Mon, Feb 24, 2025 at 01:56:46PM -0800, Nicolin Chen wrote: > On Mon, Feb 24, 2025 at 09:35:14PM +0000, Pranjal Shrivastava wrote: > > On Sat, Feb 22, 2025 at 07:54:10AM -0800, Nicolin Chen wrote: > > > +int arm_vmaster_report_event(struct arm_smmu_vmaster *vmaster, u64 *evt) > > > +{ > > > + struct iommu_vevent_arm_smmuv3 vevt; > > > + int i; > > > + > > > + lockdep_assert_held(&vmaster->vsmmu->smmu->streams_mutex); > > > + > > > + vevt.evt[0] = cpu_to_le64((evt[0] & ~EVTQ_0_SID) | > > > + FIELD_PREP(EVTQ_0_SID, vmaster->vsid)); > > > + for (i = 1; i < EVTQ_ENT_DWORDS; i++) > > > + vevt.evt[i] = cpu_to_le64(evt[i]); > > > > Just thinking out loud here: > > I understand the goal here is to "emulate" an IOMMU. But I'm just > > wondering if we could report struct events instead of the raw event? > > > > For example, can't we have something like arm_smmu_event here with the > > sid changed to vsid? > > > > Are we taking the raw event since we want to keep the `u64 event_data[]` > > field within `struct iommufd_vevent` generic to all architectures? > > The ABIs for vSMMU are defined in the HW languange, e.g. cmd, ste. > Thus, here evt in raw too. > Ack. Makes sense. > > > - ret = iommu_report_device_fault(master->dev, &fault_evt); > > > + if (event->stall) { > > > + ret = iommu_report_device_fault(master->dev, &fault_evt); > > > + } else { > > > + if (master->vmaster && !event->s2) > > > + ret = arm_vmaster_report_event(master->vmaster, evt); > > > + else > > > + ret = -EFAULT; /* Unhandled events should be pinned */ > > > + } > > > > Nit: > > I don't see the `arm_smmu_handle_event` being called elsewhere, is there > > a reason to return -EFAULT instead of -EOPNOTSUPP here? > > > > I think the current behavior here is to return -EOPNOTSUPP if (!event->stall). > > Whereas, what we're doing here is: > > if (event->stall) { > > ... > > /* do legacy stuff */ > > ... > > } > > > > else { > > if (master->vmaster && !event->s2) > > arm_vmaster_report_event(vmaster, evt); > > else > > ret = -EFAULT > > } > > > > mutex_unlock(&smmu->streams_mutex); > > return ret; > > > > Thus, we end up returning -EFAULT instead of -EOPNOTSUPP in case > > event->stall == false. I agree that we aren't really checking the return > > value in the evtq_thread handler, but I'm wondering if we should ensure > > that we end up retaining the same behaviour as we have right now? > > Oh, it looks like -EOPNOTSUPP should be returned here. Will fix. > With the fix to return `-EOPNOTSUPP`: Reviewed-by: Pranjal Shrivastava Thanks, Praan