Cover Letter Detail
Show a cover letter.
GET /api/covers/2216425/?format=api
{ "id": 2216425, "url": "http://patchwork.ozlabs.org/api/covers/2216425/?format=api", "web_url": "http://patchwork.ozlabs.org/project/opensbi/cover/20260326115517.2156-1-dave.patel@riscstar.com/", "project": { "id": 67, "url": "http://patchwork.ozlabs.org/api/projects/67/?format=api", "name": "OpenSBI development", "link_name": "opensbi", "list_id": "opensbi.lists.infradead.org", "list_email": "opensbi@lists.infradead.org", "web_url": "https://github.com/riscv/opensbi", "scm_url": "", "webscm_url": "", "list_archive_url": "", "list_archive_url_format": "", "commit_url_format": "https://github.com/riscv/opensbi/commit/{}" }, "msgid": "<20260326115517.2156-1-dave.patel@riscstar.com>", "list_archive_url": null, "date": "2026-03-26T11:55:14", "name": "[v2,0/3] Add eager FP and RISC-V vector context switching support", "submitter": { "id": 92617, "url": "http://patchwork.ozlabs.org/api/people/92617/?format=api", "name": "Dave Patel", "email": "dave.patel@riscstar.com" }, "mbox": "http://patchwork.ozlabs.org/project/opensbi/cover/20260326115517.2156-1-dave.patel@riscstar.com/mbox/", "series": [ { "id": 497579, "url": "http://patchwork.ozlabs.org/api/series/497579/?format=api", "web_url": "http://patchwork.ozlabs.org/project/opensbi/list/?series=497579", "date": "2026-03-26T11:55:16", "name": "[v2,1/3] lib: sbi: Add RISC-V vector context save/restore support (eager switching)", "version": 2, "mbox": "http://patchwork.ozlabs.org/series/497579/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/covers/2216425/comments/", "headers": { "Return-Path": "\n <opensbi-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org>", "X-Original-To": "incoming@patchwork.ozlabs.org", "Delivered-To": "patchwork-incoming@legolas.ozlabs.org", "Authentication-Results": [ "legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n secure) header.d=lists.infradead.org header.i=@lists.infradead.org\n header.a=rsa-sha256 header.s=bombadil.20210309 header.b=sXZk3QG0;\n\tdkim=fail reason=\"signature verification failed\" (2048-bit key;\n unprotected) header.d=riscstar-com.20230601.gappssmtp.com\n header.i=@riscstar-com.20230601.gappssmtp.com header.a=rsa-sha256\n header.s=20230601 header.b=IFM4d8KO;\n\tdkim-atps=neutral", "legolas.ozlabs.org;\n spf=none (no SPF record) smtp.mailfrom=lists.infradead.org\n (client-ip=2607:7c80:54:3::133; helo=bombadil.infradead.org;\n envelope-from=opensbi-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org;\n receiver=patchwork.ozlabs.org)" ], "Received": [ "from bombadil.infradead.org (bombadil.infradead.org\n [IPv6:2607:7c80:54:3::133])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fhMgd1Z2Jz1yGL\n\tfor <incoming@patchwork.ozlabs.org>; Thu, 26 Mar 2026 22:56:25 +1100 (AEDT)", "from localhost ([::1] helo=bombadil.infradead.org)\n\tby bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux))\n\tid 1w5jJv-00000005O10-0ORS;\n\tThu, 26 Mar 2026 11:56:15 +0000", "from mail-wm1-x330.google.com ([2a00:1450:4864:20::330])\n\tby bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux))\n\tid 1w5jJq-00000005Nze-2I5F\n\tfor opensbi@lists.infradead.org;\n\tThu, 26 Mar 2026 11:56:11 +0000", "by mail-wm1-x330.google.com with SMTP id\n 5b1f17b1804b1-486fc4725f0so7693935e9.1\n for <opensbi@lists.infradead.org>;\n Thu, 26 Mar 2026 04:56:09 -0700 (PDT)", "from localhost.localdomain ([78.41.211.48])\n by smtp.gmail.com with ESMTPSA id\n ffacd0b85a97d-43b9194311asm8932438f8f.10.2026.03.26.04.56.06\n (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256);\n Thu, 26 Mar 2026 04:56:07 -0700 (PDT)" ], "DKIM-Signature": [ "v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed;\n\td=lists.infradead.org; s=bombadil.20210309; h=Sender:\n\tContent-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post:\n\tList-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:Cc\n\t:To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:\n\tResent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:\n\tList-Owner; bh=cU8YSL1OIv/tyw+nBUIIQjO+YYMcy6Qdr6iYs42ieQY=; b=sXZk3QG0BUXfTz\n\tY4QOmwWllxEOwya4BF8+823Adw6enpdeHRthZGo8tTf9EAigXhI8QezzqLpVUQfON9AjLsfjc8pL/\n\ts062d3Kv8N6ICmz0rd8EybniCTFjHQPGw8SM5DsbS8wxO1LPeCgWUCev6gptlt85vX8uDIJi232Ft\n\t/03q5zpW5yMvsSlvFO3eleCV89Oca61fYVXMihSoIdh1ZzxNDJOh0NgU1U+SAhrZgjZyQiBkd64zP\n\tUn2EpZ0g/Ox59BVYfm7qKklH6CiUiAdRXi/Rhu6CM444VtQ/Bw+Ri2EIf5xKccvUYDKmx+ApagW2w\n\t9aKYQB6P/XSL94s+iTSg==;", "v=1; a=rsa-sha256; c=relaxed/relaxed;\n d=riscstar-com.20230601.gappssmtp.com; s=20230601; t=1774526168;\n x=1775130968; darn=lists.infradead.org;\n h=content-transfer-encoding:mime-version:message-id:date:subject:cc\n :to:from:from:to:cc:subject:date:message-id:reply-to;\n bh=rf9MF9MK9aXjzq/caiURCmxXQOYsQlXJbVNlxF+FtPA=;\n b=IFM4d8KOuExcTQfeRKZJ86tvXXp41enEUmWVg+bD1TWTzuBE291nBQ+T80Zk0uxQJ2\n OOdr7/YO/vbgi3AxzUEYknBBTH4CUqiZ54+OcaFiH53ECnwthfmaEmE1JtZpxHu/yU2b\n 9HxgE8GyZLxUG7OvIDstsRQ0LHTq4E6guokZUXsktU2/tU+H26VCq6ffS8m/xpu+nveu\n DGlmStJWjcSB8g6NarbOMfEQPx6kuy3lTqMXnp2kTCfc32a8ylncuWSg8SkOYFeyyCdr\n Z3UuCOWynnBVq951L2BBr/UAlqFrg196eL2jEe/gOyAZ5OFjjbWIyqXjwrx8ngnXQy0W\n PbAA==" ], "X-Google-DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/relaxed;\n d=1e100.net; s=20251104; t=1774526168; x=1775130968;\n h=content-transfer-encoding:mime-version:message-id:date:subject:cc\n :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date\n :message-id:reply-to;\n bh=rf9MF9MK9aXjzq/caiURCmxXQOYsQlXJbVNlxF+FtPA=;\n b=fueub0iOKLS+Cxx4EBeVIsd99uRQdFo1K1teJjCII97k9UuwXLPbdMh1fiLm6Y4qes\n AQ00bAAXLO8MC46biHeQNzUhoWP/6hXElShrvfz3Wk4esrZRojTqecRmlKZNnvPWVW2f\n sCH36FwmBWM/S9AlhkKGAnsSJnNd/uObv34SLBJUFkUwHAmmJ5Np1N8+xGRplHowAbG1\n QCSrx0XD6TDO/8Tsn0DkB53KR1E/cMMhJCUs4NFWLRGpxelxWGb27Rk1uo0/aQDvc0JV\n +3VzMc3ER7qSEf3dozh3mm7qWdS+2AJ91RAJHvsh3UqVpDRCE335nwKbJY+Q2Xlsc6WM\n yYgw==", "X-Forwarded-Encrypted": "i=1;\n AJvYcCWaRyVQXUKv4KiBb1GJw8bwQF0Vvz+tj4S+RJ6SmMmP/D6u18FB73owuSRYUWCu9snaCFeHciuV@lists.infradead.org", "X-Gm-Message-State": "AOJu0Ywi7cl37NLSz6qaPx5LmHAUnFaUeoZbTX/kWf3WEY1MhlDSjKTf\n\tfCFEApg3lP5GhlW87K1Aja9j4GDrU4z4xwaVFzc+1tCoZzyrGj99TVdSNp9UrL1Yez0=", "X-Gm-Gg": "ATEYQzypUycfTYFC3nGCe/TqCky3mu4EV7UWTs+Ih1WxOPaFYs48JK9yzdSTncLuQg6\n\tk7TBEqxyAQPmP+XstFX+jFpzJYzacUsyQ5jp9Fn5tbC8mwzu/g4c8cZaDoJ2ez2BmBSM+0Ye4qa\n\tjVN4/hs7os6bXKC+MmmPJOu0ps6ayWvosy6leNu9iY3RUhDK30ppZheR7ZXf1O0SQ8YiBUQL1br\n\tt6sx4YX0N97ixPIL6tk8ZcsjsgUhwDMUijcXHyyTVR6eCg2qi6QYpTAI0KabfGGApcQpkOHX9Aq\n\ty0Oz5nRmx6sDyFXfMm+r9OtQR5ADhA2VxQCjwAW5bTj0gmcd1pEZXGnUZdUY0kWjNzG8GZtkOZd\n\tCDePi1yJkcjLCdEoAx4a2G9qu7T3tiVUbZiJmuki4reqaSvA1aDttfiCi+DU/9o9dki/HDhBvss\n\tTR2RQjVVr+TDTiCfbduXuzdMfH8ACueQFexKo6cQ==", "X-Received": "by 2002:a05:600c:638e:b0:485:3c09:843 with SMTP id\n 5b1f17b1804b1-48722be44b4mr31473055e9.9.1774526167831;\n Thu, 26 Mar 2026 04:56:07 -0700 (PDT)", "From": "dave.patel@riscstar.com", "To": "Samuel Holland <samuel.holland@sifive.com>", "Cc": "Scott Bambrough <scott@riscstar.com>,\n\tRobin Randhawa <robin.randhawa@sifive.com>,\n\tAnup Patel <anup.patel@qti.qualcomm.com>,\n\tDave Patel <dave.patel@riscstar.com>,\n\tRay Mao <raymond.mao@riscstar.com>,\n\tAnup Patel <anuppate@qti.qualcomm.com>,\n\tDhaval <dhaval@rivosinc.com>,\n\tPeter Lin <peter.lin@sifive.com>,\n\topensbi@lists.infradead.org", "Subject": "[PATCH v2 0/3] Add eager FP and RISC-V vector context switching\n support", "Date": "Thu, 26 Mar 2026 11:55:14 +0000", "Message-ID": "<20260326115517.2156-1-dave.patel@riscstar.com>", "X-Mailer": "git-send-email 2.43.0", "MIME-Version": "1.0", "X-CRM114-Version": "20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 ", "X-CRM114-CacheID": "sfid-20260326_045610_740784_04511BAC ", "X-CRM114-Status": "GOOD ( 10.84 )", "X-Spam-Score": "-1.9 (-)", "X-Spam-Report": "Spam detection software,\n running on the system \"bombadil.infradead.org\",\n has NOT identified this incoming email as spam. The original\n message has been attached to this so you can view it or label\n similar future email. If you have any questions, see\n the administrator of that system for details.\n Content preview: Hi Samuel et. al,\n Thanks you for the initial review and support,\n sending out v2 set of patch to gather more consensus,\n currently the context\n switch itself in Opensbi is not being hooked up. This series enhances\n OpenSBI\n domain context switching to properly save and restore floating-point (FP)\n and vector (V) registers on multi-domain systems.\n Content analysis details: (-1.9 points, 5.0 required)\n pts rule name description\n ---- ----------------------\n --------------------------------------------------\n -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no\n trust\n [2a00:1450:4864:20:0:0:0:330 listed in]\n [list.dnswl.org]\n 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record\n -0.0 SPF_PASS SPF: sender matches SPF record\n -0.1 DKIM_VALID Message has at least one valid DKIM or DK\n signature\n 0.1 DKIM_SIGNED Message has a DKIM or DK signature,\n not necessarily valid\n -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1%\n [score: 0.0000]", "X-BeenThere": "opensbi@lists.infradead.org", "X-Mailman-Version": "2.1.34", "Precedence": "list", "List-Id": "<opensbi.lists.infradead.org>", "List-Unsubscribe": "<http://lists.infradead.org/mailman/options/opensbi>,\n <mailto:opensbi-request@lists.infradead.org?subject=unsubscribe>", "List-Archive": "<http://lists.infradead.org/pipermail/opensbi/>", "List-Post": "<mailto:opensbi@lists.infradead.org>", "List-Help": "<mailto:opensbi-request@lists.infradead.org?subject=help>", "List-Subscribe": "<http://lists.infradead.org/mailman/listinfo/opensbi>,\n <mailto:opensbi-request@lists.infradead.org?subject=subscribe>", "Content-Type": "text/plain; charset=\"utf-8\"", "Content-Transfer-Encoding": "base64", "Sender": "\"opensbi\" <opensbi-bounces@lists.infradead.org>", "Errors-To": "opensbi-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org" }, "content": "Hi Samuel et. al,\n\nThanks you for the initial review and support, sending out v2 set of patch to gather\nmore consensus, currently the context switch itself in Opensbi is not being hooked up.\n\nThis series enhances OpenSBI domain context switching to properly save and restore\nfloating-point (FP) and vector (V) registers on multi-domain systems.\n\nThe context switch has now been corrected to the domain context switch instead of\ntrap handler; there is more understanding of how the one OS can context switch to\nanother OS for eg. Rich OS with Secure OS using Opensbi as monitor and that context\nneeds saving between the domain switch.\n\nThis eager context switching approach is more efficient as an alternative to lazy\ncontext switch which cannot be used due to its limitation and is more efficient\nto only store and restore on domain context switch.\n\nThis 3-patch series introduces:\n\n1. **PATCH 1/3 – Domain data structure enhancements for Vector unit**\n - Adds domain pointers for Vector (`vec_ctx`) contexts.\n - Prepares the domain structure for storing isolated vector state.\n - Fixing compilation within each set of patch\n - Fixed all the assumptions\n\t\t-- added vstart CSR aswell for context switching.\n\t\t-- handled config based SBI_MAX_VLENB.\n\t\t-- Fixed vector support for Zve32x\n\n2. **PATCH 2/3 – FP and Vector domain init/exit routines**\n - Adds domain pointers for FP (`fp_ctx`) contexts.\n - Prepares the domain structure for storing isolated vector state.\n - Fixing compilation within the patch and issue seen in v1 series.\n - Fixed all the assumptions\n\t\t-- added support for both 64 and 32 bit FP\n\t\t-- added support for double and single precision support.\n\t\t-- Support for correct context for Zve32x.\n\t\t-- removed dependencies on PLATFORM_RISCV_ISA=rv64gcv\n\n3. **PATCH 3/3 – Domain context switch updates**\n - Updates `switch_to_next_domain_context()` to save and restore FP and vector\n registers.\n - Implements `sbi_fp_domain_init/exit` and `sbi_vector_domain_init/exit`.\n - Initializes FP/vector contexts during domain registration.\n - Cleans up context memory during shutdown.\n - Provides safe no-op versions for harts without FP or vector extensions.\n - Ensures FS and VS in `mstatus` are enabled only if Off.\n - Preserves original `mstatus` after restoring FP/vector state.\n - Works safely even on harts without FP or vector support.\n\nTogether, these changes ensure proper isolation of FP and vector registers between\ndomains, enabling robust multi-domain operation on RISC-V systems.\n\nSigned-off-by: Dave Patel <dave.patel@riscstar.com>" }