From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 35DD1CA0EEB for ; Thu, 21 Aug 2025 03:39:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=vL5Dq+9xgItvY/7x373BLKrcQOcGJ6OchzmG4I6STzo=; b=gA4NMNIz754Njc 707ntVv0LVm0oLfNxKOpzXBHDOIDW4qY3V619eaJUPMdoMlQMQTgbXjXP9jiA0HYyc3UeZnYs8LhT jVfDboq+tk051YtYtp+9ASiv43mr+p3HAmpSZrhfxlvUPopxrSR2bKdqBnwdaQhlHYSuxRupC9fd4 au3Vz8GPBu6ZLNLYwtlvo84vD4Ryy5o190AyfoWXxVTik/tQQFvY3NApEnzLWNSopmakqAxDiofCi VMpCZGBEw9iEUnTUuoJuMIVz7Y0Q+187ZhLAi/dTnz1+GzQjRWRmJDrMzyIh7I9SEO4ndzC38LWUZ EGDA4v4bnaJ38d9wGejg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uow96-0000000Fg6W-2JoS; Thu, 21 Aug 2025 03:39:24 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uovoI-0000000FbxB-2PlY; Thu, 21 Aug 2025 03:17:55 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 4FB9141A53; Thu, 21 Aug 2025 03:17:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E05C2C113CF; Thu, 21 Aug 2025 03:17:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755746274; bh=DMRWjGxN262TTh3G5XEfX36BOwhJZxZpsyMaejs1xjc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jjIATB4zD7fodr7HIVXX5acF/oLmA+F+rCzD6d36kDPuMtRAx3DH/T3oGRXgda4ON 4ADF4lBAPeSYUsiu7/1iv10poNdPIM2sc9SDTdpRV/lBsbTycsWJ9RBqZWks8e3mHk 39gcyPtpbiEd3fyMKBz46Fd4xy/osqSbGn3D8DiPF8myJ0ve3UkJ4fb75aXEkSgHAd IcsH0hU/RxeAsdIa4ZLNw6CsoKy/EdOxykwvGSJq9hLzjtztpQFn2mjS/cC9TVBVVO scyjqOL4BrYmZRGZtmfB8H/4HhPm2pkUCwEJuq/B+H/axgGd/ImyrYtMiPzE4bDfzX jYxrOalEVsyIQ== From: guoren@kernel.org To: guoren@kernel.org, troy.mitchell@linux.dev Cc: alex@ghiti.fr, anup@brainfault.org, aou@eecs.berkeley.edu, atish.patra@linux.dev, fangyu.yu@linux.alibaba.com, guoren@linux.alibaba.com, kvm-riscv@lists.infradead.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, palmer@dabbelt.com, paul.walmsley@sifive.com, Nutty Liu Subject: [PATCH V4 3/3] RISC-V: KVM: Prevent HGATP_MODE_BARE passed Date: Wed, 20 Aug 2025 23:17:18 -0400 Message-Id: <20250821031719.2366017-4-guoren@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20250821031719.2366017-1-guoren@kernel.org> References: <20250821031719.2366017-1-guoren@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250820_201754_652012_3E964C35 X-CRM114-Status: GOOD ( 11.36 ) X-BeenThere: kvm-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kvm-riscv" Errors-To: kvm-riscv-bounces+kvm-riscv=archiver.kernel.org@lists.infradead.org From: "Guo Ren (Alibaba DAMO Academy)" urrent kvm_riscv_gstage_mode_detect() assumes H-extension must have HGATP_MODE_SV39X4/SV32X4 at least, but the spec allows H-extension with HGATP_MODE_BARE alone. The KVM depends on !HGATP_MODE_BARE at least, so enhance the gstage-mode-detect to block HGATP_MODE_BARE. Move gstage-mode-check closer to gstage-mode-detect to prevent unnecessary init. Reviewed-by: Troy Mitchell Reviewed-by: Nutty Liu Signed-off-by: Guo Ren (Alibaba DAMO Academy) --- arch/riscv/kvm/gstage.c | 27 ++++++++++++++++++++++++--- arch/riscv/kvm/main.c | 35 +++++++++++++++++------------------ 2 files changed, 41 insertions(+), 21 deletions(-) diff --git a/arch/riscv/kvm/gstage.c b/arch/riscv/kvm/gstage.c index 24c270d6d0e2..b67d60d722c2 100644 --- a/arch/riscv/kvm/gstage.c +++ b/arch/riscv/kvm/gstage.c @@ -321,7 +321,7 @@ void __init kvm_riscv_gstage_mode_detect(void) if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV57X4) { kvm_riscv_gstage_mode = HGATP_MODE_SV57X4; kvm_riscv_gstage_pgd_levels = 5; - goto skip_sv48x4_test; + goto done; } /* Try Sv48x4 G-stage mode */ @@ -329,10 +329,31 @@ void __init kvm_riscv_gstage_mode_detect(void) if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV48X4) { kvm_riscv_gstage_mode = HGATP_MODE_SV48X4; kvm_riscv_gstage_pgd_levels = 4; + goto done; } -skip_sv48x4_test: + /* Try Sv39x4 G-stage mode */ + csr_write(CSR_HGATP, HGATP_MODE_SV39X4 << HGATP_MODE_SHIFT); + if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV39X4) { + kvm_riscv_gstage_mode = HGATP_MODE_SV39X4; + kvm_riscv_gstage_pgd_levels = 3; + goto done; + } +#else /* CONFIG_32BIT */ + /* Try Sv32x4 G-stage mode */ + csr_write(CSR_HGATP, HGATP_MODE_SV32X4 << HGATP_MODE_SHIFT); + if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV32X4) { + kvm_riscv_gstage_mode = HGATP_MODE_SV32X4; + kvm_riscv_gstage_pgd_levels = 2; + goto done; + } +#endif + + /* KVM depends on !HGATP_MODE_OFF */ + kvm_riscv_gstage_mode = HGATP_MODE_OFF; + kvm_riscv_gstage_pgd_levels = 0; + +done: csr_write(CSR_HGATP, 0); kvm_riscv_local_hfence_gvma_all(); -#endif } diff --git a/arch/riscv/kvm/main.c b/arch/riscv/kvm/main.c index 67c876de74ef..8ee7aaa74ddc 100644 --- a/arch/riscv/kvm/main.c +++ b/arch/riscv/kvm/main.c @@ -93,6 +93,23 @@ static int __init riscv_kvm_init(void) return rc; kvm_riscv_gstage_mode_detect(); + switch (kvm_riscv_gstage_mode) { + case HGATP_MODE_SV32X4: + str = "Sv32x4"; + break; + case HGATP_MODE_SV39X4: + str = "Sv39x4"; + break; + case HGATP_MODE_SV48X4: + str = "Sv48x4"; + break; + case HGATP_MODE_SV57X4: + str = "Sv57x4"; + break; + default: + return -ENODEV; + } + kvm_info("using %s G-stage page table format\n", str); kvm_riscv_gstage_vmid_detect(); @@ -135,24 +152,6 @@ static int __init riscv_kvm_init(void) (rc) ? slist : "no features"); } - switch (kvm_riscv_gstage_mode) { - case HGATP_MODE_SV32X4: - str = "Sv32x4"; - break; - case HGATP_MODE_SV39X4: - str = "Sv39x4"; - break; - case HGATP_MODE_SV48X4: - str = "Sv48x4"; - break; - case HGATP_MODE_SV57X4: - str = "Sv57x4"; - break; - default: - return -ENODEV; - } - kvm_info("using %s G-stage page table format\n", str); - kvm_info("VMID %ld bits available\n", kvm_riscv_gstage_vmid_bits()); if (kvm_riscv_aia_available()) -- 2.40.1 -- kvm-riscv mailing list kvm-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kvm-riscv From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 9C08F18C933; Thu, 21 Aug 2025 03:17:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755746274; cv=none; b=JC3Gc10uLvdqxHL5flIvTfDlQAflUxiY2wXPwpC7xHdfmfBg8DQS+RmJEQYivkiU21cfM0VAqqYW8adWWSXD1ZIppQsB3s62L0G0+ltUmnVP1qo4Xe9CiGZ1x9JgX4uEQQ890YN7ziZWHdVExG+z1RjoI//UNtpx5iLN9e3QXFI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755746274; c=relaxed/simple; bh=DMRWjGxN262TTh3G5XEfX36BOwhJZxZpsyMaejs1xjc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=mXrmADRaZe0vWsnYTkPtL8wr5T4JqCkUDYpO0a3tpA8MgUi9OwcJ5Nt+YfUpztKQYHAovwmv9mtW5ZHS4mVcgvZELT8jOefanHvHAkcnNwDbpUdYDUPiRDkjwhuGM/EAk4ajJbc09ceFkbxxIQmSwqu1lNPjvGeo2jBqyS2+FEo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jjIATB4z; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="jjIATB4z" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E05C2C113CF; Thu, 21 Aug 2025 03:17:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755746274; bh=DMRWjGxN262TTh3G5XEfX36BOwhJZxZpsyMaejs1xjc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jjIATB4zD7fodr7HIVXX5acF/oLmA+F+rCzD6d36kDPuMtRAx3DH/T3oGRXgda4ON 4ADF4lBAPeSYUsiu7/1iv10poNdPIM2sc9SDTdpRV/lBsbTycsWJ9RBqZWks8e3mHk 39gcyPtpbiEd3fyMKBz46Fd4xy/osqSbGn3D8DiPF8myJ0ve3UkJ4fb75aXEkSgHAd IcsH0hU/RxeAsdIa4ZLNw6CsoKy/EdOxykwvGSJq9hLzjtztpQFn2mjS/cC9TVBVVO scyjqOL4BrYmZRGZtmfB8H/4HhPm2pkUCwEJuq/B+H/axgGd/ImyrYtMiPzE4bDfzX jYxrOalEVsyIQ== From: guoren@kernel.org To: guoren@kernel.org, troy.mitchell@linux.dev Cc: alex@ghiti.fr, anup@brainfault.org, aou@eecs.berkeley.edu, atish.patra@linux.dev, fangyu.yu@linux.alibaba.com, guoren@linux.alibaba.com, kvm-riscv@lists.infradead.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, palmer@dabbelt.com, paul.walmsley@sifive.com, Nutty Liu Subject: [PATCH V4 3/3] RISC-V: KVM: Prevent HGATP_MODE_BARE passed Date: Wed, 20 Aug 2025 23:17:18 -0400 Message-Id: <20250821031719.2366017-4-guoren@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20250821031719.2366017-1-guoren@kernel.org> References: <20250821031719.2366017-1-guoren@kernel.org> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: "Guo Ren (Alibaba DAMO Academy)" urrent kvm_riscv_gstage_mode_detect() assumes H-extension must have HGATP_MODE_SV39X4/SV32X4 at least, but the spec allows H-extension with HGATP_MODE_BARE alone. The KVM depends on !HGATP_MODE_BARE at least, so enhance the gstage-mode-detect to block HGATP_MODE_BARE. Move gstage-mode-check closer to gstage-mode-detect to prevent unnecessary init. Reviewed-by: Troy Mitchell Reviewed-by: Nutty Liu Signed-off-by: Guo Ren (Alibaba DAMO Academy) --- arch/riscv/kvm/gstage.c | 27 ++++++++++++++++++++++++--- arch/riscv/kvm/main.c | 35 +++++++++++++++++------------------ 2 files changed, 41 insertions(+), 21 deletions(-) diff --git a/arch/riscv/kvm/gstage.c b/arch/riscv/kvm/gstage.c index 24c270d6d0e2..b67d60d722c2 100644 --- a/arch/riscv/kvm/gstage.c +++ b/arch/riscv/kvm/gstage.c @@ -321,7 +321,7 @@ void __init kvm_riscv_gstage_mode_detect(void) if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV57X4) { kvm_riscv_gstage_mode = HGATP_MODE_SV57X4; kvm_riscv_gstage_pgd_levels = 5; - goto skip_sv48x4_test; + goto done; } /* Try Sv48x4 G-stage mode */ @@ -329,10 +329,31 @@ void __init kvm_riscv_gstage_mode_detect(void) if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV48X4) { kvm_riscv_gstage_mode = HGATP_MODE_SV48X4; kvm_riscv_gstage_pgd_levels = 4; + goto done; } -skip_sv48x4_test: + /* Try Sv39x4 G-stage mode */ + csr_write(CSR_HGATP, HGATP_MODE_SV39X4 << HGATP_MODE_SHIFT); + if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV39X4) { + kvm_riscv_gstage_mode = HGATP_MODE_SV39X4; + kvm_riscv_gstage_pgd_levels = 3; + goto done; + } +#else /* CONFIG_32BIT */ + /* Try Sv32x4 G-stage mode */ + csr_write(CSR_HGATP, HGATP_MODE_SV32X4 << HGATP_MODE_SHIFT); + if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV32X4) { + kvm_riscv_gstage_mode = HGATP_MODE_SV32X4; + kvm_riscv_gstage_pgd_levels = 2; + goto done; + } +#endif + + /* KVM depends on !HGATP_MODE_OFF */ + kvm_riscv_gstage_mode = HGATP_MODE_OFF; + kvm_riscv_gstage_pgd_levels = 0; + +done: csr_write(CSR_HGATP, 0); kvm_riscv_local_hfence_gvma_all(); -#endif } diff --git a/arch/riscv/kvm/main.c b/arch/riscv/kvm/main.c index 67c876de74ef..8ee7aaa74ddc 100644 --- a/arch/riscv/kvm/main.c +++ b/arch/riscv/kvm/main.c @@ -93,6 +93,23 @@ static int __init riscv_kvm_init(void) return rc; kvm_riscv_gstage_mode_detect(); + switch (kvm_riscv_gstage_mode) { + case HGATP_MODE_SV32X4: + str = "Sv32x4"; + break; + case HGATP_MODE_SV39X4: + str = "Sv39x4"; + break; + case HGATP_MODE_SV48X4: + str = "Sv48x4"; + break; + case HGATP_MODE_SV57X4: + str = "Sv57x4"; + break; + default: + return -ENODEV; + } + kvm_info("using %s G-stage page table format\n", str); kvm_riscv_gstage_vmid_detect(); @@ -135,24 +152,6 @@ static int __init riscv_kvm_init(void) (rc) ? slist : "no features"); } - switch (kvm_riscv_gstage_mode) { - case HGATP_MODE_SV32X4: - str = "Sv32x4"; - break; - case HGATP_MODE_SV39X4: - str = "Sv39x4"; - break; - case HGATP_MODE_SV48X4: - str = "Sv48x4"; - break; - case HGATP_MODE_SV57X4: - str = "Sv57x4"; - break; - default: - return -ENODEV; - } - kvm_info("using %s G-stage page table format\n", str); - kvm_info("VMID %ld bits available\n", kvm_riscv_gstage_vmid_bits()); if (kvm_riscv_aia_available()) -- 2.40.1 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id BF8EACA0EEB for ; Thu, 21 Aug 2025 03:39:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=PCwBNsHfMHk44ltVWMVB/IWqwSt0n9qAgz7N67yjt/Q=; b=hm6yXVP2zuoYar +NEoGHgCSbQIfNATNiQL1Eue53BB5dWIwqgzesXa8BOOPSFIe6FppUb94UP1boJWh3kkutj9xu5F7 lJUW2AagSQHuN6ur4IbWP79WKWNNjWG2mVNFNk2LVCVeHNNJSo16NrzFjfRP6FrCNa/FFyqgJKbic 0MO1N+FrOa2inExxe2lNN2ujHZhVCPvuqeM7OD1HMnLLsjiHY7JC+fWE6IEEUN9/vyXC5GQg0saBL twN/jiq3X3Dnp39uO82FZD/6SSnWCQvS4mAxUqgnD64LsluQ7lzFEtn4rEMRfuM7LZvvqo4izuRd/ OeuAr0x+PruZ5nKZ8fng==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uow97-0000000Fg7m-25rD; Thu, 21 Aug 2025 03:39:25 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uovoI-0000000FbxB-2PlY; Thu, 21 Aug 2025 03:17:55 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 4FB9141A53; Thu, 21 Aug 2025 03:17:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E05C2C113CF; Thu, 21 Aug 2025 03:17:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755746274; bh=DMRWjGxN262TTh3G5XEfX36BOwhJZxZpsyMaejs1xjc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jjIATB4zD7fodr7HIVXX5acF/oLmA+F+rCzD6d36kDPuMtRAx3DH/T3oGRXgda4ON 4ADF4lBAPeSYUsiu7/1iv10poNdPIM2sc9SDTdpRV/lBsbTycsWJ9RBqZWks8e3mHk 39gcyPtpbiEd3fyMKBz46Fd4xy/osqSbGn3D8DiPF8myJ0ve3UkJ4fb75aXEkSgHAd IcsH0hU/RxeAsdIa4ZLNw6CsoKy/EdOxykwvGSJq9hLzjtztpQFn2mjS/cC9TVBVVO scyjqOL4BrYmZRGZtmfB8H/4HhPm2pkUCwEJuq/B+H/axgGd/ImyrYtMiPzE4bDfzX jYxrOalEVsyIQ== From: guoren@kernel.org To: guoren@kernel.org, troy.mitchell@linux.dev Cc: alex@ghiti.fr, anup@brainfault.org, aou@eecs.berkeley.edu, atish.patra@linux.dev, fangyu.yu@linux.alibaba.com, guoren@linux.alibaba.com, kvm-riscv@lists.infradead.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, palmer@dabbelt.com, paul.walmsley@sifive.com, Nutty Liu Subject: [PATCH V4 3/3] RISC-V: KVM: Prevent HGATP_MODE_BARE passed Date: Wed, 20 Aug 2025 23:17:18 -0400 Message-Id: <20250821031719.2366017-4-guoren@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20250821031719.2366017-1-guoren@kernel.org> References: <20250821031719.2366017-1-guoren@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250820_201754_652012_3E964C35 X-CRM114-Status: GOOD ( 11.36 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org From: "Guo Ren (Alibaba DAMO Academy)" urrent kvm_riscv_gstage_mode_detect() assumes H-extension must have HGATP_MODE_SV39X4/SV32X4 at least, but the spec allows H-extension with HGATP_MODE_BARE alone. The KVM depends on !HGATP_MODE_BARE at least, so enhance the gstage-mode-detect to block HGATP_MODE_BARE. Move gstage-mode-check closer to gstage-mode-detect to prevent unnecessary init. Reviewed-by: Troy Mitchell Reviewed-by: Nutty Liu Signed-off-by: Guo Ren (Alibaba DAMO Academy) --- arch/riscv/kvm/gstage.c | 27 ++++++++++++++++++++++++--- arch/riscv/kvm/main.c | 35 +++++++++++++++++------------------ 2 files changed, 41 insertions(+), 21 deletions(-) diff --git a/arch/riscv/kvm/gstage.c b/arch/riscv/kvm/gstage.c index 24c270d6d0e2..b67d60d722c2 100644 --- a/arch/riscv/kvm/gstage.c +++ b/arch/riscv/kvm/gstage.c @@ -321,7 +321,7 @@ void __init kvm_riscv_gstage_mode_detect(void) if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV57X4) { kvm_riscv_gstage_mode = HGATP_MODE_SV57X4; kvm_riscv_gstage_pgd_levels = 5; - goto skip_sv48x4_test; + goto done; } /* Try Sv48x4 G-stage mode */ @@ -329,10 +329,31 @@ void __init kvm_riscv_gstage_mode_detect(void) if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV48X4) { kvm_riscv_gstage_mode = HGATP_MODE_SV48X4; kvm_riscv_gstage_pgd_levels = 4; + goto done; } -skip_sv48x4_test: + /* Try Sv39x4 G-stage mode */ + csr_write(CSR_HGATP, HGATP_MODE_SV39X4 << HGATP_MODE_SHIFT); + if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV39X4) { + kvm_riscv_gstage_mode = HGATP_MODE_SV39X4; + kvm_riscv_gstage_pgd_levels = 3; + goto done; + } +#else /* CONFIG_32BIT */ + /* Try Sv32x4 G-stage mode */ + csr_write(CSR_HGATP, HGATP_MODE_SV32X4 << HGATP_MODE_SHIFT); + if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV32X4) { + kvm_riscv_gstage_mode = HGATP_MODE_SV32X4; + kvm_riscv_gstage_pgd_levels = 2; + goto done; + } +#endif + + /* KVM depends on !HGATP_MODE_OFF */ + kvm_riscv_gstage_mode = HGATP_MODE_OFF; + kvm_riscv_gstage_pgd_levels = 0; + +done: csr_write(CSR_HGATP, 0); kvm_riscv_local_hfence_gvma_all(); -#endif } diff --git a/arch/riscv/kvm/main.c b/arch/riscv/kvm/main.c index 67c876de74ef..8ee7aaa74ddc 100644 --- a/arch/riscv/kvm/main.c +++ b/arch/riscv/kvm/main.c @@ -93,6 +93,23 @@ static int __init riscv_kvm_init(void) return rc; kvm_riscv_gstage_mode_detect(); + switch (kvm_riscv_gstage_mode) { + case HGATP_MODE_SV32X4: + str = "Sv32x4"; + break; + case HGATP_MODE_SV39X4: + str = "Sv39x4"; + break; + case HGATP_MODE_SV48X4: + str = "Sv48x4"; + break; + case HGATP_MODE_SV57X4: + str = "Sv57x4"; + break; + default: + return -ENODEV; + } + kvm_info("using %s G-stage page table format\n", str); kvm_riscv_gstage_vmid_detect(); @@ -135,24 +152,6 @@ static int __init riscv_kvm_init(void) (rc) ? slist : "no features"); } - switch (kvm_riscv_gstage_mode) { - case HGATP_MODE_SV32X4: - str = "Sv32x4"; - break; - case HGATP_MODE_SV39X4: - str = "Sv39x4"; - break; - case HGATP_MODE_SV48X4: - str = "Sv48x4"; - break; - case HGATP_MODE_SV57X4: - str = "Sv57x4"; - break; - default: - return -ENODEV; - } - kvm_info("using %s G-stage page table format\n", str); - kvm_info("VMID %ld bits available\n", kvm_riscv_gstage_vmid_bits()); if (kvm_riscv_aia_available()) -- 2.40.1 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv