From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-132.freemail.mail.aliyun.com (out30-132.freemail.mail.aliyun.com [115.124.30.132]) (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 47758189F20; Tue, 19 Aug 2025 02:01:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.132 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755568910; cv=none; b=PpNkCj6OamJxRmp9GKXn5LJKslrxCL7qPNEkroIiu1t1VAkhCF0J/KqvGsf6TTxc8nRpxiDlyJZcFMKe1X9LKbphbeWsc3eMR6oKZWkspMRKjz2DlAPfwxvZAAc8iR49f1eOoYLhFZ0NeDQXASGJiu2iSfJ/itkCVrUdcS/J/6s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755568910; c=relaxed/simple; bh=kpJ529nLFpZYhOhFdxXRXKi3IP6YxshWJN+qitKNDeU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=meKpZiOZl9b7TN4U4HH8osBauSnT09jjm3khwAsO9UcDLl0gwpGauExzcPIpf94cImIUcT8p02t99jLdY0bVqlMI7QGepb80VzFouNALsLomoN5E7KSUMoWIyGTGkQVDtq4G21ny2sruy+JdcHKduXERuyVVU8SQQSot8o8c5PU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=pPpTDvqk; arc=none smtp.client-ip=115.124.30.132 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="pPpTDvqk" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1755568897; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=5IULTEMO8UY5UYSTMLLyWq2kUCXNHZOA+68prgWQp1U=; b=pPpTDvqkTnU5HDZis5Li5Cy7KR2rxfflSShi6+yO85bQbNmKjksR7H40Oi1CwPTdjpnvXAsKuUtWEzWDwXgmbSFRX3dxBobJcGuZ5Yoe5wluv9SMCQeUzTN2b8k3QyaW0Lz/wZY/F0XZ2dtTL8//Hq6FV1K2sff95oWet5EtfL8= Received: from localhost.localdomain(mailfrom:fangyu.yu@linux.alibaba.com fp:SMTPD_---0Wm4x1Pe_1755568895 cluster:ay36) by smtp.aliyun-inc.com; Tue, 19 Aug 2025 10:01:37 +0800 From: fangyu.yu@linux.alibaba.com To: guoren@kernel.org Cc: anup@brainfault.org, atish.patra@linux.dev, fangyu.yu@linux.alibaba.com, kvm-riscv@lists.infradead.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, paul.walmsley@sifive.com Subject: [PATCH] RISC-V: KVM: Prevent HGATP_MODE_BARE passed Date: Tue, 19 Aug 2025 10:01:33 +0800 Message-Id: <20250819020133.93545-1-fangyu.yu@linux.alibaba.com> X-Mailer: git-send-email 2.39.3 (Apple Git-146) In-Reply-To: <20250819004643.1884149-1-guoren@kernel.org> References: <20250819004643.1884149-1-guoren@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@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. This patch helps to detect hardware function missing in advance, prevent software from entering incorrect logic. Reviewed-by: Fangyu Yu >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