From nobody Wed Feb 11 01:27:35 2026 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 6B4972D6405; Thu, 21 Aug 2025 14:26:08 +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=1755786368; cv=none; b=k/qBwhoI4mKueNrXp6f1AFfNmRuTnuYCy0BTcpNS9ta8jKdo2s2HkTN6e5lwGAUmaNRbiAxqJG1A/qWqYAu986kGbZ2u4IKYJ5We5l2pSMfjx3xrUo6L18nY08aoamoqYgvVroHlnpICjCyGl4wpW0p7YmooFkxwIEjEpFs4E2Q= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755786368; c=relaxed/simple; bh=SjKIvgxvILxvhlxc+qvjcKbL1gYIOzuL2gDprUk8RXw=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=n0T4tDSmESOD4hMI7QYg97g9isX7ozyeg4ram6qb5H2PYS9/O41SrHiu57yN7ntoLAkqdkSS0ioqRlSKQ2Z6ulqlR1b1dwaP7cWMYVK9Xx1wphmcSgpFXF74lIGHbyt5qYpRze92uJGUmG1vGZcupB1VOhbBwWxTtFhrbxTjwpc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eO4X4D+e; 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="eO4X4D+e" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A355C4CEF4; Thu, 21 Aug 2025 14:26:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755786368; bh=SjKIvgxvILxvhlxc+qvjcKbL1gYIOzuL2gDprUk8RXw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eO4X4D+eJ5MIGDyLmCAoKu949pGua8tVh4BV2PyxZC+P8SacIeWNDxI2Vr5SCyFoX zy+x6Ka7BoBc1yA8X5kn0LPDzC2S8wadzowzTntqQ+vJw0yQWs6GkhJAkGJzNJ1VW0 Ly65kHNc/RhvM8K23X9Q68UCIAK51yI3QD7fzcUpECZsu8rs1r7feFufMgOkatcSqm yPcdTNvNRTTqb/NericCHeFH+vunh86qRgfYL+zkX0yJrD4MMwnHSNRWdqbYMHSurf 7PDsLy/iu64gaLE2x1ZMpRpnnS/b2U4/JtVCFfDf4t7jX1jwW8+pJqnVb92Iv21x+w zAlnWQKzeILTA== 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 , Troy Mitchell Subject: [PATCH V4 RESEND 1/3] RISC-V: KVM: Write hgatp register with valid mode bits Date: Thu, 21 Aug 2025 10:25:40 -0400 Message-Id: <20250821142542.2472079-2-guoren@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20250821142542.2472079-1-guoren@kernel.org> References: <20250821142542.2472079-1-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: quoted-printable Content-Type: text/plain; charset="utf-8" From: Fangyu Yu According to the RISC-V Privileged Architecture Spec, when MODE=3DBare is selected,software must write zero to the remaining fields of hgatp. We have detected the valid mode supported by the HW before, So using a valid mode to detect how many vmid bits are supported. Fixes: fd7bb4a251df ("RISC-V: KVM: Implement VMID allocator") Reviewed-by: Nutty Liu Reviewed-by: Troy Mitchell Reviewed-by: Guo Ren (Alibaba DAMO Academy) Signed-off-by: Fangyu Yu Signed-off-by: Guo Ren (Alibaba DAMO Academy) --- arch/riscv/kvm/vmid.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/riscv/kvm/vmid.c b/arch/riscv/kvm/vmid.c index 3b426c800480..5f33625f4070 100644 --- a/arch/riscv/kvm/vmid.c +++ b/arch/riscv/kvm/vmid.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include =20 @@ -28,7 +29,7 @@ void __init kvm_riscv_gstage_vmid_detect(void) =20 /* Figure-out number of VMID bits in HW */ old =3D csr_read(CSR_HGATP); - csr_write(CSR_HGATP, old | HGATP_VMID); + csr_write(CSR_HGATP, (kvm_riscv_gstage_mode << HGATP_MODE_SHIFT) | HGATP_= VMID); vmid_bits =3D csr_read(CSR_HGATP); vmid_bits =3D (vmid_bits & HGATP_VMID) >> HGATP_VMID_SHIFT; vmid_bits =3D fls_long(vmid_bits); --=20 2.40.1