From nobody Sat Oct 4 08:03:33 2025 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 6E5A726E6EB; Tue, 19 Aug 2025 06:45:12 +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=1755585912; cv=none; b=ldv3seipU+JPH84A61NqJKHqogtkhG6oDwghtivLmrpLLOpCfy0ChVIcbs1AfLLETTQoPUWPaFyEZPjZ4qm1PxfERbS90Q3+oz6EEevzSusXm1+PoQ+6HXNyixrG9wE9JvZNnvrZeRsxGQqmdJqZHYcoYEq29nD9rZ+cFh2fnQs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755585912; c=relaxed/simple; bh=UP9QrxfK6QYEHcUJrlYlyfxkQRb2pZ0b31ddHRriPIQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=VeXWJv6sXh7nhOUIIbE8RQt5A8j8DUjQThJ42F+4aXCCDU8eFyk3akqcLnQMFygRUHDGjkFqPctCBYpnBxQL6MxzUEHjnnOHXXnE3pCIuq/e2/Xgggkt7LrdlPOI9NwSXpPj9NUXAg72Pe+H1jzc92eeM9oUOnmFXfw1dwVDYd0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=pF7BZ0Lh; 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="pF7BZ0Lh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 25906C4CEF4; Tue, 19 Aug 2025 06:45:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755585912; bh=UP9QrxfK6QYEHcUJrlYlyfxkQRb2pZ0b31ddHRriPIQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pF7BZ0Lh144HFRdf5oCuVGgwhS7bRIQEywwzSk6HQeJ/ALSsZDqbmX1Mk168Z/kKe jx8wzNKp4rnFXGafekaeWb0JvrWmtmuqGF0cdq2pPSKfH47PD7fUhvSYR+5FQdb0Jb yjuLh6wYWTqAGcx8RghQz0VbMo2YtdGRGhH8cuz7qXaZre0aivb9DwwW4pdxQRKgRZ N6sZgsVkPlM20oc+MnJq7W9u2yH30quU+dSMjTfmiHxsq2QiksdauUpz2oXQrrx9Op JdtbmLse2hd8SIF+h0v2IZq9ZdQq8vrM6R+ibymfYLih6iS4zxZVWvDNUyqe1zhhrv LcUn7JuQFMOrQ== From: guoren@kernel.org To: guoren@kernel.org 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 Subject: [PATCH] RISC-V KVM: Remove unnecessary HGATP csr_read Date: Tue, 19 Aug 2025 02:44:29 -0400 Message-Id: <20250819064429.1947476-1-guoren@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: References: 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: "Guo Ren (Alibaba DAMO Academy)" The HGATP has been set to zero in gstage_mode_detect(), so there is no need to save the old context. Unify the code convention with gstage_mode_detect(). Signed-off-by: Guo Ren (Alibaba DAMO Academy) --- This cleanup is based on yufang.yu's vmid fixup patch. --- arch/riscv/kvm/vmid.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/arch/riscv/kvm/vmid.c b/arch/riscv/kvm/vmid.c index 5f33625f4070..abb1c2bf2542 100644 --- a/arch/riscv/kvm/vmid.c +++ b/arch/riscv/kvm/vmid.c @@ -25,15 +25,12 @@ static DEFINE_SPINLOCK(vmid_lock); =20 void __init kvm_riscv_gstage_vmid_detect(void) { - unsigned long old; - /* Figure-out number of VMID bits in HW */ - old =3D csr_read(CSR_HGATP); 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); - csr_write(CSR_HGATP, old); + csr_write(CSR_HGATP, 0); =20 /* We polluted local TLB so flush all guest TLB */ kvm_riscv_local_hfence_gvma_all(); --=20 2.40.1