From nobody Tue Feb 10 17:31:15 2026 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 90D501D6199; Tue, 11 Feb 2025 02:01:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=114.242.206.163 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739239293; cv=none; b=erfgOjMW7l1nM4xi+zjkbqkW6eY0wEVVVCsOYZh9HUY2Pwc6TyMRySLu2EJ35m+pa0ymHGLJux5qU9UDsT08ic5XTtKyQX3CayMqW2+2PFUBqIdfSOKKEHTYHh0aYngfVfi0ZU+pWI6b9tI2knrUG7rlEvK8Fw3TIFJ3AJrRkb8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739239293; c=relaxed/simple; bh=1h68JMmBoy5cvlpnj86PtrxlMUHaYCTQ/z8/Ye8D/dA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=HQsA7thU2R13Y1rlHl3pLiGfR5EjwL7LJoeiqx3vtLVtHF6QEdK1+lIZ78aTk5ENowfaWEKW/jz/MIJt1rhYiLRmoXxs6wpgmh0UbM/XSzB+ne2aMniUl2Io1twVM6P1T9vhNfXwylhA8F/c7nKbHEAerVnFWWj5v1fz8plx++8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn; spf=pass smtp.mailfrom=loongson.cn; arc=none smtp.client-ip=114.242.206.163 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=loongson.cn Received: from loongson.cn (unknown [10.2.5.213]) by gateway (Coremail) with SMTP id _____8DxfWtxr6pntM5xAA--.1560S3; Tue, 11 Feb 2025 10:01:21 +0800 (CST) Received: from localhost.localdomain (unknown [10.2.5.213]) by front1 (Coremail) with SMTP id qMiowMBxLsdur6pnLz8LAA--.44545S5; Tue, 11 Feb 2025 10:01:20 +0800 (CST) From: Bibo Mao To: Tianrui Zhao Cc: Huacai Chen , WANG Xuerui , kvm@vger.kernel.org, loongarch@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH v2 3/3] LoongArch: KVM: Set host with kernel mode when switch to VM mode Date: Tue, 11 Feb 2025 10:01:18 +0800 Message-Id: <20250211020118.3275874-4-maobibo@loongson.cn> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20250211020118.3275874-1-maobibo@loongson.cn> References: <20250211020118.3275874-1-maobibo@loongson.cn> 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 X-CM-TRANSID: qMiowMBxLsdur6pnLz8LAA--.44545S5 X-CM-SenderInfo: xpdruxter6z05rqj20fqof0/ X-Coremail-Antispam: 1Uk129KBjDUn29KB7ZKAUJUUUUU529EdanIXcx71UUUUU7KY7 ZEXasCq-sGcSsGvfJ3UbIjqfuFe4nvWSU5nxnvy29KBjDU0xBIdaVrnUUvcSsGvfC2Kfnx nUUI43ZEXa7xR_UUUUUUUUU== Content-Type: text/plain; charset="utf-8" PRMD register is only meaningful on the beginning stage of exception entry, and it is overwritten with nested irq or exception. When CPU runs in VM mode, interrupt need be enabled on host. And the mode for host had better be kernel mode rather than random or user mode. When VM is running, running mode with top command comes from CRMD register, and running mode should be kernel mode since kernel function is executing with perf command. It needs be consistent with both top and perf command. Signed-off-by: Bibo Mao --- arch/loongarch/kvm/switch.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/loongarch/kvm/switch.S b/arch/loongarch/kvm/switch.S index 0c292f818492..1be185e94807 100644 --- a/arch/loongarch/kvm/switch.S +++ b/arch/loongarch/kvm/switch.S @@ -85,7 +85,7 @@ * Guest CRMD comes from separate GCSR_CRMD register */ ori t0, zero, CSR_PRMD_PIE - csrxchg t0, t0, LOONGARCH_CSR_PRMD + csrwr t0, LOONGARCH_CSR_PRMD =20 /* Set PVM bit to setup ertn to guest context */ ori t0, zero, CSR_GSTAT_PVM --=20 2.39.3