From nobody Thu Dec 25 19:34:56 2025 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id D43EC43AB4; Fri, 12 Jan 2024 03:50:48 +0000 (UTC) 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 _____8AxCuoPt6BlOXEEAA--.9033S3; Fri, 12 Jan 2024 11:50:40 +0800 (CST) Received: from localhost.localdomain (unknown [10.2.5.213]) by localhost.localdomain (Coremail) with SMTP id AQAAf8Axqt0Pt6BlAsMSAA--.49445S2; Fri, 12 Jan 2024 11:50:39 +0800 (CST) From: Bibo Mao To: Tianrui Zhao , Huacai Chen Cc: kvm@vger.kernel.org, loongarch@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH] LoongArch: KVM: Remove unnecessary CSR register saving during enter guest Date: Fri, 12 Jan 2024 11:50:39 +0800 Message-Id: <20240112035039.833974-1-maobibo@loongson.cn> X-Mailer: git-send-email 2.39.3 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: AQAAf8Axqt0Pt6BlAsMSAA--.49445S2 X-CM-SenderInfo: xpdruxter6z05rqj20fqof0/ X-Coremail-Antispam: 1Uk129KBj9xXoWrKFyxGw1fuFy3Kr45Ww4ftFc_yoWfAFX_XF 1xtw4Durn3Janruw1Fvas5Xw1jga1kGwsY9F18uryxJa4FqrZ8Zr4Iya1DAr13KFWUZrWf ZrWxGrZ3ur1IyosvyTuYvTs0mTUanT9S1TB71UUUUUDqnTZGkaVYY2UrUUUUj1kv1TuYvT s0mT0YCTnIWjqI5I8CrVACY4xI64kE6c02F40Ex7xfYxn0WfASr-VFAUDa7-sFnT9fnUUI cSsGvfJTRUUUb7kYFVCjjxCrM7AC8VAFwI0_Jr0_Gr1l1xkIjI8I6I8E6xAIw20EY4v20x vaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVWUJVWUCwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV WUJVW8JwA2z4x0Y4vEx4A2jsIE14v26F4j6r4UJwA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_ Gr1j6F4UJwAS0I0E0xvYzxvE52x082IY62kv0487Mc804VCY07AIYIkI8VC2zVCFFI0UMc 02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUXVWUAwAv7VC2z280aVAF wI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JMxAIw28IcxkI7V AKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCj r7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUAVWUtwCIc40Y0x0EwIxGrwCI42IY6x IIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVWUJVW8JwCI42IY6xAI w20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x 0267AKxVWUJVW8JbIYCTnIWIevJa73UjIFyTuYvjxUwmhFDUUUU Content-Type: text/plain; charset="utf-8" Some CSR registers like CRMD/PRMD are saved during enter VM mode. However they are not restored for actual use, saving for these CSR registers can be removed. Signed-off-by: Bibo Mao Reviewed-by: Tianrui Zhao --- arch/loongarch/kvm/switch.S | 6 ------ 1 file changed, 6 deletions(-) diff --git a/arch/loongarch/kvm/switch.S b/arch/loongarch/kvm/switch.S index 0ed9040307b7..905b90de50e8 100644 --- a/arch/loongarch/kvm/switch.S +++ b/arch/loongarch/kvm/switch.S @@ -213,12 +213,6 @@ SYM_FUNC_START(kvm_enter_guest) /* Save host GPRs */ kvm_save_host_gpr a2 =20 - /* Save host CRMD, PRMD to stack */ - csrrd a3, LOONGARCH_CSR_CRMD - st.d a3, a2, PT_CRMD - csrrd a3, LOONGARCH_CSR_PRMD - st.d a3, a2, PT_PRMD - addi.d a2, a1, KVM_VCPU_ARCH st.d sp, a2, KVM_ARCH_HSP st.d tp, a2, KVM_ARCH_HTP base-commit: de927f6c0b07d9e698416c5b287c521b07694cac --=20 2.39.3