Message ID | 20210225134652.2127648-21-npiggin@gmail.com |
---|---|
State | Superseded |
Headers | show
Return-Path: <kvm-ppc-owner@vger.kernel.org> X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=kvm-ppc-owner@vger.kernel.org; receiver=<UNKNOWN>) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=otc6vdNM; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4DmZ0D1Rdrz9sWq for <incoming@patchwork.ozlabs.org>; Fri, 26 Feb 2021 00:49:32 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232290AbhBYNtP (ORCPT <rfc822;incoming@patchwork.ozlabs.org>); Thu, 25 Feb 2021 08:49:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44866 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229613AbhBYNtJ (ORCPT <rfc822;kvm-ppc@vger.kernel.org>); Thu, 25 Feb 2021 08:49:09 -0500 Received: from mail-pl1-x629.google.com (mail-pl1-x629.google.com [IPv6:2607:f8b0:4864:20::629]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A4E15C061356 for <kvm-ppc@vger.kernel.org>; Thu, 25 Feb 2021 05:48:12 -0800 (PST) Received: by mail-pl1-x629.google.com with SMTP id f8so3216730plg.5 for <kvm-ppc@vger.kernel.org>; Thu, 25 Feb 2021 05:48:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=5gBupD6w9IAV3hK4OXn3cqVs1/uQmmRToC//irklCQ4=; b=otc6vdNMX1R7wpi+EcZ6Sx/eMagFElg1z8C/hMvENJbfsoJiLAhL5xwPj8SfUnDy+W aY1OVgUMSruJ8aIiwH1p0tsLDQQrwXxFjbYjHWkWd+fjJxnSKkoNSZjqx/HjCAP2D35X ZjEKcid0iFjqrvMztOaDevAI2MgEJRv3m+WOn9j0x8sEj6n+uT+PZRN7BeiP6FDUQKbo EsdcsF/UTVK4qvvy5c9jNADiI6+zBA5wx2TM1h3YATs+IyB1i+tc+F1ScFXkdIMzsOvc JvbLWs3rJESGSXoCiHzOH40ijL+qUZ25IPJFtwkw4tt61odrQzzqMa32Fpnh8bJbURSy oyeQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=5gBupD6w9IAV3hK4OXn3cqVs1/uQmmRToC//irklCQ4=; b=K3bPvimTOxWlPlSqwEyFfB7zjPf8qTzIMbVx/R1oWGxjl5nRfuzE5AzeJjSBNq81EA zdDY1RB+VpOT9neeL6ALQ365nd8ghNCHp7h6GITWBZ2QfGYmtf0b9XaRUs/zRT2gq5Op 2+WCAQ40FmQz08kzmcNDvnts+ujxoxbXA/WjUvPQR49Ftlm8AP/H3+2yuEBC38aA8U2i V7byz6wsblxCBaL2mQ3I4CRFqtg42NAIrJtmhR9d9sFgmGn7cqcCzKNxqqrZ+sSkTGFX ZBS9tcCISM5i84stX2yvrSo54H5tEFlyU1NFDFLYkjNAFC7ZxDSkK0sQTkvFz+cKzmzf O5fA== X-Gm-Message-State: AOAM533STMkzCUY43Jc2u3UL7nPZAs4JH9fVc6BxW8+l7/pF0GxskCm2 XQmdsIsH4Je8FDA/1AduN93GTW1+h/s= X-Google-Smtp-Source: ABdhPJw55Z0GXGwEI7LASJoBShS68vWHDeVV6WM1gcGrjR0KrZyT0feHuIU12BgvwOse21jbUSEqfw== X-Received: by 2002:a17:902:ced2:b029:e2:8db8:266f with SMTP id d18-20020a170902ced2b02900e28db8266fmr3008957plg.34.1614260891850; Thu, 25 Feb 2021 05:48:11 -0800 (PST) Received: from bobo.ibm.com (58-6-239-121.tpgi.com.au. [58.6.239.121]) by smtp.gmail.com with ESMTPSA id a9sm5925868pjq.17.2021.02.25.05.48.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 25 Feb 2021 05:48:11 -0800 (PST) From: Nicholas Piggin <npiggin@gmail.com> To: kvm-ppc@vger.kernel.org Cc: Nicholas Piggin <npiggin@gmail.com>, linuxppc-dev@lists.ozlabs.org Subject: [PATCH v2 20/37] KVM: PPC: Book3S HV P9: Reduce mftb per guest entry/exit Date: Thu, 25 Feb 2021 23:46:35 +1000 Message-Id: <20210225134652.2127648-21-npiggin@gmail.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20210225134652.2127648-1-npiggin@gmail.com> References: <20210225134652.2127648-1-npiggin@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: <kvm-ppc.vger.kernel.org> X-Mailing-List: kvm-ppc@vger.kernel.org |
Series |
KVM: PPC: Book3S: C-ify the P9 entry/exit code
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diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 735ec40ece86..d98958b78830 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -3689,7 +3689,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit, if (!(vcpu->arch.ctrl & 1)) mtspr(SPRN_CTRLT, mfspr(SPRN_CTRLF) & ~1); - mtspr(SPRN_DEC, vcpu->arch.dec_expires - mftb()); + mtspr(SPRN_DEC, vcpu->arch.dec_expires - tb); if (kvmhv_on_pseries()) { /* @@ -3822,7 +3822,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit, vc->entry_exit_map = 0x101; vc->in_guest = 0; - mtspr(SPRN_DEC, local_paca->kvm_hstate.dec_expires - mftb()); + mtspr(SPRN_DEC, local_paca->kvm_hstate.dec_expires - tb); mtspr(SPRN_SPRG_VDSO_WRITE, local_paca->sprg_vdso); kvmhv_load_host_pmu();
mftb is serialising (dispatch next-to-complete) so it is heavy weight for a mfspr. Avoid reading it multiple times in the entry or exit paths. A small number of cycles delay to timers is tolerable. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- arch/powerpc/kvm/book3s_hv.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)