From patchwork Mon Oct 4 16:00:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicholas Piggin X-Patchwork-Id: 1536226 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20210112 header.b=mg0Iw6mc; dkim-atps=neutral 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=) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by bilbo.ozlabs.org (Postfix) with ESMTP id 4HNQTq3TRpz9t5G for ; Tue, 5 Oct 2021 03:02:39 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235212AbhJDQES (ORCPT ); Mon, 4 Oct 2021 12:04:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43628 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236289AbhJDQEN (ORCPT ); Mon, 4 Oct 2021 12:04:13 -0400 Received: from mail-pl1-x633.google.com (mail-pl1-x633.google.com [IPv6:2607:f8b0:4864:20::633]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CF858C061746 for ; Mon, 4 Oct 2021 09:02:24 -0700 (PDT) Received: by mail-pl1-x633.google.com with SMTP id j4so209455plx.4 for ; Mon, 04 Oct 2021 09:02:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=TM/HAR2kIbbjsWEciD5SVgeeCTO1PDyzdJl58aiAKUU=; b=mg0Iw6mcWciAkTXZmbSjn0fIPZxsDgy0BgteZZFXRyFvyilYuuOastBAzHwDoRBuYf LvYLGn8PfLpVon3pT+gN0MQxG0unh6NK5OpSlaS1ix4OKzf1ka9tAe+/v0hXA/Z9yLOd uadUFkDtiz7XSrutFCTO6HdJOhWxU/LiqJV3GrSK7nQO/EY7gXIVP90qaKrX1eIaMxgq 3bGmoNiiGojqCBFOFQ5cVWYdEDv8A6aUCuuC6Nnx14tQDjXkGP37p0sGzm493oSPLlF4 oBSOgPKIzX0pvUYGEziebIAt3qF915nahHz1wSM6wWBeOfGczKkCzVs4PHR1vVGWm4Nj 1H9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=TM/HAR2kIbbjsWEciD5SVgeeCTO1PDyzdJl58aiAKUU=; b=6bN2RyL8Re0OWj09I0sAs4eFIK7kek4vfrgs+ffOCP4ckdo1rp7X41LRYNdetIF2y9 ybWkJsr6cdcD2YUHC+kcIstaqE63mI7210l/3l7l5aJBwYGaya1MPVbYcQt60/SlucqV 9J/EA36NoO/JZXSZ4Ugu1z5TuPZJeOeDV2G95TAFSnZFonO+TpC7cmKf1gaMhbfRZMyS eRbSozMZxtAzwEhlTDUeI+tRAFoidX8DXCeueEnEIjFNM1Ccr0HpscP/IC/Hl67xonts oJUpPT+tTkRDQdeqvAwjGWiAY8604exUmvNl5gVaTUm863CTjgYSbObFgesF3ONb9i7t AUXg== X-Gm-Message-State: AOAM5314wVm5s0jFMp2ZnN8SkxMTs3Elgw/etozgoXijILzVf5Pb30V/ aZvcqJAURhWgejtWvLsif0S09XENGcs= X-Google-Smtp-Source: ABdhPJw9i0hkx/ZJX4gMlIdhV58CWJ6jGL1hsGTn/P4mcWSdf8vQ6enEN7lxxJB7ZPLqZykU8TlfWA== X-Received: by 2002:a17:902:868d:b0:13d:dfa7:f3f2 with SMTP id g13-20020a170902868d00b0013ddfa7f3f2mr456589plo.30.1633363344226; Mon, 04 Oct 2021 09:02:24 -0700 (PDT) Received: from bobo.ozlabs.ibm.com (115-64-153-41.tpgi.com.au. [115.64.153.41]) by smtp.gmail.com with ESMTPSA id 130sm15557223pfz.77.2021.10.04.09.02.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 04 Oct 2021 09:02:24 -0700 (PDT) From: Nicholas Piggin To: kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Cc: Nicholas Piggin Subject: [PATCH v3 34/52] KVM: PPC: Book3S HV P9: Restrict DSISR canary workaround to processors that require it Date: Tue, 5 Oct 2021 02:00:31 +1000 Message-Id: <20211004160049.1338837-35-npiggin@gmail.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20211004160049.1338837-1-npiggin@gmail.com> References: <20211004160049.1338837-1-npiggin@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org Use CPU_FTR_P9_RADIX_PREFETCH_BUG to apply the workaround, to test for DD2.1 and below processors. This saves a mtSPR in guest entry. Signed-off-by: Nicholas Piggin --- arch/powerpc/kvm/book3s_hv.c | 3 ++- arch/powerpc/kvm/book3s_hv_p9_entry.c | 6 ++++-- 2 files changed, 6 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 5a1859311b3e..6fb941aa77f1 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -1590,7 +1590,8 @@ static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu, unsigned long vsid; long err; - if (vcpu->arch.fault_dsisr == HDSISR_CANARY) { + if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG) && + unlikely(vcpu->arch.fault_dsisr == HDSISR_CANARY)) { r = RESUME_GUEST; /* Just retry if it's the canary */ break; } diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c index 619bbcd47b92..67f57b03a896 100644 --- a/arch/powerpc/kvm/book3s_hv_p9_entry.c +++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c @@ -683,9 +683,11 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc * HDSI which should correctly update the HDSISR the second time HDSI * entry. * - * Just do this on all p9 processors for now. + * The "radix prefetch bug" test can be used to test for this bug, as + * it also exists fo DD2.1 and below. */ - mtspr(SPRN_HDSISR, HDSISR_CANARY); + if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) + mtspr(SPRN_HDSISR, HDSISR_CANARY); mtspr(SPRN_SPRG0, vcpu->arch.shregs.sprg0); mtspr(SPRN_SPRG1, vcpu->arch.shregs.sprg1);