From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 30BE4C4332F for ; Sat, 1 Oct 2022 01:03:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233173AbiJABDf (ORCPT ); Fri, 30 Sep 2022 21:03:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233003AbiJABCf (ORCPT ); Fri, 30 Sep 2022 21:02:35 -0400 Received: from mail-pg1-x54a.google.com (mail-pg1-x54a.google.com [IPv6:2607:f8b0:4864:20::54a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 118DD15C5BE for ; Fri, 30 Sep 2022 18:00:23 -0700 (PDT) Received: by mail-pg1-x54a.google.com with SMTP id 128-20020a630486000000b00435b18f71b3so3696723pge.19 for ; Fri, 30 Sep 2022 18:00:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date; bh=1YftLOszR7bSMAKO/7D6fjHIUaI80mCyDkpMabfIDFg=; b=gmlPL8AGoIw5DkSBx9G/sTZrreY5P+Oe1nOe27AcScjwDo5J6rNsdmNQb0IgHx+D3p kecZ3wNctj1k1kVELmY8eA4658Usd/F1FX4RuUD/JLfB1IYWqVF0WZPPM7V9hs49mRpq zKEGEyMAUbFw8/F7lWbA6kPPZogxLCEt0e1z11EEWQn9tN7TO3WUSW/70TGQN6Mr419k kv4XrO7j1dbcTfRH0D3tBVngRbrKQiIB3vSkoB9nFheGpg+QPj9zov9ieJOTWgdMML/u MFJsLfjkZNbQZcbuA3NfT/cQyFrxS4gXzM/WpGBE20SQyy+Gxr1wNllI8cH400pMf6mb A/hQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date; bh=1YftLOszR7bSMAKO/7D6fjHIUaI80mCyDkpMabfIDFg=; b=neVRtxKObJre9rKVkWMKkl5aHq8vgIV3P7Xwn4vwAWNngmPy+apFbeMVq9lDFQy+1c SnwGdK7Gml+4OHzhn7Gyttkc7FM/3VFT2XItOefijLNyL9ofcgKazKvBN2aFDAFtZKe8 r7Se73F+uB0LpsgBq3a0egSUI+aR8WuGR6AWgfIEi17aV8LrQZDuKW6N4OmhGLlxT/mw zFyO2JRMhJFG+HPKWg7vPLTiB9nqmpN9y6Gm9LW/2mozgxYLt8kk2AjURdODsUr9Bz/Z 823DzhLmY0BfEleXocWaLP40NnT2bDOjcXXlBc2WBMgiAPh16ameq413gUbkW+UZPT0A iV6Q== X-Gm-Message-State: ACrzQf0sTPuaT+cY6hUZwDL00975PAYtkZHkK7vqr0c70j0Y+HSHryBP kCyb9Pzf58rVOMNMUgDsQMEB6iwFmww= X-Google-Smtp-Source: AMsMyM4bbivakAwydzxsOMq0VdCBO8L/n4+zGlkn++PwBMD69v5jURd9DF/bYRwI5uEcOJczCeyF1x5mwss= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:902:c950:b0:17c:2248:11b1 with SMTP id i16-20020a170902c95000b0017c224811b1mr7190067pla.165.1664586004063; Fri, 30 Sep 2022 18:00:04 -0700 (PDT) Reply-To: Sean Christopherson Date: Sat, 1 Oct 2022 00:59:10 +0000 In-Reply-To: <20221001005915.2041642-1-seanjc@google.com> Mime-Version: 1.0 References: <20221001005915.2041642-1-seanjc@google.com> X-Mailer: git-send-email 2.38.0.rc1.362.ged0d419d3c-goog Message-ID: <20221001005915.2041642-28-seanjc@google.com> Subject: [PATCH v4 27/32] KVM: SVM: Update svm->ldr_reg cache even if LDR is "bad" From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Alejandro Jimenez , Suravee Suthikulpanit , Maxim Levitsky , Li RongQing Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Update SVM's cache of the LDR even if the new value is "bad". Leaving stale information in the cache can result in KVM missing updates and/or invalidating the wrong entry, e.g. if avic_invalidate_logical_id_entry() is triggered after a different vCPU has "claimed" the old LDR. Fixes: 18f40c53e10f ("svm: Add VMEXIT handlers for AVIC") Signed-off-by: Sean Christopherson --- arch/x86/kvm/svm/avic.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c index 2b640c73f447..4b6fc9d64f4d 100644 --- a/arch/x86/kvm/svm/avic.c +++ b/arch/x86/kvm/svm/avic.c @@ -539,23 +539,24 @@ static u32 *avic_get_logical_id_entry(struct kvm_vcpu *vcpu, u32 ldr, bool flat) return &logical_apic_id_table[index]; } -static int avic_ldr_write(struct kvm_vcpu *vcpu, u8 g_physical_id, u32 ldr) +static void avic_ldr_write(struct kvm_vcpu *vcpu, u8 g_physical_id, u32 ldr) { bool flat; u32 *entry, new_entry; + if (!ldr) + return; + flat = kvm_lapic_get_reg(vcpu->arch.apic, APIC_DFR) == APIC_DFR_FLAT; entry = avic_get_logical_id_entry(vcpu, ldr, flat); if (!entry) - return -EINVAL; + return; new_entry = READ_ONCE(*entry); new_entry &= ~AVIC_LOGICAL_ID_ENTRY_GUEST_PHYSICAL_ID_MASK; new_entry |= (g_physical_id & AVIC_LOGICAL_ID_ENTRY_GUEST_PHYSICAL_ID_MASK); new_entry |= AVIC_LOGICAL_ID_ENTRY_VALID_MASK; WRITE_ONCE(*entry, new_entry); - - return 0; } static void avic_invalidate_logical_id_entry(struct kvm_vcpu *vcpu) @@ -575,7 +576,6 @@ static void avic_invalidate_logical_id_entry(struct kvm_vcpu *vcpu) static void avic_handle_ldr_update(struct kvm_vcpu *vcpu) { - int ret = 0; struct vcpu_svm *svm = to_svm(vcpu); u32 ldr = kvm_lapic_get_reg(vcpu->arch.apic, APIC_LDR); u32 id = kvm_xapic_id(vcpu->arch.apic); @@ -589,11 +589,8 @@ static void avic_handle_ldr_update(struct kvm_vcpu *vcpu) avic_invalidate_logical_id_entry(vcpu); - if (ldr) - ret = avic_ldr_write(vcpu, id, ldr); - - if (!ret) - svm->ldr_reg = ldr; + svm->ldr_reg = ldr; + avic_ldr_write(vcpu, id, ldr); } static void avic_handle_dfr_update(struct kvm_vcpu *vcpu) -- 2.38.0.rc1.362.ged0d419d3c-goog