From patchwork Wed Oct 18 19:41:03 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 13427792 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 BFB6ACDB47E for ; Wed, 18 Oct 2023 19:41:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231681AbjJRTlO (ORCPT ); Wed, 18 Oct 2023 15:41:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46178 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229694AbjJRTlM (ORCPT ); Wed, 18 Oct 2023 15:41:12 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 11C89112 for ; Wed, 18 Oct 2023 12:41:10 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-5a7af69a4baso110050487b3.0 for ; Wed, 18 Oct 2023 12:41:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1697658069; x=1698262869; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=XDwbLiOis3SdrHxTO/Y/lxRhpLoGiD6x3/AIUgIhLVk=; b=225mPG4bn22vpmEQZ/lq+lcwjZcVmHd/UgrRyJJQv/nh9BGjJUbzh4ACMeF6r9ZggD Tim2wJUR0TlkYG+5oMCTYa9+FgGhyroQo1nuaGeFHdlJgNTmP4xzvBFCKQLlkXfXaW/h 0R2meemQK9REEx3buTD4LUdnDReM4przJQSAX6ezEr5oxWaoKpwu2W2S+I0eFy8O9ymK ZM9+nbK4y0dEW4YK0QrokjdR+O1at/X62oDDoF2yGN7UWvz7VxivEiaz4Fve1p8ExpWj kCba5caUEh77WN8mSQ7pczcJlYmalwYmRhwrSPdMYuRlW/t3ngLDMfDT2W/FX8169bOX gjGA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697658069; x=1698262869; 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:message-id :reply-to; bh=XDwbLiOis3SdrHxTO/Y/lxRhpLoGiD6x3/AIUgIhLVk=; b=cDS+B4uvAKn050SotMhlMQ0NAegBBSAeychPNLNtH3vvOAZ1WFbKX0KOJjVtBebjdx VngK9cdXDiB1eWnHFEXSHpKFsaiOh6clI35Hl4v8uX+DsYF4BuRLLUp/7cCCfWWoR9i3 zFMKDWbO6bJJsC9AAQQuSciRQKOQJv5TgiK9ibn45zjD5NqEADthea4EQ6ZFrhbyc2ZR vsbUf2TTIjueuvRgk0CtDptQJ++TvtULZO32fVW/1W4D9WDWQ79gJFzbbyEttzvrim8d L5bAeMH3m5jeqS1BBXwbKJbz7P4jVm+ABwbGBVqSLNYn0oJIJ3Ns0eGXRFUPDUgXnbeS bQVg== X-Gm-Message-State: AOJu0Yy6e59cpLoeQOqDpJ2DybO4fWK9CGVOl9YFrMeLjF9F1UZPLSlk jkSCQVJKK7lMIE/usqCedNYcbe2eGzI= X-Google-Smtp-Source: AGHT+IEE1wVrW556Cd5uDxyOx/0Ua1tTpL0wLSYC675igkSjSvLsIaByHuL9JyEvU5bZFTNu2xBMZmFUKKA= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a0d:ca46:0:b0:5a2:3de0:24a9 with SMTP id m67-20020a0dca46000000b005a23de024a9mr6913ywd.1.1697658069288; Wed, 18 Oct 2023 12:41:09 -0700 (PDT) Reply-To: Sean Christopherson Date: Wed, 18 Oct 2023 12:41:03 -0700 In-Reply-To: <20231018194104.1896415-1-seanjc@google.com> Mime-Version: 1.0 References: <20231018194104.1896415-1-seanjc@google.com> X-Mailer: git-send-email 2.42.0.655.g421f12c284-goog Message-ID: <20231018194104.1896415-2-seanjc@google.com> Subject: [PATCH 1/2] Revert "nSVM: Check for reserved encodings of TLB_CONTROL in nested VMCB" From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Stefan Sterz Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Revert KVM's made-up consistency check on SVM's TLB control. The APM says that unsupported encodings are reserved, but the APM doesn't state that VMRUN checks for a supported encoding. Unless something is called out in "Canonicalization and Consistency Checks" or listed as MBZ (Must Be Zero), AMD behavior is typically to let software shoot itself in the foot. This reverts commit 174a921b6975ef959dd82ee9e8844067a62e3ec1. Fixes: 174a921b6975 ("nSVM: Check for reserved encodings of TLB_CONTROL in nested VMCB") Reported-by: Stefan Sterz Closes: https://lkml.kernel.org/r/b9915c9c-4cf6-051a-2d91-44cc6380f455%40proxmox.com Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson Reviewed-by: Maxim Levitsky --- arch/x86/kvm/svm/nested.c | 15 --------------- 1 file changed, 15 deletions(-) diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 3fea8c47679e..60891b9ce25f 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -247,18 +247,6 @@ static bool nested_svm_check_bitmap_pa(struct kvm_vcpu *vcpu, u64 pa, u32 size) kvm_vcpu_is_legal_gpa(vcpu, addr + size - 1); } -static bool nested_svm_check_tlb_ctl(struct kvm_vcpu *vcpu, u8 tlb_ctl) -{ - /* Nested FLUSHBYASID is not supported yet. */ - switch(tlb_ctl) { - case TLB_CONTROL_DO_NOTHING: - case TLB_CONTROL_FLUSH_ALL_ASID: - return true; - default: - return false; - } -} - static bool __nested_vmcb_check_controls(struct kvm_vcpu *vcpu, struct vmcb_ctrl_area_cached *control) { @@ -278,9 +266,6 @@ static bool __nested_vmcb_check_controls(struct kvm_vcpu *vcpu, IOPM_SIZE))) return false; - if (CC(!nested_svm_check_tlb_ctl(vcpu, control->tlb_ctl))) - return false; - if (CC((control->int_ctl & V_NMI_ENABLE_MASK) && !vmcb12_is_intercept(control, INTERCEPT_NMI))) { return false; From patchwork Wed Oct 18 19:41:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 13427793 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 D9AC1CDB482 for ; Wed, 18 Oct 2023 19:41:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231687AbjJRTlQ (ORCPT ); Wed, 18 Oct 2023 15:41:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46208 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231618AbjJRTlN (ORCPT ); Wed, 18 Oct 2023 15:41:13 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 04CB0AB for ; Wed, 18 Oct 2023 12:41:12 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id 3f1490d57ef6-d9b9f56489fso5652390276.1 for ; Wed, 18 Oct 2023 12:41:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1697658071; x=1698262871; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=Ofuuq8OnXnBwuNBiWtVLb1NEzqrH7XwtOSMnrh73sd8=; b=KQUyfewpiZDgHKhuBlxHffQ0dmFuq14bplh/X97tRzsZ1J4IVFw9LgSRusq4uePP7p I2fWrJB20gGOcn5OK3sPVx1Cws82eApx0yayMcRBTHMuag8ieLn/2rpiqGl3vYU4HPMP plDRDLUy8748Fghanx4KRrDiuZHDMRky8F4wOa8TUtlosUPPrnt8TW2Km2mHMOe1rfJT aNFAX76iUsrGF5vygVrg4yh/zpC/grDHqg9iEFeZfNT7U1Y0o/YXZDFBZvUTTCpBtV2t ZuO/MR0PUS/H22Pu5+Tp47+t0h+q8nJwrIqvaJ1iEY8W14kWB6immkZlwC+AABSEmehm PINg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697658071; x=1698262871; 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:message-id :reply-to; bh=Ofuuq8OnXnBwuNBiWtVLb1NEzqrH7XwtOSMnrh73sd8=; b=PRKOH9ukV0504k3WI3r5SlfLGfVm82eEZ4pTlrpl5fslNdMiMGeJKI2kR9ZsxbpspA I8zbevtlGYr9cejldEP/NXQrpJHYdYq5+z4hbX0TpgN1gsqtaB+bfIdgfaZrtIC/9J8q Zz2gxD22tWbH447cWBXOg7mbCQgUH6i7v7fb61NhunwJp/JaQYpvywocuJgC+qpAIyAb 60/ocboslsYSAeK7ZOCMyFvIuHewOlMQXU/CEqdRkkncudsHLfAuDUjT7nOsd5yLSf4G 1HG2GsBZbPwwISbxgTKzXXWTLvnvO6uUWHN390MlhJPN1mwe9ImoFVEqwFLWAHcx2bWK KkVw== X-Gm-Message-State: AOJu0YwUC5fcFU1ZKg1cEZi4qAu9xvPY21wVqWWBVSoiH387g7Pka7R8 WaDiZeyCiL3gUQq4R6lipzt4qD1yzHo= X-Google-Smtp-Source: AGHT+IGW0vvt2l55+JL2+bM3VOgMoxB7qvHv720MxhQbccRQ4nqpX0a4NV57+RPdy39vplncxaNMVHs5grk= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a05:6902:1825:b0:d9a:d272:ee58 with SMTP id cf37-20020a056902182500b00d9ad272ee58mr7884ybb.9.1697658071068; Wed, 18 Oct 2023 12:41:11 -0700 (PDT) Reply-To: Sean Christopherson Date: Wed, 18 Oct 2023 12:41:04 -0700 In-Reply-To: <20231018194104.1896415-1-seanjc@google.com> Mime-Version: 1.0 References: <20231018194104.1896415-1-seanjc@google.com> X-Mailer: git-send-email 2.42.0.655.g421f12c284-goog Message-ID: <20231018194104.1896415-3-seanjc@google.com> Subject: [PATCH 2/2] KVM: nSVM: Advertise support for flush-by-ASID From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Stefan Sterz Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Advertise support for FLUSHBYASID when nested SVM is enabled, as KVM can always emulate flushing TLB entries for a vmcb12 ASID, e.g. by running L2 with a new, fresh ASID in vmcb02. Some modern hypervisors, e.g. VMWare Workstation 17, require FLUSHBYASID support and will refuse to run if it's not present. Punt on proper support, as "Honor L1's request to flush an ASID on nested VMRUN" is one of the TODO items in the (incomplete) list of issues that need to be addressed in order for KVM to NOT do a full TLB flush on every nested SVM transition (see nested_svm_transition_tlb_flush()). Reported-by: Stefan Sterz Closes: https://lkml.kernel.org/r/b9915c9c-4cf6-051a-2d91-44cc6380f455%40proxmox.com Signed-off-by: Sean Christopherson Reviewed-by: Maxim Levitsky --- arch/x86/kvm/svm/svm.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 1785de7dc98b..9cf7eef161ff 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -5083,6 +5083,7 @@ static __init void svm_set_cpu_caps(void) if (nested) { kvm_cpu_cap_set(X86_FEATURE_SVM); kvm_cpu_cap_set(X86_FEATURE_VMCBCLEAN); + kvm_cpu_cap_set(X86_FEATURE_FLUSHBYASID); if (nrips) kvm_cpu_cap_set(X86_FEATURE_NRIPS);