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 X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3558CC433B4 for ; Mon, 19 Apr 2021 16:03:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1840761363 for ; Mon, 19 Apr 2021 16:03:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242575AbhDSQDv (ORCPT ); Mon, 19 Apr 2021 12:03:51 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:33767 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242321AbhDSQCy (ORCPT ); Mon, 19 Apr 2021 12:02:54 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1618848144; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=xzXJ0fqMhO34LTNXk4s+XbzarJu9fdziD+Dr92OHm/o=; b=CENA/adsQgkt8flrlbEW1pYWV5ED9aNB2tSfi4qlr0uXKVFPOHy3LvUsKf+v7liHxCePst VACpd3+qx4mrPInFlzx6X5oECSAUMadgXQV0TtSwhe94hRqQHGplmmSMjeSQSdjK+XhrtB 2Ltrpi0EbT3cbB8KNStj2AETkSONdyk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-151-7QY8MAdHP-qhGdo-MFZzxA-1; Mon, 19 Apr 2021 12:02:22 -0400 X-MC-Unique: 7QY8MAdHP-qhGdo-MFZzxA-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 8788C8030C9; Mon, 19 Apr 2021 16:02:21 +0000 (UTC) Received: from vitty.brq.redhat.com (unknown [10.40.193.113]) by smtp.corp.redhat.com (Postfix) with ESMTP id 76E6919809; Mon, 19 Apr 2021 16:02:19 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org, Paolo Bonzini Cc: Sean Christopherson , Wanpeng Li , Jim Mattson , Siddharth Chandrasekaran , linux-kernel@vger.kernel.org Subject: [PATCH 21/30] KVM: x86: hyper-v: Check access to HVCALL_NOTIFY_LONG_SPIN_WAIT hypercall Date: Mon, 19 Apr 2021 18:01:18 +0200 Message-Id: <20210419160127.192712-22-vkuznets@redhat.com> In-Reply-To: <20210419160127.192712-1-vkuznets@redhat.com> References: <20210419160127.192712-1-vkuznets@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org TLFS6.0b states that partition issuing HVCALL_NOTIFY_LONG_SPIN_WAIT must posess 'UseHypercallForLongSpinWait' privilege but there's no corresponding feature bit. Instead, we have "Recommended number of attempts to retry a spinlock failure before notifying the hypervisor about the failures. 0xFFFFFFFF indicates never notify." Use this to check access to the hypercall. Also, check against zero as the corresponding CPUID must be set (and '0' attempts before re-try is weird anyway). Signed-off-by: Vitaly Kuznetsov --- arch/x86/kvm/hyperv.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 4f0ab0c50c44..bd424f2d4294 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -2024,6 +2024,17 @@ static u16 kvm_hvcall_signal_event(struct kvm_vcpu *vcpu, bool fast, u64 param) static bool hv_check_hypercall_access(struct kvm_vcpu_hv *hv_vcpu, u16 code) { + if (!hv_vcpu->enforce_cpuid) + return true; + + switch (code) { + case HVCALL_NOTIFY_LONG_SPIN_WAIT: + return hv_vcpu->cpuid_cache.enlightenments_ebx && + hv_vcpu->cpuid_cache.enlightenments_ebx != U32_MAX; + default: + break; + } + return true; } -- 2.30.2