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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 321DCC47082 for ; Thu, 3 Jun 2021 23:01:13 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8F2086140C for ; Thu, 3 Jun 2021 23:01:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8F2086140C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:56348 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lowKt-0002Hb-FT for qemu-devel@archiver.kernel.org; Thu, 03 Jun 2021 19:01:11 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:41112) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lowKD-0001Vg-VI for qemu-devel@nongnu.org; Thu, 03 Jun 2021 19:00:29 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:44484) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lowK9-0002cq-8d for qemu-devel@nongnu.org; Thu, 03 Jun 2021 19:00:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1622761223; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=2StMICL2h/U8ZR7MBZv0yZEprCiFsE0qUcyQNh2yFn8=; b=hczOaS1jqDkCbu5TdIQBME9s+QVdVn94I1OmQOjvit6X3bRqP0WN4ISYkzfFft/lDIT2Mc AlpifEzTLhv/6ZITh+iZ+rKJ6ly/hJEsDsCCedA4uQEwHkMMnwglWfPWLXoCJad9pK9fYP 7lxmlYCvCxHST8kP22yIW2vElqne9pU= 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-470-feaMxbOUO8-lkHDW5b1MYw-1; Thu, 03 Jun 2021 19:00:21 -0400 X-MC-Unique: feaMxbOUO8-lkHDW5b1MYw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D0FAB8018A7 for ; Thu, 3 Jun 2021 23:00:20 +0000 (UTC) Received: from localhost (ovpn-120-94.rdu2.redhat.com [10.10.120.94]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8B9775DEAD; Thu, 3 Jun 2021 23:00:17 +0000 (UTC) Date: Thu, 3 Jun 2021 19:00:17 -0400 From: Eduardo Habkost To: Vitaly Kuznetsov Subject: Re: [PATCH v7 8/9] i386: Hyper-V SynIC requires POST_MESSAGES/SIGNAL_EVENTS priviliges Message-ID: <20210603230017.3goxm7fdu5fpdkdw@habkost.net> References: <20210603114835.847451-1-vkuznets@redhat.com> <20210603114835.847451-9-vkuznets@redhat.com> MIME-Version: 1.0 In-Reply-To: <20210603114835.847451-9-vkuznets@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=ehabkost@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Received-SPF: pass client-ip=170.10.133.124; envelope-from=ehabkost@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.37, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paolo Bonzini , Marcelo Tosatti , qemu-devel@nongnu.org, Igor Mammedov Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, Jun 03, 2021 at 01:48:34PM +0200, Vitaly Kuznetsov wrote: > When Hyper-V SynIC is enabled, we may need to allow Windows guests to make > hypercalls (POST_MESSAGES/SIGNAL_EVENTS). No issue is currently observed > because KVM is very permissive, allowing these hypercalls regarding of > guest visible CPUid bits. > > Signed-off-by: Vitaly Kuznetsov > --- > target/i386/kvm/hyperv-proto.h | 6 ++++++ > target/i386/kvm/kvm.c | 6 ++++++ > 2 files changed, 12 insertions(+) > > diff --git a/target/i386/kvm/hyperv-proto.h b/target/i386/kvm/hyperv-proto.h > index e30d64b4ade4..5fbb385cc136 100644 > --- a/target/i386/kvm/hyperv-proto.h > +++ b/target/i386/kvm/hyperv-proto.h > @@ -38,6 +38,12 @@ > #define HV_ACCESS_FREQUENCY_MSRS (1u << 11) > #define HV_ACCESS_REENLIGHTENMENTS_CONTROL (1u << 13) > > +/* > + * HV_CPUID_FEATURES.EBX bits > + */ > +#define HV_POST_MESSAGES (1u << 4) > +#define HV_SIGNAL_EVENTS (1u << 5) > + > /* > * HV_CPUID_FEATURES.EDX bits > */ > diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c > index a3897d4d8788..6a32d43e6ec1 100644 > --- a/target/i386/kvm/kvm.c > +++ b/target/i386/kvm/kvm.c > @@ -1343,6 +1343,12 @@ static int hyperv_fill_cpuids(CPUState *cs, > /* Unconditionally required with any Hyper-V enlightenment */ > c->eax |= HV_HYPERCALL_AVAILABLE; > > + /* SynIC and Vmbus devices require messages/signals hypercalls */ > + if (hyperv_feat_enabled(cpu, HYPERV_FEAT_SYNIC) && > + !cpu->hyperv_synic_kvm_only) { > + c->ebx |= HV_POST_MESSAGES | HV_SIGNAL_EVENTS; Why exactly is the hyperv_synic_kvm_only check needed? Is the hyperv_synic_kvm_only check the only reason this was done here and not at kvm_hyperv_properties? > + } > + > /* Not exposed by KVM but needed to make CPU hotplug in Windows work */ > c->edx |= HV_CPU_DYNAMIC_PARTITIONING_AVAILABLE; > > -- > 2.31.1 > -- Eduardo