From patchwork Thu Apr 22 16:11:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 1469298 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=gAmE2yzy; dkim-atps=neutral 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 ozlabs.org (Postfix) with ESMTPS id 4FR2pl1RVQz9sVq for ; Fri, 23 Apr 2021 02:25:50 +1000 (AEST) Received: from localhost ([::1]:45094 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lZc9E-0002K0-VO for incoming@patchwork.ozlabs.org; Thu, 22 Apr 2021 12:25:48 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:51118) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lZbwK-0003uZ-2Z for qemu-devel@nongnu.org; Thu, 22 Apr 2021 12:12:29 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:43346) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lZbwA-00038t-61 for qemu-devel@nongnu.org; Thu, 22 Apr 2021 12:12:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619107937; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=SmpDfYFECKgXbNmrxUMUhDB4r9v7TgPbNQQGtHlEzsY=; b=gAmE2yzy+HL4YAixWhBaNG3Efz1T+pC/hhYevi4A+5SFaqsovd9MYAQ4oocEeUY1ft+eyW 4onJ33MaONCxVXTIQCaQJ5iTkfxuC/f6Ecp6AOT19O/owglYw+zZVag5fx9bwc/dIZzaxg Iza98hZVWalRKdfW8fIqCRgfflOe1sw= 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-214-KWGwht4sMwynWwNULMOglg-1; Thu, 22 Apr 2021 12:12:15 -0400 X-MC-Unique: KWGwht4sMwynWwNULMOglg-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 A8FD9107ACE6 for ; Thu, 22 Apr 2021 16:12:14 +0000 (UTC) Received: from vitty.brq.redhat.com (unknown [10.40.194.217]) by smtp.corp.redhat.com (Postfix) with ESMTP id 041C35B4A4; Thu, 22 Apr 2021 16:12:12 +0000 (UTC) From: Vitaly Kuznetsov To: qemu-devel@nongnu.org Subject: [PATCH v6 17/19] i386: HV_HYPERCALL_AVAILABLE privilege bit is always needed Date: Thu, 22 Apr 2021 18:11:28 +0200 Message-Id: <20210422161130.652779-18-vkuznets@redhat.com> In-Reply-To: <20210422161130.652779-1-vkuznets@redhat.com> References: <20210422161130.652779-1-vkuznets@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=vkuznets@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=170.10.133.124; envelope-from=vkuznets@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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 , Eduardo Habkost , Igor Mammedov Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" According to TLFS, Hyper-V guest is supposed to check HV_HYPERCALL_AVAILABLE privilege bit before accessing HV_X64_MSR_GUEST_OS_ID/HV_X64_MSR_HYPERCALL MSRs but at least some Windows versions ignore that. As KVM is very permissive and allows accessing these MSRs unconditionally, no issue is observed. We may, however, want to tighten the checks eventually. Conforming to the spec is probably also a good idea. Add HV_HYPERCALL_AVAILABLE to all 'leaf' features with no dependencies. Signed-off-by: Vitaly Kuznetsov --- target/i386/kvm/kvm.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index 2c1a77f9b00f..d81451276cd8 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -835,6 +835,8 @@ static struct { [HYPERV_FEAT_CRASH] = { .desc = "crash MSRs (hv-crash)", .flags = { + {.func = HV_CPUID_FEATURES, .reg = R_EAX, + .bits = HV_HYPERCALL_AVAILABLE}, {.func = HV_CPUID_FEATURES, .reg = R_EDX, .bits = HV_GUEST_CRASH_MSR_AVAILABLE} } @@ -843,28 +845,28 @@ static struct { .desc = "reset MSR (hv-reset)", .flags = { {.func = HV_CPUID_FEATURES, .reg = R_EAX, - .bits = HV_RESET_AVAILABLE} + .bits = HV_HYPERCALL_AVAILABLE | HV_RESET_AVAILABLE} } }, [HYPERV_FEAT_VPINDEX] = { .desc = "VP_INDEX MSR (hv-vpindex)", .flags = { {.func = HV_CPUID_FEATURES, .reg = R_EAX, - .bits = HV_VP_INDEX_AVAILABLE} + .bits = HV_HYPERCALL_AVAILABLE | HV_VP_INDEX_AVAILABLE} } }, [HYPERV_FEAT_RUNTIME] = { .desc = "VP_RUNTIME MSR (hv-runtime)", .flags = { {.func = HV_CPUID_FEATURES, .reg = R_EAX, - .bits = HV_VP_RUNTIME_AVAILABLE} + .bits = HV_HYPERCALL_AVAILABLE | HV_VP_RUNTIME_AVAILABLE} } }, [HYPERV_FEAT_SYNIC] = { .desc = "synthetic interrupt controller (hv-synic)", .flags = { {.func = HV_CPUID_FEATURES, .reg = R_EAX, - .bits = HV_SYNIC_AVAILABLE} + .bits = HV_HYPERCALL_AVAILABLE | HV_SYNIC_AVAILABLE} } }, [HYPERV_FEAT_STIMER] = { @@ -879,7 +881,7 @@ static struct { .desc = "frequency MSRs (hv-frequencies)", .flags = { {.func = HV_CPUID_FEATURES, .reg = R_EAX, - .bits = HV_ACCESS_FREQUENCY_MSRS}, + .bits = HV_HYPERCALL_AVAILABLE | HV_ACCESS_FREQUENCY_MSRS}, {.func = HV_CPUID_FEATURES, .reg = R_EDX, .bits = HV_FREQUENCY_MSRS_AVAILABLE} } @@ -888,7 +890,8 @@ static struct { .desc = "reenlightenment MSRs (hv-reenlightenment)", .flags = { {.func = HV_CPUID_FEATURES, .reg = R_EAX, - .bits = HV_ACCESS_REENLIGHTENMENTS_CONTROL} + .bits = HV_HYPERCALL_AVAILABLE | + HV_ACCESS_REENLIGHTENMENTS_CONTROL} } }, [HYPERV_FEAT_TLBFLUSH] = {