From nobody Wed Apr 8 17:33:29 2026 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 E3D6EFA3740 for ; Thu, 27 Oct 2022 16:20:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236781AbiJ0QUV (ORCPT ); Thu, 27 Oct 2022 12:20:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54282 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236629AbiJ0QTH (ORCPT ); Thu, 27 Oct 2022 12:19:07 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B063D185408 for ; Thu, 27 Oct 2022 09:19:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1666887545; 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=WkzKsdsqzO0BIwMIdmac25pTJyVcLWN5ODcskpn+bp4=; b=UdozvJpRqgGXi99I2lR1OJp7oWnCI7Tl81tv7mwZfsPf1ORu+dFBzgW59qNoOvhMvdR2FF N5EzWMKCl9ODsghWxmT8tEYfh0N9bF8XFfj47t3EDmQm0x+dCIu0I8HU0V3eK0qiJZowg8 owphDW+Un667buT8emx6qo+kwpF39bU= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-438-hecbMnxFOY2Oz2srGaoKUw-1; Thu, 27 Oct 2022 12:18:55 -0400 X-MC-Unique: hecbMnxFOY2Oz2srGaoKUw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 4816D29AA2FF; Thu, 27 Oct 2022 16:18:53 +0000 (UTC) Received: from virtlab701.virt.lab.eng.bos.redhat.com (virtlab701.virt.lab.eng.bos.redhat.com [10.19.152.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2718A17593; Thu, 27 Oct 2022 16:18:53 +0000 (UTC) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: mhal@rbox.co, seanjc@google.com Subject: [PATCH 16/16] KVM: selftests: Mark "guest_saw_irq" as volatile in xen_shinfo_test Date: Thu, 27 Oct 2022 12:18:49 -0400 Message-Id: <20221027161849.2989332-17-pbonzini@redhat.com> In-Reply-To: <20221027161849.2989332-1-pbonzini@redhat.com> References: <20221027161849.2989332-1-pbonzini@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Sean Christopherson Tag "guest_saw_irq" as "volatile" to ensure that the compiler will never optimize away lookups. Relying on the compiler thinking that the flag is global and thus might change also works, but it's subtle, less robust, and looks like a bug at first glance, e.g. risks being "fixed" and breaking the test. Make the flag "static" as well since convincing the compiler it's global is no longer necessary. Alternatively, the flag could be accessed with {READ,WRITE}_ONCE(), but literally every access would need the wrappers, and eking out performance isn't exactly top priority for selftests. Signed-off-by: Sean Christopherson Message-Id: <20221013211234.1318131-17-seanjc@google.com> Signed-off-by: Paolo Bonzini --- tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c b/tools/t= esting/selftests/kvm/x86_64/xen_shinfo_test.c index caa3f5ab9e10..2a5727188c8d 100644 --- a/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c +++ b/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c @@ -132,7 +132,7 @@ struct { struct kvm_irq_routing_entry entries[2]; } irq_routes; =20 -bool guest_saw_irq; +static volatile bool guest_saw_irq; =20 static void evtchn_handler(struct ex_regs *regs) { --=20 2.31.1