From patchwork Fri Sep 30 16:10:13 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?UmFkaW0gS3LEjW3DocWZ?= X-Patchwork-Id: 677127 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3slxQg4sg0z9sRZ for ; Sat, 1 Oct 2016 02:16:43 +1000 (AEST) Received: from localhost ([::1]:45729 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bq0UK-0006iq-8u for incoming@patchwork.ozlabs.org; Fri, 30 Sep 2016 12:16:40 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40207) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bq0Oy-0001Aj-2q for qemu-devel@nongnu.org; Fri, 30 Sep 2016 12:11:09 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bq0Ox-0001ZD-3W for qemu-devel@nongnu.org; Fri, 30 Sep 2016 12:11:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59088) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bq0Ow-0001Z5-TT for qemu-devel@nongnu.org; Fri, 30 Sep 2016 12:11:07 -0400 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8031E4F639; Fri, 30 Sep 2016 16:11:06 +0000 (UTC) Received: from potion (dhcp-1-247.brq.redhat.com [10.34.1.247]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with SMTP id u8UGB39x026195; Fri, 30 Sep 2016 12:11:04 -0400 Received: by potion (sSMTP sendmail emulation); Fri, 30 Sep 2016 18:11:03 +0200 From: =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= To: qemu-devel@nongnu.org Date: Fri, 30 Sep 2016 18:10:13 +0200 Message-Id: <20160930161013.9832-9-rkrcmar@redhat.com> In-Reply-To: <20160930161013.9832-1-rkrcmar@redhat.com> References: <20160930161013.9832-1-rkrcmar@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.27 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Fri, 30 Sep 2016 16:11:06 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v3 8/8] target-i386/kvm: cache the return value of kvm_enable_x2apic() X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Eduardo Habkost , "Michael S. Tsirkin" , Peter Xu , Paolo Bonzini , Igor Mammedov , Richard Henderson Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Assume that KVM would have returned the same on subsequent runs. Abstract the memoizaiton pattern into macros. Signed-off-by: Radim Krčmář --- target-i386/kvm.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/target-i386/kvm.c b/target-i386/kvm.c index 0fd664648665..113c5bf058ba 100644 --- a/target-i386/kvm.c +++ b/target-i386/kvm.c @@ -129,10 +129,27 @@ static bool kvm_x2apic_api_set_flags(uint64_t flags) return !kvm_vm_enable_cap(s, KVM_CAP_X2APIC_API, 0, flags); } +#define MEMOIZE_RESULT(_result, _fn) \ + ({ \ + static bool _memoized; \ + if (_memoized) { \ + return _result; \ + } \ + _memoized = true; \ + _result = _fn; \ + }) + +#define MEMOIZE(_fn) \ + ({ \ + static typeof(_fn) _result; \ + MEMOIZE_RESULT(_result, _fn); \ + }) + bool kvm_enable_x2apic(void) { - return kvm_x2apic_api_set_flags(KVM_X2APIC_API_USE_32BIT_IDS | - KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK); + return MEMOIZE( + kvm_x2apic_api_set_flags(KVM_X2APIC_API_USE_32BIT_IDS | + KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK)); } static int kvm_get_tsc(CPUState *cs)