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[209.132.180.67]) by mx.google.com with ESMTP id r17si245820pgo.247.2018.01.31.11.56.53; Wed, 31 Jan 2018 11:57:08 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=UBgDZTRH; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751514AbeAaTzy (ORCPT + 99 others); Wed, 31 Jan 2018 14:55:54 -0500 Received: from mail-io0-f172.google.com ([209.85.223.172]:40529 "EHLO mail-io0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751326AbeAaTzx (ORCPT ); Wed, 31 Jan 2018 14:55:53 -0500 Received: by mail-io0-f172.google.com with SMTP id t22so16504731ioa.7 for ; Wed, 31 Jan 2018 11:55:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=QYQWPaXYzDBQu7UHm01LTXLZY0D7lcy9fgHnFF74JVY=; b=UBgDZTRHeUUAy1EOY52CIcHMldU24MwHd6wIXU36ZhVxnuMILRDVbvrlSXhJqr7ZFJ GIGGQCpKOAkleF2s2Sf8WVTcTKWldsU7PyQKPwFGQLSPpUxTmogjlCUJDZMd1REHXmq3 7kZp1rfVQJb89rvMzjO0w2EUyJxRl2vMrRb3AniL5lDe7id0XEKBLfoZrAAE44Oyf4do r7Q+CTH/jdhsUEI1lrO81CgptosZzCRs2yMNha6J8HlOKv8q2rfQuNuSE9eWtxdETz+m A8QGo+1N0jk0hAYHPBMHMuGv0/NeNs2M87GmMi0rJqslNQ/bS3bjbFmlqIXu+i1/LWiL tXuw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=QYQWPaXYzDBQu7UHm01LTXLZY0D7lcy9fgHnFF74JVY=; b=HlEmTg+/wgFGE0/AY0LvzTPPpZsCXQzmnwtS9LNcIMrogvT5Wq16SU082YjHLNJZZp F1Zstu9Q7tcAjdSBnVBRL+QDWcOaFQLT8Wh0kROkjDG/UdQKfJ9T9MGqBuCj645SaO3t qWBQAG7i4nX9ZkX2JVkYLnxnnTbi9OvOCEUACXpKgyZwP6Hs/m45kfL/vGWjVLPcKM9f suThfg7EGuXjU57CFVjPQbEy/ra1lzr+0ABapMGO+Ag23R0iOlI+F6BskpFcjfiu3zsW t42Y6A/th3vBG/KiSWYVhOI34snJ7qJJCQKQ4+9wDRusMLucj1JcCKIbw2FNSfxpop73 2+fw== X-Gm-Message-State: AKwxytfXZUu8vdUiSolul2k+4/G2rEW3ONjj7+BcDe9ZfcgjbHA4GCsm tpNRPPTRPD9my/A3jlrSSRz0/6CQ68zZudQO9PqrOQ== X-Received: by 10.107.97.24 with SMTP id v24mr35169826iob.296.1517428552365; Wed, 31 Jan 2018 11:55:52 -0800 (PST) MIME-Version: 1.0 Received: by 10.107.128.7 with HTTP; Wed, 31 Jan 2018 11:55:51 -0800 (PST) In-Reply-To: <1517428398.18619.197.camel@infradead.org> References: <1517427467-28567-1-git-send-email-karahmed@amazon.de> <1517427467-28567-3-git-send-email-karahmed@amazon.de> <1517428398.18619.197.camel@infradead.org> From: Jim Mattson Date: Wed, 31 Jan 2018 11:55:51 -0800 Message-ID: Subject: Re: [PATCH v5 2/5] KVM: x86: Add IBPB support To: David Woodhouse Cc: KarimAllah Ahmed , kvm list , LKML , "the arch/x86 maintainers" , Ashok Raj , Asit Mallick , Dave Hansen , Arjan Van De Ven , Tim Chen , Linus Torvalds , Andrea Arcangeli , Andi Kleen , Thomas Gleixner , Dan Williams , Jun Nakajima , Andy Lutomirski , Greg KH , Paolo Bonzini , Peter Zijlstra Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 31, 2018 at 11:53 AM, David Woodhouse wrote: > Rather than doing the expensive guest_cpu_has() every time (which is > worse now as we realised we need two of them) perhaps we should > introduce a local flag for that too? That sounds good to me.