From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x224+pE9gqSZ6YR/UdcaC5QoRQXTe+xlh96B4Zbpj8zB0lMKcr40jojUoUQ5zbINZdNuobUfR ARC-Seal: i=1; a=rsa-sha256; t=1517411519; cv=none; d=google.com; s=arc-20160816; b=g0ihdoDWYSEIgLDuetuxO+LU/HblLCdRj25MiylqlUkr8Yr5CMDjzWC47qKrU+eQ9K c03EgLdno6ikHGWYyhAbWV9O1xbBH6lb3U3tvLOww1TgqQdqEeQQ3WNizWWUG6PGHuIv pFmwAVaFMY8wMXyIzqqtKUk4hbvf6/Fq7+yBmYltfCflEhCcF6JbiVzd52EQiZMheXsk IbtSK24MfUN2YMacq7kqLaoiNsfGB22fygK/Lax4omIx1O9veU874ixLIJeGWckknyjO PAlCz+qnUaZdkHNTmGBAupFIigWX2YgXSzGnRSmjgPUn8yClg5hhnGC7TCRCRuKHrwCY FYHw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:content-language:in-reply-to:mime-version :user-agent:date:message-id:from:references:cc:to:subject :arc-authentication-results; bh=4DuG8UNc6eRsr1vjNQs5AqtIjAYMYEXa0xYq7GRw3sg=; b=hQDr64es8YhzKCf3l4mS7CP/NECOZYYej17XCOR2Ky5aZNKIZ124e35qgOVMsopg+M yWdVINRwg5bEdar8c5tXrmBAfKuQVWBjfKqqQBGwnBORlHAw61J6RdAvyfduTnixiJej 7jZFNuTJfmSviLtHlJma9z2QSdCEDpAbzYuToc/Qr3BQNhMQ8gMPwK3lUp9p25YoFQLu FjOESAfcicpV0yPEw9dG/MtQxLkPogMDtZXukXzsR732Dhi+y2GqfodeOZOvYd3nPF3H aC3LAlbJh+i/31wcyJJucZr0g84Vic6epjrSXO3r3aoLunfSlhmxNtNr8FIXb6781k/5 Mn3A== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of arjan@linux.intel.com designates 192.55.52.88 as permitted sender) smtp.mailfrom=arjan@linux.intel.com Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of arjan@linux.intel.com designates 192.55.52.88 as permitted sender) smtp.mailfrom=arjan@linux.intel.com X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,440,1511856000"; d="scan'208";a="30927900" Subject: Re: [RFC,05/10] x86/speculation: Add basic IBRS support infrastructure To: Thomas Gleixner , Christophe de Dinechin Cc: Alan Cox , Linus Torvalds , David Woodhouse , Eduardo Habkost , KarimAllah Ahmed , Linux Kernel Mailing List , Andi Kleen , Andrea Arcangeli , Andy Lutomirski , Ashok Raj , Asit Mallick , Borislav Petkov , Dan Williams , Dave Hansen , Greg Kroah-Hartman , "H . Peter Anvin" , Ingo Molnar , Janakarajan Natarajan , Joerg Roedel , Jun Nakajima , Laura Abbott , Masami Hiramatsu , Paolo Bonzini , Peter Zijlstra , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Tim Chen , Tom Lendacky , KVM list , the arch/x86 maintainers , "Dr. David Alan Gilbert" References: <1516476182-5153-6-git-send-email-karahmed@amazon.de> <20180129201404.GA1588@localhost.localdomain> <1517257022.18619.30.camel@infradead.org> <20180129204256.GV25150@localhost.localdomain> <31415b7f-9c76-c102-86cd-6bf4e23e3aee@linux.intel.com> <1517259759.18619.38.camel@infradead.org> <20180130204623.583b1a7a@alans-desktop> <200C59E8-80F3-4FEC-BA3B-E6A56FA12C74@dinechin.org> From: Arjan van de Ven Message-ID: Date: Wed, 31 Jan 2018 07:11:54 -0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.5.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1590140581449802182?= X-GMAIL-MSGID: =?utf-8?q?1591121301477184053?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On 1/31/2018 2:15 AM, Thomas Gleixner wrote: > Good luck with making all that work. on the Intel side we're checking what we can do that works and doesn't break things right now; hopefully we just end up with a bit in the arch capabilities MSR for "you should do RSB stuffing" and then the HV's can emulate that. (people sometimes think that should be a 5 minute thing, but we need to check many cpu models/etc to make sure a bit we pick is really free etc which makes it take longer than some folks have patience for)