From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from forwardcorp1b.mail.yandex.net (forwardcorp1b.mail.yandex.net [178.154.239.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 055C813BC1B for ; Mon, 27 May 2024 10:46:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.154.239.136 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716806786; cv=none; b=DlDWTBJ+LsZa3ZNHwOIpO3vliJV/GRgK1Rx74qsmnhWWZOrDytGK9muJKHD0zP9zJTixLQNH+m91pHmhnJn8SYPSYZv0H1Q6kIoVloS9ubgx8h3xunNPK7qZzhn2olNcAcmWKYkCfd01BHg94qb9zGWRSGBIDIFnP1lPPs4CP0U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716806786; c=relaxed/simple; bh=FuNZk22+jZCWwX+4yEiYRJIWKx8ZL/PckE9EdRBFaGA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=GqCDlzCui/dyiT/SoeJscNhWjFDikVu2t5KzeBuWd/6cyTasU8jTCCCmpIvI4UX3PPCaRPBIrroph6e/70gWVxqNW9BxFKHlEvMuj/p9MLXEpKsaLX2/VSuXJky1g//5Zj60haWYf8okCYeHFiA5mKzkmfD1ky3/D7cticFJJQk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=yandex-team.ru; spf=pass smtp.mailfrom=yandex-team.ru; dkim=pass (1024-bit key) header.d=yandex-team.ru header.i=@yandex-team.ru header.b=XSr7hJ01; arc=none smtp.client-ip=178.154.239.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=yandex-team.ru Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=yandex-team.ru Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=yandex-team.ru header.i=@yandex-team.ru header.b="XSr7hJ01" Received: from mail-nwsmtp-smtp-corp-main-66.iva.yp-c.yandex.net (mail-nwsmtp-smtp-corp-main-66.iva.yp-c.yandex.net [IPv6:2a02:6b8:c0c:2a2a:0:640:d546:0]) by forwardcorp1b.mail.yandex.net (Yandex) with ESMTPS id 6AFE660B21; Mon, 27 May 2024 13:46:12 +0300 (MSK) Received: from [IPV6:2a02:6b8:0:419:e50:b6d:d0ba:2947] (unknown [2a02:6b8:0:419:e50:b6d:d0ba:2947]) by mail-nwsmtp-smtp-corp-main-66.iva.yp-c.yandex.net (smtpcorp/Yandex) with ESMTPSA id xjM67Q1Ge4Y0-o3SZoNk8; Mon, 27 May 2024 13:46:11 +0300 X-Yandex-Fwd: 1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex-team.ru; s=default; t=1716806771; bh=foY6hMLRsD6gYR7HtDrQdRpmD7cyxAdDaxwZ8BWPLB8=; h=From:In-Reply-To:Cc:Date:References:To:Subject:Message-ID; b=XSr7hJ01t8JJ/ZEXNCVlZO7slr1vojyCXK1+raMxHH63QKJpl0/dAFzcskU7JgnT6 UjC/MigE8/igfAvc1N2/YMMvLtAMCyNjL+tQcaKwBRDqvZcJ6OLlmxkVYQF4Q5gEr5 yYoHVaXmlkvr4KN5U44ad3NBtfrBJHYXWNdr0bG8= Authentication-Results: mail-nwsmtp-smtp-corp-main-66.iva.yp-c.yandex.net; dkim=pass header.i=@yandex-team.ru Message-ID: <22da39f0-e73f-4e11-830e-914b5bc04029@yandex-team.ru> Date: Mon, 27 May 2024 13:45:59 +0300 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 3/3] x86/bugs: Add 'spectre_bhi=vmexit' cmdline option To: Josh Poimboeuf Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Daniel Sneddon , Linus Torvalds , Pawan Gupta , Thomas Gleixner , Alexandre Chartre , Konrad Rzeszutek Wilk , Peter Zijlstra , Greg Kroah-Hartman , Sean Christopherson , Andrew Cooper , Dave Hansen , Nikolay Borisov , KP Singh , Waiman Long , Borislav Petkov , Ingo Molnar References: <66327dcf87284a09ed17ac24227695ea3ba1f287.1715059256.git.jpoimboe@kernel.org> <20240508051953.oz3q3hdvifo6lb7o@treble> Content-Language: en-US From: Maksim Davydov In-Reply-To: <20240508051953.oz3q3hdvifo6lb7o@treble> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 5/8/24 08:19, Josh Poimboeuf wrote: > On Tue, May 07, 2024 at 07:58:07AM -0700, Daniel Sneddon wrote: >> On 5/6/24 22:30, Josh Poimboeuf wrote: >>> In cloud environments it can be useful to *only* enable the vmexit >>> mitigation and leave syscalls vulnerable. Add that as an option. >>> >>> This is similar to the old spectre_bhi=auto option which was removed >>> with the following commit: >>> >>> 36d4fe147c87 ("x86/bugs: Remove CONFIG_BHI_MITIGATION_AUTO and spectre_bhi=auto") >>> >>> with the main difference being that this has a more descriptive name and >>> is disabled by default. >>> >>> Requested-by: Maksim Davydov >>> Signed-off-by: Josh Poimboeuf >>> --- >> >> Does the KConfig option need to be updated to support this as well? > > In general we don't provide a config option for every possible > mitigation cmdline option. If someone requests it we could add it > later. > >> Reviewed-by: Daniel Sneddon > > Thanks! > I think it will be useful for us to have appropriate Kconfig option. Could you please add it to the next version? -- Best regards, Maksim Davydov