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[23.128.96.18]) by mx.google.com with ESMTP id da5si12095881edb.565.2021.03.30.09.56.56; Tue, 30 Mar 2021 09:57:18 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=LAH4582+; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232440AbhC3QwZ (ORCPT + 99 others); Tue, 30 Mar 2021 12:52:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48592 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232656AbhC3QwJ (ORCPT ); Tue, 30 Mar 2021 12:52:09 -0400 Received: from mail-io1-xd33.google.com (mail-io1-xd33.google.com [IPv6:2607:f8b0:4864:20::d33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 87251C061574 for ; Tue, 30 Mar 2021 09:52:09 -0700 (PDT) Received: by mail-io1-xd33.google.com with SMTP id n198so17197387iod.0 for ; Tue, 30 Mar 2021 09:52:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=KkAtFBgJyVrb9iuHnJExd0NJVK4yAFyTjJdaicBUnRw=; b=LAH4582+NwnCxqqe3+3sIP97xXc+BUkqqnvowuPgY9Iz4kONSGAQJUWEHtxLk+aI8l GEEB/arsdC3uv34zdRSwjrsexcA5bfXhqmfsxQGVJQeA6ALu++oTk4uU9lGgjGhKvqvX T6r31KQXcBbCdNMnnAMPdbQ0ORrLTkeCblpQ2yv0ZA4JA5eU8L6TFUmsLXYu6nKh9HAP j1xW7br0Z5pA7Itr1SNaiNps+APovmRNWrqSEH6++81C0sbbLqKIeS04aa65iduy3kBi O6HsENhq+/Bh3qW8PC2tbx7nUTCni0PPPdj2JryUft10R79qUTGiYRw94BGHCvn3JFvq GKQA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=KkAtFBgJyVrb9iuHnJExd0NJVK4yAFyTjJdaicBUnRw=; b=X8k7T7euPw4spqoK6JlSB9mKB/X68+1UbRmEpPonnecinbIC5Bre7gz9UwEDMynecU ncogpV0l7Qmk2tFpYmTYgu3lMY3Rvx3skuDRCzH8lWyNjhgLeEN0d1m2CRmAEWEDPcVc /SAsK56hvYdGEY7aMnyRKYDBbt6Wcy0rR6Y/4mX29Sa8Xf2iCVayJjIUUy8bhiQ/MaMg TOKnir+sjReDi0idkBMJ+wRDtq27zDcHBuJdNTcNwZonpWgVlPkK6DeJ1gHHErSlKQNC kmnedMZUXu6wYbYiPWqQwdEOfYYXQfGJJRv1GzGymIH5VguE+NcGY87Vj3Wrn5UXBYs4 8z6A== X-Gm-Message-State: AOAM532fKDVt0P21WjWObLQmX4IOsNV5GEKzLXVwdashtWoeAsRKZ4hS lF6poa5bY6yLfPU/sxVLu+P14kbXj7w6TTjuXhVOdw== X-Received: by 2002:a05:6638:1390:: with SMTP id w16mr30240526jad.83.1617123128593; Tue, 30 Mar 2021 09:52:08 -0700 (PDT) MIME-Version: 1.0 References: <20210323120647.454211-1-suzuki.poulose@arm.com> <20210323120647.454211-8-suzuki.poulose@arm.com> <20210326165550.GC2009902@xps15> <20210330152314.GA2329603@xps15> In-Reply-To: From: Mathieu Poirier Date: Tue, 30 Mar 2021 10:51:57 -0600 Message-ID: Subject: Re: [PATCH v5 07/19] arm64: kvm: Enable access to TRBE support for host To: Greg KH Cc: Suzuki K Poulose , Marc Zyngier , Catalin Marinas , linux-arm-kernel , Linux Kernel Mailing List , Coresight ML , Mike Leach , Leo Yan , Anshuman Khandual , Will Deacon , Mark Rutland Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 30 Mar 2021 at 10:47, Greg KH wrote: > > On Tue, Mar 30, 2021 at 10:33:51AM -0600, Mathieu Poirier wrote: > > On Tue, 30 Mar 2021 at 09:35, Greg KH wrote: > > > > > > On Tue, Mar 30, 2021 at 09:23:14AM -0600, Mathieu Poirier wrote: > > > > On Tue, Mar 30, 2021 at 11:38:18AM +0100, Suzuki K Poulose wrote: > > > > > On 26/03/2021 16:55, Mathieu Poirier wrote: > > > > > > On Tue, Mar 23, 2021 at 12:06:35PM +0000, Suzuki K Poulose wrote: > > > > > > > For a nvhe host, the EL2 must allow the EL1&0 translation > > > > > > > regime for TraceBuffer (MDCR_EL2.E2TB == 0b11). This must > > > > > > > be saved/restored over a trip to the guest. Also, before > > > > > > > entering the guest, we must flush any trace data if the > > > > > > > TRBE was enabled. And we must prohibit the generation > > > > > > > of trace while we are in EL1 by clearing the TRFCR_EL1. > > > > > > > > > > > > > > For vhe, the EL2 must prevent the EL1 access to the Trace > > > > > > > Buffer. > > > > > > > > > > > > > > Cc: Will Deacon > > > > > > > Cc: Catalin Marinas > > > > > > > Cc: Marc Zyngier > > > > > > > Cc: Mark Rutland > > > > > > > Cc: Anshuman Khandual > > > > > > > Acked-by: Mathieu Poirier > > > > > > > Signed-off-by: Suzuki K Poulose > > > > > > > --- > > > > > > > arch/arm64/include/asm/el2_setup.h | 13 +++++++++ > > > > > > > arch/arm64/include/asm/kvm_arm.h | 2 ++ > > > > > > > arch/arm64/include/asm/kvm_host.h | 2 ++ > > > > > > > arch/arm64/kernel/hyp-stub.S | 3 ++- > > > > > > > arch/arm64/kvm/debug.c | 6 ++--- > > > > > > > arch/arm64/kvm/hyp/nvhe/debug-sr.c | 42 ++++++++++++++++++++++++++++++ > > > > > > > arch/arm64/kvm/hyp/nvhe/switch.c | 1 + > > > > > > > 7 files changed, 65 insertions(+), 4 deletions(-) > > > > > > > > > > > > > > > > > > > Marc - do you want me to pick up this one? > > > > > > > > > > I think the kvmarm tree is the best route for this patch, given the amount > > > > > of changes the tree is going through, in the areas this patch > > > > > touches. Or else there would be conflicts with merging. And this patch > > > > > depends on the patches from this series that were queued. > > > > > > > > > > Here is the depency tree : > > > > > > > > > > a) kvm-arm fixes for debug (Patch 1, 2) & SPE save-restore fix (queued in > > > > > v5.12-rc3) > > > > > > > > > > b) TRBE defintions and Trace synchronization barrier (Patches 5 & 6) > > > > > > > > > > c) kvm-arm TRBE host support (Patch 7) > > > > > > > > > > d) TRBE driver support (and the ETE changes) > > > > > > > > > > > > > > > (c) code merge depends on -> (a) + (b) > > > > > (d) build (no conflicts) depends on -> (b) > > > > > > > > > > > > > > > Now (d) has an indirect dependency on (c) for operational correctness at > > > > > runtime. > > > > > So, if : > > > > > > > > > > kvmarm tree picks up : b + c > > > > > coresight tree picksup : b + d > > > > > > > > > > and if we could ensure the merge order of the trees are in > > > > > kvmarm > > > > > greg-kh (device-misc tree) (coresight goes via this tree) > > > > > > > > > > > > > Greg's char-misc tree is based on the rc releases rather than next. As such it > > > > is a while before other branches like kvmarm get merged, causing all sort of > > > > compilation breakage. > > > > > > My tree can not be based on -next, and neither can any other > > > maintainer's tree, as next is composed of maintainer trees :) > > > > > > > Exactly > > > > > > > we should be fine. > > > > > > > > > > Additionally, we could rip out the Kconfig changes from the TRBE patch > > > > > and add it only at the rc1, once we verify both the trees are in to make > > > > > sure the runtime operation dependency is not triggered. > > > > > > > > > > > > > We could also do that but Greg might frown at the tactic, and rightly so. The > > > > usual way to work with complex merge dependencies is to proceed in steps, which > > > > would mean that all KVM related patches go in the v5.13 merge window. When that > > > > is done we add the ETE/TRBE for the v5.14 merge window. I agree that we waste > > > > an entire cycle but it guarantees to avoid breaking builds and follows the > > > > conventional way to do things. > > > > > > Or someone creates a single branch with a signed tag and it gets pulled > > > into multiple maintainer's trees and never rebased. We've done that > > > lots of time, nothing new there. Or everything goes through one tree, > > > or you wait a release cycle. > > > > > > You have 3 choices, pick one :) > > > > I'm perfectly happy with getting this entire set merged via Marc's > > kvmarm tree, as long as you are fine with it. > > No objection from me at all for this to go that way. Swell - Marc, I'll send you a pull request. > > thanks, > > greg k-h