From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f202.google.com (mail-pl1-f202.google.com [209.85.214.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6959C396573 for ; Mon, 18 May 2026 21:11:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779138707; cv=none; b=jNNPKJCYT5pboshPbEhULHyIrgx0ZYzt1exVbph+K1g3wlwj1IjbCFqZTuqblYNZTumtBn6rIPFO/lTkqZHA/1HXOkGN4b1JKDVvclbQES3ge3eLm2MxFyy88dshqpzP8IPVMdZk3VfUUOB9ohtXFkCnS8O9Et8XD7qhE6X2GtQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779138707; c=relaxed/simple; bh=Y9WlSbz5Rarbpnp6OSXzG8yVO1DRu83ex3iEeD+K0qo=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Content-Type; b=p/xxvWNXB4kcFFIAx+zqREqZGusIZN3oIm/sg8evXxHcE9xraK6TTaRjmFDEVSTAlzimHbkKgXI04aEj3n0aRNqM3lInEqVv5SkzXvuPBkH7KV6MJ7vxiIcvgcCsHNqxhB0o1igMphbbH/FXcJsegsDa7wb0UJC3D59TOQ7DM3U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=hdaiDhaV; arc=none smtp.client-ip=209.85.214.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="hdaiDhaV" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-2ba3245a43dso29499935ad.0 for ; Mon, 18 May 2026 14:11:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1779138706; x=1779743506; darn=vger.kernel.org; h=to:from:subject:message-id:references:mime-version:in-reply-to:date :from:to:cc:subject:date:message-id:reply-to; bh=M0HR0/OeCt5J6wDdP6oTOA3/U+zZIegjjUJa8wpeaiw=; b=hdaiDhaVaqz/zMC0xG8RqY3S8IElZPQAKAqzBXsSuhQcsW2cjmuS+sopRWEi2Z8gs3 Ue32m7jM50i6l9zH+utiaxr4pvGz2ZTDXaqg7E+19nr8qV0fJUWn0og6789ZZOb9RnaT sp3YE1W+xsi/hw5TGgxjvFSQP7kZ6uPKrvqdDu/AMM4rkK+a6QSXLY4pdgIKPA1j82mu RBr+lm/l2kzMfkngiHucKtDvGaErUaQ1cGHTgs7VEkFdo56RS3xjrRABpxLqdJuK8OoA Yb5f/jtGO83U+xAQwyhovLb7WQUTlIVr+h6cefIA4pdl5FbApjvl3Mdl4UhgtxAmZmwA ZTQQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779138706; x=1779743506; h=to:from:subject:message-id:references:mime-version:in-reply-to:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=M0HR0/OeCt5J6wDdP6oTOA3/U+zZIegjjUJa8wpeaiw=; b=JlRBK09ofe6cHhDxJyyz2QsCdOd32gQsYvaXYzI8ab3zwz1nf6b/Vy4c9NdqlQZT2N PMqr0SawM0wPLr6Xi/+8pdQha0oZejvkJ9UZYJHs6kQkoCf5OlbbQf61Kkb7uKJp9n9e p3hskJo5CkEWEmJTdmE4TWkAR5S/+6GUb6EPWyu0QCpc9tJfpQVnIlak68l9GzBlUmoi nAVsepnmb+7P8KrxgNplhMAuG6q0RlGStPE9L7F5Q1yliDJINfiW3JL/KnsP32hTy7do d9WLEDdJyBk3ecz3HoqIid7YagnK4nsijZxfq3FwUU7+hKNxHgqIJr6dricmSCwXrsI1 gb3g== X-Forwarded-Encrypted: i=1; AFNElJ8IVkhV0KSnWphBp7LIOzmlyMK4yuT2SdptIF/p+O7hPMZJ6tio9IV6dy7sjr8/C646VibFfEL4xdHqfag=@vger.kernel.org X-Gm-Message-State: AOJu0Yx62FTw/14XRKzSbU61nNJbAzpkNjWJe0ME6LqerMULVFYuccRf 4XEZqOu7VKYHlA9g8pL4sEFEs+9ZcKHv4kfv0xKGz0ABtkwabk3xJRaXUFF5PeNFAWFL6ltFoz0 5gitukA== X-Received: from plhq16.prod.google.com ([2002:a17:903:11d0:b0:2b2:43c2:a183]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:903:11c4:b0:2bd:9766:bd2b with SMTP id d9443c01a7336-2bd9766be37mr135740745ad.19.1779138705542; Mon, 18 May 2026 14:11:45 -0700 (PDT) Date: Mon, 18 May 2026 14:11:44 -0700 In-Reply-To: <20260515191942.1892718-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-hyperv@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260515191942.1892718-1-seanjc@google.com> Message-ID: Subject: Re: [PATCH v3 00/41] x86: Try to wrangle PV clocks vs. TSC From: Sean Christopherson To: Kiryl Shutsemau , Paolo Bonzini , "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Long Li , Ajay Kaher , Alexey Makhalov , Jan Kiszka , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Juergen Gross , Daniel Lezcano , Thomas Gleixner , John Stultz , Rick Edgecombe , Vitaly Kuznetsov , Broadcom internal kernel review list , Boris Ostrovsky , Stephen Boyd , x86@kernel.org, linux-coco@lists.linux.dev, kvm@vger.kernel.org, linux-hyperv@vger.kernel.org, virtualization@lists.linux.dev, linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, Michael Kelley , Tom Lendacky , Nikunj A Dadhania , Thomas Gleixner , David Woodhouse Content-Type: text/plain; charset="us-ascii" On Fri, May 15, 2026, Sean Christopherson wrote: > Dave/Thomas/Peter/Boris, what's the going rate for bribes to take something > like this through the tip tree? > > The bulk of the changes are in kvmclock and TSC, but pretty much every > hypervisor's guest-side code gets touched at some point. I am reaonsably > confident in the correctness of the KVM changes. Michael tested Hyper-V in > v2, and while there were conflicts when rebasing, they were largely > superficial (and I've just jinxed myself). For all other hypervisors, assume > the code is compile-tested only, but those changes are all quite small and > straightforward. > > The only changes that are questionable/contentious are the last two patches, > which have KVM-as-a-guest use CPUID 0x16 to get the CPU frequency, even on > AMD (that's the dubious part). I very deliberately put them last, so that > they can be dropped at will (I don't care terribly if those patches land). > To merge them, I would want explicit Acks from Paolo and David W. > > So, except for the last two patches, to get the stuff I really care about > landed, I think/hope it's just the TSC and guest-side CoCo changes that need > reviews/acks? FYI, don't bother reviewing this version. Sashiko found several glaring flaws, but I just realized that sashiko-bot's emails are only being sent to myself and linux-hyperv@vger.kernel.org. I'll make sure to highlight the changes in the next version. In the meantime, Sashiko's feedback is archived on lore if you want to see me get torched by AI :-)