From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f202.google.com (mail-pf1-f202.google.com [209.85.210.202]) (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 DA1693E0C76 for ; Fri, 15 May 2026 19:20:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778872849; cv=none; b=lpvSc4xtTgbu5lH6LO13IN3vqRLbNf95VXRi3w+Ubev0F8a9GOxT4UrT0UrBXW8I5EsZ0pIEaGu5FQr1ondp6HkQ8MyEoHxJUX7sUO80FdINfCCpOShReRqZvhxxLJUi1dmFgGhSKqHbgqgxGTSjPXs9w0aHK9SFbzIo7f1mM9g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778872849; c=relaxed/simple; bh=bIvGpEwSZtu1dFGmRrUgP1xhupYQhI4tOk7weRcJRgU=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=GeQBX5sLR9/avZU4jj8rwIRn+jv/RVfaJYRmvsHO+6IA+LxCewwuq+eoSzOHLMU47pYWMzJ0FxQCatyXph6/EEYrBpi8JtG6y/m4GF3TxJ/DCQ5Q8dF5lOOXnybmhUxSfDWmzuDLWeaH0j2XV1x4wfw2xc8Ydw/YST5GNEcJkYc= 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=wGtyso6U; arc=none smtp.client-ip=209.85.210.202 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="wGtyso6U" Received: by mail-pf1-f202.google.com with SMTP id d2e1a72fcca58-82fa366fb79so248217b3a.2 for ; Fri, 15 May 2026 12:20:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1778872847; x=1779477647; darn=lists.linux.dev; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=eVzC+1NNlxe1k/R0gBkxcy+TPbGnZzPB3ftmmd4+5ik=; b=wGtyso6Uqxty1AiB9MEoJ7TFW/JGcjvBIfH9n/kdRgsJ2LNOzDvZYg23OD5FWesSRC mOkoW7/jY+FQdR409lGivhhDFD7xmKog8XwkPgpICSDqS1+NvVBnyVJ640qVNR3J5pif F2tSrxuv/zcLAjmCPjBf1ONAMrMgYv6MpcbIgQHuhMLoOVLWE/VT2Ml6Mj4WYGl9itZ4 JMOi45bisFe+KHkXtx50BZPbavRr7K41hHlMpduBm88vlKafh6PboU3UR0YbrQy4kd8t Cyosat61oKKh3Uw1V50ZNUUU2MVZxcvDBi5B22mtK0Q/HaIt3/h7PsMAJySYtGCPMOXl 7QkQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1778872847; x=1779477647; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=eVzC+1NNlxe1k/R0gBkxcy+TPbGnZzPB3ftmmd4+5ik=; b=eBeI3hSHxWddZ5FUheeyUrm/vYjNFhQZPGrD5SfpIt7rO1YILcTj5Z3jo19rCSpgEn Zm3U45TOMfHY0wDNRgFqKqppLechQ6IFz5xPHmp5XFkA8Ow+Ijl+TBHg3YdrCupwXGxS a5EplImLNHmVBgQZtJS7F7UM4T3nymcOtW0QvytI3sRG3T5Zmv3zBk+SJJdVIqmy/PIu OuX6RC1fcex6KqEIw5GpiggPmReeGcvrz45FAUCUrpDhTTYHkHPcezt8B2Vz9sG3060W P8MKbgCoHUgn9UWJ9uqSpGJ64890wVNfQ9ZZF0eA87H3SxDoB9UG/VD590D6DmtpqI7M youA== X-Forwarded-Encrypted: i=1; AFNElJ9lrurgGcfvXRG5ObqcCBR/X3tWarhosfXrJW8PLs8btabj8HmsPap0m3l2Lif4Qf9u+tgKx+FVqiV4@lists.linux.dev X-Gm-Message-State: AOJu0YySIH6sMzHm/eRYYMvw9qSPNcOZJpEjGjjxb0RlIJJpgO4dc9DN WxyytacVKyGLnwa4QovGaXlBvf4EKUwXqGdBrWrlVqsjfOE4zceRhGE9mXYNABmtAAZ6BDfr+6n O4IlAKA== X-Received: from pfblu4.prod.google.com ([2002:a05:6a00:7484:b0:83a:58c1:f5e2]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:1404:b0:829:9a7b:db84 with SMTP id d2e1a72fcca58-83f33f30bf8mr5787888b3a.49.1778872846903; Fri, 15 May 2026 12:20:46 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 15 May 2026 12:19:16 -0700 In-Reply-To: <20260515191942.1892718-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260515191942.1892718-1-seanjc@google.com> X-Mailer: git-send-email 2.54.0.563.g4f69b47b94-goog Message-ID: <20260515191942.1892718-16-seanjc@google.com> Subject: [PATCH v3 15/41] x86/xen/time: Nullify x86_platform's sched_clock save/restore hooks From: Sean Christopherson To: Kiryl Shutsemau , Paolo Bonzini , Sean Christopherson , "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 Cc: 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="UTF-8" Nullify the x86_platform sched_clock save/restore hooks when setting up Xen's PV clock to make it somewhat obvious the hooks aren't used when running as a Xen guest (Xen uses a paravirtualized suspend/resume flow). Signed-off-by: Sean Christopherson --- arch/x86/xen/time.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index 3d3165eef821..21d366d01985 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -568,6 +568,12 @@ static void __init xen_init_time_common(void) xen_sched_clock_offset = xen_clocksource_read(); static_call_update(pv_steal_clock, xen_steal_clock); paravirt_set_sched_clock(xen_sched_clock); + /* + * Xen has paravirtualized suspend/resume and so doesn't use the common + * x86 sched_clock save/restore hooks. + */ + x86_platform.save_sched_clock_state = NULL; + x86_platform.restore_sched_clock_state = NULL; tsc_register_calibration_routines(xen_tsc_khz, NULL); x86_platform.get_wallclock = xen_get_wallclock; -- 2.54.0.563.g4f69b47b94-goog