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 345351ACED5 for ; Thu, 27 Feb 2025 02:19:46 +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=1740622788; cv=none; b=ua/v33U/wstPLp9V25mB8OQ4xYf5D+xNU/3ukbuE3dJKHZQ3wLZBPhWZLO8hhtxXblTePX+OHPO1RZCVnP21oWD8wh39KOGyj4U/HUxa1rm9s4XNn+4RwKfzTZWVm16rouVg1AUycw4Ai6I4O1zU6opl6BcathhTWwODDM0dDNk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740622788; c=relaxed/simple; bh=zjjnD8AWfMJS2/xbCkWD8FS8YCODvYXqFbARM/Ts+/s=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=PnQB6AdRplWUqMgMjwhQ34oyYDDYrKkZnCEJylOTo5tBOCgsNaMdDkSH0CpwTdthbvh9kMfdxyv4dIOV/3dV8Biw6KqeXXX9Y7m+naDb8Lk1ZSz9acBZmiwV7Bvu8rsIGWj/zHz4AXUq8xEcaByegdjytkr++7I1Qq2qT4mycmc= 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=srqxU/lr; 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="srqxU/lr" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-2234dddbd6fso8510405ad.0 for ; Wed, 26 Feb 2025 18:19:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1740622786; x=1741227586; 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=3WIlT5dxc8eqreSuMAUxshuXGBEM8C/NLPwcD1zy3Y0=; b=srqxU/lr7W/NKyKI2tErwOkyUNziARMWiy32bc8sbzPikLiFeRl8XWxAEyr4J3SGGL UetJDLlHQHsERAUEDOlwR1bujMHp9I0iNXA2N1kws/YgeHXFGciOLGmxpB5CHYogpJQi ktmKcSsOrMxoPmyAUmW7BD/mdRrxTawCj+tMKYtcdOIuaY0CN0WkzgcnfevzMYKxt6BX eQISNCzYoBLcVGAcIQgW+LMbez37wjz72KNnr5m+gN7amYRfPzlkM+WyUPM8HC38dsLF KuFUgNYuB/1De0m2zFStiDySihijPMg5OfG/7ESLk6HHjQGH8sdiMd/vaI5HP2F3tpGw 4U+Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740622786; x=1741227586; 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=3WIlT5dxc8eqreSuMAUxshuXGBEM8C/NLPwcD1zy3Y0=; b=EJqUAjyxU2oeP5T2UH3pOjCbb8CI2WKinCYYuiWw853pUrpQgobH4TBFx6m0H4fMVj vjNwusMtRv2YIqs8OEaNAaXSzyQU1u5qP+Lqs7b/JodYbr3pM0z8TLcuN2LlyGeQWpOZ CgV1WcvZnToUEtUWCKOzsc3ZnJFIJ7vzroxB1XMBp6HP1JaZ46vqaKLvcJXsSOY5vD8r xN11vfoDjleIsIlAAfyQZRkjt4Tfz+y863ZdN+bA/BN83aiwSl7Pgx/ElAUg66daRLMT R6Xds6AaN4FQ8xqtFgQxQ317z0JSHv1gqs449bYf5mQA8kbDPZBX+8drqTY4ub6ayg2f O/OQ== X-Forwarded-Encrypted: i=1; AJvYcCXz7w1bEvSYXU5JAwCXVl74cwcRq0M6DPBbJqae3fzNdIq6+CWV8ZKV3+t7enKDY6tS29gzUiA6Ma6gatWitg==@lists.linux.dev X-Gm-Message-State: AOJu0YyEcIxpIBlIMR8Vw8Ok3AL+Cp27jRLMrzl1odDAoPs8MPTan3KZ 0tHvmOerr33mOmcgq/hEQXvJoqfFCcQFw/HyJny34uHjeDYCRISPJazp1iWVaS5inb8FKhxTFvP TGA== X-Google-Smtp-Source: AGHT+IEKa+U3XmhHVLGnMc9mY3OxJMjJ1pR3+E2erpOOt4xnyyZwND9G3ZoTVgYNZ7eny0ZZLwJ5fe0HKa8= X-Received: from pjvf4.prod.google.com ([2002:a17:90a:da84:b0:2ea:3a1b:f493]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:902:e80e:b0:21f:3d0d:2408 with SMTP id d9443c01a7336-2234a28af91mr27386885ad.10.1740622786458; Wed, 26 Feb 2025 18:19:46 -0800 (PST) Reply-To: Sean Christopherson Date: Wed, 26 Feb 2025 18:18:41 -0800 In-Reply-To: <20250227021855.3257188-1-seanjc@google.com> Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250227021855.3257188-1-seanjc@google.com> X-Mailer: git-send-email 2.48.1.711.g2feabab25a-goog Message-ID: <20250227021855.3257188-26-seanjc@google.com> Subject: [PATCH v2 25/38] x86/kvmclock: Hook clocksource.suspend/resume when kvmclock isn't sched_clock From: Sean Christopherson To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "Kirill A. Shutemov" , Paolo Bonzini , Sean Christopherson , Juergen Gross , "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Ajay Kaher , Jan Kiszka , Andy Lutomirski , Peter Zijlstra , Daniel Lezcano , John Stultz Cc: linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev, kvm@vger.kernel.org, virtualization@lists.linux.dev, linux-hyperv@vger.kernel.org, xen-devel@lists.xenproject.org, Tom Lendacky , Nikunj A Dadhania Content-Type: text/plain; charset="UTF-8" Save/restore kvmclock across suspend/resume via clocksource hooks when kvmclock isn't being used for sched_clock. This will allow using kvmclock as a clocksource (or for wallclock!) without also using it for sched_clock. Signed-off-by: Sean Christopherson --- arch/x86/kernel/kvmclock.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index 0580fe1aefa0..319f8b2d0702 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -130,7 +130,17 @@ static void kvm_setup_secondary_clock(void) static void kvm_restore_sched_clock_state(void) { - kvm_register_clock("primary cpu clock, resume"); + kvm_register_clock("primary cpu, sched_clock resume"); +} + +static void kvmclock_suspend(struct clocksource *cs) +{ + kvmclock_disable(); +} + +static void kvmclock_resume(struct clocksource *cs) +{ + kvm_register_clock("primary cpu, clocksource resume"); } void kvmclock_cpu_action(enum kvm_guest_cpu_action action) @@ -201,6 +211,8 @@ static struct clocksource kvm_clock = { .flags = CLOCK_SOURCE_IS_CONTINUOUS, .id = CSID_X86_KVM_CLK, .enable = kvm_cs_enable, + .suspend = kvmclock_suspend, + .resume = kvmclock_resume, }; static void __init kvmclock_init_mem(void) @@ -295,6 +307,15 @@ static void __init kvm_sched_clock_init(bool stable) __paravirt_set_sched_clock(kvm_sched_clock_read, stable, kvm_save_sched_clock_state, kvm_restore_sched_clock_state); + /* + * The BSP's clock is managed via dedicated sched_clock save/restore + * hooks when kvmclock is used as sched_clock, as sched_clock needs to + * be kept alive until the very end of suspend entry, and restored as + * quickly as possible after resume. + */ + kvm_clock.suspend = NULL; + kvm_clock.resume = NULL; + pr_info("kvm-clock: using sched offset of %llu cycles", kvm_sched_clock_offset); -- 2.48.1.711.g2feabab25a-goog