From nobody Mon Oct 6 13:42:09 2025 Received: from mail-yb1-f201.google.com (mail-yb1-f201.google.com [209.85.219.201]) (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 ADD2728FFE6 for ; Tue, 22 Jul 2025 05:50:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753163454; cv=none; b=EckkRX04tWAJgbCFcpmHS12yzPIA+TzcVhFr73WcEsU9cREVGRIGLPbvU3gF8hoB438JxUPe9YBaJ679vCKR7mhzCce16N0+Qa8dL/uJboSyeazcvlDJ2lzCX0puNHp4LNpXPExkOP2QKgvD1DzV1R9r0Ash4n/EqlX0Fw/7fJ8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753163454; c=relaxed/simple; bh=f2app9m1XBJQAi6+4l94hDgNDXkVwP8W7DjMeboFeKs=; h=Date:In-Reply-To:Message-Id:Mime-Version:References:Subject:From: To:Cc:Content-Type; b=bITqmnTeo5wCvVAR4Dkbaj7shApwgpY+Rp8TiBmjLlG44maGUprjSnMe3u4XvSuNXaAsllwm2O3AMOb0lN3c6R+Ue99pJQuRTA5/6vEgcnVoFG5ICSiHNsdTBGY6TBSJAlrn9wHJ7RxfCsZ0FlpGrHYfpeX22Ebsb3bQ9UH1PEg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--suleiman.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=htsuDxOK; arc=none smtp.client-ip=209.85.219.201 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--suleiman.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="htsuDxOK" Received: by mail-yb1-f201.google.com with SMTP id 3f1490d57ef6-e8bcab61882so7291956276.0 for ; Mon, 21 Jul 2025 22:50:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1753163452; x=1753768252; darn=vger.kernel.org; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=XJUgLDdqD5HwEkqjp4kNT3CMaMib66Jd7rSrX/S2lMg=; b=htsuDxOKLWcDTconWdgbl/hKNsA0naehu5CU7AULw6+bDQKkOYq9qBU9Ujh86rAbvk DmlmJC/Ug30WCVV7ZDiyvwnVmogwDHQTEm2H0unTzK6jLjtrjNtul1aNi66NCNnaXM3E Vdvob3bv1/3bJQ7JqJgPGdYjFTv2tQ+KzxB0GjGSIzPr/bc/cdFUW4bZlnzk0YykEyJc MPzGzI8WgL3eotqkdwbTic3aMpA8IJBCHcrM9bi/0mKl+KG/jpYAdwr0ntIrV9oEN3Dt RYy8ad78XQjOE4zV6sJjhKg8FxRVBxxmGpr2RXsdB4vpCXPBHzvm6tiqCMSPOFq8pcBM yyaQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1753163452; x=1753768252; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=XJUgLDdqD5HwEkqjp4kNT3CMaMib66Jd7rSrX/S2lMg=; b=FUNSTtFKqHG4LY3qtexs8dx5jgonlZa3ygbqcclUT8QPWg1hpmoXbgBRElIHeaNpLE Tqw1zS1m41FgOLdLDnL3DPwFJl1eED+P80/LdV2Aw0/aOY5W94uSLV30lCUdPyQf5hgk Lnsgj2VtkQAmNbcvVo2Im9b/cY0HF9yaIjRiLJo/iSSQwMCpj06ZUaAQ4JlBUIzIRoPe 0FxoBXmmKAMjxxTAptEgtfOxTO4dZgkifrapU45NtaYKMn1z58L2YtnZVM6ya3VVDXr8 bv9lqsf25iZHmLkEAL3h3sXpctIZ8YToQCooR35e93rEc8lY8pAvniaqbL8iqOuur299 /CtA== X-Forwarded-Encrypted: i=1; AJvYcCWhO/CQUvjfRw/osX5+NW4sPMMFJqft8puZJVxoB4qFA1F7uHwi25kadAIsjq1SviAT+/ZdLrx3wPH326I=@vger.kernel.org X-Gm-Message-State: AOJu0Yx9+Y+ypvc4aHN3w7xqG49KDdQEMrzlAbCE2Oa9RQ6NQOX8tX+O 8KnBs2rY+yyXYbF/QgrrJcu0xkXdSssgGWzAGXHrVUFiiDDKopj8/1jVPC/zEQWFthsW0nC9tTs Q9AX3IeryeFmd5A== X-Google-Smtp-Source: AGHT+IEzH5es+owsbGwJIgWMHUn6KwbtBgGKdaJcZ2YsHKNxdG3f/gO+Qi3qLfXbsU9+QlhJpAwtZwURqNvhQw== X-Received: from suleiman1.tok.corp.google.com ([2401:fa00:8f:203:eafa:b5d9:dc1:d7b1]) (user=suleiman job=sendgmr) by 2002:a25:a02a:0:b0:e8b:68e0:a7f4 with SMTP id 3f1490d57ef6-e8bc252f6afmr2612276.4.1753163451131; Mon, 21 Jul 2025 22:50:51 -0700 (PDT) Date: Tue, 22 Jul 2025 14:50:30 +0900 In-Reply-To: <20250722055030.3126772-1-suleiman@google.com> Message-Id: <20250722055030.3126772-4-suleiman@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250722055030.3126772-1-suleiman@google.com> X-Mailer: git-send-email 2.50.0.727.gbf7dc18ff4-goog Subject: [PATCH v8 3/3] KVM: x86: Add "suspendsteal" cmdline to request host to add suspend duration in steal time From: Suleiman Souhlal To: Paolo Bonzini , Sean Christopherson Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Chao Gao , David Woodhouse , Sergey Senozhatsky , Konrad Rzeszutek Wilk , Tzung-Bi Shih , John Stultz , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, ssouhlal@freebsd.org, Suleiman Souhlal Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Introduce a new command line parameter, "suspendsteal", enabling the guest to use MSR_KVM_SUSPEND_STEAL, which tells the host that it would like host suspend duration to be included in steal time. Signed-off-by: Suleiman Souhlal --- Documentation/admin-guide/kernel-parameters.txt | 5 +++++ arch/x86/kernel/kvm.c | 15 +++++++++++++++ 2 files changed, 20 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentatio= n/admin-guide/kernel-parameters.txt index 07e22ba5bfe3..9a5490539bb2 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -7074,6 +7074,11 @@ improve throughput, but will also increase the amount of memory reserved for use by the client. =20 + suspendsteal + [X86,PV_OPS] + Enable requesting the host to include the duration the + host was suspended in steal time. Disabled by default. + suspend.pm_test_delay=3D [SUSPEND] Sets the number of seconds to remain in a suspend test diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 921c1c783bc1..35d1bb2283c2 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -320,6 +320,18 @@ static void __init paravirt_ops_setup(void) #endif } =20 +static bool suspend_steal; + +static int __init suspendsteal_setup(char *s) +{ + if (kvm_para_has_feature(KVM_FEATURE_SUSPEND_STEAL)) + suspend_steal =3D true; + + return 0; +} + +early_param("suspendsteal", suspendsteal_setup); + static void kvm_register_steal_time(void) { int cpu =3D smp_processor_id(); @@ -331,6 +343,9 @@ static void kvm_register_steal_time(void) wrmsrq(MSR_KVM_STEAL_TIME, (slow_virt_to_phys(st) | KVM_MSR_ENABLED)); pr_debug("stealtime: cpu %d, msr %llx\n", cpu, (unsigned long long) slow_virt_to_phys(st)); + + if (suspend_steal) + wrmsrl(MSR_KVM_SUSPEND_STEAL, KVM_MSR_ENABLED); } =20 static DEFINE_PER_CPU_DECRYPTED(unsigned long, kvm_apic_eoi) =3D KVM_PV_EO= I_DISABLED; --=20 2.50.0.727.gbf7dc18ff4-goog