From patchwork Sat Feb 1 02:17:12 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 13956075 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 B35861A4F0A for ; Sat, 1 Feb 2025 02:17:45 +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=1738376267; cv=none; b=LIocQH/6Zbv9dcd07cH4tzLcolfCooEzYhS2CmMajwYyPMPdnDICG7fAeXAo01FeYKSZvdP6AQK3nFRWr7BirFhoxfcWKYP7J/Bi2iDjyoS0u6T2wKDnxkLlaKHjJfE5gdUwkwpJxVuYHXKiLHOBNSSiOHpiNT1vys4KxYPfKF8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738376267; c=relaxed/simple; bh=kx1WuhibcuTx6WiHPmvUxDfP1htj6y2KJdDmu/FjmBY=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=GuuuoKEjEmKyiuq5NBSAKmSsS5+aMuHEvKgoTbZGaA91vfhlvAYFT51mUo3QqrZqPyi92VYxgKkvOYkbBy05pclDCQB9TbUkGR2wJRL2n+JowA9U6J/CdDpsE5OwBT/0Jb+jRnSGQ5kIo4y4DpF3SB7hrvflEakbTsoGH/3392I= 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=wVK9N+FI; 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="wVK9N+FI" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-2163a2a1ec2so84584305ad.1 for ; Fri, 31 Jan 2025 18:17:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1738376265; x=1738981065; darn=vger.kernel.org; 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=W1XV2ZKxBzpt6fRRKseHNiWV51nuIILy1d39LBlT9SE=; b=wVK9N+FI4a2ceQOs7i0AkqT31sCQJmoaHqMMyptLTslSjOcDBE8Ilnx3viQKaXVXDH q2cIO9ilRm10t+7wHx6WV0reM/uqdKvGwoeB164bSV+wzhiH/IdkdJWDx6PhfsBV29Q9 YR5MTjav3JjL7QB+qv0Sb4LJ6n0lRbr7ozI6QRfmuW6deEEmgVu2cxyNwwxdBNhiV0Bt bipYle1qf4jcKQjyHx2CDEH4uvOFD+LIp979llQaI6PgZ+bO+Zdfws2Vyi+C+P+jM9NS KrGnDAGI2gdzkz8Ws6TMx9SdyPsZOGGV+EZdw2+XMdnI3eukjkR/XMLmcmm10GNiIxsJ 6XLg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1738376265; x=1738981065; 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=W1XV2ZKxBzpt6fRRKseHNiWV51nuIILy1d39LBlT9SE=; b=RmxXDsfVxfMgVJ+2jTCCGQdnCd0kXtifywaXmRHh2vfuuXW67gmKhFc/O/23klXQ2B A3LMhGz7HVCNM1z44ruiQQ197wZboqXxAl0Rba7RAjXk1tz3vD2W0Ig2nDFJa0ATolgB VLrM9bUkHIm2b3Xz+FAbwmYq0BJZ2w3H1XfYSi3czQk0cwpfQ9+EvIPa1DUmsJm91L+l 5JoGy9FY4TiCojNkO6SKPS+iG03XFDwBjWQRL/SpGrQ+qmS9JALowc/bTHh+p6icJVLr OC+TiZPCz8RNgqcm0MeMrIGZjGOfVtlPboMKegPXKGRh6CKGCo4cER/WjGQL/G4uzJQs 4O/w== X-Forwarded-Encrypted: i=1; AJvYcCUw2aafx+XSuymQIRDkyC7gclIuR7duj3hAQ3RcbhenYAQ7lR2Ws3aM25Y8taj/99Acjwc=@vger.kernel.org X-Gm-Message-State: AOJu0YwzOQPtaZDZ0xzX2hC7fwlzS8l4EsMM951lz3qG1ux/Ca7wnjcH AXjjAEWztazKjn8VqL+fmL2/tiFeo4MtuEUPUd8LGIVrTcTWWPVVwQnDJic1A9R4zYzA3ohxBKG kLA== X-Google-Smtp-Source: AGHT+IGSSeREbj02hPb3cDa39T9c0oKEk7xpncELnx14V1Vrs2HnSpCp6+OTk/Z1j4CkHarX3h8UUIGOLcI= X-Received: from pjbsb14.prod.google.com ([2002:a17:90b:50ce:b0:2f4:465d:5c61]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:903:244c:b0:215:f1c2:fcc4 with SMTP id d9443c01a7336-21dd7deeff4mr227157665ad.41.1738376264849; Fri, 31 Jan 2025 18:17:44 -0800 (PST) Reply-To: Sean Christopherson Date: Fri, 31 Jan 2025 18:17:12 -0800 In-Reply-To: <20250201021718.699411-1-seanjc@google.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250201021718.699411-1-seanjc@google.com> X-Mailer: git-send-email 2.48.1.362.g079036d154-goog Message-ID: <20250201021718.699411-11-seanjc@google.com> Subject: [PATCH 10/16] x86/paravirt: Move handling of unstable PV clocks into paravirt_set_sched_clock() From: Sean Christopherson To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "Kirill A. Shutemov" , Juergen Gross , "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Ajay Kaher , Alexey Makhalov , Jan Kiszka , Paolo Bonzini , Andy Lutomirski , Peter Zijlstra Cc: linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev, virtualization@lists.linux.dev, linux-hyperv@vger.kernel.org, jailhouse-dev@googlegroups.com, kvm@vger.kernel.org, xen-devel@lists.xenproject.org, Sean Christopherson , Nikunj A Dadhania , Tom Lendacky Move the handling of unstable PV clocks, of which kvmclock is the only example, into paravirt_set_sched_clock(). This will allow modifying paravirt_set_sched_clock() to keep using the TSC for sched_clock in certain scenarios without unintentionally marking the TSC-based clock as unstable. No functional change intended. Signed-off-by: Sean Christopherson --- arch/x86/include/asm/paravirt.h | 7 ++++++- arch/x86/kernel/kvmclock.c | 5 +---- arch/x86/kernel/paravirt.c | 6 +++++- 3 files changed, 12 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index 041aff51eb50..cfceabd5f7e1 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -28,7 +28,12 @@ u64 dummy_sched_clock(void); DECLARE_STATIC_CALL(pv_steal_clock, dummy_steal_clock); DECLARE_STATIC_CALL(pv_sched_clock, dummy_sched_clock); -void paravirt_set_sched_clock(u64 (*func)(void)); +void __paravirt_set_sched_clock(u64 (*func)(void), bool stable); + +static inline void paravirt_set_sched_clock(u64 (*func)(void)) +{ + __paravirt_set_sched_clock(func, true); +} static __always_inline u64 paravirt_sched_clock(void) { diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index b41ac7f27b9f..890535ddc059 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -12,7 +12,6 @@ #include #include #include -#include #include #include #include @@ -93,10 +92,8 @@ static noinstr u64 kvm_sched_clock_read(void) static inline void kvm_sched_clock_init(bool stable) { - if (!stable) - clear_sched_clock_stable(); kvm_sched_clock_offset = kvm_clock_read(); - paravirt_set_sched_clock(kvm_sched_clock_read); + __paravirt_set_sched_clock(kvm_sched_clock_read, stable); pr_info("kvm-clock: using sched offset of %llu cycles", kvm_sched_clock_offset); diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index 1ccaa3397a67..55c819673a9d 100644 --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include @@ -85,8 +86,11 @@ static u64 native_steal_clock(int cpu) DEFINE_STATIC_CALL(pv_steal_clock, native_steal_clock); DEFINE_STATIC_CALL(pv_sched_clock, native_sched_clock); -void paravirt_set_sched_clock(u64 (*func)(void)) +void __paravirt_set_sched_clock(u64 (*func)(void), bool stable) { + if (!stable) + clear_sched_clock_stable(); + static_call_update(pv_sched_clock, func); }