From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f201.google.com (mail-pg1-f201.google.com [209.85.215.201]) (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 2F43D37BE8E for ; Fri, 15 May 2026 22:29:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778884158; cv=none; b=QRQZ6KGt9sHhbpXRWZyV0ohunJlFS5w3UI40wYkmjaSEBw+v4tFPP6YcRffnBfTNw+LO45R7FDXj3hlTAGyoNVME8xh2yPDtsIX3M1CBJFj2H4FPxsd41JPmeNOGGbA/Yrzfzuvle7DQsHXr0mTH1uBXszNU2kJu6oNUU96q6QY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778884158; c=relaxed/simple; bh=3kBs+LoK/41x7KTyqa5sAHIy4wlL0hqntfKNUvehlXc=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=Yr7va6FEAPmxz3p+PHF0lG/7jObBIF8cm90IWTS4JOkB3RUloKBVUsD5RejqIPy24pHwweWEi3GYUxQwWfBKUsXPdTjlZfi/U7GZvCYmg161nKboifkpKVD488vmlbey3Q00ha1b2wvmqzY8pHD6oIPvdNXN9uisVD8mTNx4wx0= 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=bTKv+1wG; arc=none smtp.client-ip=209.85.215.201 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--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="bTKv+1wG" Received: by mail-pg1-f201.google.com with SMTP id 41be03b00d2f7-c829366cf25so379101a12.0 for ; Fri, 15 May 2026 15:29:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1778884156; x=1779488956; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=MJEFaPkKBrp+ZhLTHzWdmAHs7LO5UggosySgozYIFoU=; b=bTKv+1wGONPYNf5K9rQAOCM6BWyw4TVLJGDtWZ0hDL+ukwxCJV5brNH9rYpWAzvzWH AkPFqtyQdvAnt0NCLN0Sqgro0hLN8Qr+Uw1zaY/Ox3/stKbretrBlwlGMwJRJbX/iC50 +oXHQ7VxEaAUjPygesOigNcbOgBYlw4My+NaLpCguqxi/5LRVa5mfH7uXmXyjmjQcGtq RcheIfJksIyGBKDd9kEsmyyXoMoWI5vae+TL6aS9AXOuJvoVr0LSPD2Y3JS246E7nJNe usmn4MUyEgIqs2hlvZYudnpBjRUwM/RUDYI7yYccU5AUCYAg22AIwjRpvcBe9+yYqyMj 7BSA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1778884156; x=1779488956; h=cc: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=MJEFaPkKBrp+ZhLTHzWdmAHs7LO5UggosySgozYIFoU=; b=P5TQuRyQ76nok2frHYKamW1skWisJdUvQ5PjQZ3PQTlVxqQ7GZU9O28g2Seg01rSQn wg3dFRG4PPWDWH0EtBFA1oesW9aSqELlhXQDzEWlSfse/CnP4dLsKGTiYrsPQP+UvaWn 3owVn4H4Ga2S2B/IQi7lXvCaK9dlEj/yx+thxcylcrmXkc3jsaP9VZm8fxFubug3Inr+ QUQxnBlTTihmiCYg+N7jEfvUdQDEpr93WvbHfCILKQOax5InNAIns8TmI/TdvAZfc4rj 6s4ED0QSqD8EAE+vNPLC7/nX4Y/IHcNRqGzz6dM1WMGeH7iiy0DvbkYHSw3WubGQMs59 wazw== X-Gm-Message-State: AOJu0YwI7SqkWGLpAU4Sp1CU1vs4vXF36Z369v06Nwl3Ejek8HUI2ICG WnqAlcroZCNrLFaxvmf8twLYyOGS2uFmNEaj5EzhD0OCPh9ZfjAnnTMewPgdc3jeuJJUpy3H4G9 NsrH4lg== X-Received: from pfoo19.prod.google.com ([2002:a05:6a00:1a13:b0:82f:20ed:8059]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:3028:b0:82f:2243:e445 with SMTP id d2e1a72fcca58-83f33d9dc40mr6348229b3a.32.1778884156219; Fri, 15 May 2026 15:29:16 -0700 (PDT) Date: Fri, 15 May 2026 15:29:15 -0700 In-Reply-To: <20260515203447.ED0E7C2BCB0@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-hyperv@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260515191942.1892718-12-seanjc@google.com> <20260515203447.ED0E7C2BCB0@smtp.kernel.org> Message-ID: Subject: Re: [PATCH v3 11/41] x86/kvm: Don't disable kvmclock on BSP in syscore_suspend() From: Sean Christopherson To: sashiko-reviews@lists.linux.dev Cc: linux-hyperv@vger.kernel.org Content-Type: text/plain; charset="us-ascii" On Fri, May 15, 2026, sashiko-bot@kernel.org wrote: > Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider: > > diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c > > index df95516a9d899..006e3a13500b4 100644 > > --- a/arch/x86/kernel/kvmclock.c > > +++ b/arch/x86/kernel/kvmclock.c > [ ... ] > > @@ -178,8 +178,22 @@ static void kvm_register_clock(char *txt) > > pr_debug("kvm-clock: cpu %d, msr %llx, %s", smp_processor_id(), pa, txt); > > } > > > > +static void kvmclock_disable(void) > > +{ > > + if (msr_kvm_system_time) > > + native_write_msr(msr_kvm_system_time, 0); > > +} > > + > > static void kvm_save_sched_clock_state(void) > > { > > + /* > > + * Stop host writes to kvmclock immediately prior to suspend/hibernate. > > + * If the system is hibernating, then kvmclock will likely reside at a > > + * different physical address when the system awakens, and host writes > > + * to the old address prior to reconfiguring kvmclock would clobber > > + * random memory. > > + */ > > + kvmclock_disable(); > > } > > Can this lead to memory corruption if another clocksource overwrites the > x86_platform.save_sched_clock_state callback? Yes, that's why the kernel only allows one "main" hypervisor.