From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2526F32ABF3; Mon, 8 Dec 2025 09:35:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765186526; cv=none; b=pGyzm3282E725/dgcu8EJFndlhc0lwwMx5c1By/L0STyVo/WAnsPsPDls1NHr4jwRKR0yE8f13cthSJFMkdLtn5x9DaaLM0rv6u9gFsaHbhJEfMZVAdeJRXjjr4VP91Gbc+1hBtedvlf7yoXcHtCe1muhUflyoICSNY5z//nG+o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765186526; c=relaxed/simple; bh=dxwlUYyotMAj1FOCT7HUPg377L9SdqVfiNdsHHzR+yM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=b0eD/w9EJb/Ddf9XXsNTUDR9q5q5luQ7B2QiSBPqQ//t2+xOQPsagmVZalVw+lnRjxsDMx/eorBIn3kNzGsFiK4ml+lyhr4eGPgio230QGDk+LglNL0z+vxP0dguNbum66i1LN2xxB00MTAGVUK2tkosJlati3b1I+/3DkJE0CA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=PuKCZyqO; arc=none smtp.client-ip=198.175.65.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="PuKCZyqO" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1765186525; x=1796722525; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=dxwlUYyotMAj1FOCT7HUPg377L9SdqVfiNdsHHzR+yM=; b=PuKCZyqOjReTjq8jEzdtw98j6Asvg3VBZVzEepHmgcG+kd/UdjB6DMm9 QeWnVGXvXcBIOPzfRsOIIr8wNxdDJhHMLCzv/twpO9p/1W4dypsT6eo0U TR0oFBEqYdtXyuc+jTmKwWBnwrdynpk2rD3Vmroy1iT+OBm13TZoN86v8 zzmg7PEL/6Fup2Fz+zsCk/KgHdUP+jovSbQjswyp4aTDQDPIdVCGMNHfC iJh65ND4f3shKVNknV7HpnZVrkfnLAcxcwZURDxVaCIF7JAF034NO21QR obQwZ7KhUom/eRoHQTdVp8OIAh1nKy9rpzqmyTDRkH0sbVzC/ssWWgoaX Q==; X-CSE-ConnectionGUID: sO3ovh3hR92iVWzonwBloA== X-CSE-MsgGUID: pOOUNsrzTr+8q6MxT1HfNg== X-IronPort-AV: E=McAfee;i="6800,10657,11635"; a="67288202" X-IronPort-AV: E=Sophos;i="6.20,258,1758610800"; d="scan'208";a="67288202" Received: from fmviesa008.fm.intel.com ([10.60.135.148]) by orvoesa108.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Dec 2025 01:35:24 -0800 X-CSE-ConnectionGUID: GvTBKVl5QN2hGFwHvhUlpA== X-CSE-MsgGUID: UZpj0zMRTM69UjjLsI6NgA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.20,258,1758610800"; d="scan'208";a="196157405" Received: from dapengmi-mobl1.ccr.corp.intel.com (HELO [10.124.240.12]) ([10.124.240.12]) by fmviesa008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Dec 2025 01:35:15 -0800 Message-ID: Date: Mon, 8 Dec 2025 17:35:13 +0800 Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 40/44] KVM: VMX: Set MSR index auto-load entry if and only if entry is "new" To: Sean Christopherson , Marc Zyngier , Oliver Upton , Tianrui Zhao , Bibo Mao , Huacai Chen , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Xin Li , "H. Peter Anvin" , Andy Lutomirski , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Paolo Bonzini Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, kvm@vger.kernel.org, loongarch@lists.linux.dev, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Mingwei Zhang , Xudong Hao , Sandipan Das , Xiong Zhang , Manali Shukla , Jim Mattson References: <20251206001720.468579-1-seanjc@google.com> <20251206001720.468579-41-seanjc@google.com> Content-Language: en-US From: "Mi, Dapeng" In-Reply-To: <20251206001720.468579-41-seanjc@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 12/6/2025 8:17 AM, Sean Christopherson wrote: > When adding an MSR to the auto-load lists, update the MSR index in the > list entry if and only if a new entry is being inserted, as 'i' can only > be non-negative if vmx_find_loadstore_msr_slot() found an entry with the > MSR's index. Unnecessarily setting the index is benign, but it makes it > harder to see that updating the value is necessary even when an existing > entry for the MSR was found. > > No functional change intended. > > Signed-off-by: Sean Christopherson > --- > arch/x86/kvm/vmx/vmx.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c > index 2c50ebf4ff1b..be2a2580e8f1 100644 > --- a/arch/x86/kvm/vmx/vmx.c > +++ b/arch/x86/kvm/vmx/vmx.c > @@ -1141,16 +1141,16 @@ static void add_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr, > > if (i < 0) { > i = m->guest.nr++; > + m->guest.val[i].index = msr; > vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, m->guest.nr); > } > - m->guest.val[i].index = msr; > m->guest.val[i].value = guest_val; > > if (j < 0) { > j = m->host.nr++; > + m->host.val[j].index = msr; > vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, m->host.nr); > } > - m->host.val[j].index = msr; > m->host.val[j].value = host_val; > } > Reviewed-by: Dapeng Mi