From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.11]) (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 BC8853B14BA for ; Wed, 12 Aug 2026 08:23:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786523035; cv=none; b=IKIgW6jq5678ZdZGql55IrT/aUrcwZxP1QYzLv+Eb1XI3m9twtjvayMQlTdB3Iwu3SYS9G1/cXa0J2bZu6vSL8FFqGx4Re/+468Pwax7wb5CO+HifgWCe0CLFh7tHWpsRQJXMXd0lEDp1IDkjoWy9lEFXlwPEcQGKjk1Ys6HUkw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786523035; c=relaxed/simple; bh=W+jcq+2Wzamwh76nz0OcGlGI0ou5c5gwJ2B1PP/p9zc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=HwreTf6X3VTtVSMbiKMaQyYHoqBZvaCQhr0lTYgrsiMzaTpgXJrMEyetoEyjPiUKOjkAUxs+0we3MYyH2rw7tuFPnuZHn5uqXvAi9oa9teoHkjbnp5LZhDhK51BBbcyRx7O1Sz8BBpRGqLmp3SFZOwyLuDq4i4CEnowhhzyzeDQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=iwAyO77L; arc=none smtp.client-ip=198.175.65.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="iwAyO77L" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1786523034; x=1818059034; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=W+jcq+2Wzamwh76nz0OcGlGI0ou5c5gwJ2B1PP/p9zc=; b=iwAyO77Lo6lBb6+g4b2tI7LUg2VT6cotOs2bWrp4VmWDIAASSOMBrT5U qIIRuv+/SQNvzUU4ihHx+QN4SjUC/jm9ZCNtdtCB2tA5/yFTdJVeiGZyh xC48v+DpXl2gAZ3fEM0goc2rFtVeSyyY9rV0zci2ydjsglRLjtdaTnSNj HLK7z3qVSICsRWxGL25m5oZN0eZ2LWj2ifw3CIeV2IfwiXX6zwPYIVcqS ussQYa9GvThMdSsKLsPJNvthSMhyDMan40zsS1b4ijc6EEerosC0hNyoQ 42bMXuxtOzhcmIH6ZWnKlE4KRMoM/s66C9oL+c9QD7TX8P95O4do4R5Zq w==; X-CSE-ConnectionGUID: ZI8EHYzbQI+g7mhrU8RNfw== X-CSE-MsgGUID: oEdWN1ZlQj6WgcOn6018vw== X-IronPort-AV: E=McAfee;i="6800,10657,11872"; a="97414849" X-IronPort-AV: E=Sophos;i="6.25,219,1779174000"; d="scan'208";a="97414849" Received: from fmviesa009.fm.intel.com ([10.60.135.149]) by orvoesa103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Aug 2026 01:23:53 -0700 X-CSE-ConnectionGUID: BVDpwXjLQ5mrX6YTBE6jjA== X-CSE-MsgGUID: wd0espIgTjCF/EZNhS5SlA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,219,1779174000"; d="scan'208";a="257380624" Received: from unknown (HELO [10.238.208.98]) ([10.238.208.98]) by fmviesa009-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Aug 2026 01:23:34 -0700 Message-ID: <2f68b143-f3e1-48b7-8666-52072249e0be@intel.com> Date: Wed, 12 Aug 2026 16:23:31 +0800 Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v10 04/41] KVM: Enumerate support for PRIVATE memory iff kvm_arch_has_private_mem is defined To: ackerleytng@google.com, aik@amd.com, andrew.jones@linux.dev, binbin.wu@linux.intel.com, brauner@kernel.org, chao.p.peng@linux.intel.com, david@kernel.org, jmattson@google.com, jthoughton@google.com, michael.roth@amd.com, oupton@kernel.org, pankaj.gupta@amd.com, qperret@google.com, rick.p.edgecombe@intel.com, rientjes@google.com, shivankg@amd.com, steven.price@arm.com, tabba@google.com, willy@infradead.org, wyihan@google.com, yan.y.zhao@intel.com, forkloop@google.com, pratyush@kernel.org, suzuki.poulose@arm.com, aneesh.kumar@kernel.org, liam@infradead.org, Paolo Bonzini , Sean Christopherson , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Jonathan Corbet , Shuah Khan , Shuah Khan , Vishal Annapurve , Andrew Morton , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Youngjun Park , Qi Zheng , Shakeel Butt , Kiryl Shutsemau , Baoquan He , Jason Gunthorpe , John Hubbard , Peter Xu , tarunsahu@google.com, Vlastimil Babka Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev References: <20260807-gmem-inplace-conversion-v10-0-2fc18ee6d3ba@google.com> <20260807-gmem-inplace-conversion-v10-4-2fc18ee6d3ba@google.com> Content-Language: en-US From: Xiaoyao Li In-Reply-To: <20260807-gmem-inplace-conversion-v10-4-2fc18ee6d3ba@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 8/8/2026 5:52 AM, Ackerley Tng via B4 Relay wrote: > From: Sean Christopherson > > Explicitly guard reporting support for KVM_MEMORY_ATTRIBUTE_PRIVATE based > on kvm_arch_has_private_mem being #defined in anticipation of tracking > PRIVATE vs. SHARED state per-guest_memfd, not per-VM (to allow in-place > conversion). > > guest_memfd support for memory attributes is expected to be unconditional > to avoid yet more macros (all architectures that support guest_memfd are > expected to use per-gmem attributes at some point), at which point > enumerating support KVM_MEMORY_ATTRIBUTE_PRIVATE based solely on memory > attributes being supported by KVM at-large would result in a system-scope > check (NULL @kvm) over-reporting support on arm64. > > Give architectures full control over overriding the default definition of > kvm_arch_has_private_mem() by removing the coupling with > CONFIG_KVM_VM_MEMORY_ATTRIBUTES. > > In a later patch, kvm_arch_has_private_mem() will be defined based on > whether architectural features are compiled in, and made orthogonal to > CONFIG_KVM_VM_MEMORY_ATTRIBUTES. > > Signed-off-by: Sean Christopherson > Reviewed-by: Fuad Tabba > Reviewed-by: Binbin Wu > Tested-by: Shivank Garg > Signed-off-by: Ackerley Tng Reviewed-by: Xiaoyao Li > --- > include/linux/kvm_host.h | 2 +- > virt/kvm/kvm_main.c | 2 ++ > 2 files changed, 3 insertions(+), 1 deletion(-) > > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h > index 3e86cdd00e59b..e3666d0b40b74 100644 > --- a/include/linux/kvm_host.h > +++ b/include/linux/kvm_host.h > @@ -722,7 +722,7 @@ static inline int kvm_arch_vcpu_memslots_id(struct kvm_vcpu *vcpu) > } > #endif > > -#ifndef CONFIG_KVM_VM_MEMORY_ATTRIBUTES > +#ifndef kvm_arch_has_private_mem > static inline bool kvm_arch_has_private_mem(struct kvm *kvm) > { > return false; > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index e3a77d1e6d8ae..560ff05e95959 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -2422,8 +2422,10 @@ static int kvm_vm_ioctl_clear_dirty_log(struct kvm *kvm, > #ifdef CONFIG_KVM_VM_MEMORY_ATTRIBUTES > static u64 kvm_supported_mem_attributes(struct kvm *kvm) > { > +#ifdef kvm_arch_has_private_mem > if (!kvm || kvm_arch_has_private_mem(kvm)) > return KVM_MEMORY_ATTRIBUTE_PRIVATE; > +#endif > > return 0; > } >