From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.15]) (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 95A503597E; Wed, 16 Jul 2025 05:07:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.15 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752642480; cv=none; b=q5GIL0RNI0zf6Ut3IA55H4KiwbwzztT6R2Z2dsp1Re5TBfI2K92BdBFqwnHg7d4+gHNTvOKQGk5hfUeEUpDSzm0g+6lRgk6pwZqq+f1SMgUjZbL39W8mkQgZCQCFYe5y8UqJQVCG1O2nWug8Qlv7qD31HQJp7ScTdu9DU5JCZow= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752642480; c=relaxed/simple; bh=QMCcgS8H6b0NTyUy16oi1nPFHtz7ibymTuYgq5x4YN8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=XtQr7+CBqD6KgfLJZ6kgFbNi0q9pFxYJqqpdBqVPaLsh8POKFCA6zhuzWf4MFUwTkkNalLMidoRZjM1MuCCd5bYRi9C3mYL88kiYftQrV7OElRGYeoK7MtU7guNxaf4xGn2PXrFW/6nRrbjhsnuTjaObnXIwPJGKMEUyDeplE28= 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=jM1EtteE; arc=none smtp.client-ip=192.198.163.15 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="jM1EtteE" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1752642479; x=1784178479; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=QMCcgS8H6b0NTyUy16oi1nPFHtz7ibymTuYgq5x4YN8=; b=jM1EtteEzY1kUERXKxWzh9JLBzjQl0+Df2Cy76CEFstoRjP/SaxbFSSv ori2/W9mbRgwyUwDGy/DIdh6dmcEYFj772Zw+/PScJH8O1g5xExbx4VV6 4Ev/ddL/Fu5mAzZHMQpSUiK74YpbsrDFePO95bdBhs5USRJp6Vd53+3uY cSutS1PrNip55IqnBQctEnIroA9FnkQqTHz2lrnv5puDBHWXxJwKL4Qrd T6jzV/pWK1wJJNFPlvg9AuqsBkD/pQM3ncx8+tbHkoIz5JUwwS47hnNYA dWVCIS920Cu78BK2QlIItaUMDjRgZq+G9iqoT/XXB4KQP7Wa4OJXIpG5f A==; X-CSE-ConnectionGUID: pww3+7DITD+g0E2rlJ7Pvg== X-CSE-MsgGUID: EgkvVJuKTPaUbFZxc0DSvQ== X-IronPort-AV: E=McAfee;i="6800,10657,11493"; a="55026216" X-IronPort-AV: E=Sophos;i="6.16,315,1744095600"; d="scan'208";a="55026216" Received: from fmviesa001.fm.intel.com ([10.60.135.141]) by fmvoesa109.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Jul 2025 22:07:57 -0700 X-CSE-ConnectionGUID: 42ThZuFZT06jHaEFVlQWfw== X-CSE-MsgGUID: /IlBCgamRSmR6+bWLAGcGg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.16,315,1744095600"; d="scan'208";a="188408979" Received: from xiaoyaol-hp-g830.ccr.corp.intel.com (HELO [10.124.247.1]) ([10.124.247.1]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Jul 2025 22:07:43 -0700 Message-ID: <83d124c1-2d1d-4ba4-a72b-82a008a97301@intel.com> Date: Wed, 16 Jul 2025 13:07:38 +0800 Precedence: bulk X-Mailing-List: linux-arm-msm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v14 03/21] KVM: Introduce kvm_arch_supports_gmem() To: Fuad Tabba , kvm@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-mm@kvack.org, kvmarm@lists.linux.dev Cc: pbonzini@redhat.com, chenhuacai@kernel.org, mpe@ellerman.id.au, anup@brainfault.org, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, seanjc@google.com, viro@zeniv.linux.org.uk, brauner@kernel.org, willy@infradead.org, akpm@linux-foundation.org, yilun.xu@intel.com, chao.p.peng@linux.intel.com, jarkko@kernel.org, amoorthy@google.com, dmatlack@google.com, isaku.yamahata@intel.com, mic@digikod.net, vbabka@suse.cz, vannapurve@google.com, ackerleytng@google.com, mail@maciej.szmigiero.name, david@redhat.com, michael.roth@amd.com, wei.w.wang@intel.com, liam.merwick@oracle.com, isaku.yamahata@gmail.com, kirill.shutemov@linux.intel.com, suzuki.poulose@arm.com, steven.price@arm.com, quic_eberman@quicinc.com, quic_mnalajal@quicinc.com, quic_tsoni@quicinc.com, quic_svaddagi@quicinc.com, quic_cvanscha@quicinc.com, quic_pderrin@quicinc.com, quic_pheragu@quicinc.com, catalin.marinas@arm.com, james.morse@arm.com, yuzenghui@huawei.com, oliver.upton@linux.dev, maz@kernel.org, will@kernel.org, qperret@google.com, keirf@google.com, roypat@amazon.co.uk, shuah@kernel.org, hch@infradead.org, jgg@nvidia.com, rientjes@google.com, jhubbard@nvidia.com, fvdl@google.com, hughd@google.com, jthoughton@google.com, peterx@redhat.com, pankaj.gupta@amd.com, ira.weiny@intel.com References: <20250715093350.2584932-1-tabba@google.com> <20250715093350.2584932-4-tabba@google.com> Content-Language: en-US From: Xiaoyao Li In-Reply-To: <20250715093350.2584932-4-tabba@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 7/15/2025 5:33 PM, Fuad Tabba wrote: > Introduce kvm_arch_supports_gmem() to explicitly indicate whether an > architecture supports guest_memfd. > > Previously, kvm_arch_has_private_mem() was used to check for guest_memfd > support. However, this conflated guest_memfd with "private" memory, > implying that guest_memfd was exclusively for CoCo VMs or other private > memory use cases. > > With the expansion of guest_memfd to support non-private memory, such as > shared host mappings, it is necessary to decouple these concepts. The > new kvm_arch_supports_gmem() function provides a clear way to check for > guest_memfd support. > > Reviewed-by: Ira Weiny > Reviewed-by: Gavin Shan > Reviewed-by: Shivank Garg > Reviewed-by: Vlastimil Babka > Co-developed-by: David Hildenbrand > Signed-off-by: David Hildenbrand > Signed-off-by: Fuad Tabba > --- > arch/x86/include/asm/kvm_host.h | 4 +++- > include/linux/kvm_host.h | 11 +++++++++++ > virt/kvm/kvm_main.c | 4 ++-- > 3 files changed, 16 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index acb25f935d84..bde811b2d303 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -2277,8 +2277,10 @@ void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level, > > #ifdef CONFIG_KVM_GMEM > #define kvm_arch_has_private_mem(kvm) ((kvm)->arch.has_private_mem) > +#define kvm_arch_supports_gmem(kvm) kvm_arch_has_private_mem(kvm) > #else > #define kvm_arch_has_private_mem(kvm) false > +#define kvm_arch_supports_gmem(kvm) false > #endif > > #define kvm_arch_has_readonly_mem(kvm) (!(kvm)->arch.has_protected_state) > @@ -2331,7 +2333,7 @@ enum { > #define HF_SMM_INSIDE_NMI_MASK (1 << 2) > > # define KVM_MAX_NR_ADDRESS_SPACES 2 > -/* SMM is currently unsupported for guests with private memory. */ > +/* SMM is currently unsupported for guests with guest_memfd private memory. */ Please don't change the comment. As below, it checks kvm_arch_has_private_mem(). Nothing to do with guest_memfd. Otherwise, Reviewed-by: Xiaoyao Li > # define kvm_arch_nr_memslot_as_ids(kvm) (kvm_arch_has_private_mem(kvm) ? 1 : 2) > # define kvm_arch_vcpu_memslots_id(vcpu) ((vcpu)->arch.hflags & HF_SMM_MASK ? 1 : 0) > # define kvm_memslots_for_spte_role(kvm, role) __kvm_memslots(kvm, (role).smm)