From nobody Mon Feb 9 02:27:16 2026 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (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 C6E2920E032 for ; Thu, 16 Oct 2025 17:30:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760635812; cv=none; b=d9fIF7fjL8kLVpzmb9xcD/NaFbo597QLemvbB4f/zZJKOL7pOrSBEJqrY/prwtSlRhHmgiOroXmhTq99e4r/4S2XY3pEbgQMjKtyrQSCzG124VDQi6KwdIiX4wE7KV4B24SSe+VInltrikVu6vUOewgMygUnN3eSJNoxg24MLHI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760635812; c=relaxed/simple; bh=itHMf3dOY7/pa7dZPvih/oiz3WtoZDKZziAtaSntews=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=l1tEGeCMnpbE18DwsRIJTrq9EI2NMsdHs9xc/PyrIzL9d7dlCz6W4Dd9gufQM6CeYKgbaJkyr3y18a4ajSVwkDbPBhkXddJF4T9tf3fTcZC1V9RswKXJJYXuCFpTDky4kVjb6zJtfAfB+2OvagmsQhNqNhMihqWLhHKDktOGbVE= 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=HNL2KZ4A; arc=none smtp.client-ip=209.85.216.74 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="HNL2KZ4A" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-33ba9047881so1480471a91.1 for ; Thu, 16 Oct 2025 10:30:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1760635810; x=1761240610; 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=KbValAQi3mVPkQeBnxJpdOpCqapDSSet7GA9qMeIyHY=; b=HNL2KZ4AOT9K71o2gYUKDXFit7lkZ80BQC7xCdfe+kvoKF8gg0FU/46nb7TGngVkjP njH8uDClKREohAbd9+nTj2+c2INp9w/DKg46L9upWm+QeN/7szO8uQK9d9VHQ7zz1exf aiOvOtcYKSXVcxMpCEvpYBoT/dl7ura7EfQwM75Dsxq11X3a172/Ae1srW33+AiD9/48 wwAofBkhE0mu/E1go8MPRbveOwlTwEK3oKSLMwnyQQhP4bpSg9OT1ktHICtFCoS3xm2x rnOWZbvFDLNpc99aGeOURvtiEKhzMD7aUrY4EVXTGsUZFWep1TvVK+uPsMOBCboey06G dR6A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1760635810; x=1761240610; 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=KbValAQi3mVPkQeBnxJpdOpCqapDSSet7GA9qMeIyHY=; b=gR6CXsyUlg4XZoBUWG7xu1IS/qz8xsqPRi3A699qTZChZ4YJce8F7vjhzDT7ZeXMhV HZM/yvDQUK0mCtvtL7djVAWyoB2XJbsf9SpXQrpqEptch1bLAVPgaPcM0ddEpNG2jDed Yai7oGbbv6/0WD4hkNo/TzcXZ3h30aDSNTe9ZA32FWi+rXAiovUYQuxp7bQTMmucU2oP TZu7cOsokVu6+JU/LWkYXDXR16KrKJrytRz+f0rMoNRSv4zEAl5/z1nDpQs3ERxsbpIM 7xKvp6P28RNfWRo0c1fTFmHbaseaeoBJMOAZTYbG7awdHrX/fJVHR0vyGwh5MG1PK1mW Lrcg== X-Forwarded-Encrypted: i=1; AJvYcCV+Wpe1wphAuWhIUESk3uR1Afa4HdME7fQ5N5o3rk5Hgoz2R19RQvY7RObhHVQ3ckrxXItJgtXpK1SdKqM=@vger.kernel.org X-Gm-Message-State: AOJu0YxlhYL0evzk2t2E1MUmaoHFtQy4e9fQlaYNEVLQ9pAW3kI8UTtt tdxq0zXdswrTYCVPaO3nPohLQI+5NE5iC/nxFvSIkaHQHvgT8Uebhk7MCZuUTfBi6OU0vuLbA49 OCvME9Q== X-Google-Smtp-Source: AGHT+IF8IBthLJ6j6SkHq4SrSxFmPl9P4miDt7bIY6TTq8tVebOV0t9zTlMTT00ono8S6O8EZ924QZsF6IQ= X-Received: from pjre3.prod.google.com ([2002:a17:90a:b383:b0:33b:51fe:1a75]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:1dc4:b0:32e:716d:4d2b with SMTP id 98e67ed59e1d1-33bc9b77638mr1287133a91.3.1760635810154; Thu, 16 Oct 2025 10:30:10 -0700 (PDT) Reply-To: Sean Christopherson Date: Thu, 16 Oct 2025 10:28:42 -0700 In-Reply-To: <20251016172853.52451-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20251016172853.52451-1-seanjc@google.com> X-Mailer: git-send-email 2.51.0.858.gf9c4a03a3a-goog Message-ID: <20251016172853.52451-2-seanjc@google.com> Subject: [PATCH v13 01/12] KVM: guest_memfd: Rename "struct kvm_gmem" to "struct gmem_file" From: Sean Christopherson To: Miguel Ojeda , Marc Zyngier , Oliver Upton , Paolo Bonzini , Sean Christopherson Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Ackerley Tng , Shivank Garg , David Hildenbrand , Fuad Tabba , Ashish Kalra , Vlastimil Babka Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Rename the "kvm_gmem" structure to "gmem_file" in anticipation of using dedicated guest_memfd inodes instead of anonyomous inodes, at which point the "kvm_gmem" nomenclature becomes quite misleading. In guest_memfd, inodes are effectively the raw underlying physical storage, and will be used to track properties of the physical memory, while each gmem file is effectively a single VM's view of that storage, and is used to track assets specific to its associated VM, e.g. memslots=3D>gmem bindings. Using "kvm_gmem" suggests that the per-VM/per-file structures are _the_ guest_memfd instance, which almost the exact opposite of reality. Opportunistically rename local variables from "gmem" to "f", again to avoid confusion once guest_memfd specific inodes come along. No functional change intended. Reviewed-by: Ackerley Tng Tested-by: Ackerley Tng Reviewed-by: Shivank Garg Signed-off-by: Sean Christopherson Tested-by: Shivank Garg --- virt/kvm/guest_memfd.c | 98 +++++++++++++++++++++++------------------- 1 file changed, 53 insertions(+), 45 deletions(-) diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c index 1e4af29159ea..2989c5fe426f 100644 --- a/virt/kvm/guest_memfd.c +++ b/virt/kvm/guest_memfd.c @@ -7,7 +7,16 @@ =20 #include "kvm_mm.h" =20 -struct kvm_gmem { +/* + * A guest_memfd instance can be associated multiple VMs, each with its own + * "view" of the underlying physical memory. + * + * The gmem's inode is effectively the raw underlying physical storage, an= d is + * used to track properties of the physical memory, while each gmem file is + * effectively a single VM's view of that storage, and is used to track as= sets + * specific to its associated VM, e.g. memslots=3D>gmem bindings. + */ +struct gmem_file { struct kvm *kvm; struct xarray bindings; struct list_head entry; @@ -115,16 +124,16 @@ static enum kvm_gfn_range_filter kvm_gmem_get_invalid= ate_filter(struct inode *in return KVM_FILTER_PRIVATE; } =20 -static void __kvm_gmem_invalidate_begin(struct kvm_gmem *gmem, pgoff_t sta= rt, +static void __kvm_gmem_invalidate_begin(struct gmem_file *f, pgoff_t start, pgoff_t end, enum kvm_gfn_range_filter attr_filter) { bool flush =3D false, found_memslot =3D false; struct kvm_memory_slot *slot; - struct kvm *kvm =3D gmem->kvm; + struct kvm *kvm =3D f->kvm; unsigned long index; =20 - xa_for_each_range(&gmem->bindings, index, slot, start, end - 1) { + xa_for_each_range(&f->bindings, index, slot, start, end - 1) { pgoff_t pgoff =3D slot->gmem.pgoff; =20 struct kvm_gfn_range gfn_range =3D { @@ -157,20 +166,20 @@ static void kvm_gmem_invalidate_begin(struct inode *i= node, pgoff_t start, { struct list_head *gmem_list =3D &inode->i_mapping->i_private_list; enum kvm_gfn_range_filter attr_filter; - struct kvm_gmem *gmem; + struct gmem_file *f; =20 attr_filter =3D kvm_gmem_get_invalidate_filter(inode); =20 - list_for_each_entry(gmem, gmem_list, entry) - __kvm_gmem_invalidate_begin(gmem, start, end, attr_filter); + list_for_each_entry(f, gmem_list, entry) + __kvm_gmem_invalidate_begin(f, start, end, attr_filter); } =20 -static void __kvm_gmem_invalidate_end(struct kvm_gmem *gmem, pgoff_t start, +static void __kvm_gmem_invalidate_end(struct gmem_file *f, pgoff_t start, pgoff_t end) { - struct kvm *kvm =3D gmem->kvm; + struct kvm *kvm =3D f->kvm; =20 - if (xa_find(&gmem->bindings, &start, end - 1, XA_PRESENT)) { + if (xa_find(&f->bindings, &start, end - 1, XA_PRESENT)) { KVM_MMU_LOCK(kvm); kvm_mmu_invalidate_end(kvm); KVM_MMU_UNLOCK(kvm); @@ -181,10 +190,10 @@ static void kvm_gmem_invalidate_end(struct inode *ino= de, pgoff_t start, pgoff_t end) { struct list_head *gmem_list =3D &inode->i_mapping->i_private_list; - struct kvm_gmem *gmem; + struct gmem_file *f; =20 - list_for_each_entry(gmem, gmem_list, entry) - __kvm_gmem_invalidate_end(gmem, start, end); + list_for_each_entry(f, gmem_list, entry) + __kvm_gmem_invalidate_end(f, start, end); } =20 static long kvm_gmem_punch_hole(struct inode *inode, loff_t offset, loff_t= len) @@ -282,9 +291,9 @@ static long kvm_gmem_fallocate(struct file *file, int m= ode, loff_t offset, =20 static int kvm_gmem_release(struct inode *inode, struct file *file) { - struct kvm_gmem *gmem =3D file->private_data; + struct gmem_file *f =3D file->private_data; struct kvm_memory_slot *slot; - struct kvm *kvm =3D gmem->kvm; + struct kvm *kvm =3D f->kvm; unsigned long index; =20 /* @@ -304,7 +313,7 @@ static int kvm_gmem_release(struct inode *inode, struct= file *file) =20 filemap_invalidate_lock(inode->i_mapping); =20 - xa_for_each(&gmem->bindings, index, slot) + xa_for_each(&f->bindings, index, slot) WRITE_ONCE(slot->gmem.file, NULL); =20 /* @@ -312,18 +321,18 @@ static int kvm_gmem_release(struct inode *inode, stru= ct file *file) * Zap all SPTEs pointed at by this file. Do not free the backing * memory, as its lifetime is associated with the inode, not the file. */ - __kvm_gmem_invalidate_begin(gmem, 0, -1ul, + __kvm_gmem_invalidate_begin(f, 0, -1ul, kvm_gmem_get_invalidate_filter(inode)); - __kvm_gmem_invalidate_end(gmem, 0, -1ul); + __kvm_gmem_invalidate_end(f, 0, -1ul); =20 - list_del(&gmem->entry); + list_del(&f->entry); =20 filemap_invalidate_unlock(inode->i_mapping); =20 mutex_unlock(&kvm->slots_lock); =20 - xa_destroy(&gmem->bindings); - kfree(gmem); + xa_destroy(&f->bindings); + kfree(f); =20 kvm_put_kvm(kvm); =20 @@ -491,7 +500,7 @@ bool __weak kvm_arch_supports_gmem_init_shared(struct k= vm *kvm) static int __kvm_gmem_create(struct kvm *kvm, loff_t size, u64 flags) { const char *anon_name =3D "[kvm-gmem]"; - struct kvm_gmem *gmem; + struct gmem_file *f; struct inode *inode; struct file *file; int fd, err; @@ -500,14 +509,13 @@ static int __kvm_gmem_create(struct kvm *kvm, loff_t = size, u64 flags) if (fd < 0) return fd; =20 - gmem =3D kzalloc(sizeof(*gmem), GFP_KERNEL); - if (!gmem) { + f =3D kzalloc(sizeof(*f), GFP_KERNEL); + if (!f) { err =3D -ENOMEM; goto err_fd; } =20 - file =3D anon_inode_create_getfile(anon_name, &kvm_gmem_fops, gmem, - O_RDWR, NULL); + file =3D anon_inode_create_getfile(anon_name, &kvm_gmem_fops, f, O_RDWR, = NULL); if (IS_ERR(file)) { err =3D PTR_ERR(file); goto err_gmem; @@ -529,15 +537,15 @@ static int __kvm_gmem_create(struct kvm *kvm, loff_t = size, u64 flags) WARN_ON_ONCE(!mapping_unevictable(inode->i_mapping)); =20 kvm_get_kvm(kvm); - gmem->kvm =3D kvm; - xa_init(&gmem->bindings); - list_add(&gmem->entry, &inode->i_mapping->i_private_list); + f->kvm =3D kvm; + xa_init(&f->bindings); + list_add(&f->entry, &inode->i_mapping->i_private_list); =20 fd_install(fd, file); return fd; =20 err_gmem: - kfree(gmem); + kfree(f); err_fd: put_unused_fd(fd); return err; @@ -562,7 +570,7 @@ int kvm_gmem_bind(struct kvm *kvm, struct kvm_memory_sl= ot *slot, { loff_t size =3D slot->npages << PAGE_SHIFT; unsigned long start, end; - struct kvm_gmem *gmem; + struct gmem_file *f; struct inode *inode; struct file *file; int r =3D -EINVAL; @@ -576,8 +584,8 @@ int kvm_gmem_bind(struct kvm *kvm, struct kvm_memory_sl= ot *slot, if (file->f_op !=3D &kvm_gmem_fops) goto err; =20 - gmem =3D file->private_data; - if (gmem->kvm !=3D kvm) + f =3D file->private_data; + if (f->kvm !=3D kvm) goto err; =20 inode =3D file_inode(file); @@ -591,8 +599,8 @@ int kvm_gmem_bind(struct kvm *kvm, struct kvm_memory_sl= ot *slot, start =3D offset >> PAGE_SHIFT; end =3D start + slot->npages; =20 - if (!xa_empty(&gmem->bindings) && - xa_find(&gmem->bindings, &start, end - 1, XA_PRESENT)) { + if (!xa_empty(&f->bindings) && + xa_find(&f->bindings, &start, end - 1, XA_PRESENT)) { filemap_invalidate_unlock(inode->i_mapping); goto err; } @@ -607,7 +615,7 @@ int kvm_gmem_bind(struct kvm *kvm, struct kvm_memory_sl= ot *slot, if (kvm_gmem_supports_mmap(inode)) slot->flags |=3D KVM_MEMSLOT_GMEM_ONLY; =20 - xa_store_range(&gmem->bindings, start, end - 1, slot, GFP_KERNEL); + xa_store_range(&f->bindings, start, end - 1, slot, GFP_KERNEL); filemap_invalidate_unlock(inode->i_mapping); =20 /* @@ -625,7 +633,7 @@ void kvm_gmem_unbind(struct kvm_memory_slot *slot) { unsigned long start =3D slot->gmem.pgoff; unsigned long end =3D start + slot->npages; - struct kvm_gmem *gmem; + struct gmem_file *f; struct file *file; =20 /* @@ -636,10 +644,10 @@ void kvm_gmem_unbind(struct kvm_memory_slot *slot) if (!file) return; =20 - gmem =3D file->private_data; + f =3D file->private_data; =20 filemap_invalidate_lock(file->f_mapping); - xa_store_range(&gmem->bindings, start, end - 1, NULL, GFP_KERNEL); + xa_store_range(&f->bindings, start, end - 1, NULL, GFP_KERNEL); =20 /* * synchronize_srcu(&kvm->srcu) ensured that kvm_gmem_get_pfn() @@ -657,17 +665,17 @@ static struct folio *__kvm_gmem_get_pfn(struct file *= file, pgoff_t index, kvm_pfn_t *pfn, bool *is_prepared, int *max_order) { - struct file *gmem_file =3D READ_ONCE(slot->gmem.file); - struct kvm_gmem *gmem =3D file->private_data; + struct file *slot_file =3D READ_ONCE(slot->gmem.file); + struct gmem_file *f =3D file->private_data; struct folio *folio; =20 - if (file !=3D gmem_file) { - WARN_ON_ONCE(gmem_file); + if (file !=3D slot_file) { + WARN_ON_ONCE(slot_file); return ERR_PTR(-EFAULT); } =20 - if (xa_load(&gmem->bindings, index) !=3D slot) { - WARN_ON_ONCE(xa_load(&gmem->bindings, index)); + if (xa_load(&f->bindings, index) !=3D slot) { + WARN_ON_ONCE(xa_load(&f->bindings, index)); return ERR_PTR(-EIO); } =20 --=20 2.51.0.858.gf9c4a03a3a-goog