From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ed1-f74.google.com (mail-ed1-f74.google.com [209.85.208.74]) (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 68773348C7D for ; Mon, 22 Jun 2026 18:49:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782154151; cv=none; b=g0N5CzQLFNdzI2h9VtqtOUo1GYYRZGSL91A3bgTQd6LJgUqTpyIgFwDaD3uwpCzTXATmLgdtw8xgR7yfj5hEjXm/jsn++NS8ur/jHzQ5aqgP4dESSK96/fRqTH1Pvq2s+t5S6M+L2xeNaOIRdz7esVf6cwbZqPUaYMs9uD4yFaI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782154151; c=relaxed/simple; bh=eSsWjg7+Xo0AyadgQytCuqK0tjsGOi6I8g06Sl8yFn4=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=VArLLvlJrZ4Cmj3oM/8BbifulPxe5ucm1JHtEZIxG3pzQpVj8Kke01jfnvBw6LNGEY0EhuKIdgsEWV+314N9NusrPBPwe6JQt+jI+pRFwR+fghLXY8/VVNWgGzxtFaqgJAR5v/3Q3x8mHkxKgCqznG8NdZXwlqZ0NvsylieCMWs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--tarunsahu.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=WNEHDTJF; arc=none smtp.client-ip=209.85.208.74 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--tarunsahu.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="WNEHDTJF" Received: by mail-ed1-f74.google.com with SMTP id 4fb4d7f45d1cf-6960fb32b73so4305992a12.3 for ; Mon, 22 Jun 2026 11:49:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1782154146; x=1782758946; 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=vrCK2iLTFuPkCKKXsEtILhMjhO8cYkJcRVq4TpiCh/Y=; b=WNEHDTJFRR+c8NsWPLxQ2QcGrI1YuQpKfqoZi8ml5Iqsn7oGqu6f6mVBgJfhuM4xtB OD7RATSFTmdsCde4ycwQcIU2R4LirjnkvpLSoFy9gQI9XiQ3jSvKPc1jPputg6SL4Ifv 1c7SvNBBW/3P3XONzjwQvGiNqqt77CvnN1gsPf1rrLZqyCCUgbAVMmZg6tkz0tBHIhh1 LfdtvjDGx5wstoNGR1XcAfFoUyR2Ena9qi6ToDYY7wDbffPKQmdLt9njkAoSqSU2p7q6 Nfh2h6mBiYlEoKci8JGvyoY73sgyYnhuyFJ+d772lhIq1XMXEnGR+VfrjJrKnUMczi8J b2tQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782154146; x=1782758946; 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=vrCK2iLTFuPkCKKXsEtILhMjhO8cYkJcRVq4TpiCh/Y=; b=X0hECE5aDUbhc4zr6HEiFUsPvOj6hRXFYEZasgdxrRmyvoFQlZpN7tUnlPgrI+yqOX pQ1Vxc4eihqrek9hzWcNjrySzgiWvuJLCW9ajmxetMZTgpYzBCoGAB01QenY6nfe3+AY m32Sf925Zwa4k/lPpMEjJ7ylLBXOcv0FmfjBFrW0rWgcOULlcSK7ZkfVcL9IE6+I5eos xsOh6b592HukeFaHAOjlwiqoPBynXH6wiWv79q4YHWxh4aRpDm/OkyL4UdffeV7sNf+x ZjWDrRvgilyi9PUx6NfkeJAVpkn5/CTNId5POHIXij9VVzkv3lw4bgyttck08CP1MpyR Nn2Q== X-Forwarded-Encrypted: i=1; AFNElJ9ApIlVvAUDSBiNntat+AP+SzbdAy5f4a5i9rESAXEX7vbYH0YxzOHLo6AwoUFb+DB68B4gZM7RTrs=@vger.kernel.org X-Gm-Message-State: AOJu0YxDAhxJ1n9n8JLvLlpJYuXqYlBCG1JjmiuTsSnyyGJSydvcwyUY LLJeBo5pS5uWLoCF4XmIHFlZpViYXKi6twjSdaPuGMlzCTO79TLLyRN6xQfl32nIexvPBaWb+vi mS0+hN4b6ct3Ytj5pKA== X-Received: from edsl17.prod.google.com ([2002:aa7:d951:0:b0:695:f6a4:adb4]) (user=tarunsahu job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6402:35ca:b0:697:bd1d:116d with SMTP id 4fb4d7f45d1cf-697bd1d14acmr2221698a12.27.1782154145133; Mon, 22 Jun 2026 11:49:05 -0700 (PDT) Date: Mon, 22 Jun 2026 18:48:46 +0000 In-Reply-To: <20260622184851.2309827-1-tarunsahu@google.com> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260622184851.2309827-1-tarunsahu@google.com> X-Mailer: git-send-email 2.55.0.rc0.786.g65d90a0328-goog Message-ID: <20260622184851.2309827-5-tarunsahu@google.com> Subject: [PATCH v3 4/9] kvm: guest_memfd: Move internal definitions and helper to new header From: Tarun Sahu To: Jonathan Corbet , Mike Rapoport , Paolo Bonzini , Alexander Graf , Shuah Khan , Pratyush Yadav , Tarun Sahu , Pasha Tatashin Cc: kvm@vger.kernel.org, linux-mm@kvack.org, kexec@lists.infradead.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" To support guest_memfd memory preservation with LUO, guest_memfd luo code needs to access guest_memfd internals and reconstruct guest_memfd file instances from a preserved state. Extract gmem_file, gmem_inode, and the GMEM_I() helper from guest_memfd.c into a new internal header virt/kvm/guest_memfd.h. Additionally, split __kvm_gmem_create() to expose a non-static __kvm_gmem_create_file() helper. This helper returns a struct file instead of a file descriptor, enabling file creation and initialization without installing it into a file descriptor table. Signed-off-by: Tarun Sahu --- virt/kvm/guest_memfd.c | 68 +++++++++++++++++------------------------- virt/kvm/guest_memfd.h | 39 ++++++++++++++++++++++++ 2 files changed, 67 insertions(+), 40 deletions(-) create mode 100644 virt/kvm/guest_memfd.h diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c index 8669068..fe1adc9b 100644 --- a/virt/kvm/guest_memfd.c +++ b/virt/kvm/guest_memfd.c @@ -7,38 +7,12 @@ #include #include #include +#include "guest_memfd.h" #include "kvm_mm.h" static struct vfsmount *kvm_gmem_mnt; -/* - * 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, and 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 assets - * specific to its associated VM, e.g. memslots=>gmem bindings. - */ -struct gmem_file { - struct kvm *kvm; - struct xarray bindings; - struct list_head entry; -}; - -struct gmem_inode { - struct shared_policy policy; - struct inode vfs_inode; - struct list_head gmem_file_list; - - u64 flags; -}; - -static __always_inline struct gmem_inode *GMEM_I(struct inode *inode) -{ - return container_of(inode, struct gmem_inode, vfs_inode); -} #define kvm_gmem_for_each_file(f, inode) \ list_for_each_entry(f, &GMEM_I(inode)->gmem_file_list, entry) @@ -557,23 +531,17 @@ bool __weak kvm_arch_supports_gmem_init_shared(struct kvm *kvm) return true; } -static int __kvm_gmem_create(struct kvm *kvm, loff_t size, u64 flags) +struct file *__kvm_gmem_create_file(struct kvm *kvm, loff_t size, u64 flags) { static const char *name = "[kvm-gmem]"; struct gmem_file *f; struct inode *inode; struct file *file; - int fd, err; - - fd = get_unused_fd_flags(0); - if (fd < 0) - return fd; + int err; f = kzalloc_obj(*f); - if (!f) { - err = -ENOMEM; - goto err_fd; - } + if (!f) + return ERR_PTR(-ENOMEM); /* __fput() will take care of fops_put(). */ if (!fops_get(&kvm_gmem_fops)) { @@ -612,8 +580,7 @@ static int __kvm_gmem_create(struct kvm *kvm, loff_t size, u64 flags) xa_init(&f->bindings); list_add(&f->entry, &GMEM_I(inode)->gmem_file_list); - fd_install(fd, file); - return fd; + return file; err_inode: iput(inode); @@ -621,7 +588,28 @@ static int __kvm_gmem_create(struct kvm *kvm, loff_t size, u64 flags) fops_put(&kvm_gmem_fops); err_gmem: kfree(f); -err_fd: + return ERR_PTR(err); +} + +static int __kvm_gmem_create(struct kvm *kvm, loff_t size, u64 flags) +{ + struct file *file; + int fd, err; + + fd = get_unused_fd_flags(0); + if (fd < 0) + return fd; + + file = __kvm_gmem_create_file(kvm, size, flags); + if (IS_ERR(file)) { + err = PTR_ERR(file); + goto err_put_fd; + } + + fd_install(fd, file); + return fd; + +err_put_fd: put_unused_fd(fd); return err; } diff --git a/virt/kvm/guest_memfd.h b/virt/kvm/guest_memfd.h new file mode 100644 index 0000000..c528b04 --- /dev/null +++ b/virt/kvm/guest_memfd.h @@ -0,0 +1,39 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef __KVM_GUEST_MEMFD_H__ +#define __KVM_GUEST_MEMFD_H__ 1 + +#include +#include +#include + +/* + * 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, and 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 assets + * specific to its associated VM, e.g. memslots=>gmem bindings. + */ +struct gmem_file { + struct kvm *kvm; + struct xarray bindings; + struct list_head entry; +}; + +struct gmem_inode { + struct shared_policy policy; + struct inode vfs_inode; + struct list_head gmem_file_list; + + u64 flags; +}; + +static inline struct gmem_inode *GMEM_I(struct inode *inode) +{ + return container_of(inode, struct gmem_inode, vfs_inode); +} + +struct file *__kvm_gmem_create_file(struct kvm *kvm, loff_t size, u64 flags); + +#endif /* __KVM_GUEST_MEMFD_H__ */ -- 2.55.0.rc0.786.g65d90a0328-goog