From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E04DF2FB09A for ; Thu, 20 Nov 2025 22:33:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763678035; cv=none; b=dVfUmLDWtSHseV7/dl2ANNNuBoFhvl2H0wMElvnogbAF45YLfoE05aN82Q/XWeo/oJBVP1aMARDiS75MwEFAr5I0wqw3x3pBLMtu/kz+XOAVa1ubQevW6ZKsRWI0UDA88nPDNfKVe/wQzMwMKLG1AfH4A3s3t0rHsFYueQFqM5A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763678035; c=relaxed/simple; bh=pnsN1eWNLvBaN626N+uhslNofKWgHfrtxabNK2ZIO0Q=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=NsMyyUpaqff+zbEvUYIuwLq/0WfWl3zTDYjoCOw0I2+Pz52VqvoA3lt53RRJDeypBe5TPvU8NZOAYC/OsVqrLXjgEykWBhFw1TWxcN2y6mhoupwHYhw4PltgT2YFq3usItoGX6/V3dMFdzT+hLdDeSzWC9NL7iQd9sQWbm1Im9w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=A9DmDs0h; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="A9DmDs0h" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 28840C4CEF1; Thu, 20 Nov 2025 22:33:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1763678034; bh=pnsN1eWNLvBaN626N+uhslNofKWgHfrtxabNK2ZIO0Q=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=A9DmDs0hKFLVZXTdFee1VZUG5iD1oTlmF3AH1dr33EOd+rxNtfm3rblAUaNqSp2TU c6FppBPU+KC7SEPJiv/GaP4B7NzjWPNs5Vis/dj8pjY+gqDve7dAjd9La6C6R8Q2EB pVP/nRYKVCuk+cYyporpaVWeHin92xL8wE0T/rtPHeE6EexcW9Aez6W1bzwaarSt4j amiQau+5rFplTrkhpnY8Ypsr4s1jCtdQU6LGc8TUJmmYdLbEzqW+/LtmLAI8OjiKn/ Nc0cBuIzxaft78X+5a6vGcaDpJbdcpvBTjGhQY53Mm8qR3oCOKVEUH5ri78/ME6er/ 7MdHB0TVQ/iWg== From: Christian Brauner Date: Thu, 20 Nov 2025 23:32:44 +0100 Subject: [PATCH RFC v2 47/48] kvm: convert kvm_arch_supports_gmem_init_shared() to FD_PREPARE() Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20251120-work-fd-prepare-v2-47-fef6ebda05d3@kernel.org> References: <20251120-work-fd-prepare-v2-0-fef6ebda05d3@kernel.org> In-Reply-To: <20251120-work-fd-prepare-v2-0-fef6ebda05d3@kernel.org> To: Linus Torvalds , Jeff Layton , Amir Goldstein , Jens Axboe Cc: Alexander Viro , Jan Kara , linux-fsdevel@vger.kernel.org, Christian Brauner X-Mailer: b4 0.15-dev-a6db3 X-Developer-Signature: v=1; a=openpgp-sha256; l=2997; i=brauner@kernel.org; h=from:subject:message-id; bh=pnsN1eWNLvBaN626N+uhslNofKWgHfrtxabNK2ZIO0Q=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWTKT3vfsG+n5BuT9k8/g7PNZOIsfp2UEMupWZmx9PdGH 3dhIekzHaUsDGJcDLJiiiwO7Sbhcst5KjYbZWrAzGFlAhnCwMUpABORnMrwP+iWbPDaD+7LTi3K elK1UHoep6rr/mdcd25Ol9Eqy2a0OsTI0Mlj02L1cQ//y1SWtx3Mx0PjjgS9nG+6bWF06GRBGbZ 5XAA= X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Signed-off-by: Christian Brauner --- virt/kvm/guest_memfd.c | 81 ++++++++++++++++++++++---------------------------- 1 file changed, 35 insertions(+), 46 deletions(-) diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c index fbca8c0972da..c536423424ef 100644 --- a/virt/kvm/guest_memfd.c +++ b/virt/kvm/guest_memfd.c @@ -493,56 +493,45 @@ bool __weak kvm_arch_supports_gmem_init_shared(struct kvm *kvm) static int __kvm_gmem_create(struct kvm *kvm, loff_t size, u64 flags) { const char *anon_name = "[kvm-gmem]"; - struct kvm_gmem *gmem; + struct kvm_gmem *gmem __free(kfree) = NULL; struct inode *inode; - struct file *file; - int fd, err; - - fd = get_unused_fd_flags(0); - if (fd < 0) - return fd; gmem = kzalloc(sizeof(*gmem), GFP_KERNEL); - if (!gmem) { - err = -ENOMEM; - goto err_fd; + if (!gmem) + return -ENOMEM; + + FD_PREPARE(fdf, 0, anon_inode_create_getfile(anon_name, &kvm_gmem_fops, + gmem, O_RDWR, NULL)) { + struct file *file; + + if (fd_prepare_failed(fdf)) + return fd_prepare_error(fdf); + + file = fd_prepare_file(fdf); + file->f_flags |= O_LARGEFILE; + + inode = file->f_inode; + WARN_ON(file->f_mapping != inode->i_mapping); + + inode->i_private = (void *)(unsigned long)flags; + inode->i_op = &kvm_gmem_iops; + inode->i_mapping->a_ops = &kvm_gmem_aops; + inode->i_mode |= S_IFREG; + inode->i_size = size; + mapping_set_gfp_mask(inode->i_mapping, GFP_HIGHUSER); + mapping_set_inaccessible(inode->i_mapping); + /* Unmovable mappings are supposed to be marked unevictable as well. */ + WARN_ON_ONCE(!mapping_unevictable(inode->i_mapping)); + + kvm_get_kvm(kvm); + gmem->kvm = kvm; + xa_init(&gmem->bindings); + list_add(&gmem->entry, &inode->i_mapping->i_private_list); + + /* Ownership of gmem transferred to file */ + retain_and_null_ptr(gmem); + return fd_publish(fdf); } - - file = anon_inode_create_getfile(anon_name, &kvm_gmem_fops, gmem, - O_RDWR, NULL); - if (IS_ERR(file)) { - err = PTR_ERR(file); - goto err_gmem; - } - - file->f_flags |= O_LARGEFILE; - - inode = file->f_inode; - WARN_ON(file->f_mapping != inode->i_mapping); - - inode->i_private = (void *)(unsigned long)flags; - inode->i_op = &kvm_gmem_iops; - inode->i_mapping->a_ops = &kvm_gmem_aops; - inode->i_mode |= S_IFREG; - inode->i_size = size; - mapping_set_gfp_mask(inode->i_mapping, GFP_HIGHUSER); - mapping_set_inaccessible(inode->i_mapping); - /* Unmovable mappings are supposed to be marked unevictable as well. */ - WARN_ON_ONCE(!mapping_unevictable(inode->i_mapping)); - - kvm_get_kvm(kvm); - gmem->kvm = kvm; - xa_init(&gmem->bindings); - list_add(&gmem->entry, &inode->i_mapping->i_private_list); - - fd_install(fd, file); - return fd; - -err_gmem: - kfree(gmem); -err_fd: - put_unused_fd(fd); - return err; } int kvm_gmem_create(struct kvm *kvm, struct kvm_create_guest_memfd *args) -- 2.47.3