From nobody Sun Feb 8 05:07:55 2026 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 69D60387564; Tue, 20 Jan 2026 06:43:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768891430; cv=none; b=RXVaPxqKrFa67B0z5JSXglbU0xrAP1ChzPFyowW4NilgqMTRD7+IUy7fpRdQN8Szbl6VOCLlpRQX0fK7BKsw9uEzjSFIsjPtKz8WqgaatlAb2vzRHOzxFEPUv5cDOX7LokjiSit3gATkSXzHwz+q4P/utOMcM8OMI7mDEwiWIUQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768891430; c=relaxed/simple; bh=5lHBBMfqPqoiY8Jb5i1UmMDSCU6QId/cFabKNEhXapA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=B9brgOlpVwpaJUVBfo7OwNJR7EzIEaFSujNcmhnFD7zv3tSmn6/gBhV1Ew1XvTHRSS4WVYLND8mY+AakwjYF/fVKNGMIsWwyGp1ugrHBpf/yyTIJ9cqGO7KJub1cBsJP2mb8ilr9XTnxv/v3MfVqxuiq933vaZsYywYdOKvQXJg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=XooknD8V; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="XooknD8V" Received: from mrdev.corp.microsoft.com (192-184-212-33.fiber.dynamic.sonic.net [192.184.212.33]) by linux.microsoft.com (Postfix) with ESMTPSA id F3B4F20B7170; Mon, 19 Jan 2026 22:43:34 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com F3B4F20B7170 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1768891415; bh=zpXyH34CFeKZeTaTWBElXlgUbMpP958BejYtbygF9WU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XooknD8V3y1L7GC5cut7FI2hLyVvn6UK2r3zNP70pOOrJOGkL2XgdHyUFQhkvqH+s a2RAD3LH4gUbnfx4u/9xJnauVpk+rbZvmVon1tdkvwqWrzcIdMVTfcOr9i82ENiIG+ 9hTmsE68dqA36HuiiMpMrCAkEEFwOF3W1KpplTro= From: Mukesh R To: linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-arm-kernel@lists.infradead.org, iommu@lists.linux.dev, linux-pci@vger.kernel.org, linux-arch@vger.kernel.org Cc: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, longli@microsoft.com, catalin.marinas@arm.com, will@kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, joro@8bytes.org, lpieralisi@kernel.org, kwilczynski@kernel.org, mani@kernel.org, robh@kernel.org, bhelgaas@google.com, arnd@arndb.de, nunodasneves@linux.microsoft.com, mhklinux@outlook.com, romank@linux.microsoft.com Subject: [PATCH v0 07/15] mshv: Add ioctl support for MSHV-VFIO bridge device Date: Mon, 19 Jan 2026 22:42:22 -0800 Message-ID: <20260120064230.3602565-8-mrathor@linux.microsoft.com> X-Mailer: git-send-email 2.51.2.vfs.0.1 In-Reply-To: <20260120064230.3602565-1-mrathor@linux.microsoft.com> References: <20260120064230.3602565-1-mrathor@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Mukesh Rathor Add ioctl support for creating MSHV devices for a paritition. At present only VFIO device types are supported, but more could be added. At a high level, a partition ioctl to create device verifies it is of type VFIO and does some setup for bridge code in mshv_vfio.c. Adapted from KVM device ioctls. Credits: Original author: Wei Liu NB: Slightly modified from the original version. Signed-off-by: Mukesh Rathor --- drivers/hv/mshv_root_main.c | 126 ++++++++++++++++++++++++++++++++++++ 1 file changed, 126 insertions(+) diff --git a/drivers/hv/mshv_root_main.c b/drivers/hv/mshv_root_main.c index 83c7bad269a0..27313419828d 100644 --- a/drivers/hv/mshv_root_main.c +++ b/drivers/hv/mshv_root_main.c @@ -1551,6 +1551,129 @@ mshv_partition_ioctl_initialize(struct mshv_partiti= on *partition) return ret; } =20 +static long mshv_device_attr_ioctl(struct mshv_device *mshv_dev, int cmd, + ulong uarg) +{ + struct mshv_device_attr attr; + const struct mshv_device_ops *devops =3D mshv_dev->device_ops; + + if (copy_from_user(&attr, (void __user *)uarg, sizeof(attr))) + return -EFAULT; + + switch (cmd) { + case MSHV_SET_DEVICE_ATTR: + if (devops->device_set_attr) + return devops->device_set_attr(mshv_dev, &attr); + break; + case MSHV_HAS_DEVICE_ATTR: + if (devops->device_has_attr) + return devops->device_has_attr(mshv_dev, &attr); + break; + } + + return -EPERM; +} + +static long mshv_device_fop_ioctl(struct file *filp, unsigned int cmd, + ulong uarg) +{ + struct mshv_device *mshv_dev =3D filp->private_data; + + switch (cmd) { + case MSHV_SET_DEVICE_ATTR: + case MSHV_HAS_DEVICE_ATTR: + return mshv_device_attr_ioctl(mshv_dev, cmd, uarg); + } + + return -ENOTTY; +} + +static int mshv_device_fop_release(struct inode *inode, struct file *filp) +{ + struct mshv_device *mshv_dev =3D filp->private_data; + struct mshv_partition *partition =3D mshv_dev->device_pt; + + if (mshv_dev->device_ops->device_release) { + mutex_lock(&partition->pt_mutex); + hlist_del(&mshv_dev->device_ptnode); + mshv_dev->device_ops->device_release(mshv_dev); + mutex_unlock(&partition->pt_mutex); + } + + mshv_partition_put(partition); + return 0; +} + +static const struct file_operations mshv_device_fops =3D { + .owner =3D THIS_MODULE, + .unlocked_ioctl =3D mshv_device_fop_ioctl, + .release =3D mshv_device_fop_release, +}; + +long mshv_partition_ioctl_create_device(struct mshv_partition *partition, + void __user *uarg) +{ + long rc; + struct mshv_create_device devargk; + struct mshv_device *mshv_dev; + const struct mshv_device_ops *vfio_ops; + int type; + + if (copy_from_user(&devargk, uarg, sizeof(devargk))) { + rc =3D -EFAULT; + goto out; + } + + /* At present, only VFIO is supported */ + if (devargk.type !=3D MSHV_DEV_TYPE_VFIO) { + rc =3D -ENODEV; + goto out; + } + + if (devargk.flags & MSHV_CREATE_DEVICE_TEST) { + rc =3D 0; + goto out; + } + + mshv_dev =3D kzalloc(sizeof(*mshv_dev), GFP_KERNEL_ACCOUNT); + if (mshv_dev =3D=3D NULL) { + rc =3D -ENOMEM; + goto out; + } + + vfio_ops =3D &mshv_vfio_device_ops; + mshv_dev->device_ops =3D vfio_ops; + mshv_dev->device_pt =3D partition; + + rc =3D vfio_ops->device_create(mshv_dev, type); + if (rc < 0) { + kfree(mshv_dev); + goto out; + } + + hlist_add_head(&mshv_dev->device_ptnode, &partition->pt_devices); + + mshv_partition_get(partition); + rc =3D anon_inode_getfd(vfio_ops->device_name, &mshv_device_fops, + mshv_dev, O_RDWR | O_CLOEXEC); + if (rc < 0) { + mshv_partition_put(partition); + hlist_del(&mshv_dev->device_ptnode); + vfio_ops->device_release(mshv_dev); + goto out; + } + + devargk.fd =3D rc; + rc =3D 0; + + if (copy_to_user(uarg, &devargk, sizeof(devargk))) { + rc =3D -EFAULT; + goto out; + } +out: + return rc; +} + static long mshv_partition_ioctl(struct file *filp, unsigned int ioctl, unsigned long = arg) { @@ -1587,6 +1710,9 @@ mshv_partition_ioctl(struct file *filp, unsigned int = ioctl, unsigned long arg) case MSHV_ROOT_HVCALL: ret =3D mshv_ioctl_passthru_hvcall(partition, true, uarg); break; + case MSHV_CREATE_DEVICE: + ret =3D mshv_partition_ioctl_create_device(partition, uarg); + break; default: ret =3D -ENOTTY; } --=20 2.51.2.vfs.0.1