From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B96F3C4332F for ; Thu, 17 Feb 2022 12:40:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231514AbiBQMlH (ORCPT ); Thu, 17 Feb 2022 07:41:07 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:57264 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240488AbiBQMlG (ORCPT ); Thu, 17 Feb 2022 07:41:06 -0500 X-Greylist: delayed 451 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Thu, 17 Feb 2022 04:40:52 PST Received: from wnew2-smtp.messagingengine.com (wnew2-smtp.messagingengine.com [64.147.123.27]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6B5A326A2C1; Thu, 17 Feb 2022 04:40:52 -0800 (PST) Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailnew.west.internal (Postfix) with ESMTP id 9B9912B00220; Thu, 17 Feb 2022 07:33:17 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute1.internal (MEProxy); Thu, 17 Feb 2022 07:33:19 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kroah.com; h=cc :cc:content-type:date:date:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:sender:subject :subject:to:to; s=fm3; bh=jJAvTOP7DGVsKlnoRNy0hAex2AFIzRV/iOCzuW 6+yeY=; b=hgaPpn4DeJWqY6HlpXxhuFMDj2Nd8g1/jrrnDKbfgGuiIzw3m5k8O+ LkR4s9fE9o9Ze7knvpTs5AajB9rHPjLWfNmfox1DE463gupahqmIblOacIDCI6Ez Vl2qpwuLMMeXsbb/AJU3zwx9mRIJfbymTuAyDLm5xawr+JpyzDLQ9HoVkpFXKJgj OzqauBFiOz2FdKsRfe/gB6YMILcCe4seIGxL4Q00xFGHeFYrRxevqYBixjoSlqFT B5tyaXvgCPC630gwtDSWKPwuzE4KK6YkX8QBD4Dv15cWekBMTycKfGzsEWEq8RBI QR2H1PZpnOK/hPxGkEtHQ6ur48UeRpIA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:date:date:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:sender:subject:subject:to:to:x-me-proxy:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=jJAvTOP7DGVsKlnoR Ny0hAex2AFIzRV/iOCzuW6+yeY=; b=f6jMRqyFzz1WLJjPGriGZQPPXj4bRGKiY TzBBBmYGL5kt8IOI/nS7SxgqzywCWptKfYihaw5wjnsAWsN0cOiDd8YXzS5OFw3o nBtoBWjMDORAQ8Yw1j9A0qM3opr7uHF6zrKj/WScu2wEM9eBF7mIQcluWBTuDB3r Wjj66ls1hCO39Y7plvkxbHxiavZV7W14Zvgb01iBjL5J9TvZ8g4GaF+Uxryy2B/m /oR2x/9Djl/Q8EoKnmr6/RUXle8+xlqnt/29i7lxVGNgKlX16216XLH3hIbPtFZd DrgUXc1UJFJQpsXSdM7nYurBsghzmZnwC5madTPCGf1Ic26bK3KJg== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvvddrjeekgdegtdcutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpeffhffvuffkfhggtggujgesthdtredttddtvdenucfhrhhomhepifhrvghgucfm jfcuoehgrhgvgheskhhrohgrhhdrtghomheqnecuggftrfgrthhtvghrnhepveeuheejgf ffgfeivddukedvkedtleelleeghfeljeeiueeggeevueduudekvdetnecuvehluhhsthgv rhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepghhrvghgsehkrhhorghhrd gtohhm X-ME-Proxy: Received: by mail.messagingengine.com (Postfix) with ESMTPA; Thu, 17 Feb 2022 07:33:15 -0500 (EST) Date: Thu, 17 Feb 2022 13:33:13 +0100 From: Greg KH To: Steffen Eiden Cc: Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Alexander Gordeev , Janosch Frank , David Hildenbrand , Claudio Imbrenda , Shuah Khan , linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH 1/3] drivers/s390/char: Add Ultravisor io device Message-ID: References: <20220217113717.46624-1-seiden@linux.ibm.com> <20220217113717.46624-2-seiden@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220217113717.46624-2-seiden@linux.ibm.com> Precedence: bulk List-ID: X-Mailing-List: linux-s390@vger.kernel.org On Thu, Feb 17, 2022 at 06:37:15AM -0500, Steffen Eiden wrote: > This patch adds a new miscdevice to expose some Ultravisor functions > to userspace. Userspace can send IOCTLis to the uvdevice that will then > emit a corresponding Ultravisor Call and hands the result over to > userspace. The uvdevice is available if the Ultravisor Call facility is > present. > > Userspace is now able to call the Query Ultravisor Information > Ultravisor Command through the uvdevice. > > Signed-off-by: Steffen Eiden > --- > MAINTAINERS | 2 + > arch/s390/include/uapi/asm/uvdevice.h | 27 +++++ > drivers/s390/char/Kconfig | 9 ++ > drivers/s390/char/Makefile | 1 + > drivers/s390/char/uvdevice.c | 162 ++++++++++++++++++++++++++ > 5 files changed, 201 insertions(+) > create mode 100644 arch/s390/include/uapi/asm/uvdevice.h > create mode 100644 drivers/s390/char/uvdevice.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 5250298d2817..c7d8d0fe48cf 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -10457,9 +10457,11 @@ F: Documentation/virt/kvm/s390* > F: arch/s390/include/asm/gmap.h > F: arch/s390/include/asm/kvm* > F: arch/s390/include/uapi/asm/kvm* > +F: arch/s390/include/uapi/asm/uvdevice.h > F: arch/s390/kernel/uv.c > F: arch/s390/kvm/ > F: arch/s390/mm/gmap.c > +F: drivers/s390/char/uvdevice.c > F: tools/testing/selftests/kvm/*/s390x/ > F: tools/testing/selftests/kvm/s390x/ > > diff --git a/arch/s390/include/uapi/asm/uvdevice.h b/arch/s390/include/uapi/asm/uvdevice.h > new file mode 100644 > index 000000000000..f2e4984a6e2e > --- /dev/null > +++ b/arch/s390/include/uapi/asm/uvdevice.h > @@ -0,0 +1,27 @@ > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ > +/* > + * Copyright IBM Corp. 2022 > + * Author(s): Steffen Eiden > + */ > +#ifndef __S390X_ASM_UVDEVICE_H > +#define __S390X_ASM_UVDEVICE_H > + > +#include > + > +struct uvio_ioctl_cb { > + __u32 flags; /* Currently no flags defined, must be zero */ > + __u16 uv_rc; /* UV header rc value */ > + __u16 uv_rrc; /* UV header rrc value */ > + __u64 argument_addr; /* Userspace address of uvio argument */ > + __u32 argument_len; > + __u8 reserved14[0x40 - 0x14]; /* must be zero */ > +}; > + > +#define UVIO_QUI_MAX_LEN 0x8000 > + > +#define UVIO_DEVICE_NAME "uv" > +#define UVIO_TYPE_UVC 'u' > + > +#define UVIO_IOCTL_QUI _IOWR(UVIO_TYPE_UVC, 0x01, struct uvio_ioctl_cb) > + > +#endif /* __S390X_ASM_UVDEVICE_H */ > diff --git a/drivers/s390/char/Kconfig b/drivers/s390/char/Kconfig > index 6cc4b19acf85..933c0d0062d6 100644 > --- a/drivers/s390/char/Kconfig > +++ b/drivers/s390/char/Kconfig > @@ -184,3 +184,12 @@ config S390_VMUR > depends on S390 > help > Character device driver for z/VM reader, puncher and printer. > + > +config UV_UAPI > + def_tristate m > + prompt "Ultravisor userspace API" > + depends on PROTECTED_VIRTUALIZATION_GUEST > + help > + Selecting exposes parts of the UV interface to userspace > + by providing a misc character device. Using IOCTLs one > + can interact with the UV. > diff --git a/drivers/s390/char/Makefile b/drivers/s390/char/Makefile > index c6fdb81a068a..b5c83092210e 100644 > --- a/drivers/s390/char/Makefile > +++ b/drivers/s390/char/Makefile > @@ -48,6 +48,7 @@ obj-$(CONFIG_MONREADER) += monreader.o > obj-$(CONFIG_MONWRITER) += monwriter.o > obj-$(CONFIG_S390_VMUR) += vmur.o > obj-$(CONFIG_CRASH_DUMP) += sclp_sdias.o zcore.o > +obj-$(CONFIG_UV_UAPI) += uvdevice.o > > hmcdrv-objs := hmcdrv_mod.o hmcdrv_dev.o hmcdrv_ftp.o hmcdrv_cache.o diag_ftp.o sclp_ftp.o > obj-$(CONFIG_HMC_DRV) += hmcdrv.o > diff --git a/drivers/s390/char/uvdevice.c b/drivers/s390/char/uvdevice.c > new file mode 100644 > index 000000000000..e8efcbf0e7ab > --- /dev/null > +++ b/drivers/s390/char/uvdevice.c > @@ -0,0 +1,162 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright IBM Corp. 2022 > + * Author(s): Steffen Eiden > + */ > +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt ".\n" > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include > +#include > + > +/** > + * uvio_qui() - Perform a Query Ultravisor Information UVC. > + * > + * uv_ioctl: ioctl control block > + * > + * uvio_qui() does a Query Ultravisor Information (QUI) Ultravisor Call. > + * It creates the uvc qui request and sends it to the Ultravisor. After that > + * it copies the response to userspace and fills the rc and rrc of uv_ioctl > + * uv_call with the response values of the Ultravisor. > + * > + * Create the UVC structure, send the UVC to UV and write the response in the ioctl struct. > + * > + * Return: 0 on success or a negative error code on error. > + */ > +static int uvio_qui(struct uvio_ioctl_cb *uv_ioctl) > +{ > + u8 __user *user_buf_addr = (__user u8 *)uv_ioctl->argument_addr; > + size_t user_buf_len = uv_ioctl->argument_len; > + struct uv_cb_header *uvcb_qui = NULL; > + int ret; > + > + /* > + * Do not check for a too small buffer. If userspace provides a buffer > + * that is too small the Ultravisor will complain. > + */ > + ret = -EINVAL; > + if (!user_buf_len || user_buf_len > UVIO_QUI_MAX_LEN) > + goto out; > + ret = -ENOMEM; > + uvcb_qui = kvzalloc(user_buf_len, GFP_KERNEL); > + if (!uvcb_qui) > + goto out; > + uvcb_qui->len = user_buf_len; > + uvcb_qui->cmd = UVC_CMD_QUI; > + > + uv_call(0, (u64)uvcb_qui); > + > + ret = -EFAULT; > + if (copy_to_user(user_buf_addr, uvcb_qui, uvcb_qui->len)) > + goto out; > + uv_ioctl->uv_rc = uvcb_qui->rc; > + uv_ioctl->uv_rrc = uvcb_qui->rrc; > + > + ret = 0; > +out: > + kvfree(uvcb_qui); > + return ret; > +} > + > +static int uvio_copy_and_check_ioctl(struct uvio_ioctl_cb *ioctl, void __user *argp) > +{ > + u64 sum = 0; > + u64 i; > + > + if (copy_from_user(ioctl, argp, sizeof(*ioctl))) > + return -EFAULT; > + if (ioctl->flags != 0) > + return -EINVAL; > + for (i = 0; i < ARRAY_SIZE(ioctl->reserved14); i++) > + sum += ioctl->reserved14[i]; > + if (sum) > + return -EINVAL; So you can have -1, 1, -1, 1, and so on and cause this to be an incorrect check. Just test for 0 and bail out early please. > + > + return 0; > +} > + > +static int uvio_dev_open(struct inode *inode, struct file *filp) > +{ > + return 0; > +} > + > +static int uvio_dev_close(struct inode *inodep, struct file *filp) > +{ > + return 0; > +} If open/close do nothing, no need to provide it at all, just drop them. > + > +/* > + * IOCTL entry point for the Ultravisor device. > + */ > +static long uvio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) > +{ > + void __user *argp = (void __user *)arg; > + struct uvio_ioctl_cb *uv_ioctl; > + long ret; > + > + ret = -ENOMEM; > + uv_ioctl = vzalloc(sizeof(*uv_ioctl)); > + if (!uv_ioctl) > + goto out; > + > + switch (cmd) { > + case UVIO_IOCTL_QUI: > + ret = uvio_copy_and_check_ioctl(uv_ioctl, argp); > + if (ret) > + goto out; > + ret = uvio_qui(uv_ioctl); > + break; > + default: > + ret = -EINVAL; Wrong error value :( > + break; > + } > + if (ret) > + goto out; > + > + if (copy_to_user(argp, uv_ioctl, sizeof(*uv_ioctl))) > + ret = -EFAULT; > + > + out: > + vfree(uv_ioctl); > + return ret; > +} > + > +static const struct file_operations uvio_dev_fops = { > + .owner = THIS_MODULE, > + .unlocked_ioctl = uvio_ioctl, > + .open = uvio_dev_open, > + .release = uvio_dev_close, > + .llseek = no_llseek, > +}; > + > +static struct miscdevice uvio_dev_miscdev = { > + .minor = MISC_DYNAMIC_MINOR, > + .name = UVIO_DEVICE_NAME, > + .fops = &uvio_dev_fops, > +}; > + > +static void __exit uvio_dev_exit(void) > +{ > + misc_deregister(&uvio_dev_miscdev); > +} > + > +static int __init uvio_dev_init(void) > +{ > + if (!test_facility(158)) > + return -ENXIO; > + return misc_register(&uvio_dev_miscdev); > +} > + > +module_init(uvio_dev_init); > +module_exit(uvio_dev_exit); > + > +MODULE_AUTHOR("IBM Corporation"); > +MODULE_LICENSE("GPL"); > +MODULE_DESCRIPTION("Ultravisor UAPI driver"); Nothing to cause this to automatically be loaded when the "hardware" is present? thanks, greg k-h