From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754541AbbIIUtD (ORCPT ); Wed, 9 Sep 2015 16:49:03 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37305 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754126AbbIIUs7 (ORCPT ); Wed, 9 Sep 2015 16:48:59 -0400 Message-ID: <1441831738.20355.542.camel@redhat.com> Subject: Re: [RFC PATCH v4 3/3] vfio: platform: return device properties as arrays of unsigned integers From: Alex Williamson To: Baptiste Reynal Cc: kvmarm@lists.cs.columbia.edu, iommu@lists.linux-foundation.org, christoffer.dall@linaro.org, eric.auger@linaro.org, tech@virtualopensystems.com, Antonios Motakis , "open list:VFIO PLATFORM DRIVER" , open list Date: Wed, 09 Sep 2015 14:48:58 -0600 In-Reply-To: <1441790231-22920-4-git-send-email-b.reynal@virtualopensystems.com> References: <1441790231-22920-1-git-send-email-b.reynal@virtualopensystems.com> <1441790231-22920-4-git-send-email-b.reynal@virtualopensystems.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2015-09-09 at 11:17 +0200, Baptiste Reynal wrote: > From: Antonios Motakis > > Certain properties of a device are accessible as an array of unsigned > integers, either u64, u32, u16, or u8. Let the VFIO user query this > type of device properties. > > Signed-off-by: Antonios Motakis > Signed-off-by: Baptiste Reynal > --- > drivers/vfio/platform/properties.c | 62 +++++++++++++++++++++++++++++++++++++- > 1 file changed, 61 insertions(+), 1 deletion(-) > > diff --git a/drivers/vfio/platform/properties.c b/drivers/vfio/platform/properties.c > index 8bf9c8f..625e2d3 100644 > --- a/drivers/vfio/platform/properties.c > +++ b/drivers/vfio/platform/properties.c > @@ -70,7 +70,67 @@ static int dev_property_get_uint(struct device *dev, uint32_t *flags, > char *name, uint32_t type, unsigned *lenp, > void __user *datap, unsigned long datasz) > { > - return -EINVAL; > + int ret, n; > + u8 *out; > + size_t sz; > + int (*func)(const struct device *, const char *, void *, size_t) > + = NULL; > + > + switch (type) { > + case VFIO_DEV_PROPERTY_TYPE_U64: > + sz = sizeof(u64); > + func = (int (*)(const struct device *, > + const char *, void *, size_t)) > + device_property_read_u64_array; > + break; > + case VFIO_DEV_PROPERTY_TYPE_U32: > + sz = sizeof(u32); > + func = (int (*)(const struct device *, > + const char *, void *, size_t)) > + device_property_read_u32_array; > + break; > + case VFIO_DEV_PROPERTY_TYPE_U16: > + sz = sizeof(u16); > + func = (int (*)(const struct device *, > + const char *, void *, size_t)) > + device_property_read_u16_array; > + break; > + case VFIO_DEV_PROPERTY_TYPE_U8: > + sz = sizeof(u8); > + func = (int (*)(const struct device *, > + const char *, void *, size_t)) > + device_property_read_u8_array; > + break; > + > + default: > + return -EINVAL; > + } > + > + /* get size of array */ > + n = func(dev, name, NULL, 0); > + if (n < 0) > + return n; > + > + if (lenp) > + *lenp = n * sz; Why is this conditional? > + > + if (n * sz > datasz) > + return -EOVERFLOW; Ugh, this isn't E2BIG or ENOSPC... > + > + out = kcalloc(n, sz, GFP_KERNEL); > + if (!out) > + return -ENOMEM; > + > + ret = func(dev, name, out, n); > + if (ret) > + goto out; > + > + if (copy_to_user(datap, out, n * sz)) > + ret = -EFAULT; > + > +out: > + kfree(out); > + return ret; > } > > int vfio_platform_dev_properties(struct device *dev, uint32_t *flags,