From mboxrd@z Thu Jan 1 00:00:00 1970 From: Auger Eric Subject: Re: [PATCH v6 07/22] vfio: VFIO_IOMMU_ATTACH/DETACH_PASID_TABLE Date: Fri, 22 Mar 2019 08:58:16 +0100 Message-ID: References: <20190317172232.1068-1-eric.auger@redhat.com> <20190317172232.1068-8-eric.auger@redhat.com> <20190321161938.4358b436@x1.home> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190321161938.4358b436@x1.home> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Alex Williamson Cc: eric.auger.pro@gmail.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, joro@8bytes.org, jacob.jun.pan@linux.intel.com, yi.l.liu@linux.intel.com, jean-philippe.brucker@arm.com, will.deacon@arm.com, robin.murphy@arm.com, kevin.tian@intel.com, ashok.raj@intel.com, marc.zyngier@arm.com, christoffer.dall@arm.com, peter.maydell@linaro.org, vincent.stehle@arm.com List-Id: iommu@lists.linux-foundation.org Hi Alex, On 3/21/19 11:19 PM, Alex Williamson wrote: > On Sun, 17 Mar 2019 18:22:17 +0100 > Eric Auger wrote: > >> From: "Liu, Yi L" >> >> This patch adds VFIO_IOMMU_ATTACH/DETACH_PASID_TABLE ioctl >> which aims to pass/withdraw the virtual iommu guest configuration >> to/from the VFIO driver downto to the iommu subsystem. >> >> Signed-off-by: Jacob Pan >> Signed-off-by: Liu, Yi L >> Signed-off-by: Eric Auger >> >> --- >> v3 -> v4: >> - restore ATTACH/DETACH >> - add unwind on failure >> >> v2 -> v3: >> - s/BIND_PASID_TABLE/SET_PASID_TABLE >> >> v1 -> v2: >> - s/BIND_GUEST_STAGE/BIND_PASID_TABLE >> - remove the struct device arg >> --- >> drivers/vfio/vfio_iommu_type1.c | 53 +++++++++++++++++++++++++++++++++ >> include/uapi/linux/vfio.h | 17 +++++++++++ >> 2 files changed, 70 insertions(+) >> >> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c >> index 73652e21efec..222e9199edbf 100644 >> --- a/drivers/vfio/vfio_iommu_type1.c >> +++ b/drivers/vfio/vfio_iommu_type1.c >> @@ -1644,6 +1644,43 @@ static int vfio_domains_have_iommu_cache(struct vfio_iommu *iommu) >> return ret; >> } >> >> +static void >> +vfio_detach_pasid_table(struct vfio_iommu *iommu) >> +{ >> + struct vfio_domain *d; >> + >> + mutex_lock(&iommu->lock); >> + >> + list_for_each_entry(d, &iommu->domain_list, next) { >> + iommu_detach_pasid_table(d->domain); >> + } >> + mutex_unlock(&iommu->lock); >> +} >> + >> +static int >> +vfio_attach_pasid_table(struct vfio_iommu *iommu, >> + struct vfio_iommu_type1_attach_pasid_table *ustruct) >> +{ >> + struct vfio_domain *d; >> + int ret = 0; >> + >> + mutex_lock(&iommu->lock); >> + >> + list_for_each_entry(d, &iommu->domain_list, next) { >> + ret = iommu_attach_pasid_table(d->domain, &ustruct->config); >> + if (ret) >> + goto unwind; >> + } >> + goto unlock; >> +unwind: >> + list_for_each_entry_continue_reverse(d, &iommu->domain_list, next) { >> + iommu_detach_pasid_table(d->domain); >> + } >> +unlock: >> + mutex_unlock(&iommu->lock); >> + return ret; >> +} >> + >> static long vfio_iommu_type1_ioctl(void *iommu_data, >> unsigned int cmd, unsigned long arg) >> { >> @@ -1714,6 +1751,22 @@ static long vfio_iommu_type1_ioctl(void *iommu_data, >> >> return copy_to_user((void __user *)arg, &unmap, minsz) ? >> -EFAULT : 0; >> + } else if (cmd == VFIO_IOMMU_ATTACH_PASID_TABLE) { >> + struct vfio_iommu_type1_attach_pasid_table ustruct; >> + >> + minsz = offsetofend(struct vfio_iommu_type1_attach_pasid_table, >> + config); >> + >> + if (copy_from_user(&ustruct, (void __user *)arg, minsz)) >> + return -EFAULT; >> + >> + if (ustruct.argsz < minsz || ustruct.flags) >> + return -EINVAL; > > Who is responsible for validating the ustruct.config? > arm_smmu_attach_pasid_table() only looks at the format, ignoring the > version field :-\ In fact, where is struct iommu_pasid_smmuv3 ever used > from the config? This is something missing and to be fixed in smmuv3 arm_smmu_attach_pasid_table(). At the moment the virtual SMMUv3 only supports a single context descriptor hence the shortcut. Should the padding fields be forced to zero? We > don't have flags to incorporate use of them with future extensions, so > maybe we don't care? My guess is if we were to add new fields in iommu_pasid_smmuv3, we would both increment iommu_pasid_smmuv3.version and iommu_pasid_table_config.version. I don't think padding fields are meant to be filled here (ie. no flag needed). > >> + >> + return vfio_attach_pasid_table(iommu, &ustruct); >> + } else if (cmd == VFIO_IOMMU_DETACH_PASID_TABLE) { >> + vfio_detach_pasid_table(iommu); >> + return 0; >> } >> >> return -ENOTTY; >> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h >> index 02bb7ad6e986..329d378565d9 100644 >> --- a/include/uapi/linux/vfio.h >> +++ b/include/uapi/linux/vfio.h >> @@ -14,6 +14,7 @@ >> >> #include >> #include >> +#include >> >> #define VFIO_API_VERSION 0 >> >> @@ -759,6 +760,22 @@ struct vfio_iommu_type1_dma_unmap { >> #define VFIO_IOMMU_ENABLE _IO(VFIO_TYPE, VFIO_BASE + 15) >> #define VFIO_IOMMU_DISABLE _IO(VFIO_TYPE, VFIO_BASE + 16) >> >> +/** >> + * VFIO_IOMMU_ATTACH_PASID_TABLE - _IOWR(VFIO_TYPE, VFIO_BASE + 22, >> + * struct vfio_iommu_type1_attach_pasid_table) >> + * >> + * Passes the PASID table to the host. Calling ATTACH_PASID_TABLE >> + * while a table is already installed is allowed: it replaces the old >> + * table. DETACH does a comprehensive tear down of the nested mode. >> + */ >> +struct vfio_iommu_type1_attach_pasid_table { >> + __u32 argsz; >> + __u32 flags; >> + struct iommu_pasid_table_config config; >> +}; >> +#define VFIO_IOMMU_ATTACH_PASID_TABLE _IO(VFIO_TYPE, VFIO_BASE + 22) >> +#define VFIO_IOMMU_DETACH_PASID_TABLE _IO(VFIO_TYPE, VFIO_BASE + 23) >> + > > DETACH should also be documented, it's not clear from the uapi that it > requires no parameters. Thanks, sure Thanks Eric > > Alex >