From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Auger Subject: [PATCH v7 7/7] vfio/type1: return MSI mapping requirements with VFIO_IOMMU_GET_INFO Date: Tue, 19 Apr 2016 17:24:47 +0000 Message-ID: <1461086687-2658-8-git-send-email-eric.auger@linaro.org> References: <1461086687-2658-1-git-send-email-eric.auger@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1461086687-2658-1-git-send-email-eric.auger-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: eric.auger-qxv4g6HH51o@public.gmane.org, eric.auger-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, robin.murphy-5wv7dgnIgG8@public.gmane.org, alex.williamson-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, will.deacon-5wv7dgnIgG8@public.gmane.org, joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org, tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org, jason-NLaQJdtUoK4Be96aLqz0jA@public.gmane.org, marc.zyngier-5wv7dgnIgG8@public.gmane.org, christoffer.dall-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org Cc: julien.grall-5wv7dgnIgG8@public.gmane.org, patches-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, p.fedin-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, pranav.sawargaonkar-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org List-Id: iommu@lists.linux-foundation.org This patch allows the user-space to know whether MSI addresses need to be mapped in the IOMMU. The user-space uses VFIO_IOMMU_GET_INFO ioctl and IOMMU_INFO_REQUIRE_MSI_MAP gets set if they need to. The computation of the number of IOVA pages to be provided by the user space will be implemented in a separate patch using capability chains. Signed-off-by: Eric Auger --- v6 -> v7: - remove the computation of the number of IOVA pages to be provisionned. This number depends on the domain/group/device topology which can dynamically change. Let's rely instead rely on an arbitrary max depending on the system v4 -> v5: - move msi_info and ret declaration within the conditional code v3 -> v4: - replace former vfio_domains_require_msi_mapping by more complex computation of MSI mapping requirements, especially the number of pages to be provided by the user-space. - reword patch title RFC v1 -> v1: - derived from [RFC PATCH 3/6] vfio: Extend iommu-info to return MSIs automap state - renamed allow_msi_reconfig into require_msi_mapping - fixed VFIO_IOMMU_GET_INFO --- drivers/vfio/vfio_iommu_type1.c | 24 ++++++++++++++++++++++++ include/uapi/linux/vfio.h | 5 ++++- 2 files changed, 28 insertions(+), 1 deletion(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 51b1f15..a63ce6f 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -310,6 +310,27 @@ static int vaddr_get_pfn(unsigned long vaddr, int prot, unsigned long *pfn) } /* + * vfio_domains_require_msi_mapping: return whether MSI doorbells must be + * iommu mapped + * + * returns true if msi mapping is requested + */ +static bool vfio_domains_require_msi_mapping(struct vfio_iommu *iommu) +{ + struct vfio_domain *d; + bool flag; + + mutex_lock(&iommu->lock); + /* All domains have same require_msi_map property, pick first */ + d = list_first_entry(&iommu->domain_list, struct vfio_domain, next); + flag = (!(iommu_domain_get_attr(d->domain, + DOMAIN_ATTR_MSI_MAPPING, NULL))); + + mutex_unlock(&iommu->lock); + + return flag; +} +/* * Attempt to pin pages. We really don't want to track all the pfns and * the iommu can only map chunks of consecutive pfns anyway, so get the * first page and all consecutive pages with the same locking. @@ -1231,6 +1252,9 @@ static long vfio_iommu_type1_ioctl(void *iommu_data, info.flags = VFIO_IOMMU_INFO_PGSIZES; + if (vfio_domains_require_msi_mapping(iommu)) + info.flags |= VFIO_IOMMU_INFO_REQUIRE_MSI_MAP; + info.iova_pgsizes = vfio_pgsize_bitmap(iommu); return copy_to_user((void __user *)arg, &info, minsz) ? diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index 0637f35..4d9c97d 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -488,6 +488,7 @@ struct vfio_iommu_type1_info { __u32 argsz; __u32 flags; #define VFIO_IOMMU_INFO_PGSIZES (1 << 0) /* supported page sizes info */ +#define VFIO_IOMMU_INFO_REQUIRE_MSI_MAP (1 << 1)/* MSI must be mapped */ __u64 iova_pgsizes; /* Bitmap of supported page sizes */ }; @@ -501,7 +502,9 @@ struct vfio_iommu_type1_info { * * In case RESERVED_MSI_IOVA flag is set, the API only aims at registering an * IOVA region that will be used on some platforms to map the host MSI frames. - * In that specific case, vaddr is ignored. + * In that specific case, vaddr is ignored. The requirement for provisioning + * such reserved IOVA range can be checked by calling VFIO_IOMMU_GET_INFO and + * testing the VFIO_IOMMU_INFO_REQUIRE_MSI_MAP flag. */ struct vfio_iommu_type1_dma_map { __u32 argsz; -- 1.9.1