From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Auger Subject: [RFC v5 15/17] vfio/type1: also check IRQ remapping capability at msi domain Date: Tue, 1 Mar 2016 18:27:55 +0000 Message-ID: <1456856877-4817-16-git-send-email-eric.auger@linaro.org> References: <1456856877-4817-1-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: <1456856877-4817-1-git-send-email-eric.auger@linaro.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: eric.auger@st.com, eric.auger@linaro.org, robin.murphy@arm.com, alex.williamson@redhat.com, will.deacon@arm.com, joro@8bytes.org, tglx@linutronix.de, jason@lakedaemon.net, marc.zyngier@arm.com, christoffer.dall@linaro.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Cc: patches@linaro.org, Manish.Jaggi@caviumnetworks.com, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org List-Id: iommu@lists.linux-foundation.org On x86 IRQ remapping is abstracted by the IOMMU. On ARM this is abstracted by the msi controller. vfio_safe_irq_domain allows to check whether interrupts are "safe" for a given device. They are if the device does not use MSI or if the device uses MSI and the msi-parent controller supports IRQ remapping. Then we check at group level if all devices have safe interrupts: if not, we only allow the group to be attached if allow_unsafe_interrupts is set. At this point ARM sMMU still advertises IOMMU_CAP_INTR_REMAP. This is changed in next patch. Signed-off-by: Eric Auger --- v3 -> v4: - rename vfio_msi_parent_irq_remapping_capable into vfio_safe_irq_domain and irq_remapping into safe_irq_domains v2 -> v3: - protect vfio_msi_parent_irq_remapping_capable with CONFIG_GENERIC_MSI_IRQ_DOMAIN --- drivers/vfio/vfio_iommu_type1.c | 44 +++++++++++++++++++++++++++++++++++++++-- 1 file changed, 42 insertions(+), 2 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 4e01ebe..88a40f1 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -37,6 +37,8 @@ #include #include #include +#include +#include #define DRIVER_VERSION "0.2" #define DRIVER_AUTHOR "Alex Williamson " @@ -788,6 +790,33 @@ static int vfio_bus_type(struct device *dev, void *data) return 0; } +/** + * vfio_safe_irq_domain: returns whether the irq domain + * the device is attached to is safe with respect to MSI isolation. + * If the irq domain is not an MSI domain, we return it is safe. + * + * @dev: device handle + * @data: unused + * returns 0 if the irq domain is safe, -1 if not. + */ +static int vfio_safe_irq_domain(struct device *dev, void *data) +{ +#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN + struct irq_domain *domain; + struct msi_domain_info *info; + + domain = dev_get_msi_domain(dev); + if (!domain) + return 0; + + info = msi_get_domain_info(domain); + + if (!(info->flags & MSI_FLAG_IRQ_REMAPPING)) + return -1; +#endif + return 0; +} + static int vfio_iommu_replay(struct vfio_iommu *iommu, struct vfio_domain *domain) { @@ -882,7 +911,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data, struct vfio_group *group, *g; struct vfio_domain *domain, *d; struct bus_type *bus = NULL; - int ret; + int ret, safe_irq_domains; mutex_lock(&iommu->lock); @@ -905,6 +934,13 @@ static int vfio_iommu_type1_attach_group(void *iommu_data, group->iommu_group = iommu_group; + /* + * Determine if all the devices of the group have a safe irq domain + * with respect to MSI isolation + */ + safe_irq_domains = !iommu_group_for_each_dev(iommu_group, &bus, + vfio_safe_irq_domain); + /* Determine bus_type in order to allocate a domain */ ret = iommu_group_for_each_dev(iommu_group, &bus, vfio_bus_type); if (ret) @@ -932,8 +968,12 @@ static int vfio_iommu_type1_attach_group(void *iommu_data, INIT_LIST_HEAD(&domain->group_list); list_add(&group->next, &domain->group_list); + /* + * to advertise safe interrupts either the IOMMU or the MSI controllers + * must support IRQ remapping/interrupt translation + */ if (!allow_unsafe_interrupts && - !iommu_capable(bus, IOMMU_CAP_INTR_REMAP)) { + (!iommu_capable(bus, IOMMU_CAP_INTR_REMAP) && !safe_irq_domains)) { pr_warn("%s: No interrupt remapping support. Use the module param \"allow_unsafe_interrupts\" to enable VFIO IOMMU support on this platform\n", __func__); ret = -EPERM; -- 1.9.1