Allow for removing devices from SMMUv3. arm_smmu_deassign_dev handles most of the work by disabling ATS and zeroing STEs. Additionally, unset the dt_device_is_protected flag and free no longer needed smmu_master. Tested on QEMU with SRIOV series[1] by repeatedly enabling/disabling VFs. [1]: https://patchew.org/Xen/cover.1772806036.git.mykyta._5Fpoturai@epam.com/ Signed-off-by: Mykyta Poturai <mykyta_poturai@epam.com> --- xen/drivers/passthrough/arm/smmu-v3.c | 59 +++++++++++++++++++++++++++ xen/include/xen/device_tree.h | 5 +++ 2 files changed, 64 insertions(+) diff --git a/xen/drivers/passthrough/arm/smmu-v3.c b/xen/drivers/passthrough/arm/smmu-v3.c index XXXXXXX..XXXXXXX 100644 --- a/xen/drivers/passthrough/arm/smmu-v3.c +++ b/xen/drivers/passthrough/arm/smmu-v3.c @@ -XXX,XX +XXX,XX @@ static int arm_smmu_assign_dev(struct domain *d, u8 devfn, struct device *dev, static int arm_smmu_deassign_dev(struct domain *d, uint8_t devfn, struct device *dev); +static int arm_smmu_remove_device(u8 devfn, struct device *dev) +{ + int ret = 0; + struct arm_smmu_master *master; + struct iommu_fwspec *fwspec; + + fwspec = dev_iommu_fwspec_get(dev); + if ( !fwspec ) + return -ENODEV; + + master = dev_iommu_priv_get(dev); + if ( !master ) + return -ENODEV; + +#ifdef CONFIG_HAS_PCI + if ( dev_is_pci(dev) ) + { + struct pci_dev *pdev = dev_to_pci(dev); + + if ( pdev->domain ) + { + ret = arm_smmu_deassign_dev(pdev->domain, devfn, dev); + if ( ret ) + printk(XENLOG_WARNING "Failed to deassign device %pp from SMMU\n", + &pdev->sbdf); + } + } +#endif + + if ( !dev_is_pci(dev) ) + { + if ( !dt_device_is_protected(dev_to_dt(dev)) ) + { + dev_err(dev, "Not added to SMMUv3\n"); + ret = -ENODEV; + goto out_free; + } + + if ( master->domain && master->domain->d ) + { + ret = arm_smmu_deassign_dev(master->domain->d, 0, dev); + if ( ret ) + dev_warn(dev, "Failed to deassign device from SMMU\n"); + } + dt_device_unset_protected(dev_to_dt(dev)); + } + + arm_smmu_disable_pasid(master); + + dev_info(dev, "Removed master device (SMMUv3 %s StreamIds %u)\n", + dev_name(fwspec->iommu_dev), fwspec->num_ids); + +out_free: + xfree(master); + dev_iommu_priv_set(dev, NULL); + return ret; +} + static int arm_smmu_add_device(u8 devfn, struct device *dev) { int i, ret; @@ -XXX,XX +XXX,XX @@ static const struct iommu_ops arm_smmu_iommu_ops = { .unmap_page = arm_iommu_unmap_page, .dt_xlate = arm_smmu_dt_xlate, .add_device = arm_smmu_add_device, + .remove_device = arm_smmu_remove_device, }; static __init int arm_smmu_dt_init(struct dt_device_node *dev, diff --git a/xen/include/xen/device_tree.h b/xen/include/xen/device_tree.h index XXXXXXX..XXXXXXX 100644 --- a/xen/include/xen/device_tree.h +++ b/xen/include/xen/device_tree.h @@ -XXX,XX +XXX,XX @@ static inline void dt_device_set_protected(struct dt_device_node *device) device->is_protected = true; } +static inline void dt_device_unset_protected(struct dt_device_node *device) +{ + device->is_protected = false; +} + static inline bool dt_device_is_protected(const struct dt_device_node *device) { return device->is_protected; -- 2.51.2 Allow for removing devices from SMMUv3. arm_smmu_deassign_dev handles most of the work by disabling ATS and zeroing STEs. Additionally, unset the dt_device_is_protected flag and free no longer needed smmu_master. Rework dt_device_set_protected to accept a boolean parameter, update callsites. Tested on QEMU with SRIOV series[1] by repeatedly enabling/disabling VFs. [1]: https://patchew.org/Xen/cover.1772806036.git.mykyta._5Fpoturai@epam.com/ Signed-off-by: Mykyta Poturai <mykyta_poturai@epam.com> --- V1-V2: * check for phantom functions * simplify pci/dt device split * improve error handling * don't try to free master for unprotected devices * rework dt_device_set_protected --- xen/drivers/passthrough/arm/ipmmu-vmsa.c | 2 +- xen/drivers/passthrough/arm/smmu-v3.c | 57 +++++++++++++++++++++++- xen/drivers/passthrough/arm/smmu.c | 4 +- xen/include/xen/device_tree.h | 5 ++- 4 files changed, 62 insertions(+), 6 deletions(-) diff --git a/xen/drivers/passthrough/arm/ipmmu-vmsa.c b/xen/drivers/passthrough/arm/ipmmu-vmsa.c index XXXXXXX..XXXXXXX 100644 --- a/xen/drivers/passthrough/arm/ipmmu-vmsa.c +++ b/xen/drivers/passthrough/arm/ipmmu-vmsa.c @@ -XXX,XX +XXX,XX @@ static int ipmmu_add_device(u8 devfn, struct device *dev) } /* Let Xen know that the master device is protected by an IOMMU. */ - dt_device_set_protected(dev_to_dt(dev)); + dt_device_set_protected(dev_to_dt(dev), true); } #ifdef CONFIG_HAS_PCI if ( dev_is_pci(dev) ) diff --git a/xen/drivers/passthrough/arm/smmu-v3.c b/xen/drivers/passthrough/arm/smmu-v3.c index XXXXXXX..XXXXXXX 100644 --- a/xen/drivers/passthrough/arm/smmu-v3.c +++ b/xen/drivers/passthrough/arm/smmu-v3.c @@ -XXX,XX +XXX,XX @@ static int arm_smmu_assign_dev(struct domain *d, u8 devfn, struct device *dev, static int arm_smmu_deassign_dev(struct domain *d, uint8_t devfn, struct device *dev); +static int arm_smmu_remove_device(u8 devfn, struct device *dev) +{ + struct arm_smmu_master *master; + struct iommu_fwspec *fwspec; + struct domain *d = NULL; + + fwspec = dev_iommu_fwspec_get(dev); + if ( !fwspec ) + return -ENODEV; + + master = dev_iommu_priv_get(dev); + if ( !master ) + return -ENODEV; + + if ( IS_ENABLED(CONFIG_HAS_PCI) && dev_is_pci(dev) ) + { + struct pci_dev *pdev = dev_to_pci(dev); + + /* Ignore calls for phantom functions */ + if ( devfn != pdev->devfn ) + return 0; + + d = pdev->domain; + } + else + { + if ( !dt_device_is_protected(dev_to_dt(dev)) ) + { + dev_err(dev, "Not added to SMMUv3\n"); + return -ENODEV; + } + + dt_device_set_protected(dev_to_dt(dev), false); + if ( master->domain && master->domain->d ) + d = master->domain->d; + } + + if ( d ) + { + int ret = arm_smmu_deassign_dev(d, devfn, dev); + /* This should never fail because we already checked the domain */ + ASSERT(!ret); + } + + arm_smmu_disable_pasid(master); + + dev_info(dev, "Removed master device (SMMUv3 %s StreamIds %u)\n", + dev_name(fwspec->iommu_dev), fwspec->num_ids); + + xfree(master); + dev_iommu_priv_set(dev, NULL); + return 0; +} + static int arm_smmu_add_device(u8 devfn, struct device *dev) { int i, ret; @@ -XXX,XX +XXX,XX @@ static int arm_smmu_add_device(u8 devfn, struct device *dev) } /* Let Xen know that the master device is protected by an IOMMU. */ - dt_device_set_protected(dev_to_dt(dev)); + dt_device_set_protected(dev_to_dt(dev), true); } dev_info(dev, "Added master device (SMMUv3 %s StreamIds %u)\n", @@ -XXX,XX +XXX,XX @@ static const struct iommu_ops arm_smmu_iommu_ops = { .unmap_page = arm_iommu_unmap_page, .dt_xlate = arm_smmu_dt_xlate, .add_device = arm_smmu_add_device, + .remove_device = arm_smmu_remove_device, }; static __init int arm_smmu_dt_init(struct dt_device_node *dev, diff --git a/xen/drivers/passthrough/arm/smmu.c b/xen/drivers/passthrough/arm/smmu.c index XXXXXXX..XXXXXXX 100644 --- a/xen/drivers/passthrough/arm/smmu.c +++ b/xen/drivers/passthrough/arm/smmu.c @@ -XXX,XX +XXX,XX @@ static int arm_smmu_dt_add_device_legacy(struct arm_smmu_device *smmu, if ( !dev_is_pci(dev) ) { /* Xen: Let Xen know that the device is protected by an SMMU */ - dt_device_set_protected(dev_node); + dt_device_set_protected(dev_node, true); } for (i = 0; i < fwspec->num_ids; ++i) { @@ -XXX,XX +XXX,XX @@ static int arm_smmu_dt_remove_device_legacy(struct arm_smmu_device *smmu, if ( !dev_is_pci(dev) ) /* Protected by dt_host_lock and dtdevs_lock as caller holds these locks. */ - dev_node->is_protected = false; + dt_device_set_protected(dev_node, false); kfree(master); return 0; diff --git a/xen/include/xen/device_tree.h b/xen/include/xen/device_tree.h index XXXXXXX..XXXXXXX 100644 --- a/xen/include/xen/device_tree.h +++ b/xen/include/xen/device_tree.h @@ -XXX,XX +XXX,XX @@ static inline domid_t dt_device_used_by(const struct dt_device_node *device) return device->used_by; } -static inline void dt_device_set_protected(struct dt_device_node *device) +static inline void dt_device_set_protected(struct dt_device_node *device, + bool protected) { - device->is_protected = true; + device->is_protected = protected; } static inline bool dt_device_is_protected(const struct dt_device_node *device) -- 2.51.2