From: Samiullah Khawaja <skhawaja@google.com>
To: David Woodhouse <dwmw2@infradead.org>,
Lu Baolu <baolu.lu@linux.intel.com>,
Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
Jason Gunthorpe <jgg@ziepe.ca>
Cc: Samiullah Khawaja <skhawaja@google.com>,
Robin Murphy <robin.murphy@arm.com>,
Kevin Tian <kevin.tian@intel.com>,
Alex Williamson <alex@shazbot.org>, Shuah Khan <shuah@kernel.org>,
iommu@lists.linux.dev, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org, Pratyush Yadav <pratyush@kernel.org>,
Pasha Tatashin <pasha.tatashin@soleen.com>,
David Matlack <dmatlack@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Pranjal Shrivastava <praan@google.com>,
Vipin Sharma <vipinsh@google.com>
Subject: [PATCH v5 12/18] iommu/vt-d: Handle reattach of the restored domain
Date: Mon, 21 Sep 2026 00:48:28 +0000 [thread overview]
Message-ID: <20260921004834.2601285-13-skhawaja@google.com> (raw)
In-Reply-To: <20260921004834.2601285-1-skhawaja@google.com>
Reattach the restored domain to the preserved device using restored
domain ID. While reattaching do not setup the context and PASID entries
as those are preserved during liveupdate.
Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
---
drivers/iommu/intel/iommu.c | 32 +++++--
drivers/iommu/intel/iommu.h | 14 +++
drivers/iommu/intel/liveupdate.c | 159 +++++++++++++++++++++++++++++++
3 files changed, 197 insertions(+), 8 deletions(-)
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index c5044e834337..6d3cbe0745c9 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -2819,6 +2819,9 @@ static int blocking_domain_attach_dev(struct iommu_domain *domain,
{
struct device_domain_info *info = dev_iommu_priv_get(dev);
+ if (dev_iommu_restored_state(dev))
+ return -EBUSY;
+
iopf_for_domain_remove(info->domain ? &info->domain->domain : NULL, dev);
device_block_translation(dev);
return 0;
@@ -3187,6 +3190,9 @@ static int intel_iommu_attach_device(struct iommu_domain *domain,
{
int ret;
+ if (dev_iommu_restored_state(dev))
+ return intel_iommu_restore_device(domain, dev);
+
device_block_translation(dev);
ret = paging_domain_compatible(domain, dev);
@@ -3317,7 +3323,8 @@ static struct iommu_device *intel_iommu_probe_device(struct device *dev)
info->iommu = iommu;
RB_CLEAR_NODE(&info->node);
if (dev_is_pci(dev)) {
- if (ecap_dev_iotlb_support(iommu->ecap) &&
+ if (!dev_iommu_restored_state(dev) &&
+ ecap_dev_iotlb_support(iommu->ecap) &&
pci_ats_supported(pdev) &&
dmar_ats_supported(pdev, iommu)) {
info->ats_supported = 1;
@@ -3421,12 +3428,16 @@ static void intel_iommu_release_device(struct device *dev)
struct device_domain_info *info = dev_iommu_priv_get(dev);
struct intel_iommu *iommu = info->iommu;
- iommu_disable_pci_pri(info);
- iommu_disable_pci_ats(info);
+ if (!dev_iommu_restored_state(dev)) {
+ iommu_disable_pci_pri(info);
+ iommu_disable_pci_ats(info);
- if (info->pasid_enabled) {
- pci_disable_pasid(to_pci_dev(dev));
- info->pasid_enabled = 0;
+ if (info->pasid_enabled) {
+ pci_disable_pasid(to_pci_dev(dev));
+ info->pasid_enabled = 0;
+ }
+ } else {
+ intel_iommu_detach_restored_device(dev);
}
mutex_lock(&iommu->iopf_lock);
@@ -3434,11 +3445,13 @@ static void intel_iommu_release_device(struct device *dev)
device_rbtree_remove(info);
mutex_unlock(&iommu->iopf_lock);
- if (sm_supported(iommu) && !dev_is_real_dma_subdevice(dev) &&
+ if (!dev_iommu_restored_state(dev) && sm_supported(iommu) &&
+ !dev_is_real_dma_subdevice(dev) &&
!context_copied(iommu, info->bus, info->devfn))
intel_pasid_teardown_sm_context(dev);
- intel_pasid_free_table(dev);
+ if (!dev_iommu_restored_state(dev))
+ intel_pasid_free_table(dev);
intel_iommu_debugfs_remove_dev(info);
kfree(info);
}
@@ -3900,6 +3913,9 @@ static int identity_domain_attach_dev(struct iommu_domain *domain,
struct intel_iommu *iommu = info->iommu;
int ret;
+ if (dev_iommu_restored_state(dev))
+ return -EBUSY;
+
device_block_translation(dev);
if (dev_is_real_dma_subdevice(dev))
diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index 3a2cb08c0ac1..25104644317c 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -1310,6 +1310,9 @@ void intel_iommu_unpreserve(struct iommu_device *iommu,
void clear_unpreserved_context_entries(struct intel_iommu *iommu);
void intel_iommu_liveupdate_restore_root_table(struct intel_iommu *iommu,
struct iommu_hw_ser *iommu_ser);
+int intel_iommu_restore_device(struct iommu_domain *domain,
+ struct device *dev);
+int intel_iommu_detach_restored_device(struct device *dev);
#else
static inline void clear_unpreserved_context_entries(struct intel_iommu *iommu)
{
@@ -1319,6 +1322,17 @@ static inline void intel_iommu_liveupdate_restore_root_table(struct intel_iommu
struct iommu_hw_ser *iommu_ser)
{
}
+
+static inline int intel_iommu_restore_device(struct iommu_domain *domain,
+ struct device *dev)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline int intel_iommu_detach_restored_device(struct device *dev)
+{
+ return -EOPNOTSUPP;
+}
#endif
#ifdef CONFIG_INTEL_IOMMU_SVM
diff --git a/drivers/iommu/intel/liveupdate.c b/drivers/iommu/intel/liveupdate.c
index c9e553379683..6e6707eefc8c 100644
--- a/drivers/iommu/intel/liveupdate.c
+++ b/drivers/iommu/intel/liveupdate.c
@@ -351,6 +351,165 @@ void intel_iommu_liveupdate_restore_root_table(struct intel_iommu *iommu,
BUG_ON(iommu_for_each_preserved_device(_restore_used_domain_ids, iommu));
}
+static void domain_detach_reattached_iommu(struct dmar_domain *domain,
+ struct intel_iommu *iommu)
+{
+ struct iommu_domain_info *info;
+
+ guard(mutex)(&iommu->did_lock);
+ info = xa_load(&domain->iommu_array, iommu->seq_id);
+ if (--info->refcnt == 0) {
+ xa_erase(&domain->iommu_array, iommu->seq_id);
+ kfree(info);
+ }
+}
+
+static int domain_reattach_iommu(struct dmar_domain *domain,
+ struct intel_iommu *iommu,
+ struct iommu_device_ser *device_ser)
+{
+ struct iommu_domain_info *info, *curr;
+ struct iommu_domain_ser *domain_ser;
+ struct iommu_hw_ser *iommu_hw_ser;
+ int restored_did;
+ int ret;
+
+ if (!iommu_domain_restored_state(&domain->domain))
+ return -EINVAL;
+
+ if (!device_ser->domain_iommu_ser.domain_phys ||
+ !device_ser->domain_iommu_ser.iommu_phys)
+ return -EINVAL;
+
+ domain_ser = phys_to_virt(device_ser->domain_iommu_ser.domain_phys);
+ if (domain_ser->restored_domain != &domain->domain)
+ return -EINVAL;
+
+ iommu_hw_ser = phys_to_virt(device_ser->domain_iommu_ser.iommu_phys);
+ if (iommu_hw_ser->type != IOMMU_INTEL ||
+ iommu_hw_ser->intel.phys_addr != iommu->reg_phys)
+ return -EINVAL;
+
+ restored_did = device_ser->domain_iommu_ser.attachment_id;
+ if (!ida_exists(&iommu->domain_ida, restored_did))
+ return -EINVAL;
+
+ info = kzalloc_obj(*info);
+ if (!info)
+ return -ENOMEM;
+
+ guard(mutex)(&iommu->did_lock);
+ curr = xa_load(&domain->iommu_array, iommu->seq_id);
+ if (curr) {
+ curr->refcnt++;
+ kfree(info);
+ return 0;
+ }
+
+ info->refcnt = 1;
+ info->did = restored_did;
+ info->iommu = iommu;
+ curr = xa_cmpxchg(&domain->iommu_array, iommu->seq_id,
+ NULL, info, GFP_KERNEL);
+ if (curr) {
+ ret = xa_err(curr) ? : -EBUSY;
+ goto err_unlock;
+ }
+
+ return 0;
+
+err_unlock:
+ kfree(info);
+ return ret;
+}
+
+/**
+ * intel_iommu_restore_device() - Restore device domain attachment after live update
+ * @domain: Restored domain
+ * @dev: Restored device
+ *
+ * Return: 0 on success, or negative error code.
+ */
+int intel_iommu_restore_device(struct iommu_domain *domain,
+ struct device *dev)
+{
+ struct iommu_device_ser *device_ser = dev_iommu_restored_state(dev);
+ struct device_domain_info *info = dev_iommu_priv_get(dev);
+ struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+ struct intel_iommu *iommu = info->iommu;
+ unsigned long flags;
+ int ret;
+
+ if (!device_ser)
+ return -EINVAL;
+
+ if (dev_is_real_dma_subdevice(dev))
+ return -EOPNOTSUPP;
+
+ ret = domain_reattach_iommu(dmar_domain, iommu, device_ser);
+ if (ret)
+ return ret;
+
+ info->domain = dmar_domain;
+ info->domain_attached = true;
+ spin_lock_irqsave(&dmar_domain->lock, flags);
+ list_add(&info->link, &dmar_domain->devices);
+ spin_unlock_irqrestore(&dmar_domain->lock, flags);
+
+ ret = cache_tag_assign_domain(dmar_domain, dev, IOMMU_NO_PASID);
+ if (ret)
+ goto err;
+
+ ret = iopf_for_domain_set(domain, dev);
+ if (ret)
+ goto err;
+
+ return 0;
+
+err:
+ /*
+ * Detach the restored domain from device and iommu on failure, but keep
+ * the hardware state intact.
+ */
+ info->domain_attached = false;
+ cache_tag_unassign_domain(info->domain, dev, IOMMU_NO_PASID);
+ spin_lock_irqsave(&info->domain->lock, flags);
+ list_del(&info->link);
+ spin_unlock_irqrestore(&info->domain->lock, flags);
+
+ domain_detach_reattached_iommu(info->domain, iommu);
+ info->domain = NULL;
+ return ret;
+}
+
+int intel_iommu_detach_restored_device(struct device *dev)
+{
+ struct device_domain_info *info = dev_iommu_priv_get(dev);
+ struct intel_iommu *iommu = info->iommu;
+ struct iommu_domain *domain;
+ unsigned long flags;
+
+ if (!info->domain_attached || !info->domain)
+ return -EINVAL;
+
+ domain = &info->domain->domain;
+ if (!iommu_domain_restored_state(domain))
+ return -EINVAL;
+
+ iopf_for_domain_remove(domain, dev);
+ cache_tag_unassign_domain(info->domain, dev, IOMMU_NO_PASID);
+ info->domain_attached = false;
+
+ spin_lock_irqsave(&info->domain->lock, flags);
+ list_del(&info->link);
+ spin_unlock_irqrestore(&info->domain->lock, flags);
+
+ domain_detach_reattached_iommu(info->domain, iommu);
+ info->domain = NULL;
+
+ return 0;
+}
+
/**
* intel_iommu_preserve_device() - Intel IOMMU callback to preserve device state
* @dev: Target device
--
2.55.0.1082.g2b9226bbc0-goog
next prev parent reply other threads:[~2026-09-21 0:48 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-21 0:48 [PATCH v5 00/18] iommu: Add live update state preservation Samiullah Khawaja
2026-09-21 0:48 ` [PATCH v5 01/18] memfd: export memfd_get_seals() Samiullah Khawaja
2026-09-21 0:48 ` [PATCH v5 02/18] iommu: Implement IOMMU Live update FLB callbacks Samiullah Khawaja
2026-10-06 23:31 ` Nicolin Chen
2026-09-21 0:48 ` [PATCH v5 03/18] iommu/pages: Add APIs to preserve/unpreserve/restore iommu pages Samiullah Khawaja
2026-09-21 0:48 ` [PATCH v5 04/18] iommupt: Implement preserve/unpreserve/restore callbacks Samiullah Khawaja
2026-09-21 0:48 ` [PATCH v5 05/18] iommu: Implement IOMMU domain preservation Samiullah Khawaja
2026-09-21 0:48 ` [PATCH v5 06/18] iommu: Implement device and IOMMU HW preservation Samiullah Khawaja
2026-10-07 3:21 ` Nicolin Chen
2026-09-21 0:48 ` [PATCH v5 07/18] iommu/vt-d: Implement device and iommu preserve/unpreserve ops Samiullah Khawaja
2026-10-08 7:54 ` Baolu Lu
2026-09-21 0:48 ` [PATCH v5 08/18] iommu/vt-d: Clear unpreserved context entries during shutdown Samiullah Khawaja
2026-09-21 0:48 ` [PATCH v5 09/18] iommu: Add APIs to get iommu and device preserved state Samiullah Khawaja
2026-09-21 0:48 ` [PATCH v5 10/18] iommu/vt-d: Restore IOMMU state and reclaimed domain ids Samiullah Khawaja
2026-09-21 0:48 ` [PATCH v5 11/18] iommu: Restore and reattach preserved domains to devices Samiullah Khawaja
2026-10-07 19:44 ` Nicolin Chen
2026-09-21 0:48 ` Samiullah Khawaja [this message]
2026-09-21 0:48 ` [PATCH v5 13/18] iommu/vt-d: Preserve PASID table of preserved device Samiullah Khawaja
2026-09-21 0:48 ` [PATCH v5 14/18] iommufd: Implement ioctl to mark HWPT for preservation Samiullah Khawaja
2026-10-07 20:17 ` Nicolin Chen
2026-09-21 0:48 ` [PATCH v5 15/18] iommufd: Persist iommu hardware pagetables for live update Samiullah Khawaja
2026-09-23 23:59 ` John Starks
2026-09-24 17:49 ` Samiullah Khawaja
2026-10-07 21:31 ` Nicolin Chen
2026-09-21 0:48 ` [PATCH v5 16/18] iommufd: Add APIs to preserve/unpreserve a vfio cdev Samiullah Khawaja
2026-10-07 22:00 ` Nicolin Chen
2026-09-21 0:48 ` [PATCH v5 17/18] vfio/pci: Preserve the iommufd state of the " Samiullah Khawaja
2026-09-21 0:48 ` [PATCH v5 18/18] iommufd/selftest: Add test to verify iommufd preservation Samiullah Khawaja
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