From: Samiullah Khawaja <skhawaja@google.com>
To: Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
Lu Baolu <baolu.lu@linux.intel.com>,
Jason Gunthorpe <jgg@ziepe.ca>,
David Woodhouse <dwmw2@infradead.org>
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>,
Ankit Soni <Ankit.Soni@amd.com>,
Nicolin Chen <nicolinc@nvidia.com>,
John Starks <dev@jstarks.net>
Subject: [PATCH v6 13/18] iommu/vt-d: Handle reattach of the restored domain
Date: Sun, 25 Oct 2026 02:19:24 +0000 [thread overview]
Message-ID: <20261025021930.674647-14-skhawaja@google.com> (raw)
In-Reply-To: <20261025021930.674647-1-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 | 34 ++++++--
drivers/iommu/intel/iommu.h | 14 ++++
drivers/iommu/intel/liveupdate.c | 131 +++++++++++++++++++++++++++++++
3 files changed, 171 insertions(+), 8 deletions(-)
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index ecec057f78dd..4f01aa34ccb5 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -2926,6 +2926,9 @@ static int blocking_domain_attach_dev(struct iommu_domain *domain,
struct device *dev,
struct iommu_domain *old)
{
+ if (dev_iommu_restored_state(dev))
+ return -EBUSY;
+
iopf_for_domain_remove(old, dev);
device_block_translation(dev);
return 0;
@@ -3294,6 +3297,9 @@ static int intel_iommu_attach_device(struct iommu_domain *domain,
{
int ret;
+ if (dev_iommu_restored_state(dev))
+ return intel_iommu_attach_restored_device(domain, dev);
+
device_block_translation(dev);
ret = paging_domain_compatible(domain, dev);
@@ -3424,7 +3430,8 @@ 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;
@@ -3529,12 +3536,16 @@ 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);
@@ -3542,11 +3553,15 @@ 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);
+ else
+ kfree(info->pasid_table);
intel_iommu_debugfs_remove_dev(info);
kfree(info);
}
@@ -4003,6 +4018,9 @@ 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 260c7a5b1240..f910e5383e12 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -1322,6 +1322,9 @@ 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);
void intel_iommu_handle_drhd_restore_failure(struct intel_iommu *iommu);
+int intel_iommu_attach_restored_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)
{
@@ -1335,6 +1338,17 @@ static inline void intel_iommu_liveupdate_restore_root_table(struct intel_iommu
static inline void intel_iommu_handle_drhd_restore_failure(struct intel_iommu *iommu)
{
}
+
+static inline int intel_iommu_attach_restored_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 36816d3651e6..665ebb81bd61 100644
--- a/drivers/iommu/intel/liveupdate.c
+++ b/drivers/iommu/intel/liveupdate.c
@@ -394,6 +394,137 @@ void intel_iommu_handle_drhd_restore_failure(struct intel_iommu *iommu)
iommu->name);
}
+static void domain_detach_restored_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_attach_restored_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->attachment.domain_phys ||
+ !device_ser->iommu_phys)
+ return -EINVAL;
+
+ domain_ser = phys_to_virt(device_ser->attachment.domain_phys);
+ if (domain_ser->restored_domain != &domain->domain)
+ return -EINVAL;
+
+ iommu_hw_ser = phys_to_virt(device_ser->iommu_phys);
+ if (iommu_hw_ser->type != IOMMU_SER_TYPE_INTEL ||
+ iommu_hw_ser->intel.phys_addr != iommu->reg_phys)
+ return -EINVAL;
+
+ restored_did = device_ser->attachment.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_attach_restored_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_attach_restored_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;
+
+ ret = domain_attach_restored_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);
+
+ return 0;
+}
+
+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;
+
+ info->domain_attached = false;
+
+ spin_lock_irqsave(&info->domain->lock, flags);
+ list_del(&info->link);
+ spin_unlock_irqrestore(&info->domain->lock, flags);
+
+ domain_detach_restored_iommu(info->domain, iommu);
+ info->domain = NULL;
+
+ return 0;
+}
+
enum pasid_lu_op {
PASID_LU_OP_PRESERVE = 1,
PASID_LU_OP_UNPRESERVE,
--
2.56.0.257.gf7497c7d27-goog
next prev parent reply other threads:[~2026-10-25 2:19 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-25 2:19 [PATCH v6 00/18] iommu: Add live update state preservation Samiullah Khawaja
2026-10-25 2:19 ` [PATCH v6 01/18] iommu: Implement IOMMU Live update FLB callbacks Samiullah Khawaja
2026-10-25 2:19 ` [PATCH v6 02/18] iommu/pages: Add APIs to preserve/unpreserve/restore iommu pages Samiullah Khawaja
2026-10-25 2:19 ` [PATCH v6 03/18] iommupt: Implement preserve/unpreserve/restore callbacks Samiullah Khawaja
2026-10-25 2:19 ` [PATCH v6 04/18] iommu: Implement IOMMU domain preservation Samiullah Khawaja
2026-10-25 2:19 ` [PATCH v6 05/18] iommu: Implement device and IOMMU HW preservation Samiullah Khawaja
2026-10-25 2:19 ` [PATCH v6 06/18] iommu/vt-d: Implement device and iommu preserve/unpreserve ops Samiullah Khawaja
2026-10-25 2:19 ` [PATCH v6 07/18] iommu/vt-d: Clear unpreserved context entries during shutdown Samiullah Khawaja
2026-10-25 2:19 ` [PATCH v6 08/18] iommu: Add APIs to get iommu and device preserved state Samiullah Khawaja
2026-10-25 2:19 ` [PATCH v6 09/18] iommu/vt-d: Combine disable_dmar_iommu() and free_dmar_iommu() Samiullah Khawaja
2026-10-25 2:19 ` [PATCH v6 10/18] iommu/vt-d: Restore IOMMU state and reclaimed domain ids Samiullah Khawaja
2026-10-25 2:19 ` [PATCH v6 11/18] iommu/vt-d: Preserve PASID table of preserved device Samiullah Khawaja
2026-10-25 2:19 ` [PATCH v6 12/18] iommu: Restore and reattach preserved domains to devices Samiullah Khawaja
2026-10-25 2:19 ` Samiullah Khawaja [this message]
2026-10-25 2:19 ` [PATCH v6 14/18] iommufd: Implement ioctl to mark HWPT for preservation Samiullah Khawaja
2026-10-25 2:19 ` [PATCH v6 15/18] iommufd: Persist iommu hardware pagetables for live update Samiullah Khawaja
2026-10-25 2:19 ` [PATCH v6 16/18] iommufd: Add APIs to preserve/unpreserve a vfio cdev Samiullah Khawaja
2026-10-25 2:19 ` [PATCH v6 17/18] vfio/pci: Preserve the iommufd state of the " Samiullah Khawaja
2026-10-25 2:19 ` [PATCH v6 18/18] iommufd/selftest: Add test to verify iommufd preservation Samiullah Khawaja
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