During boot fetch the preserved state of IOMMU unit and if found then restore the state. - Reuse the root_table that was preserved in the previous kernel. - Reclaim the domain ids of the preserved domains for each preserved devices so these are not acquired by another domain. Signed-off-by: Samiullah Khawaja --- drivers/iommu/intel/iommu.c | 26 +++++++++++++++------ drivers/iommu/intel/iommu.h | 7 ++++++ drivers/iommu/intel/liveupdate.c | 40 ++++++++++++++++++++++++++++++++ 3 files changed, 66 insertions(+), 7 deletions(-) diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index c95de93fb72f..8acb7f8a7627 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -222,12 +222,12 @@ static void clear_translation_pre_enabled(struct intel_iommu *iommu) iommu->flags &= ~VTD_FLAG_TRANS_PRE_ENABLED; } -static void init_translation_status(struct intel_iommu *iommu) +static void init_translation_status(struct intel_iommu *iommu, bool restoring) { u32 gsts; gsts = readl(iommu->reg + DMAR_GSTS_REG); - if (gsts & DMA_GSTS_TES) + if (!restoring && (gsts & DMA_GSTS_TES)) iommu->flags |= VTD_FLAG_TRANS_PRE_ENABLED; } @@ -670,10 +670,16 @@ void dmar_fault_dump_ptes(struct intel_iommu *iommu, u16 source_id, #endif /* iommu handling */ -static int iommu_alloc_root_entry(struct intel_iommu *iommu) +static int iommu_alloc_root_entry(struct intel_iommu *iommu, struct iommu_ser *restored_state) { struct root_entry *root; + if (restored_state) { + intel_iommu_liveupdate_restore_root_table(iommu, restored_state); + __iommu_flush_cache(iommu, iommu->root_entry, ROOT_SIZE); + return 0; + } + root = iommu_alloc_pages_node_sz(iommu->node, GFP_ATOMIC, SZ_4K); if (!root) { pr_err("Allocating root entry for %s failed\n", @@ -1614,6 +1620,7 @@ static int copy_translation_tables(struct intel_iommu *iommu) static int __init init_dmars(void) { + struct iommu_ser *iommu_ser = NULL; struct dmar_drhd_unit *drhd; struct intel_iommu *iommu; int ret; @@ -1636,8 +1643,10 @@ static int __init init_dmars(void) intel_pasid_max_id); } + iommu_ser = iommu_get_preserved_data(iommu->reg_phys, IOMMU_INTEL); + intel_iommu_init_qi(iommu); - init_translation_status(iommu); + init_translation_status(iommu, !!iommu_ser); if (translation_pre_enabled(iommu) && !is_kdump_kernel()) { iommu_disable_translation(iommu); @@ -1651,7 +1660,7 @@ static int __init init_dmars(void) * we could share the same root & context tables * among all IOMMU's. Need to Split it later. */ - ret = iommu_alloc_root_entry(iommu); + ret = iommu_alloc_root_entry(iommu, iommu_ser); if (ret) goto free_iommu; @@ -2110,15 +2119,18 @@ int dmar_parse_one_satc(struct acpi_dmar_header *hdr, void *arg) static int intel_iommu_add(struct dmar_drhd_unit *dmaru) { struct intel_iommu *iommu = dmaru->iommu; + struct iommu_ser *iommu_ser = NULL; int ret; + iommu_ser = iommu_get_preserved_data(iommu->reg_phys, IOMMU_INTEL); + /* * Disable translation if already enabled prior to OS handover. */ - if (iommu->gcmd & DMA_GCMD_TE) + if (!iommu_ser && iommu->gcmd & DMA_GCMD_TE) iommu_disable_translation(iommu); - ret = iommu_alloc_root_entry(iommu); + ret = iommu_alloc_root_entry(iommu, iommu_ser); if (ret) goto out; diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h index 70032e86437d..d7bf63aff17d 100644 --- a/drivers/iommu/intel/iommu.h +++ b/drivers/iommu/intel/iommu.h @@ -1283,6 +1283,8 @@ int intel_iommu_preserve_device(struct device *dev, struct device_ser *device_se void intel_iommu_unpreserve_device(struct device *dev, struct device_ser *device_ser); int intel_iommu_preserve(struct iommu_device *iommu, struct iommu_ser *iommu_ser); void intel_iommu_unpreserve(struct iommu_device *iommu, struct iommu_ser *iommu_ser); +void intel_iommu_liveupdate_restore_root_table(struct intel_iommu *iommu, + struct iommu_ser *iommu_ser); #else static inline int intel_iommu_preserve_device(struct device *dev, struct device_ser *device_ser) { @@ -1301,6 +1303,11 @@ static inline int intel_iommu_preserve(struct iommu_device *iommu, struct iommu_ static inline void intel_iommu_unpreserve(struct iommu_device *iommu, struct iommu_ser *iommu_ser) { } + +static inline void intel_iommu_liveupdate_restore_root_table(struct intel_iommu *iommu, + struct iommu_ser *iommu_ser) +{ +} #endif #ifdef CONFIG_INTEL_IOMMU_SVM diff --git a/drivers/iommu/intel/liveupdate.c b/drivers/iommu/intel/liveupdate.c index 82ba1daf1711..6dcb5783d1db 100644 --- a/drivers/iommu/intel/liveupdate.c +++ b/drivers/iommu/intel/liveupdate.c @@ -73,6 +73,46 @@ static int preserve_iommu_context(struct intel_iommu *iommu) return ret; } +static void restore_iommu_context(struct intel_iommu *iommu) +{ + struct context_entry *context; + int i; + + for (i = 0; i < ROOT_ENTRY_NR; i++) { + context = iommu_context_addr(iommu, i, 0, 0); + if (context) + BUG_ON(!kho_restore_folio(virt_to_phys(context))); + + if (!sm_supported(iommu)) + continue; + + context = iommu_context_addr(iommu, i, 0x80, 0); + if (context) + BUG_ON(!kho_restore_folio(virt_to_phys(context))); + } +} + +static int __restore_used_domain_ids(struct device_ser *ser, void *arg) +{ + int id = ser->domain_iommu_ser.did; + struct intel_iommu *iommu = arg; + + ida_alloc_range(&iommu->domain_ida, id, id, GFP_ATOMIC); + return 0; +} + +void intel_iommu_liveupdate_restore_root_table(struct intel_iommu *iommu, + struct iommu_ser *iommu_ser) +{ + BUG_ON(!kho_restore_folio(iommu_ser->intel.root_table)); + iommu->root_entry = __va(iommu_ser->intel.root_table); + + restore_iommu_context(iommu); + iommu_for_each_preserved_device(__restore_used_domain_ids, iommu); + pr_info("Restored IOMMU[0x%llx] Root Table at: 0x%llx\n", + iommu->reg_phys, iommu_ser->intel.root_table); +} + int intel_iommu_preserve_device(struct device *dev, struct device_ser *device_ser) { struct device_domain_info *info = dev_iommu_priv_get(dev); -- 2.53.0.rc2.204.g2597b5adb4-goog