iommu/vt-d: Fix kdump kernels boot failure with scalable mode

[ Upstream commit 0c5f6c0d8201a809a6585b07b6263e9db2c874a3 ]

The translation table copying code for kdump kernels is currently based
on the extended root/context entry formats of ECS mode defined in older
VT-d v2.5, and doesn't handle the scalable mode formats. This causes
the kexec capture kernel boot failure with DMAR faults if the IOMMU was
enabled in scalable mode by the previous kernel.

The ECS mode has already been deprecated by the VT-d spec since v3.0 and
Intel IOMMU driver doesn't support this mode as there's no real hardware
implementation. Hence this converts ECS checking in copying table code
into scalable mode.

The existing copying code consumes a bit in the context entry as a mark
of copied entry. It needs to work for the old format as well as for the
extended context entries. As it's hard to find such a common bit for both
legacy and scalable mode context entries. This replaces it with a per-
IOMMU bitmap.

Fixes: 7373a8cc38197 ("iommu/vt-d: Setup context and enable RID2PASID support")
Cc: stable@vger.kernel.org
Reported-by: Jerry Snitselaar <jsnitsel@redhat.com>
Tested-by: Wen Jin <wen.jin@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20220817011035.3250131-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

1 files changed, 6 insertions, 3 deletions

diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 05a65eb155f7..81da7107e3bd 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -196,7 +196,6 @@
 #define ecap_dis(e)		(((e) >> 27) & 0x1)
 #define ecap_nest(e)		(((e) >> 26) & 0x1)
 #define ecap_mts(e)		(((e) >> 25) & 0x1)
-#define ecap_ecs(e)		(((e) >> 24) & 0x1)
 #define ecap_iotlb_offset(e) 	((((e) >> 8) & 0x3ff) * 16)
 #define ecap_max_iotlb_offset(e) (ecap_iotlb_offset(e) + 16)
 #define ecap_coherent(e)	((e) & 0x1)
@@ -264,7 +263,6 @@
 #define DMA_GSTS_CFIS (((u32)1) << 23)
 
 /* DMA_RTADDR_REG */
-#define DMA_RTADDR_RTT (((u64)1) << 11)
 #define DMA_RTADDR_SMT (((u64)1) << 10)
 
 /* CCMD_REG */
@@ -594,6 +592,7 @@ struct intel_iommu {
 #ifdef CONFIG_INTEL_IOMMU
 	unsigned long 	*domain_ids; /* bitmap of domains */
 	struct dmar_domain ***domains; /* ptr to domains */
+	unsigned long	*copied_tables; /* bitmap of copied tables */
 	spinlock_t	lock; /* protect context, domain ids */
 	struct root_entry *root_entry; /* virtual address */
 
@@ -713,6 +712,11 @@ static inline int first_pte_in_page(struct dma_pte *pte)
 	return !((unsigned long)pte & ~VTD_PAGE_MASK);
 }
 
+static inline bool context_present(struct context_entry *context)
+{
+	return (context->lo & 1);
+}
+
 extern struct dmar_drhd_unit * dmar_find_matched_drhd_unit(struct pci_dev *dev);
 extern int dmar_find_matched_atsr_unit(struct pci_dev *dev);
 
@@ -806,7 +810,6 @@ static inline void intel_iommu_debugfs_init(void) {}
 #endif /* CONFIG_INTEL_IOMMU_DEBUGFS */
 
 extern const struct attribute_group *intel_iommu_groups[];
-bool context_present(struct context_entry *context);
 struct context_entry *iommu_context_addr(struct intel_iommu *iommu, u8 bus,
 					 u8 devfn, int alloc);