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iommu/amd: Set translation valid bit only when IO page tables are in use

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On AMD system with SNP enabled, IOMMU hardware checks the host translation
valid (TV) and guest translation valid (GV) bits in the device table entry
(DTE) before accessing the corresponded page tables.

However, current IOMMU driver sets the TV bit for all devices regardless
of whether the host page table is in use. This results in
ILLEGAL_DEV_TABLE_ENTRY event for devices, which do not the host page
table root pointer set up.

Thefore, when SNP is enabled, only set TV bit when DMA remapping is not
used, which is when domain ID in the AMD IOMMU device table entry (DTE)
is zero.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Link: https://lore.kernel.org/r/20220713225651.20758-8-suravee.suthikulpanit@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Suravee Suthikulpanit 2022-07-13 17:56:49 -05:00 committed by Joerg Roedel
parent fb2accadaa
commit b9f0043e1e
2 changed files with 16 additions and 3 deletions
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3
drivers/iommu/amd/init.c
View File

@ -2569,7 +2569,8 @@ static void init_device_table_dma(struct amd_iommu_pci_seg *pci_seg)
for (devid = 0; devid <= pci_seg->last_bdf; ++devid) {
__set_dev_entry_bit(dev_table, devid, DEV_ENTRY_VALID);
__set_dev_entry_bit(dev_table, devid, DEV_ENTRY_TRANSLATION);
if (!amd_iommu_snp_en)
__set_dev_entry_bit(dev_table, devid, DEV_ENTRY_TRANSLATION);
}
}

16
drivers/iommu/amd/iommu.c
View File

@ -1552,7 +1552,15 @@ static void set_dte_entry(struct amd_iommu *iommu, u16 devid,
pte_root |= (domain->iop.mode & DEV_ENTRY_MODE_MASK)
<< DEV_ENTRY_MODE_SHIFT;
pte_root |= DTE_FLAG_IR | DTE_FLAG_IW | DTE_FLAG_V | DTE_FLAG_TV;
pte_root |= DTE_FLAG_IR | DTE_FLAG_IW | DTE_FLAG_V;
/*
* When SNP is enabled, Only set TV bit when IOMMU
* page translation is in use.
*/
if (!amd_iommu_snp_en || (domain->id != 0))
pte_root |= DTE_FLAG_TV;
flags = dev_table[devid].data[1];
@ -1612,7 +1620,11 @@ static void clear_dte_entry(struct amd_iommu *iommu, u16 devid)
struct dev_table_entry *dev_table = get_dev_table(iommu);
/* remove entry from the device table seen by the hardware */
dev_table[devid].data[0] = DTE_FLAG_V | DTE_FLAG_TV;
dev_table[devid].data[0] = DTE_FLAG_V;
if (!amd_iommu_snp_en)
dev_table[devid].data[0] |= DTE_FLAG_TV;
dev_table[devid].data[1] &= DTE_FLAG_MASK;
amd_iommu_apply_erratum_63(iommu, devid);