iommu/amd: Remap the IOMMU device table with the memory encryption mask for kdump

The kdump kernel copies the IOMMU device table from the old device table
which is encrypted when SME is enabled in the first kernel. So remap the
old device table with the memory encryption mask in the kdump kernel.

 [ bp: Massage commit message. ]

Signed-off-by: Lianbo Jiang <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Reviewed-by: Tom Lendacky <[email protected]>
Acked-by: Joerg Roedel <[email protected]>
Cc: [email protected]
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Cc: [email protected]
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Cc: [email protected]
Cc: [email protected]
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Link: https://lkml.kernel.org/r/[email protected]
This commit is contained in:
Lianbo Jiang 2018-09-30 11:10:32 +08:00 • committed by Borislav Petkov
commit 8780158cf9

View file

@ -902,12 +902,22 @@ static bool copy_device_table(void)
}
}
old_devtb_phys = entry & PAGE_MASK;
/*
* When SME is enabled in the first kernel, the entry includes the
* memory encryption mask(sme_me_mask), we must remove the memory
* encryption mask to obtain the true physical address in kdump kernel.
*/
old_devtb_phys = __sme_clr(entry) & PAGE_MASK;
if (old_devtb_phys >= 0x100000000ULL) {
pr_err("The address of old device table is above 4G, not trustworthy!\n");
return false;
}
old_devtb = memremap(old_devtb_phys, dev_table_size, MEMREMAP_WB);
old_devtb = (sme_active() && is_kdump_kernel())
? (__force void *)ioremap_encrypted(old_devtb_phys,
dev_table_size)
: memremap(old_devtb_phys, dev_table_size, MEMREMAP_WB);
if (!old_devtb)
return false;