From 8780158cf977ea5f9912931a30b3d575b36dba22 Mon Sep 17 00:00:00 2001 From: Lianbo Jiang Date: Sun, 30 Sep 2018 11:10:32 +0800 Subject: [PATCH] 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 Signed-off-by: Borislav Petkov Reviewed-by: Tom Lendacky Acked-by: Joerg Roedel Cc: kexec@lists.infradead.org Cc: tglx@linutronix.de Cc: mingo@redhat.com Cc: hpa@zytor.com Cc: akpm@linux-foundation.org Cc: dan.j.williams@intel.com Cc: bhelgaas@google.com Cc: baiyaowei@cmss.chinamobile.com Cc: tiwai@suse.de Cc: brijesh.singh@amd.com Cc: dyoung@redhat.com Cc: bhe@redhat.com Link: https://lkml.kernel.org/r/20180930031033.22110-4-lijiang@redhat.com --- drivers/iommu/amd_iommu_init.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c index 84b3e4445d46..3931c7de7c69 100644 --- a/drivers/iommu/amd_iommu_init.c +++ b/drivers/iommu/amd_iommu_init.c @@ -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;