lkml.org 
[lkml]   [2018]   [Sep]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH v7 RESEND 3/4] iommu/amd: Remap the device table of IOMMU with the memory encryption mask for kdump
    Date
    In kdump kernel, it will copy the device table of IOMMU from the old device
    table, which is encrypted when SME is enabled in the first kernel. So we
    have to remap the old device table with the memory encryption mask.

    Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
    Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
    Acked-by: Joerg Roedel <jroedel@suse.de>
    ---
    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;

    --
    2.17.1
    \
     
     \ /
      Last update: 2018-09-27 09:21    [W:4.073 / U:0.200 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site