lkml.org 
[lkml]   [2021]   [Aug]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH Part1 v5 15/38] x86/kernel: Make the bss.decrypted section shared in RMP table
    Date
    The encryption attribute for the bss.decrypted region is cleared in the
    initial page table build. This is because the section contains the data
    that need to be shared between the guest and the hypervisor.

    When SEV-SNP is active, just clearing the encryption attribute in the
    page table is not enough. The page state need to be updated in the RMP
    table.

    Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
    ---
    arch/x86/kernel/head64.c | 7 +++++++
    1 file changed, 7 insertions(+)

    diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
    index eee24b427237..a1711c4594fa 100644
    --- a/arch/x86/kernel/head64.c
    +++ b/arch/x86/kernel/head64.c
    @@ -143,7 +143,14 @@ static unsigned long sme_postprocess_startup(struct boot_params *bp, pmdval_t *p
    if (mem_encrypt_active()) {
    vaddr = (unsigned long)__start_bss_decrypted;
    vaddr_end = (unsigned long)__end_bss_decrypted;
    +
    for (; vaddr < vaddr_end; vaddr += PMD_SIZE) {
    + /*
    + * When SEV-SNP is active then transition the page to shared in the RMP
    + * table so that it is consistent with the page table attribute change.
    + */
    + early_snp_set_memory_shared(__pa(vaddr), __pa(vaddr), PTRS_PER_PMD);
    +
    i = pmd_index(vaddr);
    pmd[i] -= sme_get_me_mask();
    }
    --
    2.17.1
    \
     
     \ /
      Last update: 2021-08-20 17:22    [W:4.022 / U:0.220 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site