lkml.org 
[lkml]   [2019]   [May]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH 2/3 v3] x86/kexec: Set the C-bit in the identity map page table when SEV is active
On Tue, Apr 30, 2019 at 03:44:20PM +0800, Lianbo Jiang wrote:
> When SEV is active, the second kernel image is loaded into the
> encrypted memory. Lets make sure that when kexec builds the
> identity mapping page table it adds the memory encryption mask(C-bit).
>
> Co-developed-by: Brijesh Singh <brijesh.singh@amd.com>
> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
> Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
> ---
> arch/x86/kernel/machine_kexec_64.c | 12 +++++++++++-
> 1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
> index f60611531d17..11fe352f7344 100644
> --- a/arch/x86/kernel/machine_kexec_64.c
> +++ b/arch/x86/kernel/machine_kexec_64.c
> @@ -56,6 +56,7 @@ static int init_transition_pgtable(struct kimage *image, pgd_t *pgd)
> pte_t *pte;
> unsigned long vaddr, paddr;
> int result = -ENOMEM;
> + pgprot_t prot = PAGE_KERNEL_EXEC_NOENC;
>
> vaddr = (unsigned long)relocate_kernel;
> paddr = __pa(page_address(image->control_code_page)+PAGE_SIZE);
> @@ -92,7 +93,11 @@ static int init_transition_pgtable(struct kimage *image, pgd_t *pgd)
> set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE));
> }
> pte = pte_offset_kernel(pmd, vaddr);
> - set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL_EXEC_NOENC));
> +
> + if (sev_active())
> + prot = PAGE_KERNEL_EXEC;
> +
> + set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, prot));
> return 0;
> err:
> return result;
> @@ -129,6 +134,11 @@ static int init_pgtable(struct kimage *image, unsigned long start_pgtable)
> level4p = (pgd_t *)__va(start_pgtable);
> clear_page(level4p);
>
> + if (sev_active()) {
> + info.page_flag |= _PAGE_ENC;
> + info.kernpg_flag = _KERNPG_TABLE;

kernpg_flag above is initialized to _KERNPG_TABLE_NOENC so you can do here

info.kernpg_flag |= _PAGE_ENC;

too, to make it even more clear what this does, right?

IOW:

diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
index 783ce5184405..16c37fe489bc 100644
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -135,8 +135,8 @@ static int init_pgtable(struct kimage *image, unsigned long start_pgtable)
clear_page(level4p);

if (sev_active()) {
- info.page_flag |= _PAGE_ENC;
- info.kernpg_flag = _KERNPG_TABLE;
+ info.page_flag |= _PAGE_ENC;
+ info.kernpg_flag |= _PAGE_ENC;
}

if (direct_gbpages)

--
Regards/Gruss,
Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

\
 
 \ /
  Last update: 2019-05-15 15:31    [W:0.080 / U:2.484 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site