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x86/kexec: Set the C-bit in the identity map page table when SEV is active

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When SEV is active, the second kernel image is loaded into encrypted
memory. For that, make sure that when kexec builds the identity mapping
page table, the memory is encrypted (i.e., _PAGE_ENC is set).

 [ bp: Sort local args and OR in _PAGE_ENC for more clarity. ]

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>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: bhe@redhat.com
Cc: dyoung@redhat.com
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: kexec@lists.infradead.org
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190430074421.7852-3-lijiang@redhat.com
This commit is contained in:
Lianbo Jiang 2019-04-30 15:44:20 +08:00 committed by Borislav Petkov
parent 1a79c1b8a0
commit 85784d16c2
1 changed files with 13 additions and 3 deletions
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16
arch/x86/kernel/machine_kexec_64.c
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@ -50,12 +50,13 @@ static void free_transition_pgtable(struct kimage *image)
static int init_transition_pgtable(struct kimage *image, pgd_t *pgd)
{
pgprot_t prot = PAGE_KERNEL_EXEC_NOENC;
unsigned long vaddr, paddr;
int result = -ENOMEM;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
unsigned long vaddr, paddr;
int result = -ENOMEM;
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 |= _PAGE_ENC;
}
if (direct_gbpages)
info.direct_gbpages = true;