x86/kexec: Set the C-bit in the identity map page table when SEV is active (85784d16) · Commits · 戴 / test

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:

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

arch/x86/kernel/machine_kexec_64.c

+13 −3

Original line number	Diff line number	Diff line
		@@ -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;

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