[PATCHv4 17/18] x86/mm: Handle encrypted memory in page_to_virt() and __pa()

From: Kirill A. Shutemov
Date: Tue Jun 26 2018 - 10:23:21 EST


Per-KeyID direct mappings require changes into how we find the right
virtual address for a page and virt-to-phys address translations.

page_to_virt() definition overwrites default macros provided by
<linux/mm.h>. We only overwrite the macros if MTKME is enabled
compile-time.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
arch/x86/include/asm/mktme.h | 3 +++
arch/x86/include/asm/page_64.h | 2 +-
2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/mktme.h b/arch/x86/include/asm/mktme.h
index ba83fba4f9b3..dbfbd955da98 100644
--- a/arch/x86/include/asm/mktme.h
+++ b/arch/x86/include/asm/mktme.h
@@ -29,6 +29,9 @@ void arch_free_page(struct page *page, int order);

int sync_direct_mapping(void);

+#define page_to_virt(x) \
+ (__va(PFN_PHYS(page_to_pfn(x))) + page_keyid(x) * direct_mapping_size)
+
#else
#define mktme_keyid_mask ((phys_addr_t)0)
#define mktme_nr_keyids 0
diff --git a/arch/x86/include/asm/page_64.h b/arch/x86/include/asm/page_64.h
index 53c32af895ab..ffad496aadad 100644
--- a/arch/x86/include/asm/page_64.h
+++ b/arch/x86/include/asm/page_64.h
@@ -23,7 +23,7 @@ static inline unsigned long __phys_addr_nodebug(unsigned long x)
/* use the carry flag to determine if x was < __START_KERNEL_map */
x = y + ((x > y) ? phys_base : (__START_KERNEL_map - PAGE_OFFSET));

- return x;
+ return x % direct_mapping_size;
}

#ifdef CONFIG_DEBUG_VIRTUAL
--
2.18.0