From f88a68facd9a15b94f8c195d9d2c0b30c76c595a Mon Sep 17 00:00:00 2001 From: Tom Lendacky Date: Mon, 17 Jul 2017 16:10:09 -0500 Subject: x86/mm: Extend early_memremap() support with additional attrs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add early_memremap() support to be able to specify encrypted and decrypted mappings with and without write-protection. The use of write-protection is necessary when encrypting data "in place". The write-protect attribute is considered cacheable for loads, but not stores. This implies that the hardware will never give the core a dirty line with this memtype. Signed-off-by: Tom Lendacky Reviewed-by: Thomas Gleixner Reviewed-by: Borislav Petkov Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Brijesh Singh Cc: Dave Young Cc: Dmitry Vyukov Cc: Jonathan Corbet Cc: Konrad Rzeszutek Wilk Cc: Larry Woodman Cc: Linus Torvalds Cc: Matt Fleming Cc: Michael S. Tsirkin Cc: Paolo Bonzini Cc: Peter Zijlstra Cc: Radim Krčmář Cc: Rik van Riel Cc: Toshimitsu Kani Cc: kasan-dev@googlegroups.com Cc: kvm@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-efi@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/479b5832c30fae3efa7932e48f81794e86397229.1500319216.git.thomas.lendacky@amd.com Signed-off-by: Ingo Molnar --- arch/x86/mm/ioremap.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) (limited to 'arch/x86/mm/ioremap.c') diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 66ddf5e8ffc8..570201bbf442 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -417,6 +417,50 @@ void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr) iounmap((void __iomem *)((unsigned long)addr & PAGE_MASK)); } +#ifdef CONFIG_ARCH_USE_MEMREMAP_PROT +/* Remap memory with encryption */ +void __init *early_memremap_encrypted(resource_size_t phys_addr, + unsigned long size) +{ + return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_ENC); +} + +/* + * Remap memory with encryption and write-protected - cannot be called + * before pat_init() is called + */ +void __init *early_memremap_encrypted_wp(resource_size_t phys_addr, + unsigned long size) +{ + /* Be sure the write-protect PAT entry is set for write-protect */ + if (__pte2cachemode_tbl[_PAGE_CACHE_MODE_WP] != _PAGE_CACHE_MODE_WP) + return NULL; + + return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_ENC_WP); +} + +/* Remap memory without encryption */ +void __init *early_memremap_decrypted(resource_size_t phys_addr, + unsigned long size) +{ + return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_NOENC); +} + +/* + * Remap memory without encryption and write-protected - cannot be called + * before pat_init() is called + */ +void __init *early_memremap_decrypted_wp(resource_size_t phys_addr, + unsigned long size) +{ + /* Be sure the write-protect PAT entry is set for write-protect */ + if (__pte2cachemode_tbl[_PAGE_CACHE_MODE_WP] != _PAGE_CACHE_MODE_WP) + return NULL; + + return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_NOENC_WP); +} +#endif /* CONFIG_ARCH_USE_MEMREMAP_PROT */ + static pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)] __page_aligned_bss; static inline pmd_t * __init early_ioremap_pmd(unsigned long addr) -- cgit v1.2.3