This patch adds support to be change the memory encryption attribute for one or more memory pages. Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx> --- arch/x86/include/asm/cacheflush.h | 3 + arch/x86/include/asm/mem_encrypt.h | 13 ++++++ arch/x86/mm/mem_encrypt.c | 43 +++++++++++++++++++++ arch/x86/mm/pageattr.c | 75 ++++++++++++++++++++++++++++++++++++ 4 files changed, 134 insertions(+) diff --git a/arch/x86/include/asm/cacheflush.h b/arch/x86/include/asm/cacheflush.h index 61518cf..bfb08e5 100644 --- a/arch/x86/include/asm/cacheflush.h +++ b/arch/x86/include/asm/cacheflush.h @@ -13,6 +13,7 @@ * Executability : eXeutable, NoteXecutable * Read/Write : ReadOnly, ReadWrite * Presence : NotPresent + * Encryption : ENCrypted, DECrypted * * Within a category, the attributes are mutually exclusive. * @@ -48,6 +49,8 @@ int set_memory_ro(unsigned long addr, int numpages); int set_memory_rw(unsigned long addr, int numpages); int set_memory_np(unsigned long addr, int numpages); int set_memory_4k(unsigned long addr, int numpages); +int set_memory_enc(unsigned long addr, int numpages); +int set_memory_dec(unsigned long addr, int numpages); int set_memory_array_uc(unsigned long *addr, int addrinarray); int set_memory_array_wc(unsigned long *addr, int addrinarray); diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h index 2785493..5616ed1 100644 --- a/arch/x86/include/asm/mem_encrypt.h +++ b/arch/x86/include/asm/mem_encrypt.h @@ -23,6 +23,9 @@ extern unsigned long sme_me_mask; u8 sme_get_me_loss(void); +int sme_set_mem_enc(void *vaddr, unsigned long size); +int sme_set_mem_dec(void *vaddr, unsigned long size); + void __init sme_early_mem_enc(resource_size_t paddr, unsigned long size); void __init sme_early_mem_dec(resource_size_t paddr, @@ -44,6 +47,16 @@ static inline u8 sme_get_me_loss(void) return 0; } +static inline int sme_set_mem_enc(void *vaddr, unsigned long size) +{ + return 0; +} + +static inline int sme_set_mem_dec(void *vaddr, unsigned long size) +{ + return 0; +} + static inline void __init sme_early_mem_enc(resource_size_t paddr, unsigned long size) { diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c index f35a646..b0f39c5 100644 --- a/arch/x86/mm/mem_encrypt.c +++ b/arch/x86/mm/mem_encrypt.c @@ -14,12 +14,55 @@ #include <linux/mm.h> #include <asm/mem_encrypt.h> +#include <asm/cacheflush.h> #include <asm/tlbflush.h> #include <asm/fixmap.h> /* Buffer used for early in-place encryption by BSP, no locking needed */ static char me_early_buffer[PAGE_SIZE] __aligned(PAGE_SIZE); +int sme_set_mem_enc(void *vaddr, unsigned long size) +{ + unsigned long addr, numpages; + + if (!sme_me_mask) + return 0; + + addr = (unsigned long)vaddr & PAGE_MASK; + numpages = PAGE_ALIGN(size) >> PAGE_SHIFT; + + /* + * The set_memory_xxx functions take an integer for numpages, make + * sure it doesn't exceed that. + */ + if (numpages > INT_MAX) + return -EINVAL; + + return set_memory_enc(addr, numpages); +} +EXPORT_SYMBOL_GPL(sme_set_mem_enc); + +int sme_set_mem_dec(void *vaddr, unsigned long size) +{ + unsigned long addr, numpages; + + if (!sme_me_mask) + return 0; + + addr = (unsigned long)vaddr & PAGE_MASK; + numpages = PAGE_ALIGN(size) >> PAGE_SHIFT; + + /* + * The set_memory_xxx functions take an integer for numpages, make + * sure it doesn't exceed that. + */ + if (numpages > INT_MAX) + return -EINVAL; + + return set_memory_dec(addr, numpages); +} +EXPORT_SYMBOL_GPL(sme_set_mem_dec); + /* * This routine does not change the underlying encryption setting of the * page(s) that map this memory. It assumes that eventually the memory is diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 72c292d..0ba9382 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -1728,6 +1728,81 @@ int set_memory_4k(unsigned long addr, int numpages) __pgprot(0), 1, 0, NULL); } +static int __set_memory_enc_dec(struct cpa_data *cpa) +{ + unsigned long addr; + int numpages; + int ret; + + if (*cpa->vaddr & ~PAGE_MASK) { + *cpa->vaddr &= PAGE_MASK; + + /* People should not be passing in unaligned addresses */ + WARN_ON_ONCE(1); + } + + addr = *cpa->vaddr; + numpages = cpa->numpages; + + /* Must avoid aliasing mappings in the highmem code */ + kmap_flush_unused(); + vm_unmap_aliases(); + + ret = __change_page_attr_set_clr(cpa, 1); + + /* Check whether we really changed something */ + if (!(cpa->flags & CPA_FLUSHTLB)) + goto out; + + /* + * On success we use CLFLUSH, when the CPU supports it to + * avoid the WBINVD. + */ + if (!ret && static_cpu_has(X86_FEATURE_CLFLUSH)) + cpa_flush_range(addr, numpages, 1); + else + cpa_flush_all(1); + +out: + return ret; +} + +int set_memory_enc(unsigned long addr, int numpages) +{ + struct cpa_data cpa; + + if (!sme_me_mask) + return 0; + + memset(&cpa, 0, sizeof(cpa)); + cpa.vaddr = &addr; + cpa.numpages = numpages; + cpa.mask_set = __pgprot(_PAGE_ENC); + cpa.mask_clr = __pgprot(0); + cpa.pgd = init_mm.pgd; + + return __set_memory_enc_dec(&cpa); +} +EXPORT_SYMBOL(set_memory_enc); + +int set_memory_dec(unsigned long addr, int numpages) +{ + struct cpa_data cpa; + + if (!sme_me_mask) + return 0; + + memset(&cpa, 0, sizeof(cpa)); + cpa.vaddr = &addr; + cpa.numpages = numpages; + cpa.mask_set = __pgprot(0); + cpa.mask_clr = __pgprot(_PAGE_ENC); + cpa.pgd = init_mm.pgd; + + return __set_memory_enc_dec(&cpa); +} +EXPORT_SYMBOL(set_memory_dec); + int set_pages_uc(struct page *page, int numpages) { unsigned long addr = (unsigned long)page_address(page); -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html