From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brijesh Singh Subject: Re: [RFC PATCH v2 15/32] x86: Add support for changing memory encryption attribute in early boot Date: Mon, 27 Mar 2017 10:07:00 -0500 Message-ID: References: <148846752022.2349.13667498174822419498.stgit@brijesh-build-machine> <148846772794.2349.1396854638510933455.stgit@brijesh-build-machine> <20170324171257.lgvqcdqec3nla5nb@pd.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Cc: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Return-path: In-Reply-To: <20170324171257.lgvqcdqec3nla5nb@pd.tnic> Sender: owner-linux-mm@kvack.org List-Id: linux-crypto.vger.kernel.org Hi Boris, On 03/24/2017 12:12 PM, Borislav Petkov wrote: >> } >> >> +static inline int __init early_set_memory_decrypted(void *addr, >> + unsigned long size) >> +{ >> + return 1; > ^^^^^^^^ > > return 1 when !CONFIG_AMD_MEM_ENCRYPT ? > > The non-early variants return 0. > I will fix it and use the same return value. >> +} >> + >> +static inline int __init early_set_memory_encrypted(void *addr, >> + unsigned long size) >> +{ >> + return 1; >> +} >> + >> #define __sme_pa __pa >> + unsigned long pfn, npages; >> + unsigned long addr = (unsigned long)vaddr & PAGE_MASK; >> + >> + /* We are going to change the physical page attribute from C=1 to C=0. >> + * Flush the caches to ensure that all the data with C=1 is flushed to >> + * memory. Any caching of the vaddr after function returns will >> + * use C=0. >> + */ > > Kernel comments style is: > > /* > * A sentence ending with a full-stop. > * Another sentence. ... > * More sentences. ... > */ > I will update to use kernel comment style. >> + clflush_cache_range(vaddr, size); >> + >> + npages = PAGE_ALIGN(size) >> PAGE_SHIFT; >> + pfn = slow_virt_to_phys((void *)addr) >> PAGE_SHIFT; >> + >> + return kernel_map_pages_in_pgd(init_mm.pgd, pfn, addr, npages, >> + flags & ~sme_me_mask); >> + >> +} >> + >> +int __init early_set_memory_decrypted(void *vaddr, unsigned long size) >> +{ >> + unsigned long flags = get_pte_flags((unsigned long)vaddr); > > So this does lookup_address()... > >> + return early_set_memory_enc_dec(vaddr, size, flags & ~sme_me_mask); > > ... and this does it too in slow_virt_to_phys(). So you do it twice per > vaddr. > > So why don't you define a __slow_virt_to_phys() helper - notice > the "__" - which returns flags in its second parameter and which > slow_virt_to_phys() calls with a NULL second parameter in the other > cases? > I will look into creating a helper function. thanks -Brijesh -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org