From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Lendacky Subject: Re: [PATCH v6 14/34] x86/mm: Insure that boot memory areas are mapped properly Date: Mon, 12 Jun 2017 08:31:58 -0500 Message-ID: <64d7cb4e-64fe-0882-ad17-fc3918c3a09a@amd.com> References: <20170607191309.28645.15241.stgit@tlendack-t1.amdoffice.net> <20170607191539.28645.70161.stgit@tlendack-t1.amdoffice.net> <20170610160119.bnx5ir5dj3i27igx@pd.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170610160119.bnx5ir5dj3i27igx-fF5Pk5pvG8Y@public.gmane.org> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Borislav Petkov Cc: linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Brijesh Singh , Toshimitsu Kani , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Matt Fleming , x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, Alexander Potapenko , "H. Peter Anvin" , Larry Woodman , linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Jonathan Corbet , linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kasan-dev-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, Ingo Molnar , Andrey Ryabinin , Dave Young , Rik van Riel , Arnd Bergmann , Andy Lutomirski , Thomas Gleixner , Dmitry Vyukov , kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, "Michael S. Tsirkin" List-Id: linux-efi@vger.kernel.org On 6/10/2017 11:01 AM, Borislav Petkov wrote: > On Wed, Jun 07, 2017 at 02:15:39PM -0500, Tom Lendacky wrote: >> The boot data and command line data are present in memory in a decrypted >> state and are copied early in the boot process. The early page fault >> support will map these areas as encrypted, so before attempting to copy >> them, add decrypted mappings so the data is accessed properly when copied. >> >> For the initrd, encrypt this data in place. Since the future mapping of the >> initrd area will be mapped as encrypted the data will be accessed properly. >> >> Signed-off-by: Tom Lendacky >> --- >> arch/x86/include/asm/mem_encrypt.h | 11 +++++ >> arch/x86/include/asm/pgtable.h | 3 + >> arch/x86/kernel/head64.c | 30 ++++++++++++-- >> arch/x86/kernel/setup.c | 9 ++++ >> arch/x86/mm/mem_encrypt.c | 77 ++++++++++++++++++++++++++++++++++++ >> 5 files changed, 126 insertions(+), 4 deletions(-) > > Some cleanups ontop in case you get to send v7: There will be a v7. > > diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h > index 61a704945294..5959a42dd4d5 100644 > --- a/arch/x86/include/asm/mem_encrypt.h > +++ b/arch/x86/include/asm/mem_encrypt.h > @@ -45,13 +45,8 @@ static inline void __init sme_early_decrypt(resource_size_t paddr, > { > } > > -static inline void __init sme_map_bootdata(char *real_mode_data) > -{ > -} > - > -static inline void __init sme_unmap_bootdata(char *real_mode_data) > -{ > -} > +static inline void __init sme_map_bootdata(char *real_mode_data) { } > +static inline void __init sme_unmap_bootdata(char *real_mode_data) { } > > static inline void __init sme_early_init(void) > { > diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c > index 2321f05045e5..32ebbe0ab04d 100644 > --- a/arch/x86/mm/mem_encrypt.c > +++ b/arch/x86/mm/mem_encrypt.c > @@ -132,6 +132,10 @@ static void __init __sme_map_unmap_bootdata(char *real_mode_data, bool map) > struct boot_params *boot_data; > unsigned long cmdline_paddr; > > + /* If SME is not active, the bootdata is in the correct state */ > + if (!sme_active()) > + return; > + > __sme_early_map_unmap_mem(real_mode_data, sizeof(boot_params), map); > boot_data = (struct boot_params *)real_mode_data; > > @@ -142,40 +146,22 @@ static void __init __sme_map_unmap_bootdata(char *real_mode_data, bool map) > cmdline_paddr = boot_data->hdr.cmd_line_ptr | > ((u64)boot_data->ext_cmd_line_ptr << 32); > > - if (cmdline_paddr) > - __sme_early_map_unmap_mem(__va(cmdline_paddr), > - COMMAND_LINE_SIZE, map); > + if (!cmdline_paddr) > + return; > + > + __sme_early_map_unmap_mem(__va(cmdline_paddr), COMMAND_LINE_SIZE, map); > + > + sme_early_pgtable_flush(); Yup, overall it definitely simplifies things. I have to call sme_early_pgtable_flush() even if cmdline_paddr is NULL, so I'll either keep the if and have one flush at the end or I can move the flush into __sme_early_map_unmap_mem(). I'm leaning towards the latter. Thanks, Tom > } > > void __init sme_unmap_bootdata(char *real_mode_data) > { > - /* If SME is not active, the bootdata is in the correct state */ > - if (!sme_active()) > - return; > - > - /* > - * The bootdata and command line aren't needed anymore so clear > - * any mapping of them. > - */ > __sme_map_unmap_bootdata(real_mode_data, false); > - > - sme_early_pgtable_flush(); > } > > void __init sme_map_bootdata(char *real_mode_data) > { > - /* If SME is not active, the bootdata is in the correct state */ > - if (!sme_active()) > - return; > - > - /* > - * The bootdata and command line will not be encrypted, so they > - * need to be mapped as decrypted memory so they can be copied > - * properly. > - */ > __sme_map_unmap_bootdata(real_mode_data, true); > - > - sme_early_pgtable_flush(); > } > > void __init sme_early_init(void) >