From mboxrd@z Thu Jan 1 00:00:00 1970 From: liushiwei Date: Sat, 28 Jan 2023 16:33:34 +0800 Subject: [PATCH 1/1] Add RISC-V TEE support Message-ID: <002f01d932f3$36610530$a3230f90$@eswincomputing.com> List-Id: To: opensbi@lists.infradead.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Hi, Atish Thank you for your reply. I submitted my ideas to https://github.com/riscv-non-isa/riscv-sbi-doc/pull/106 as requested by other members of the email. You can preview them at https://github.com/liushiwei007/riscv-sbi-doc/blob/master/riscv-sbi.adoc . I'm not sure if I need to send an email to tech-prs at lists.riscv.org or sig-trusted-computing at lists.riscv.org after submitting to riscv-sbi-doc? If so, Is it to send the patch of opensbi I submitted before? Regards, Liushiwei -----????----- ???: Atish Patra [mailto:atishp at atishpatra.org] ????: 2023?1?25? 3:12 ???: liushiwei ??: Himanshu Chauhan ; opensbi at lists.infradead.org; chenchaokai at eswincomputing.com ??: Re: ??: [PATCH 1/1] Add RISC-V TEE support On Wed, Jan 11, 2023 at 11:08 PM liushiwei wrote: > > Hi, Himanshu , These are my description: > > In my design, The entire linux space is called REE (Rich Execution > Environment), and TEE OS includes its user state called TEE (Trusted execution environment). > adding TEE functionality to opensbi requires two configuration items. > For example: > add CONFIG_SBI_ECALL_TEE=y in platform/generic/configs/defconfig file. > add CONFIG_TEE_LOAD_ADDR=0x27C000000 platform/generic/objects.mk. > The value of CONFIG_TEE_LOAD_ADDR depends on the actual memory layout, > It's a physical address. > > When TEE is configured, opensbi adds the following functionality: > 1. Boot TEE OS. > If TEE is enabled, tee_os_init() is called before entering > sbi_hart_switch_mode(). tee_os_init saves the current context, > sets a new trap stack address, and runs to CONFIG_TEE_LOAD_ADDR as configured > to complete TEE OS initialization. TEE OS returns via ecall, Go to opensbi > sbi_ecall_tee_handler and use the characteristic value RETURN_ENTRY_DONE > to indicate the return after the TEE OS completes booting. Check whether the > TEE OS boot successfully according to the parameter. If fails, > the system enters wfi and terminates the startup process of opensbi. If successful, > it returns REE to switch into TEE's vector. then trap stack memory is restored, > the context is restored, the tee_os_init call is returned, > and the rest of the process is performed. > 2. REE switches to TEE. > When the TEE OS boot successfully, it returns an entry vector for REE into the TEE. > It represents various entry points into TEE OS and is stored in opensbi's global variables. > It is the optee_vectors_t structure, which contains nine entry cases: > 1. yield_smc_entry; > 2. fast_smc_entry; > 3. cpu_on_entry; > 4. cpu_off_entry; > 5. cpu_resume_entry; > 6. cpu_suspend_entry; > 7. fiq_entry; > 8. system_off_entry; > 9. system_reset_entry; > yield_smc_entry means that this function entry TEE will start the thread function > and enter the user state of TEE. It may also switch back to REE with RPC function, > and then return to TEE after REE completes the corresponding function. > For the REE process that sent you this call, it may cause sleep. > > fast_smc_entry indicates that this is a quick function that returns after > the TEE OS does something, and that it does not cause the caller to sleep. > > yield_smc_entry and fast_smc_entry return opensbi use eigenvalue RETURN_CALL_DONE. > for yield_smc_entry, whether the call returns or the RPC returns is decided by linux. > > cpu_on_entry/cpu_off_entry/cpu_resume_entry/cpu_suspend_entry and > fiq_entry/system_off_entry/system_reset_entry they are not implemented currently. > > 3. TEE switches to REE. > opensbi needs to save the context when REE enters the TEE, > and restore the context when it returns from the TEE. > > 4. TEE/REE Request a special function. > We have some specific functions, like get hartid from TEE, > it need save and restore the TEE context. > > Data structure. > opensbi adds the sbi_save_context declaration > struct sbi_save_context { > struct sbi_trap_regs regs; > unsigned long sepc; > unsigned long satp; > unsigned long sstatus; > unsigned long sie; > unsigned long stvec; > unsigned long sscratch; > unsigned long scounteren; > unsigned long scause; > unsigned long stval; > unsigned long sip; > }; > sbi_save_context include sbi_trap_regs and S mode csr. Used to hold > the context of TEE or REE > > typedef struct optee_vectors { > optee_vector_isn_t yield_smc_entry; > optee_vector_isn_t fast_smc_entry; > optee_vector_isn_t cpu_on_entry; > optee_vector_isn_t cpu_off_entry; > optee_vector_isn_t cpu_resume_entry; > optee_vector_isn_t cpu_suspend_entry; > optee_vector_isn_t fiq_entry; > optee_vector_isn_t system_off_entry; > optee_vector_isn_t system_reset_entry; > } optee_vectors_t; > optee_vectors represent the various entry points into TEE OS. > > Variables defined by opensbi > optee_vectors_t *optee_vector_table; > struct sbi_save_context nsec_cpu_context[OPTEED_CORE_COUNT]; > struct sbi_save_context sec_cpu_context[OPTEED_CORE_COUNT]; > struct sbi_trap_regs cpu_start_context[OPTEED_CORE_COUNT]; > typedef ulong tee_tmp_trap_stack[1024]; > static tee_tmp_trap_stack tmp_stack[OPTEED_CORE_COUNT]; > > optee_vector_table value is assigned after the TEE OS boot succeeds. > nsec_cpu_context and sec_cpu_context is to save the context of TEE and REE, > cpu_start_context save the context of opensbi before tee_os_init enter TEE OS, > tee_tmp_stack is the trap stack when TEE OS return tee_os_init. > > Under the current design, REE does not enable interrupts when entering > TEE, and the entire TEE, including opensbi, is the process context of linux. > TEE processing must be brief and quick. > Great. Thanks. Your PR should include more details like this with proper FID allocation and description. In order to make it a standard RISC-V SBI extension, you need to present this in tech-prs mailing list (https://lists.riscv.org/g/tech-prs) and get it approved within the group. Here is the policy document[1] https://docs.google.com/document/d/1bQGHU-wD4uN4mU07oH9adpXbH51NqUbFxcL8qTTIqhA/edit I think it would be good if you can present your work in trusted computing SIG (https://lists.riscv.org/g/sig-trusted-computing) as well. > > Regards, > liushiwei > -----????----- > ???: Himanshu Chauhan [mailto:hchauhan at ventanamicro.com] > ????: 2023?1?11? 23:39 > ???: liushiwei > ??: opensbi at lists.infradead.org; chenchaokai at eswincomputing.com > ??: Re: ??: [PATCH 1/1] Add RISC-V TEE support > > On Wed, Jan 11, 2023 at 08:27:59PM +0800, liushiwei wrote: > > Do you mean hardware? Our hardware design referred to arm's > > trustzone technology. optee os is a software solution using arm > > trustzone hardware, which mainly includes REE(linux), TEE(optee os), > > ATF(ARM Trusted firmware), and then our software also developed > > these three parts. opensbi is similar to ATF. whether if this is what you want? > > The current committed code is not hardware-dependent, but just > > continues the idea of this workaround, and we may commit hardware-dependent code later. > > > No, I meant the software specification. > > > -----????----- > > ???: hchauhan at ventanamicro.com [mailto:hchauhan at ventanamicro.com] > > ????: 2023?1?11? 20:03 > > ???: 'liushiwei' ; opensbi at lists.infradead. > > org > > ??: chenchaokai at eswincomputing.com > > ??: RE: [PATCH 1/1] Add RISC-V TEE support > > > > -----Original Message----- > > > From: opensbi On Behalf Of > > > liushiwei > > > Sent: 11 January 2023 07:32 > > > To: opensbi at lists.infradead.org > > > Cc: chenchaokai at eswincomputing.com; liushiwei > > > > > Subject: [PATCH 1/1] Add RISC-V TEE support > > > > >RISC-V Trusted Executable Environment security software includes > > >linux, > > opensbi, and OP-TEE OS. linux is the non-secure domain, and OP-TEE > > OS is the secure domain. At boot time, opensbi boots OP->TEE OS and then starts linux. > > At runtime, opensbi acts as a secure monitor, responsible for > > context saving and restoring when switching between linux and OP-TEE OS. > > >TEE function is off by default, when using configuration is added > > >in the > > config and objects file, such as platform/generic/configs/defconfig > > add CONFIG_SBI_ECALL_TEE = y, In the >platform/generic/objects.mk > > add CONFIG_TEE_LOAD_ADDR = 0x27c000000, CONFIG_TEE_LOAD_ADDR is the > > starting address of the OP-TEE OS. > > > > Hi Liushiwei, > > > > Was there any formal specification or draft for this? Could you > > please point me to the draft or specification? > > > > Regards > > Himanshu > > > > -- > > opensbi mailing list > > opensbi at lists.infradead.org > > http://lists.infradead.org/mailman/listinfo/opensbi > > > > > -- > opensbi mailing list > opensbi at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/opensbi -- Regards, Atish