On Thu, Jun 25, 2020 at 07:23:19PM +0200, Borislav Petkov wrote: > On Thu, Jun 18, 2020 at 01:08:33AM +0300, Jarkko Sakkinen wrote: > > Intel Software Guard eXtensions (SGX) is a set of CPU instructions that > > can be used by applications to set aside private regions of code and > > data. The code outside the SGX hosted software entity is disallowed to > > access the memory inside the enclave enforced by the CPU. We call these > > entities as enclaves. > > > > This commit implements a driver that provides an ioctl API to construct > > and run enclaves. Enclaves are constructed from pages residing in > > reserved physical memory areas. The contents of these pages can only be > > accessed when they are mapped as part of an enclave, by a hardware > > thread running inside the enclave. > > > > The starting state of an enclave consists of a fixed measured set of > > pages that are copied to the EPC during the construction process by > > using ENCLS leaf functions and Software Enclave Control Structure (SECS) > > that defines the enclave properties. > > > > Enclave are constructed by using ENCLS leaf functions ECREATE, EADD and > > EINIT. ECREATE initializes SECS, EADD copies pages from system memory to > > the EPC and EINIT check a given signed measurement and moves the enclave > > into a state ready for execution. > > > > An initialized enclave can only be accessed through special Thread Control > > Structure (TCS) pages by using ENCLU (ring-3 only) leaf EENTER. This leaf > > function converts a thread into enclave mode and continues the execution in > > the offset defined by the TCS provided to EENTER. An enclave is exited > > through syscall, exception, interrupts or by explicitly calling another > > ENCLU leaf EEXIT. > > > > The permissions, which enclave page is added will set the limit for maximum > > permissions that can be set for mmap() and mprotect(). This will > > effectively allow to build different security schemes between producers and > > consumers of enclaves. Later on we can increase granularity with LSM hooks > > for page addition (i.e. for producers) and mapping of the enclave (i.e. for > > consumers) > > > > Cc: linux-security-module@xxxxxxxxxxxxxxx > > Acked-by: Jethro Beekman <jethro@xxxxxxxxxxxx> > > Tested-by: Jethro Beekman <jethro@xxxxxxxxxxxx> > > Tested-by: Haitao Huang <haitao.huang@xxxxxxxxxxxxxxx> > > Tested-by: Chunyang Hui <sanqian.hcy@xxxxxxxxxx> > > Tested-by: Jordan Hand <jorhand@xxxxxxxxxxxxxxxxxxx> > > Tested-by: Nathaniel McCallum <npmccallum@xxxxxxxxxx> > > Tested-by: Seth Moore <sethmo@xxxxxxxxxx> > > Co-developed-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> > > Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> > > Co-developed-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx> > > Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx> > > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx> > > --- > > .../userspace-api/ioctl/ioctl-number.rst | 1 + > > arch/x86/include/uapi/asm/sgx.h | 66 ++ > > arch/x86/kernel/cpu/sgx/Makefile | 3 + > > arch/x86/kernel/cpu/sgx/driver.c | 194 +++++ > > arch/x86/kernel/cpu/sgx/driver.h | 30 + > > arch/x86/kernel/cpu/sgx/encl.c | 335 +++++++++ > > arch/x86/kernel/cpu/sgx/encl.h | 87 +++ > > arch/x86/kernel/cpu/sgx/ioctl.c | 706 ++++++++++++++++++ > > arch/x86/kernel/cpu/sgx/main.c | 11 + > > 9 files changed, 1433 insertions(+) > > create mode 100644 arch/x86/include/uapi/asm/sgx.h > > create mode 100644 arch/x86/kernel/cpu/sgx/driver.c > > create mode 100644 arch/x86/kernel/cpu/sgx/driver.h > > create mode 100644 arch/x86/kernel/cpu/sgx/encl.c > > create mode 100644 arch/x86/kernel/cpu/sgx/encl.h > > create mode 100644 arch/x86/kernel/cpu/sgx/ioctl.c > > > > diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst > > index 59472cd6a11d..35f713e3a267 100644 > > --- a/Documentation/userspace-api/ioctl/ioctl-number.rst > > +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst > > @@ -323,6 +323,7 @@ Code Seq# Include File Comments > > <mailto:tlewis@xxxxxxxxxxxxxx> > > 0xA3 90-9F linux/dtlk.h > > 0xA4 00-1F uapi/linux/tee.h Generic TEE subsystem > > +0xA4 00-1F uapi/asm/sgx.h Intel SGX subsystem (a legit conflict as TEE and SGX do not co-exist) > > 0xAA 00-3F linux/uapi/linux/userfaultfd.h > > 0xAB 00-1F linux/nbd.h > > 0xAC 00-1F linux/raw.h > > diff --git a/arch/x86/include/uapi/asm/sgx.h b/arch/x86/include/uapi/asm/sgx.h > > new file mode 100644 > > index 000000000000..5edb08ab8fd0 > > --- /dev/null > > +++ b/arch/x86/include/uapi/asm/sgx.h > > @@ -0,0 +1,66 @@ > > +/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) WITH Linux-syscall-note */ > > Checkpatch complains here: > > WARNING: 'SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) WITH Linux-syscall-note */' is not supported in LICENSES/... > #114: FILE: arch/x86/include/uapi/asm/sgx.h:1: > +/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) WITH Linux-syscall-note */ > > Also, you had all patches until now split nice and logically doing one > thing only. > > But this one is huge. Why? > > Why can't you split out the facilities which the driver uses: encl.[ch] > into a patch, then ioctl.c into a separate one and then the driver into > a third one? Or do they all belong together inseparably? > > I guess I'll find out eventually but it would've been nice if they were > split out... It's still kind a strongly connected set of functionalities, but I get your point. I'd consider splitting for a slighly different angle: 1. Commit for the base driver. 2. Commit for each ioctl, adding the necessary "framework" to get that piece of functionality completed. The order would be: A. Create B. Add C. Initialize Would be probably easier to review also this way because the commit kind of rationalizes why things exist. What do you think? /Jarkko /Jarkko /Jarkko
