From: Borislav Petkov <bp@alien8.de>
To: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
linux-sgx@vger.kernel.org, akpm@linux-foundation.org,
dave.hansen@intel.com, sean.j.christopherson@intel.com,
nhorman@redhat.com, npmccallum@redhat.com,
haitao.huang@intel.com, andriy.shevchenko@linux.intel.com,
tglx@linutronix.de, kai.svahn@intel.com, josh@joshtriplett.org,
luto@kernel.org, kai.huang@intel.com, rientjes@google.com,
cedric.xing@intel.com, puiterwijk@redhat.com,
Serge Ayoun <serge.ayoun@intel.com>,
Jethro Beekman <jethro@fortanix.com>
Subject: Re: [PATCH v30 07/20] x86/sgx: Enumerate and track EPC sections
Date: Mon, 25 May 2020 11:23:04 +0200 [thread overview]
Message-ID: <20200525092304.GD25636@zn.tnic> (raw)
In-Reply-To: <20200515004410.723949-8-jarkko.sakkinen@linux.intel.com>
On Fri, May 15, 2020 at 03:43:57AM +0300, Jarkko Sakkinen wrote:
> +config INTEL_SGX
> + bool "Intel SGX"
> + depends on X86_64 && CPU_SUP_INTEL
> + select SRCU
> + select MMU_NOTIFIER
> + help
> + Intel(R) SGX is a set of CPU instructions that can be used by
> + applications to set aside private regions of code and data, referred
> + to as enclaves. An enclave's private memory can only be accessed by
> + code running within the enclave. Accesses from outside the enclave,
> + including other enclaves, are disallowed by hardware.
> +
> + If unsure, say N.
> +
Enabling this gives:
In file included from arch/x86/kernel/cpu/sgx/main.c:11:
arch/x86/kernel/cpu/sgx/encls.h:189:51: warning: ‘struct sgx_einittoken’ declared inside parameter list will not be visible outside of this definition or declaration
189 | static inline int __einit(void *sigstruct, struct sgx_einittoken *einittoken,
| ^~~~~~~~~~~~~~
In file included from arch/x86/kernel/cpu/sgx/reclaim.c:12:
arch/x86/kernel/cpu/sgx/encls.h:189:51: warning: ‘struct sgx_einittoken’ declared inside parameter list will not be visible outside of this definition or declaration
189 | static inline int __einit(void *sigstruct, struct sgx_einittoken *einittoken,
|
You need a forward declaration somewhere.
> config EFI
> bool "EFI runtime service support"
> depends on ACPI
> diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
> index 7dc4ad68eb41..45534fb81007 100644
> --- a/arch/x86/kernel/cpu/Makefile
> +++ b/arch/x86/kernel/cpu/Makefile
> @@ -46,6 +46,7 @@ obj-$(CONFIG_X86_MCE) += mce/
> obj-$(CONFIG_MTRR) += mtrr/
> obj-$(CONFIG_MICROCODE) += microcode/
> obj-$(CONFIG_X86_CPU_RESCTRL) += resctrl/
> +obj-$(CONFIG_INTEL_SGX) += sgx/
>
> obj-$(CONFIG_X86_LOCAL_APIC) += perfctr-watchdog.o
>
> diff --git a/arch/x86/kernel/cpu/sgx/Makefile b/arch/x86/kernel/cpu/sgx/Makefile
> new file mode 100644
> index 000000000000..2dec75916a5e
> --- /dev/null
> +++ b/arch/x86/kernel/cpu/sgx/Makefile
> @@ -0,0 +1,3 @@
> +obj-y += \
> + main.o \
> + reclaim.o
> diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
> new file mode 100644
> index 000000000000..38424c1e8341
> --- /dev/null
> +++ b/arch/x86/kernel/cpu/sgx/main.c
> @@ -0,0 +1,151 @@
> +// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
> +// Copyright(c) 2016-17 Intel Corporation.
> +
> +#include <linux/freezer.h>
> +#include <linux/highmem.h>
> +#include <linux/kthread.h>
> +#include <linux/pagemap.h>
> +#include <linux/ratelimit.h>
> +#include <linux/sched/signal.h>
> +#include <linux/slab.h>
> +#include "encls.h"
> +
> +struct sgx_epc_section sgx_epc_sections[SGX_MAX_EPC_SECTIONS];
> +int sgx_nr_epc_sections;
We have become very averse against global stuff. What is going to use
those, only sgx code I assume...?
> +static bool __init sgx_page_cache_init(void)
> +{
> + u32 eax, ebx, ecx, edx, type;
> + u64 pa, size;
> + int i;
> +
> + for (i = 0; i <= ARRAY_SIZE(sgx_epc_sections); i++) {
> + cpuid_count(SGX_CPUID, i + SGX_CPUID_FIRST_VARIABLE_SUB_LEAF,
> + &eax, &ebx, &ecx, &edx);
> +
> + type = eax & SGX_CPUID_SUB_LEAF_TYPE_MASK;
> + if (type == SGX_CPUID_SUB_LEAF_INVALID)
> + break;
> +
> + if (type != SGX_CPUID_SUB_LEAF_EPC_SECTION) {
> + pr_err_once("Unknown EPC section type: %u\n", type);
> + break;
> + }
> +
> + if (i == ARRAY_SIZE(sgx_epc_sections)) {
> + pr_warn("No free slot for an EPC section\n");
> + break;
> + }
This is also the loop termination: do we really need this warn or can
the loop simply do "i < ARRAY_SIZE" ?
If the warn is needed, it can be after the loop too.
> +
> + pa = sgx_calc_section_metric(eax, ebx);
> + size = sgx_calc_section_metric(ecx, edx);
> +
> + pr_info("EPC section 0x%llx-0x%llx\n", pa, pa + size - 1);
I'm assuming that's useful information to issue in dmesg?
> diff --git a/arch/x86/kernel/cpu/sgx/reclaim.c b/arch/x86/kernel/cpu/sgx/reclaim.c
> new file mode 100644
> index 000000000000..215371588a25
> --- /dev/null
> +++ b/arch/x86/kernel/cpu/sgx/reclaim.c
> @@ -0,0 +1,82 @@
> +// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
> +// Copyright(c) 2016-19 Intel Corporation.
> +
> +#include <linux/freezer.h>
> +#include <linux/highmem.h>
> +#include <linux/kthread.h>
> +#include <linux/pagemap.h>
> +#include <linux/ratelimit.h>
> +#include <linux/slab.h>
> +#include <linux/sched/mm.h>
> +#include <linux/sched/signal.h>
> +#include "encls.h"
> +
> +struct task_struct *ksgxswapd_tsk;
Same for this one: also shared only among sgx code?
> +/**
> + * enum sgx_epc_page_desc - bits and masks for an EPC page's descriptor
> + * %SGX_EPC_SECTION_MASK: SGX allows to have multiple EPC sections in the
> + * physical memory. The existing and near-future
> + * hardware defines at most eight sections, hence
> + * three bits to hold a section.
> + */
> +enum sgx_epc_page_desc {
> + SGX_EPC_SECTION_MASK = GENMASK_ULL(3, 0),
If that should be three bits, then it should be (2, 0). Because now you
have 4 bits:
# arch/x86/kernel/cpu/sgx/sgx.h:56: return &sgx_epc_sections[page->desc & SGX_EPC_SECTION_MASK];
andl $15, %edx #, _22
^^^
> + /* bits 12-63 are reserved for the physical page address of the page */
> +};
> +
> +#define SGX_MAX_EPC_SECTIONS (SGX_EPC_SECTION_MASK + 1)
> +
> +extern struct sgx_epc_section sgx_epc_sections[SGX_MAX_EPC_SECTIONS];
> +
> +static inline struct sgx_epc_section *sgx_epc_section(struct sgx_epc_page *page)
This function name needs a verb. "get" sounds fitting. :)
> +{
> + return &sgx_epc_sections[page->desc & SGX_EPC_SECTION_MASK];
> +}
> +
> +static inline void *sgx_epc_addr(struct sgx_epc_page *page)
Ditto.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2020-05-25 9:23 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-15 0:43 [PATCH v30 00/20] Intel SGX foundations Jarkko Sakkinen
2020-05-15 0:43 ` [PATCH v30 01/20] x86/cpufeatures: x86/msr: Add Intel SGX hardware bits Jarkko Sakkinen
2020-05-20 12:16 ` Borislav Petkov
2020-05-20 14:00 ` Jarkko Sakkinen
2020-05-15 0:43 ` [PATCH v30 02/20] x86/cpufeatures: x86/msr: Intel SGX Launch Control " Jarkko Sakkinen
2020-05-20 12:23 ` Borislav Petkov
2020-05-20 14:04 ` Jarkko Sakkinen
2020-05-15 0:43 ` [PATCH v30 03/20] x86/mm: x86/sgx: Signal SIGSEGV with PF_SGX Jarkko Sakkinen
2020-05-15 0:43 ` [PATCH v30 04/20] x86/sgx: Add SGX microarchitectural data structures Jarkko Sakkinen
2020-05-20 18:47 ` Borislav Petkov
2020-05-20 21:04 ` Sean Christopherson
2020-05-22 15:54 ` Jarkko Sakkinen
2020-05-22 16:13 ` Sean Christopherson
2020-05-22 19:50 ` Jarkko Sakkinen
2020-05-25 8:20 ` Borislav Petkov
2020-05-27 19:43 ` Jarkko Sakkinen
2020-05-15 0:43 ` [PATCH v30 05/20] x86/sgx: Add wrappers for ENCLS leaf functions Jarkko Sakkinen
2020-05-15 0:43 ` [PATCH v30 06/20] x86/cpu/intel: Detect SGX support Jarkko Sakkinen
2020-05-15 0:43 ` [PATCH v30 07/20] x86/sgx: Enumerate and track EPC sections Jarkko Sakkinen
2020-05-25 9:23 ` Borislav Petkov [this message]
2020-05-27 3:56 ` Sean Christopherson
2020-05-27 20:35 ` Borislav Petkov
2020-05-28 7:36 ` Jarkko Sakkinen
2020-05-28 5:25 ` Jarkko Sakkinen
2020-05-28 5:35 ` Jarkko Sakkinen
2020-05-28 6:14 ` Jarkko Sakkinen
2020-05-28 6:16 ` Jarkko Sakkinen
2020-05-28 5:13 ` Jarkko Sakkinen
2020-05-15 0:43 ` [PATCH v30 08/20] x86/sgx: Add functions to allocate and free EPC pages Jarkko Sakkinen
2020-05-26 12:52 ` Borislav Petkov
2020-05-27 4:21 ` Sean Christopherson
2020-05-27 20:46 ` Borislav Petkov
2020-05-28 0:52 ` Sean Christopherson
2020-05-28 6:51 ` Jarkko Sakkinen
2020-05-28 1:23 ` Jarkko Sakkinen
2020-05-28 1:36 ` Sean Christopherson
2020-05-28 6:52 ` Jarkko Sakkinen
2020-05-28 17:16 ` Borislav Petkov
2020-05-28 17:19 ` Sean Christopherson
2020-05-28 17:27 ` Borislav Petkov
2020-05-28 17:34 ` Sean Christopherson
2020-05-28 19:07 ` Jarkko Sakkinen
2020-05-28 19:59 ` Sean Christopherson
2020-05-29 3:28 ` Jarkko Sakkinen
2020-05-29 3:37 ` Sean Christopherson
2020-05-29 5:07 ` Jarkko Sakkinen
2020-05-29 8:12 ` Jarkko Sakkinen
2020-05-29 8:13 ` Jarkko Sakkinen
2020-05-29 3:38 ` Jarkko Sakkinen
2020-05-15 0:43 ` [PATCH v30 09/20] mm: Introduce vm_ops->may_mprotect() Jarkko Sakkinen
2020-05-29 12:10 ` Borislav Petkov
2020-05-29 18:18 ` Jarkko Sakkinen
2020-05-29 18:28 ` Dave Hansen
2020-05-31 23:12 ` Jarkko Sakkinen
2020-05-15 0:44 ` [PATCH v30 10/20] x86/sgx: Linux Enclave Driver Jarkko Sakkinen
2020-05-21 19:12 ` Sean Christopherson
2020-05-22 19:26 ` Jarkko Sakkinen
2020-05-22 19:39 ` Jarkko Sakkinen
2020-05-22 3:33 ` Sean Christopherson
2020-05-15 0:44 ` [PATCH v30 11/20] x86/sgx: Add provisioning Jarkko Sakkinen
2020-05-15 0:44 ` [PATCH v30 12/20] x86/sgx: Add a page reclaimer Jarkko Sakkinen
2020-05-22 6:58 ` Sean Christopherson
2020-05-22 19:57 ` Jarkko Sakkinen
2020-05-22 21:52 ` Sean Christopherson
2020-05-22 7:15 ` Sean Christopherson
2020-05-22 19:47 ` Jarkko Sakkinen
2020-05-15 0:44 ` [PATCH v30 13/20] x86/sgx: ptrace() support for the SGX driver Jarkko Sakkinen
2020-05-15 0:44 ` [PATCH v30 14/20] x86/vdso: Add support for exception fixup in vDSO functions Jarkko Sakkinen
2020-05-15 0:44 ` [PATCH v30 15/20] x86/fault: Add helper function to sanitize error code Jarkko Sakkinen
2020-05-15 0:44 ` [PATCH v30 16/20] x86/traps: Attempt to fixup exceptions in vDSO before signaling Jarkko Sakkinen
2020-05-15 0:44 ` [PATCH v30 17/20] x86/vdso: Implement a vDSO for Intel SGX enclave call Jarkko Sakkinen
2020-05-15 0:44 ` [PATCH v30 18/20] selftests/x86: Add a selftest for SGX Jarkko Sakkinen
2020-05-15 0:44 ` [PATCH v30 19/20] docs: x86/sgx: Document SGX micro architecture and kernel internals Jarkko Sakkinen
2020-05-15 0:44 ` [PATCH v30 20/20] x86/sgx: Update MAINTAINERS Jarkko Sakkinen
2020-05-16 8:57 ` [PATCH] x86/cpu/intel: Add nosgx kernel parameter Jarkko Sakkinen
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