From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: x86@kernel.org, platform-driver-x86@vger.kernel.org
Cc: dave.hansen@intel.com, sean.j.christopherson@intel.com,
nhorman@redhat.com, npmccallum@redhat.com, serge.ayoun@intel.com,
shay.katz-zamir@intel.com, linux-sgx@vger.kernel.org,
andriy.shevchenko@linux.intel.com,
Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"H. Peter Anvin" <hpa@zytor.com>,
Suresh Siddha <suresh.b.siddha@intel.com>,
linux-kernel@vger.kernel.org (open list:X86 ARCHITECTURE (32-BIT
AND 64-BIT))
Subject: [PATCH v14 13/19] x86/sgx: Enclave Page Cache (EPC) memory manager
Date: Tue, 25 Sep 2018 16:06:50 +0300 [thread overview]
Message-ID: <20180925130845.9962-14-jarkko.sakkinen@linux.intel.com> (raw)
In-Reply-To: <20180925130845.9962-1-jarkko.sakkinen@linux.intel.com>
Add a Enclave Page Cache (EPC) memory manager that can be used to
allocate and free EPC pages.
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/include/asm/sgx.h | 7 ++-
arch/x86/kernel/cpu/intel_sgx.c | 86 +++++++++++++++++++++++++++++++++
2 files changed, 92 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h
index 468e609147cd..6ea5a6dbd36d 100644
--- a/arch/x86/include/asm/sgx.h
+++ b/arch/x86/include/asm/sgx.h
@@ -14,6 +14,7 @@
struct sgx_epc_page {
unsigned long desc;
+ void *owner;
struct list_head list;
};
@@ -65,7 +66,7 @@ static inline void __iomem *sgx_epc_addr(struct sgx_epc_page *page)
return section->va + (page->desc & PAGE_MASK) - section->pa;
}
-/**
+/*
* ENCLS_FAULT_FLAG - flag signifying an ENCLS return code is a trapnr
*
* ENCLS has its own (positive value) error codes and also generates
@@ -309,4 +310,8 @@ static inline int __emodt(struct sgx_secinfo *secinfo, void __iomem *addr)
return __encls_ret_2(SGX_EMODT, secinfo, addr);
}
+struct sgx_epc_page *sgx_alloc_page(void *owner, bool reclaim);
+int __sgx_free_page(struct sgx_epc_page *page);
+void sgx_free_page(struct sgx_epc_page *page);
+
#endif /* _ASM_X86_SGX_H */
diff --git a/arch/x86/kernel/cpu/intel_sgx.c b/arch/x86/kernel/cpu/intel_sgx.c
index b24d6287442d..ef30d6730859 100644
--- a/arch/x86/kernel/cpu/intel_sgx.c
+++ b/arch/x86/kernel/cpu/intel_sgx.c
@@ -19,6 +19,92 @@ EXPORT_SYMBOL_GPL(sgx_epc_sections);
static int sgx_nr_epc_sections;
+/**
+ * sgx_alloc_page - Allocate an EPC page
+ * @owner: the owner of the EPC page
+ * @reclaim: wait and reclaim pages up until we get one
+ *
+ * Try to grab a page from the free EPC page list. If there is a free page
+ * available, it is returned to the caller. The @reclaim parameter hints
+ * the EPC memory manager to swap pages when required.
+ *
+ * Return:
+ * a pointer to a &struct sgx_epc_page instace,
+ * -errno on error
+ */
+struct sgx_epc_page *sgx_alloc_page(void *owner, bool reclaim)
+{
+ struct sgx_epc_section *section;
+ struct sgx_epc_page *page;
+ int i;
+
+ for (i = 0; i < sgx_nr_epc_sections; i++) {
+ section = &sgx_epc_sections[i];
+ spin_lock(§ion->lock);
+ if (section->free_cnt) {
+ page = section->pages[section->free_cnt - 1];
+ section->free_cnt--;
+ }
+ spin_unlock(§ion->lock);
+
+ if (page) {
+ page->owner = owner;
+ return page;
+ }
+ }
+
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(sgx_alloc_page);
+
+/**
+ * __sgx_free_page - Free an EPC page
+ * @page: pointer a previously allocated EPC page
+ *
+ * Invaldate an EPC page and insert it back to the list of free pages.
+ *
+ * Return:
+ * 0 on success
+ * -EBUSY if the page cannot be removed from the active list
+ * SGX error code if EREMOVE fails
+ */
+int __sgx_free_page(struct sgx_epc_page *page)
+{
+ struct sgx_epc_section *section = sgx_epc_section(page);
+ int ret;
+
+ ret = __eremove(sgx_epc_addr(page));
+ if (ret)
+ return ret;
+
+ spin_lock(§ion->lock);
+ section->pages[section->free_cnt++] = page;
+ spin_unlock(§ion->lock);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(__sgx_free_page);
+
+/**
+ * sgx_free_page - Free an EPC page and WARN on failure
+ * @page: pointer to a previously allocated EPC page
+ *
+ * EREMOVE an EPC page and insert it back to the list of free pages.
+ * If the page is reclaimable, deletes it from the active page list.
+ * WARN on any failure. For use when the call site cannot (or chooses
+ * not to) handle failure, i.e. the page is leaked on failure.
+ */
+void sgx_free_page(struct sgx_epc_page *page)
+{
+ int ret;
+
+ ret = __sgx_free_page(page);
+ WARN(ret < 0, "sgx: cannot free page, reclaim in-progress");
+ WARN(ret > 0, "sgx: EREMOVE returned %d (0x%x)", ret, ret);
+}
+EXPORT_SYMBOL_GPL(sgx_free_page);
+
+
static __init void sgx_free_epc_section(struct sgx_epc_section *section)
{
int i;
--
2.17.1
next prev parent reply other threads:[~2018-09-25 13:13 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-25 13:06 [PATCH v14 00/19] Intel SGX1 support Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 01/19] x86/sgx: Update MAINTAINERS Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 02/19] x86/sgx: Architectural structures Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 03/19] x86/cpufeature: Add SGX and SGX_LC CPU features Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 04/19] x86/cpufeatures: Add SGX feature bits Jarkko Sakkinen
2018-09-25 16:48 ` Borislav Petkov
2018-09-26 11:11 ` Jarkko Sakkinen
2018-09-26 11:36 ` Borislav Petkov
2018-09-27 13:16 ` Jarkko Sakkinen
2018-09-27 13:51 ` Borislav Petkov
2018-09-27 14:52 ` Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 05/19] x86/msr: Add SGX definitions to msr-index.h Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 06/19] x86/mm: x86/sgx: Add new 'PF_SGX' page fault error code bit Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 07/19] x86/fault: x86/mm/pkeys: relocate stale comment regarding OSPKE Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 08/19] signal: x86/sgx: Add SIGSEGV siginfo code for SGX EPCM fault Jarkko Sakkinen
2018-09-26 19:14 ` Sean Christopherson
2018-09-27 18:41 ` Eric W. Biederman
2018-09-25 13:06 ` [PATCH v14 09/19] x86/mm: x86/sgx: Signal SEGV_SGXERR for #PFs w/ PF_SGX Jarkko Sakkinen
2018-09-25 22:53 ` Andy Lutomirski
2018-09-26 17:35 ` Sean Christopherson
2018-09-26 18:12 ` Andy Lutomirski
2018-09-26 20:16 ` Dave Hansen
2018-09-26 20:44 ` Sean Christopherson
2018-09-26 20:49 ` Dave Hansen
2018-09-26 21:15 ` Andy Lutomirski
2018-09-26 21:45 ` Dave Hansen
2018-09-26 22:37 ` Andy Lutomirski
2018-09-27 14:21 ` Jarkko Sakkinen
2018-09-27 14:41 ` Andy Lutomirski
2018-09-27 13:56 ` Jarkko Sakkinen
2018-10-01 21:42 ` Jethro Beekman
2018-10-01 22:03 ` Dave Hansen
2018-10-31 21:30 ` Sean Christopherson
2018-10-31 21:35 ` Dave Hansen
2018-11-01 17:42 ` Jarkko Sakkinen
2018-11-01 17:44 ` Jarkko Sakkinen
2018-10-02 0:31 ` Jarkko Sakkinen
2018-10-01 14:29 ` Sean Christopherson
2018-10-01 14:41 ` Dave Hansen
2018-10-02 0:07 ` Jarkko Sakkinen
2018-09-27 13:42 ` Jarkko Sakkinen
2018-09-27 14:58 ` Dave Hansen
2018-09-27 15:39 ` Jarkko Sakkinen
2018-09-27 15:53 ` Dave Hansen
2018-09-27 13:14 ` Jarkko Sakkinen
2018-09-27 19:43 ` Eric W. Biederman
2018-09-28 12:17 ` Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 10/19] x86/sgx: Detect Intel SGX Jarkko Sakkinen
2018-09-25 20:02 ` Randy Dunlap
2018-09-27 13:13 ` Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 11/19] x86/sgx: Add wrappers for ENCLS leaf functions Jarkko Sakkinen
2018-09-25 20:01 ` Randy Dunlap
2018-09-27 13:12 ` Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 12/19] x86/sgx: Add data structures for tracking the EPC pages Jarkko Sakkinen
2018-09-25 20:00 ` Randy Dunlap
2018-09-27 13:11 ` Jarkko Sakkinen
2018-09-25 13:06 ` Jarkko Sakkinen [this message]
2018-09-25 13:06 ` [PATCH v14 14/19] x86/sgx: Add sgx_einit() for initializing enclaves Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 15/19] platform/x86: Intel SGX driver Jarkko Sakkinen
2018-10-04 18:01 ` Sean Christopherson
2018-10-05 11:32 ` Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 16/19] platform/x86: Add swapping functionality to the " Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 17/19] x86/sgx: Add a simple swapper for the EPC memory manager Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 18/19] platform/x86: ptrace() support for the SGX driver Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 19/19] x86/sgx: Driver documentation Jarkko Sakkinen
2018-09-25 13:27 ` Jonathan Corbet
2018-10-15 20:54 ` Pavel Machek
2018-10-17 23:45 ` Jarkko Sakkinen
2018-10-18 9:57 ` Pavel Machek
2018-10-19 23:59 ` Jarkko Sakkinen
2018-10-17 23:56 ` Dave Hansen
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