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From: Alison Schofield <alison.schofield@intel.com>
To: dhowells@redhat.com, tglx@linutronix.de
Cc: jmorris@namei.org, mingo@redhat.com, hpa@zytor.com, bp@alien8.de,
	luto@kernel.org, peterz@infradead.org,
	kirill.shutemov@linux.intel.com, dave.hansen@intel.com,
	kai.huang@intel.com, jun.nakajima@intel.com,
	dan.j.williams@intel.com, jarkko.sakkinen@intel.com,
	keyrings@vger.kernel.org, linux-security-module@vger.kernel.org,
	linux-mm@kvack.org, x86@kernel.org
Subject: [RFC v2 04/13] x86/mm: Add helper functions for MKTME memory encryption keys
Date: Mon,  3 Dec 2018 23:39:51 -0800
Message-ID: <bd83f72d30ccfc7c1bc7ce9ab81bdf66e78a1d7d.1543903910.git.alison.schofield@intel.com> (raw)
In-Reply-To: <cover.1543903910.git.alison.schofield@intel.com>

Define a global mapping structure to manage the mapping of userspace
Keys to hardware KeyIDs in MKTME (Multi-Key Total Memory Encryption).
Implement helper functions that access this mapping structure.

The helpers will be used by these MKTME API's:
 >  Key Service API: security/keys/mktme_keys.c
 >  encrypt_mprotect() system call: mm/mprotect.c

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 arch/x86/include/asm/mktme.h | 12 ++++++
 arch/x86/mm/mktme.c          | 91 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 103 insertions(+)

diff --git a/arch/x86/include/asm/mktme.h b/arch/x86/include/asm/mktme.h
index f05baa15e6f6..dbb49909d665 100644
--- a/arch/x86/include/asm/mktme.h
+++ b/arch/x86/include/asm/mktme.h
@@ -12,6 +12,18 @@ extern phys_addr_t mktme_keyid_mask;
 extern int mktme_nr_keyids;
 extern int mktme_keyid_shift;
 
+/* Manage mappings between hardware KeyIDs and userspace Keys */
+extern int mktme_map_alloc(void);
+extern void mktme_map_free(void);
+extern void mktme_map_lock(void);
+extern void mktme_map_unlock(void);
+extern int mktme_map_mapped_keyids(void);
+extern void mktme_map_set_keyid(int keyid, void *key);
+extern void mktme_map_free_keyid(int keyid);
+extern int mktme_map_keyid_from_key(void *key);
+extern void *mktme_map_key_from_keyid(int keyid);
+extern int mktme_map_get_free_keyid(void);
+
 DECLARE_STATIC_KEY_FALSE(mktme_enabled_key);
 static inline bool mktme_enabled(void)
 {
diff --git a/arch/x86/mm/mktme.c b/arch/x86/mm/mktme.c
index c81727540e7c..34224d4e3f45 100644
--- a/arch/x86/mm/mktme.c
+++ b/arch/x86/mm/mktme.c
@@ -40,6 +40,97 @@ int __vma_keyid(struct vm_area_struct *vma)
 	return (prot & mktme_keyid_mask) >> mktme_keyid_shift;
 }
 
+/*
+ * struct mktme_map and the mktme_map_* functions manage the mapping
+ * of userspace Keys to hardware KeyIDs. These are used by the MKTME Key
+ * Service API and the encrypt_mprotect() system call.
+ */
+
+struct mktme_mapping {
+	struct mutex	lock;		/* protect this map & HW state */
+	unsigned int	mapped_keyids;
+	void		*key[];
+};
+
+struct mktme_mapping *mktme_map;
+
+static inline long mktme_map_size(void)
+{
+	long size = 0;
+
+	size += sizeof(*mktme_map);
+	size += sizeof(mktme_map->key[0]) * (mktme_nr_keyids + 1);
+	return size;
+}
+
+int mktme_map_alloc(void)
+{
+	mktme_map = kvzalloc(mktme_map_size(), GFP_KERNEL);
+	if (!mktme_map)
+		return 0;
+	mutex_init(&mktme_map->lock);
+	return 1;
+}
+
+void mktme_map_free(void)
+{
+	kvfree(mktme_map);
+}
+
+void mktme_map_lock(void)
+{
+	mutex_lock(&mktme_map->lock);
+}
+
+void mktme_map_unlock(void)
+{
+	mutex_unlock(&mktme_map->lock);
+}
+
+int mktme_map_mapped_keyids(void)
+{
+	return mktme_map->mapped_keyids;
+}
+
+void mktme_map_set_keyid(int keyid, void *key)
+{
+	mktme_map->key[keyid] = key;
+	mktme_map->mapped_keyids++;
+}
+
+void mktme_map_free_keyid(int keyid)
+{
+	mktme_map->key[keyid] = 0;
+	mktme_map->mapped_keyids--;
+}
+
+int mktme_map_keyid_from_key(void *key)
+{
+	int i;
+
+	for (i = 1; i <= mktme_nr_keyids; i++)
+		if (mktme_map->key[i] == key)
+			return i;
+	return 0;
+}
+
+void *mktme_map_key_from_keyid(int keyid)
+{
+	return mktme_map->key[keyid];
+}
+
+int mktme_map_get_free_keyid(void)
+{
+	int i;
+
+	if (mktme_map->mapped_keyids < mktme_nr_keyids) {
+		for (i = 1; i <= mktme_nr_keyids; i++)
+			if (mktme_map->key[i] == 0)
+				return i;
+	}
+	return 0;
+}
+
 /* Prepare page to be used for encryption. Called from page allocator. */
 void __prep_encrypted_page(struct page *page, int order, int keyid, bool zero)
 {
-- 
2.14.1


  parent reply index

Thread overview: 91+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-12-04  7:39 [RFC v2 00/13] Multi-Key Total Memory Encryption API (MKTME) Alison Schofield
2018-12-04  7:39 ` [RFC v2 01/13] x86/mktme: Document the MKTME APIs Alison Schofield
2018-12-05 18:11   ` Andy Lutomirski
2018-12-05 19:22     ` Alison Schofield
2018-12-05 23:35       ` Andy Lutomirski
2018-12-06  8:04   ` Sakkinen, Jarkko
2018-12-04  7:39 ` [RFC v2 02/13] mm: Generalize the mprotect implementation to support extensions Alison Schofield
2018-12-06  8:08   ` Sakkinen, Jarkko
2018-12-04  7:39 ` [RFC v2 03/13] syscall/x86: Wire up a new system call for memory encryption keys Alison Schofield
2018-12-04  7:39 ` Alison Schofield [this message]
2018-12-04  9:14   ` [RFC v2 04/13] x86/mm: Add helper functions for MKTME " Peter Zijlstra
2018-12-05  5:49     ` Alison Schofield
2018-12-04 15:35   ` Andy Lutomirski
2018-12-05  5:52     ` Alison Schofield
2018-12-06  8:31   ` Sakkinen, Jarkko
2018-12-04  7:39 ` [RFC v2 05/13] x86/mm: Set KeyIDs in encrypted VMAs Alison Schofield
2018-12-06  8:37   ` Sakkinen, Jarkko
2018-12-04  7:39 ` [RFC v2 06/13] mm: Add the encrypt_mprotect() system call Alison Schofield
2018-12-06  8:38   ` Sakkinen, Jarkko
2018-12-04  7:39 ` [RFC v2 07/13] x86/mm: Add helpers for reference counting encrypted VMAs Alison Schofield
2018-12-04  8:58   ` Peter Zijlstra
2018-12-05  5:28     ` Alison Schofield
2018-12-04  7:39 ` [RFC v2 08/13] mm: Use reference counting for " Alison Schofield
2018-12-04  7:39 ` [RFC v2 09/13] mm: Restrict memory encryption to anonymous VMA's Alison Schofield
2018-12-04  9:10   ` Peter Zijlstra
2018-12-05  5:30     ` Alison Schofield
2018-12-05  9:07       ` Peter Zijlstra
2018-12-04  7:39 ` [RFC v2 10/13] keys/mktme: Add the MKTME Key Service type for memory encryption Alison Schofield
2018-12-06  8:51   ` Sakkinen, Jarkko
2018-12-06  8:54     ` Sakkinen, Jarkko
2018-12-06 15:11     ` Dave Hansen
2018-12-06 22:56       ` Sakkinen, Jarkko
2018-12-04  7:39 ` [RFC v2 11/13] keys/mktme: Program memory encryption keys on a system wide basis Alison Schofield
2018-12-04  9:21   ` Peter Zijlstra
2018-12-04  9:50     ` Kirill A. Shutemov
2018-12-05  5:44       ` Alison Schofield
2018-12-05  5:43     ` Alison Schofield
2018-12-05  9:10       ` Peter Zijlstra
2018-12-05 17:26         ` Alison Schofield
2018-12-04  7:39 ` [RFC v2 12/13] keys/mktme: Save MKTME data if kernel cmdline parameter allows Alison Schofield
2018-12-04  9:22   ` Peter Zijlstra
2018-12-07  2:14   ` Huang, Kai
2018-12-07  3:42     ` Alison Schofield
2018-12-07  6:39     ` Jarkko Sakkinen
2018-12-07  6:45       ` Jarkko Sakkinen
2018-12-07 11:47     ` Kirill A. Shutemov
2018-12-04  7:40 ` [RFC v2 13/13] keys/mktme: Support CPU Hotplug for MKTME keys Alison Schofield
2018-12-04  9:28   ` Peter Zijlstra
2018-12-05  5:32     ` Alison Schofield
2018-12-04  9:31   ` Peter Zijlstra
2018-12-05  5:36     ` Alison Schofield
2018-12-04  9:25 ` [RFC v2 00/13] Multi-Key Total Memory Encryption API (MKTME) Peter Zijlstra
2018-12-04  9:46   ` Kirill A. Shutemov
2018-12-05 20:32     ` Sakkinen, Jarkko
2018-12-06 11:22       ` Kirill A. Shutemov
2018-12-06 14:59         ` Dave Hansen
2018-12-07 10:12           ` Huang, Kai
2018-12-06 21:23         ` Sakkinen, Jarkko
2018-12-07 11:54           ` Kirill A. Shutemov
2018-12-04 19:19 ` Andy Lutomirski
2018-12-04 20:00   ` Andy Lutomirski
2018-12-04 20:32     ` Dave Hansen
2018-12-05 22:19   ` Sakkinen, Jarkko
2018-12-07  2:05     ` Huang, Kai
2018-12-07  6:48       ` Jarkko Sakkinen
2018-12-07 11:57     ` Kirill A. Shutemov
2018-12-07 21:59       ` Sakkinen, Jarkko
2018-12-07 23:45         ` Sakkinen, Jarkko
2018-12-07 23:48           ` Andy Lutomirski
2018-12-08  1:33           ` Huang, Kai
2018-12-08  3:53             ` Sakkinen, Jarkko
2018-12-12 15:31           ` Sakkinen, Jarkko
2018-12-12 16:29             ` Andy Lutomirski
2018-12-12 16:43               ` Sakkinen, Jarkko
2018-12-12 23:27                 ` Huang, Kai
2018-12-13  5:49                   ` Sakkinen, Jarkko
2018-12-13  5:52                     ` Sakkinen, Jarkko
2018-12-12 23:24               ` Huang, Kai
2018-12-07 23:35       ` Eric Rannaud
2018-12-05 23:49   ` Dave Hansen
2018-12-06  1:09     ` Andy Lutomirski
2018-12-06  1:25       ` Dan Williams
2018-12-06 15:39       ` Dave Hansen
2018-12-06 19:10         ` Andy Lutomirski
2018-12-06 19:31           ` Dave Hansen
2018-12-07  1:55       ` Huang, Kai
2018-12-07  4:23         ` Dave Hansen
2018-12-07 23:53         ` Andy Lutomirski
2018-12-08  1:11           ` Dave Hansen
2018-12-08  2:07           ` Huang, Kai
2018-12-05 20:30 ` Sakkinen, Jarkko

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