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From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To: Andrew Morton <akpm@linux-foundation.org>,
	x86@kernel.org, Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
	Borislav Petkov <bp@alien8.de>,
	Peter Zijlstra <peterz@infradead.org>,
	Andy Lutomirski <luto@amacapital.net>,
	David Howells <dhowells@redhat.com>
Cc: Kees Cook <keescook@chromium.org>,
	Dave Hansen <dave.hansen@intel.com>,
	Kai Huang <kai.huang@linux.intel.com>,
	Jacob Pan <jacob.jun.pan@linux.intel.com>,
	Alison Schofield <alison.schofield@intel.com>,
	linux-mm@kvack.org, kvm@vger.kernel.org,
	keyrings@vger.kernel.org, linux-kernel@vger.kernel.org,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: [PATCH, RFC 11/62] x86/mm: Add a helper to retrieve KeyID for a page
Date: Wed,  8 May 2019 17:43:31 +0300
Message-ID: <20190508144422.13171-12-kirill.shutemov@linux.intel.com> (raw)
In-Reply-To: <20190508144422.13171-1-kirill.shutemov@linux.intel.com>

page_ext allows to store additional per-page information without growing
main struct page. The additional space can be requested at boot time.

Store KeyID in bits 31:16 of extended page flags. These bits are unused.

page_keyid() returns zero until page_ext is ready. page_ext initializer
enables a static branch to indicate that page_keyid() can use page_ext.
The same static branch will gate MKTME readiness in general.

We don't yet set KeyID for the page. It will come in the following
patch that implements prep_encrypted_page(). All pages have KeyID-0 for
now.

page_keyid() will be used by KVM which can be built as a module. We need
to export mktme_enabled_key to be able to inline page_keyid().

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 arch/x86/include/asm/mktme.h | 28 ++++++++++++++++++++++++++++
 arch/x86/include/asm/page.h  |  1 +
 arch/x86/mm/mktme.c          | 21 +++++++++++++++++++++
 include/linux/mm.h           |  2 +-
 include/linux/page_ext.h     | 11 ++++++++++-
 mm/page_ext.c                |  3 +++
 6 files changed, 64 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/mktme.h b/arch/x86/include/asm/mktme.h
index df31876ec48c..51f831b94179 100644
--- a/arch/x86/include/asm/mktme.h
+++ b/arch/x86/include/asm/mktme.h
@@ -2,15 +2,43 @@
 #define	_ASM_X86_MKTME_H
 
 #include <linux/types.h>
+#include <linux/page_ext.h>
+#include <linux/jump_label.h>
 
 #ifdef CONFIG_X86_INTEL_MKTME
 extern phys_addr_t mktme_keyid_mask;
 extern int mktme_nr_keyids;
 extern int mktme_keyid_shift;
+
+DECLARE_STATIC_KEY_FALSE(mktme_enabled_key);
+static inline bool mktme_enabled(void)
+{
+	return static_branch_unlikely(&mktme_enabled_key);
+}
+
+extern struct page_ext_operations page_mktme_ops;
+
+#define page_keyid page_keyid
+static inline int page_keyid(const struct page *page)
+{
+	if (!mktme_enabled())
+		return 0;
+
+	return lookup_page_ext(page)->keyid;
+}
+
+
 #else
 #define mktme_keyid_mask	((phys_addr_t)0)
 #define mktme_nr_keyids		0
 #define mktme_keyid_shift	0
+
+#define page_keyid(page) 0
+
+static inline bool mktme_enabled(void)
+{
+	return false;
+}
 #endif
 
 #endif
diff --git a/arch/x86/include/asm/page.h b/arch/x86/include/asm/page.h
index 7555b48803a8..39af59487d5f 100644
--- a/arch/x86/include/asm/page.h
+++ b/arch/x86/include/asm/page.h
@@ -19,6 +19,7 @@
 struct page;
 
 #include <linux/range.h>
+#include <asm/mktme.h>
 extern struct range pfn_mapped[];
 extern int nr_pfn_mapped;
 
diff --git a/arch/x86/mm/mktme.c b/arch/x86/mm/mktme.c
index 91a415612519..9dc256e3654b 100644
--- a/arch/x86/mm/mktme.c
+++ b/arch/x86/mm/mktme.c
@@ -9,3 +9,24 @@ phys_addr_t mktme_keyid_mask;
 int mktme_nr_keyids;
 /* Shift of KeyID within physical address. */
 int mktme_keyid_shift;
+
+DEFINE_STATIC_KEY_FALSE(mktme_enabled_key);
+EXPORT_SYMBOL_GPL(mktme_enabled_key);
+
+static bool need_page_mktme(void)
+{
+	/* Make sure keyid doesn't collide with extended page flags */
+	BUILD_BUG_ON(__NR_PAGE_EXT_FLAGS > 16);
+
+	return !!mktme_nr_keyids;
+}
+
+static void init_page_mktme(void)
+{
+	static_branch_enable(&mktme_enabled_key);
+}
+
+struct page_ext_operations page_mktme_ops = {
+	.need = need_page_mktme,
+	.init = init_page_mktme,
+};
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 07c36f4673f6..2684245f8503 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1607,7 +1607,7 @@ static inline int vma_keyid(struct vm_area_struct *vma)
 #endif
 
 #ifndef page_keyid
-static inline int page_keyid(struct page *page)
+static inline int page_keyid(const struct page *page)
 {
 	return 0;
 }
diff --git a/include/linux/page_ext.h b/include/linux/page_ext.h
index f84f167ec04c..d9c5aae9523f 100644
--- a/include/linux/page_ext.h
+++ b/include/linux/page_ext.h
@@ -23,6 +23,7 @@ enum page_ext_flags {
 	PAGE_EXT_YOUNG,
 	PAGE_EXT_IDLE,
 #endif
+	__NR_PAGE_EXT_FLAGS
 };
 
 /*
@@ -33,7 +34,15 @@ enum page_ext_flags {
  * then the page_ext for pfn always exists.
  */
 struct page_ext {
-	unsigned long flags;
+	union {
+		unsigned long flags;
+#ifdef CONFIG_X86_INTEL_MKTME
+		struct {
+			unsigned short __pad;
+			unsigned short keyid;
+		};
+#endif
+	};
 };
 
 extern void pgdat_page_ext_init(struct pglist_data *pgdat);
diff --git a/mm/page_ext.c b/mm/page_ext.c
index d8f1aca4ad43..1af8b82087f2 100644
--- a/mm/page_ext.c
+++ b/mm/page_ext.c
@@ -68,6 +68,9 @@ static struct page_ext_operations *page_ext_ops[] = {
 #if defined(CONFIG_IDLE_PAGE_TRACKING) && !defined(CONFIG_64BIT)
 	&page_idle_ops,
 #endif
+#ifdef CONFIG_X86_INTEL_MKTME
+	&page_mktme_ops,
+#endif
 };
 
 static unsigned long total_usage;
-- 
2.20.1


  parent reply index

Thread overview: 153+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-08 14:43 [PATCH, RFC 00/62] Intel MKTME enabling Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 01/62] mm: Do no merge VMAs with different encryption KeyIDs Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 02/62] mm: Add helpers to setup zero page mappings Kirill A. Shutemov
2019-05-29  7:21   ` Mike Rapoport
2019-05-08 14:43 ` [PATCH, RFC 03/62] mm/ksm: Do not merge pages with different KeyIDs Kirill A. Shutemov
2019-05-10 18:07   ` Dave Hansen
2019-05-13 14:27     ` Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 04/62] mm/page_alloc: Unify alloc_hugepage_vma() Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 05/62] mm/page_alloc: Handle allocation for encrypted memory Kirill A. Shutemov
2019-05-29  7:21   ` Mike Rapoport
2019-05-29 12:47     ` Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 06/62] mm/khugepaged: Handle encrypted pages Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 07/62] x86/mm: Mask out KeyID bits from page table entry pfn Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 08/62] x86/mm: Introduce variables to store number, shift and mask of KeyIDs Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 09/62] x86/mm: Preserve KeyID on pte_modify() and pgprot_modify() Kirill A. Shutemov
2019-06-14  9:15   ` Peter Zijlstra
2019-06-14 13:03     ` Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 10/62] x86/mm: Detect MKTME early Kirill A. Shutemov
2019-05-08 14:43 ` Kirill A. Shutemov [this message]
2019-05-08 14:43 ` [PATCH, RFC 12/62] x86/mm: Add a helper to retrieve KeyID for a VMA Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 13/62] x86/mm: Add hooks to allocate and free encrypted pages Kirill A. Shutemov
2019-06-14  9:34   ` Peter Zijlstra
2019-06-14 11:04     ` Peter Zijlstra
2019-06-14 13:28       ` Kirill A. Shutemov
2019-06-14 13:43         ` Peter Zijlstra
2019-06-14 22:41           ` Kirill A. Shutemov
2019-06-17  9:25             ` Peter Zijlstra
2019-06-14 13:14     ` Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 14/62] x86/mm: Map zero pages into encrypted mappings correctly Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 15/62] x86/mm: Rename CONFIG_RANDOMIZE_MEMORY_PHYSICAL_PADDING Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 16/62] x86/mm: Allow to disable MKTME after enumeration Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 17/62] x86/mm: Calculate direct mapping size Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 18/62] x86/mm: Implement syncing per-KeyID direct mappings Kirill A. Shutemov
2019-06-14  9:51   ` Peter Zijlstra
2019-06-14 22:43     ` Kirill A. Shutemov
2019-06-17  9:27       ` Peter Zijlstra
2019-06-17 14:43         ` Kirill A. Shutemov
2019-06-17 14:51           ` Peter Zijlstra
2019-06-17 15:17             ` Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 19/62] x86/mm: Handle encrypted memory in page_to_virt() and __pa() Kirill A. Shutemov
2019-06-14 11:10   ` Peter Zijlstra
2019-05-08 14:43 ` [PATCH, RFC 20/62] mm/page_ext: Export lookup_page_ext() symbol Kirill A. Shutemov
2019-06-14 11:12   ` Peter Zijlstra
2019-06-14 22:44     ` Kirill A. Shutemov
2019-06-17  9:30       ` Peter Zijlstra
2019-06-17 11:01         ` Kai Huang
2019-06-17 11:13           ` Huang, Kai
2019-05-08 14:43 ` [PATCH, RFC 21/62] mm/rmap: Clear vma->anon_vma on unlink_anon_vmas() Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 22/62] x86/pconfig: Set a valid encryption algorithm for all MKTME commands Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 23/62] keys/mktme: Introduce a Kernel Key Service for MKTME Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 24/62] keys/mktme: Preparse the MKTME key payload Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 25/62] keys/mktme: Instantiate and destroy MKTME keys Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 26/62] keys/mktme: Move the MKTME payload into a cache aligned structure Kirill A. Shutemov
2019-06-14 11:35   ` Peter Zijlstra
2019-06-14 17:10     ` Alison Schofield
2019-05-08 14:43 ` [PATCH, RFC 27/62] keys/mktme: Strengthen the entropy of CPU generated MKTME keys Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 28/62] keys/mktme: Set up PCONFIG programming targets for " Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 29/62] keys/mktme: Program MKTME keys into the platform hardware Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 30/62] keys/mktme: Set up a percpu_ref_count for MKTME keys Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 31/62] keys/mktme: Require CAP_SYS_RESOURCE capability " Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 32/62] keys/mktme: Store MKTME payloads if cmdline parameter allows Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 33/62] acpi: Remove __init from acpi table parsing functions Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 34/62] acpi/hmat: Determine existence of an ACPI HMAT Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 35/62] keys/mktme: Require ACPI HMAT to register the MKTME Key Service Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 36/62] acpi/hmat: Evaluate topology presented in ACPI HMAT for MKTME Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 37/62] keys/mktme: Do not allow key creation in unsafe topologies Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 38/62] keys/mktme: Support CPU hotplug for MKTME key service Kirill A. Shutemov
2019-05-08 14:43 ` [PATCH, RFC 39/62] keys/mktme: Find new PCONFIG targets during memory hotplug Kirill A. Shutemov
2019-05-08 14:44 ` [PATCH, RFC 40/62] keys/mktme: Program new PCONFIG targets with MKTME keys Kirill A. Shutemov
2019-05-08 14:44 ` [PATCH, RFC 41/62] keys/mktme: Support memory hotplug for " Kirill A. Shutemov
2019-05-08 14:44 ` [PATCH, RFC 42/62] mm: Generalize the mprotect implementation to support extensions Kirill A. Shutemov
2019-05-08 14:44 ` [PATCH, RFC 43/62] syscall/x86: Wire up a system call for MKTME encryption keys Kirill A. Shutemov
2019-05-29  7:21   ` Mike Rapoport
2019-05-29 18:12     ` Alison Schofield
2019-05-08 14:44 ` [PATCH, RFC 44/62] x86/mm: Set KeyIDs in encrypted VMAs for MKTME Kirill A. Shutemov
2019-06-14 11:44   ` Peter Zijlstra
2019-06-14 17:33     ` Alison Schofield
2019-06-14 18:26       ` Dave Hansen
2019-06-14 18:46         ` Alison Schofield
2019-06-14 19:11           ` Dave Hansen
2019-06-17  9:10             ` Peter Zijlstra
2019-05-08 14:44 ` [PATCH, RFC 45/62] mm: Add the encrypt_mprotect() system call " Kirill A. Shutemov
2019-06-14 11:47   ` Peter Zijlstra
2019-06-14 17:35     ` Alison Schofield
2019-06-14 11:51   ` Peter Zijlstra
2019-06-15  0:32     ` Alison Schofield
2019-06-17  9:08       ` Peter Zijlstra
2019-06-17 15:07   ` Andy Lutomirski
2019-06-17 15:28     ` Dave Hansen
2019-06-17 15:46       ` Andy Lutomirski
2019-06-17 18:27         ` Dave Hansen
2019-06-17 19:12           ` Andy Lutomirski
2019-06-17 21:36             ` Dave Hansen
2019-06-18  0:48               ` Kai Huang
2019-06-18  1:50                 ` Andy Lutomirski
2019-06-18  2:11                   ` Kai Huang
2019-06-18  4:24                     ` Andy Lutomirski
2019-06-18 14:19                   ` Dave Hansen
2019-06-18  0:05             ` Kai Huang
2019-06-18  0:15               ` Andy Lutomirski
2019-06-18  1:35                 ` Kai Huang
2019-06-18  1:43                   ` Andy Lutomirski
2019-06-18  2:23                     ` Kai Huang
2019-06-18  9:12                       ` Peter Zijlstra
2019-06-18 14:09                         ` Dave Hansen
2019-06-18 16:15                           ` Kirill A. Shutemov
2019-06-18 16:22                             ` Dave Hansen
2019-06-18 16:36                               ` Andy Lutomirski
2019-06-18 16:48                                 ` Dave Hansen
2019-06-18 14:13                 ` Dave Hansen
2019-06-17 23:59           ` Kai Huang
2019-06-18  1:34             ` Lendacky, Thomas
2019-06-18  1:40               ` Andy Lutomirski
2019-06-18  2:02                 ` Lendacky, Thomas
2019-06-18  4:19                 ` Andy Lutomirski
2019-05-08 14:44 ` [PATCH, RFC 46/62] x86/mm: Keep reference counts on encrypted VMAs " Kirill A. Shutemov
2019-06-14 11:54   ` Peter Zijlstra
2019-06-14 18:39     ` Alison Schofield
2019-05-08 14:44 ` [PATCH, RFC 47/62] mm: Restrict MKTME memory encryption to anonymous VMAs Kirill A. Shutemov
2019-06-14 11:55   ` Peter Zijlstra
2019-06-15  0:07     ` Alison Schofield
2019-05-08 14:44 ` [PATCH, RFC 48/62] selftests/x86/mktme: Test the MKTME APIs Kirill A. Shutemov
2019-05-08 17:09   ` Alison Schofield
2019-05-08 14:44 ` [PATCH, RFC 49/62] mm, x86: export several MKTME variables Kirill A. Shutemov
2019-06-14 11:56   ` Peter Zijlstra
2019-06-17  3:14     ` Kai Huang
2019-06-17  7:46       ` Peter Zijlstra
2019-06-17  8:39         ` Kai Huang
2019-06-17 11:25           ` Kirill A. Shutemov
2019-05-08 14:44 ` [PATCH, RFC 50/62] kvm, x86, mmu: setup MKTME keyID to spte for given PFN Kirill A. Shutemov
2019-05-08 14:44 ` [PATCH, RFC 51/62] iommu/vt-d: Support MKTME in DMA remapping Kirill A. Shutemov
2019-06-14 12:04   ` Peter Zijlstra
2019-05-08 14:44 ` [PATCH, RFC 52/62] x86/mm: introduce common code for mem encryption Kirill A. Shutemov
2019-05-08 16:58   ` Christoph Hellwig
2019-05-08 20:52     ` Jacob Pan
2019-05-08 21:21       ` Kirill A. Shutemov
2019-05-08 14:44 ` [PATCH, RFC 53/62] x86/mm: Use common code for DMA memory encryption Kirill A. Shutemov
2019-05-08 14:44 ` [PATCH, RFC 54/62] x86/mm: Disable MKTME on incompatible platform configurations Kirill A. Shutemov
2019-05-08 14:44 ` [PATCH, RFC 55/62] x86/mm: Disable MKTME if not all system memory supports encryption Kirill A. Shutemov
2019-05-08 14:44 ` [PATCH, RFC 56/62] x86: Introduce CONFIG_X86_INTEL_MKTME Kirill A. Shutemov
2019-05-08 14:44 ` [PATCH, RFC 57/62] x86/mktme: Overview of Multi-Key Total Memory Encryption Kirill A. Shutemov
2019-05-29  7:21   ` Mike Rapoport
2019-05-29 18:13     ` Alison Schofield
2019-07-14 18:16   ` Randy Dunlap
2019-07-15  9:02     ` Kirill A. Shutemov
2019-05-08 14:44 ` [PATCH, RFC 58/62] x86/mktme: Document the MKTME provided security mitigations Kirill A. Shutemov
2019-05-08 14:44 ` [PATCH, RFC 59/62] x86/mktme: Document the MKTME kernel configuration requirements Kirill A. Shutemov
2019-05-08 14:44 ` [PATCH, RFC 60/62] x86/mktme: Document the MKTME Key Service API Kirill A. Shutemov
2019-05-08 14:44 ` [PATCH, RFC 61/62] x86/mktme: Document the MKTME API for anonymous memory encryption Kirill A. Shutemov
2019-05-08 14:44 ` [PATCH, RFC 62/62] x86/mktme: Demonstration program using the MKTME APIs Kirill A. Shutemov
2019-05-29  7:30 ` [PATCH, RFC 00/62] Intel MKTME enabling Mike Rapoport
2019-05-29 18:20   ` Alison Schofield
2019-06-14 12:15 ` Peter Zijlstra

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