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From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: Peter Zijlstra <peterz@infradead.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	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>,
	Andy Lutomirski <luto@amacapital.net>,
	David Howells <dhowells@redhat.com>,
	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
Subject: Re: [PATCH, RFC 18/62] x86/mm: Implement syncing per-KeyID direct mappings
Date: Mon, 17 Jun 2019 17:43:28 +0300	[thread overview]
Message-ID: <20190617144328.oqwx5rb5yfm2ziws@box> (raw)
In-Reply-To: <20190617092755.GA3419@hirez.programming.kicks-ass.net>

On Mon, Jun 17, 2019 at 11:27:55AM +0200, Peter Zijlstra wrote:
> On Sat, Jun 15, 2019 at 01:43:09AM +0300, Kirill A. Shutemov wrote:
> > On Fri, Jun 14, 2019 at 11:51:32AM +0200, Peter Zijlstra wrote:
> > > On Wed, May 08, 2019 at 05:43:38PM +0300, Kirill A. Shutemov wrote:
> > > > For MKTME we use per-KeyID direct mappings. This allows kernel to have
> > > > access to encrypted memory.
> > > > 
> > > > sync_direct_mapping() sync per-KeyID direct mappings with a canonical
> > > > one -- KeyID-0.
> > > > 
> > > > The function tracks changes in the canonical mapping:
> > > >  - creating or removing chunks of the translation tree;
> > > >  - changes in mapping flags (i.e. protection bits);
> > > >  - splitting huge page mapping into a page table;
> > > >  - replacing page table with a huge page mapping;
> > > > 
> > > > The function need to be called on every change to the direct mapping:
> > > > hotplug, hotremove, changes in permissions bits, etc.
> > > 
> > > And yet I don't see anything in pageattr.c.
> > 
> > You're right. I've hooked up the sync in the wrong place.
> > > 
> > > Also, this seems like an expensive scheme; if you know where the changes
> > > where, a more fine-grained update would be faster.
> > 
> > Do we have any hot enough pageattr users that makes it crucial?
> > 
> > I'll look into this anyway.
> 
> The graphics people would be the most agressive users of this I'd think.
> They're the ones that yelled when I broke it last ;-)

I think something like this should do (I'll fold it in after testing):

diff --git a/arch/x86/include/asm/mktme.h b/arch/x86/include/asm/mktme.h
index 6c973cb1e64c..b30386d84281 100644
--- a/arch/x86/include/asm/mktme.h
+++ b/arch/x86/include/asm/mktme.h
@@ -68,7 +68,7 @@ static inline void arch_free_page(struct page *page, int order)
 		free_encrypted_page(page, order);
 }
 
-int sync_direct_mapping(void);
+int sync_direct_mapping(unsigned long start, unsigned long end);
 
 int mktme_get_alg(int keyid);
 
@@ -86,7 +86,7 @@ static inline bool mktme_enabled(void)
 
 static inline void mktme_disable(void) {}
 
-static inline int sync_direct_mapping(void)
+static inline int sync_direct_mapping(unsigned long start, unsigned long end)
 {
 	return 0;
 }
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index f50a38d86cc4..f8123aeb24a6 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -761,7 +761,7 @@ __kernel_physical_mapping_init(unsigned long paddr_start,
 		pgd_changed = true;
 	}
 
-	ret = sync_direct_mapping();
+	ret = sync_direct_mapping(vaddr_start, vaddr_end);
 	WARN_ON(ret);
 
 	if (pgd_changed)
@@ -1209,7 +1209,7 @@ kernel_physical_mapping_remove(unsigned long start, unsigned long end)
 	end = (unsigned long)__va(end);
 
 	remove_pagetable(start, end, true, NULL);
-	ret = sync_direct_mapping();
+	ret = sync_direct_mapping(start, end);
 	WARN_ON(ret);
 }
 
@@ -1315,7 +1315,6 @@ void mark_rodata_ro(void)
 	unsigned long text_end = PFN_ALIGN(&__stop___ex_table);
 	unsigned long rodata_end = PFN_ALIGN(&__end_rodata);
 	unsigned long all_end;
-	int ret;
 
 	printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
 	       (end - start) >> 10);
@@ -1349,8 +1348,6 @@ void mark_rodata_ro(void)
 	free_kernel_image_pages((void *)text_end, (void *)rodata_start);
 	free_kernel_image_pages((void *)rodata_end, (void *)_sdata);
 
-	ret = sync_direct_mapping();
-	WARN_ON(ret);
 	debug_checkwx();
 }
 
diff --git a/arch/x86/mm/mktme.c b/arch/x86/mm/mktme.c
index 9d2bb534f2ba..c099e1da055b 100644
--- a/arch/x86/mm/mktme.c
+++ b/arch/x86/mm/mktme.c
@@ -76,7 +76,7 @@ static void init_page_mktme(void)
 {
 	static_branch_enable(&mktme_enabled_key);
 
-	sync_direct_mapping();
+	sync_direct_mapping(PAGE_OFFSET, PAGE_OFFSET + direct_mapping_size);
 }
 
 struct page_ext_operations page_mktme_ops = {
@@ -596,15 +596,13 @@ static int sync_direct_mapping_p4d(unsigned long keyid,
 	return ret;
 }
 
-static int sync_direct_mapping_keyid(unsigned long keyid)
+static int sync_direct_mapping_keyid(unsigned long keyid,
+		unsigned long addr, unsigned long end)
 {
 	pgd_t *src_pgd, *dst_pgd;
-	unsigned long addr, end, next;
+	unsigned long next;
 	int ret = 0;
 
-	addr = PAGE_OFFSET;
-	end = PAGE_OFFSET + direct_mapping_size;
-
 	dst_pgd = pgd_offset_k(addr + keyid * direct_mapping_size);
 	src_pgd = pgd_offset_k(addr);
 
@@ -643,7 +641,7 @@ static int sync_direct_mapping_keyid(unsigned long keyid)
  *
  * The function is nop until MKTME is enabled.
  */
-int sync_direct_mapping(void)
+int sync_direct_mapping(unsigned long start, unsigned long end)
 {
 	int i, ret = 0;
 
@@ -651,7 +649,7 @@ int sync_direct_mapping(void)
 		return 0;
 
 	for (i = 1; !ret && i <= mktme_nr_keyids; i++)
-		ret = sync_direct_mapping_keyid(i);
+		ret = sync_direct_mapping_keyid(i, start, end);
 
 	flush_tlb_all();
 
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 6a9a77a403c9..eafbe0d8c44f 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -347,6 +347,28 @@ static void cpa_flush(struct cpa_data *data, int cache)
 
 	BUG_ON(irqs_disabled() && !early_boot_irqs_disabled);
 
+	if (mktme_enabled()) {
+		unsigned long start, end;
+
+		start = *cpa->vaddr;
+		end = *cpa->vaddr + cpa->numpages * PAGE_SIZE;
+
+		/* Sync all direct mapping for an array */
+		if (cpa->flags & CPA_ARRAY) {
+			start = PAGE_OFFSET;
+			end = PAGE_OFFSET + direct_mapping_size;
+		}
+
+		/*
+		 * Sync per-KeyID direct mappings with the canonical one
+		 * (KeyID-0).
+		 *
+		 * sync_direct_mapping() does full TLB flush.
+		 */
+		sync_direct_mapping(start, end);
+		return;
+	}
+
 	if (cache && !static_cpu_has(X86_FEATURE_CLFLUSH)) {
 		cpa_flush_all(cache);
 		return;
-- 
 Kirill A. Shutemov

  reply	other threads:[~2019-06-17 14:43 UTC|newest]

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 ` [PATCH, RFC 11/62] x86/mm: Add a helper to retrieve KeyID for a page Kirill A. Shutemov
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 [this message]
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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