Linux-mm Archive on lore.kernel.org
 help / color / Atom feed
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 38/62] keys/mktme: Support CPU hotplug for MKTME key service
Date: Wed,  8 May 2019 17:43:58 +0300
Message-ID: <20190508144422.13171-39-kirill.shutemov@linux.intel.com> (raw)
In-Reply-To: <20190508144422.13171-1-kirill.shutemov@linux.intel.com>

From: Alison Schofield <alison.schofield@intel.com>

The MKTME encryption hardware resides on each physical package.
The encryption hardware includes 'Key Tables' that must be
programmed identically across all physical packages in the
platform. Although every CPU in a package can program its key
table, the kernel uses one lead CPU per package for programming.

CPU Hotplug Teardown
--------------------
MKTME manages CPU hotplug teardown to make sure the ability to
program all packages is preserved when MKTME keys are present.

When MKTME keys are not currently programmed, simply allow
the teardown, and set "mktme_allow_keys" to false. This will
force a re-evaluation of the platform topology before the next
key creation. If this CPU teardown mattered, MKTME key service
will report an error and fail to create the key. (User can
online that CPU and try again)

When MKTME keys are currently programmed, allow teardowns
of non 'lead CPU's' and of CPUs where another, core sibling
CPU, can take over as lead. Do not allow teardown of any
lead CPU that would render a hardware key table unreachable!

CPU Hotplug Startup
-------------------
CPUs coming online are of interest to the key service, but since
the service never needs to block a CPU startup event, nor does it
need to prepare for an onlining CPU, a callback is not implemented.

MKTME will catch the availability of the new CPU, if it is
needed, at the next key creation time. If keys are not allowed,
that new CPU will be part of the topology evaluation to determine
if keys should now be allowed.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 security/keys/mktme_keys.c | 51 +++++++++++++++++++++++++++++++++++---
 1 file changed, 48 insertions(+), 3 deletions(-)

diff --git a/security/keys/mktme_keys.c b/security/keys/mktme_keys.c
index 734e1d28eb24..3dfc0647f1e5 100644
--- a/security/keys/mktme_keys.c
+++ b/security/keys/mktme_keys.c
@@ -102,9 +102,9 @@ void mktme_percpu_ref_release(struct percpu_ref *ref)
 		return;
 	}
 	percpu_ref_exit(ref);
-	spin_lock_irqsave(&mktme_map_lock, flags);
+	spin_lock_irqsave(&mktme_lock, flags);
 	mktme_release_keyid(keyid);
-	spin_unlock_irqrestore(&mktme_map_lock, flags);
+	spin_unlock_irqrestore(&mktme_lock, flags);
 }
 
 enum mktme_opt_id {
@@ -506,9 +506,46 @@ static int mktme_alloc_pconfig_targets(void)
 	return 0;
 }
 
+static int mktme_cpu_teardown(unsigned int cpu)
+{
+	int new_leadcpu, ret = 0;
+	unsigned long flags;
+
+	/* Do not allow key programming during cpu hotplug event */
+	spin_lock_irqsave(&mktme_lock, flags);
+
+	/*
+	 * When no keys are in use, allow the teardown, and set
+	 * mktme_allow_keys to FALSE. That forces an evaluation
+	 * of the topology before the next key creation.
+	 */
+	if (!mktme_map->mapped_keyids) {
+		mktme_allow_keys = false;
+		goto out;
+	}
+	/* Teardown CPU is not a lead CPU. Allow teardown. */
+	if (!cpumask_test_cpu(cpu, mktme_leadcpus))
+		goto out;
+
+	/* Teardown CPU is a lead CPU. Look for a new lead CPU. */
+	new_leadcpu = cpumask_any_but(topology_core_cpumask(cpu), cpu);
+
+	if (new_leadcpu < nr_cpumask_bits) {
+		/* New lead CPU found. Update the programming mask */
+		__cpumask_clear_cpu(cpu, mktme_leadcpus);
+		__cpumask_set_cpu(new_leadcpu, mktme_leadcpus);
+	} else {
+		/* New lead CPU not found. Do not allow CPU teardown */
+		ret = -1;
+	}
+out:
+	spin_unlock_irqrestore(&mktme_lock, flags);
+	return ret;
+}
+
 static int __init init_mktme(void)
 {
-	int ret;
+	int ret, cpuhp;
 
 	/* Verify keys are present */
 	if (mktme_nr_keyids < 1)
@@ -553,10 +590,18 @@ static int __init init_mktme(void)
 	if (!mktme_key_store)
 		goto free_bitmap;
 
+	cpuhp = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
+					  "keys/mktme_keys:online",
+					  NULL, mktme_cpu_teardown);
+	if (cpuhp < 0)
+		goto free_store;
+
 	ret = register_key_type(&key_type_mktme);
 	if (!ret)
 		return ret;			/* SUCCESS */
 
+	cpuhp_remove_state_nocalls(cpuhp);
+free_store:
 	kfree(mktme_key_store);
 free_bitmap:
 	bitmap_free(mktme_bitmap_user_type);
-- 
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 ` [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
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 ` Kirill A. Shutemov [this message]
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

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190508144422.13171-39-kirill.shutemov@linux.intel.com \
    --to=kirill.shutemov@linux.intel.com \
    --cc=akpm@linux-foundation.org \
    --cc=alison.schofield@intel.com \
    --cc=bp@alien8.de \
    --cc=dave.hansen@intel.com \
    --cc=dhowells@redhat.com \
    --cc=hpa@zytor.com \
    --cc=jacob.jun.pan@linux.intel.com \
    --cc=kai.huang@linux.intel.com \
    --cc=keescook@chromium.org \
    --cc=keyrings@vger.kernel.org \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=luto@amacapital.net \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-mm Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-mm/0 linux-mm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-mm linux-mm/ https://lore.kernel.org/linux-mm \
		linux-mm@kvack.org linux-mm@archiver.kernel.org
	public-inbox-index linux-mm


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kvack.linux-mm


AGPL code for this site: git clone https://public-inbox.org/ public-inbox