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From: Ram Pai <linuxram@us.ibm.com>
To: Balbir Singh <bsingharora@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
	linux-arch@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org,
	linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org,
	benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au,
	khandual@linux.vnet.ibm.com, aneesh.kumar@linux.vnet.ibm.com,
	dave.hansen@intel.com, hbabu@us.ibm.com, arnd@arndb.de,
	akpm@linux-foundation.org, corbet@lwn.net, mingo@redhat.com
Subject: Re: [RFC v5 14/38] powerpc: initial plumbing for key management
Date: Thu, 13 Jul 2017 13:37:04 -0700	[thread overview]
Message-ID: <20170713203704.GA5538@ram.oc3035372033.ibm.com> (raw)
In-Reply-To: <20170713074500.GF5525@ram.oc3035372033.ibm.com>

On Thu, Jul 13, 2017 at 12:45:00AM -0700, Ram Pai wrote:
> On Wed, Jul 12, 2017 at 01:28:25PM +1000, Balbir Singh wrote:
> > On Wed,  5 Jul 2017 14:21:51 -0700
> > Ram Pai <linuxram@us.ibm.com> wrote:
> > 
> > > Initial plumbing to manage all the keys supported by the
> > > hardware.
> > > 
> > > Total 32 keys are supported on powerpc. However pkey 0,1
> > > and 31 are reserved. So effectively we have 29 pkeys.
> > > 
> > > This patch keeps track of reserved keys, allocated  keys
> > > and keys that are currently free.
> > 
> > It looks like this patch will only work in guest mode?
> > Is that an assumption we've made? What happens if I use
> > keys when running in hypervisor mode?
> 
> It works in supervisor mode, as a guest aswell as a bare-metal
> kernel. Whatever needs to be done in hypervisor mode
> is already there in power-kvm.

I realize i did not answer your question accurately...
"What happens if I use keys when running in hypervisor mode?"

Its not clear what happens. As far as I can tell the MMU does
not check key violation when in hypervisor mode. So effectively
I think, keys are ineffective when in hypervisor mode.

RP

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  reply	other threads:[~2017-07-13 20:37 UTC|newest]

Thread overview: 92+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-07-05 21:21 [RFC v5 00/38] powerpc: Memory Protection Keys Ram Pai
2017-07-05 21:21 ` [RFC v5 01/38] powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Ram Pai
2017-07-07  7:25   ` Balbir Singh
2017-07-05 21:21 ` [RFC v5 02/38] powerpc: Free up four 64K PTE bits in 64K " Ram Pai
2017-07-11  5:59   ` Balbir Singh
2017-07-11 15:44     ` Ram Pai
2017-07-12  3:10       ` Balbir Singh
2017-07-13  7:39         ` Ram Pai
2017-07-05 21:21 ` [RFC v5 03/38] powerpc: introduce pte_set_hash_slot() helper Ram Pai
2017-07-05 21:21 ` [RFC v5 04/38] powerpc: introduce pte_get_hash_gslot() helper Ram Pai
2017-07-05 21:21 ` [RFC v5 05/38] powerpc: capture the PTE format changes in the dump pte report Ram Pai
2017-07-05 21:21 ` [RFC v5 06/38] powerpc: use helper functions in __hash_page_64K() for 64K PTE Ram Pai
2017-07-05 21:21 ` [RFC v5 07/38] powerpc: use helper functions in __hash_page_huge() " Ram Pai
2017-07-05 21:21 ` [RFC v5 08/38] powerpc: use helper functions in __hash_page_4K() " Ram Pai
2017-07-05 21:21 ` [RFC v5 09/38] powerpc: use helper functions in __hash_page_4K() for 4K PTE Ram Pai
2017-07-05 21:21 ` [RFC v5 10/38] powerpc: use helper functions in flush_hash_page() Ram Pai
2017-07-05 21:21 ` [RFC v5 11/38] mm: introduce an additional vma bit for powerpc pkey Ram Pai
2017-07-11 18:10   ` Dave Hansen
2017-07-12 22:23     ` Ram Pai
2017-07-12 22:40       ` Benjamin Herrenschmidt
2017-07-05 21:21 ` [RFC v5 12/38] mm: ability to disable execute permission on a key at creation Ram Pai
2017-07-11 18:11   ` Dave Hansen
2017-07-11 21:29     ` Benjamin Herrenschmidt
2017-07-11 21:51       ` Ram Pai
2017-07-11 21:57         ` Dave Hansen
2017-07-11 22:14           ` Ram Pai
2017-07-11 22:19             ` Dave Hansen
2017-07-11 22:08         ` Benjamin Herrenschmidt
2017-07-11 22:19           ` Ram Pai
2017-07-05 21:21 ` [RFC v5 13/38] x86: disallow pkey creation with PKEY_DISABLE_EXECUTE Ram Pai
2017-07-11 18:12   ` Dave Hansen
2017-07-05 21:21 ` [RFC v5 14/38] powerpc: initial plumbing for key management Ram Pai
2017-07-12  3:28   ` Balbir Singh
2017-07-13  7:45     ` Ram Pai
2017-07-13 20:37       ` Ram Pai [this message]
2017-07-13 21:30         ` Balbir Singh
2017-07-05 21:21 ` [RFC v5 15/38] powerpc: helper function to read,write AMR,IAMR,UAMOR registers Ram Pai
2017-07-12  5:26   ` Balbir Singh
2017-07-13  7:55     ` Ram Pai
2017-07-13  9:49       ` Balbir Singh
2017-07-13 23:29         ` Ram Pai
2017-07-05 21:21 ` [RFC v5 16/38] powerpc: implementation for arch_set_user_pkey_access() Ram Pai
2017-07-05 21:21 ` [RFC v5 17/38] powerpc: sys_pkey_alloc() and sys_pkey_free() system calls Ram Pai
2017-07-05 21:21 ` [RFC v5 18/38] powerpc: store and restore the pkey state across context switches Ram Pai
2017-07-05 21:21 ` [RFC v5 19/38] powerpc: introduce execute-only pkey Ram Pai
2017-07-05 21:21 ` [RFC v5 20/38] powerpc: ability to associate pkey to a vma Ram Pai
2017-07-05 21:21 ` [RFC v5 21/38] powerpc: implementation for arch_override_mprotect_pkey() Ram Pai
2017-07-05 21:21 ` [RFC v5 22/38] powerpc: map vma key-protection bits to pte key bits Ram Pai
2017-07-05 21:22 ` [RFC v5 23/38] powerpc: sys_pkey_mprotect() system call Ram Pai
2017-07-05 21:22 ` [RFC v5 24/38] powerpc: Program HPTE key protection bits Ram Pai
2017-07-05 21:22 ` [RFC v5 25/38] powerpc: helper to validate key-access permissions of a pte Ram Pai
2017-07-05 21:22 ` [RFC v5 26/38] powerpc: check key protection for user page access Ram Pai
2017-07-05 21:22 ` [RFC v5 27/38] powerpc: Macro the mask used for checking DSI exception Ram Pai
2017-07-05 21:22 ` [RFC v5 28/38] powerpc: implementation for arch_vma_access_permitted() Ram Pai
2017-07-05 21:22 ` [RFC v5 29/38] powerpc: Handle exceptions caused by pkey violation Ram Pai
2017-07-05 21:22 ` [RFC v5 30/38] powerpc: capture AMR register content on " Ram Pai
2017-07-05 21:22 ` [RFC v5 31/38] powerpc: introduce get_pte_pkey() helper Ram Pai
2017-07-10  3:11   ` Anshuman Khandual
2017-07-10  5:55     ` Ram Pai
2017-07-11 11:22       ` Anshuman Khandual
2017-07-05 21:22 ` [RFC v5 32/38] powerpc: capture the violated protection key on fault Ram Pai
2017-07-10  3:10   ` Anshuman Khandual
2017-07-10  5:49     ` Ram Pai
2017-07-05 21:22 ` [RFC v5 33/38] powerpc: Deliver SEGV signal on pkey violation Ram Pai
2017-07-10  3:08   ` Anshuman Khandual
2017-07-05 21:22 ` [RFC v5 34/38] procfs: display the protection-key number associated with a vma Ram Pai
2017-07-10  3:07   ` Anshuman Khandual
2017-07-10  6:01     ` Ram Pai
2017-07-11 18:13   ` Dave Hansen
2017-07-13  8:03     ` Ram Pai
2017-07-13 14:07       ` Dave Hansen
2017-07-13 17:04         ` Ram Pai
2017-07-05 21:22 ` [RFC v5 35/38] selftest: Move protecton key selftest to arch neutral directory Ram Pai
2017-07-05 21:22 ` [RFC v5 36/38] selftest: PowerPC specific test updates to memory protection keys Ram Pai
2017-07-11 17:33   ` Dave Hansen
2017-07-12 21:57     ` Ram Pai
2017-07-05 21:22 ` [RFC v5 37/38] Documentation: Move protecton key documentation to arch neutral directory Ram Pai
2017-07-05 21:22 ` [RFC v5 38/38] Documentation: PowerPC specific updates to memory protection keys Ram Pai
2017-07-10  3:07   ` Anshuman Khandual
2017-07-10  5:59     ` Ram Pai
2017-07-11 18:23   ` Dave Hansen
2017-07-13 19:56     ` Ram Pai
2017-07-10  5:43 ` [RFC v5 00/38] powerpc: Memory Protection Keys Anshuman Khandual
2017-07-10  6:05   ` Ram Pai
2017-07-10 17:15     ` Ram Pai
2017-07-11 14:52 ` Michal Hocko
2017-07-11 19:32   ` Ram Pai
2017-07-11 21:30     ` Benjamin Herrenschmidt
2017-07-12  7:23     ` Michal Hocko
2017-07-12  7:39       ` Michal Hocko
2017-07-12 22:53       ` Benjamin Herrenschmidt
2017-07-13  6:20         ` Michal Hocko

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