From: Tom Lendacky <thomas.lendacky@amd.com>
To: Borislav Petkov <bp@alien8.de>
Cc: linux-arch@vger.kernel.org, linux-efi@vger.kernel.org,
kvm@vger.kernel.org, linux-doc@vger.kernel.org, x86@kernel.org,
linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com,
linux-mm@kvack.org, iommu@lists.linux-foundation.org,
"Radim Krčmář" <rkrcmar@redhat.com>,
"Arnd Bergmann" <arnd@arndb.de>,
"Jonathan Corbet" <corbet@lwn.net>,
"Matt Fleming" <matt@codeblueprint.co.uk>,
"Joerg Roedel" <joro@8bytes.org>,
"Konrad Rzeszutek Wilk" <konrad.wilk@oracle.com>,
"Andrey Ryabinin" <aryabinin@virtuozzo.com>,
"Ingo Molnar" <mingo@redhat.com>,
"Andy Lutomirski" <luto@kernel.org>,
"H. Peter Anvin" <hpa@zytor.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Alexander Potapenko" <glider@google.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Dmitry Vyukov" <dvyukov@google.com>
Subject: Re: [RFC PATCH v2 19/20] x86: Access the setup data through debugfs un-encrypted
Date: Wed, 14 Sep 2016 09:29:41 -0500 [thread overview]
Message-ID: <4a357b9b-7d53-5bd6-81db-9d8cc63a6c72@amd.com> (raw)
In-Reply-To: <20160912165944.rpqbwxz2biathnt3@pd.tnic>
On 09/12/2016 11:59 AM, Borislav Petkov wrote:
> On Mon, Aug 22, 2016 at 05:38:59PM -0500, Tom Lendacky wrote:
>> Since the setup data is in memory in the clear, it must be accessed as
>> un-encrypted. Always use ioremap (similar to sysfs setup data support)
>> to map the data.
>>
>> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
>> ---
>> arch/x86/kernel/kdebugfs.c | 30 +++++++++++-------------------
>> 1 file changed, 11 insertions(+), 19 deletions(-)
>>
>> diff --git a/arch/x86/kernel/kdebugfs.c b/arch/x86/kernel/kdebugfs.c
>> index bdb83e4..a58a82e 100644
>> --- a/arch/x86/kernel/kdebugfs.c
>> +++ b/arch/x86/kernel/kdebugfs.c
>> @@ -48,17 +48,13 @@ static ssize_t setup_data_read(struct file *file, char __user *user_buf,
>>
>> pa = node->paddr + sizeof(struct setup_data) + pos;
>> pg = pfn_to_page((pa + count - 1) >> PAGE_SHIFT);
>> - if (PageHighMem(pg)) {
>
> Why is it ok to get rid of the PageHighMem() check?
Since the change is to perform the ioremap call no matter what the check
for PageHighMem() wasn't needed anymore.
>
> Btw, we did talk earlier in the thread about making __va() clear the SME
> mask and then you won't really need to change stuff here. Or?
This is still required because just using the __va() would still cause
the mapping created to have the encryption bit set. The ioremap call
will result in the mapping not having the encryption bit set.
Thanks,
Tom
>
next prev parent reply other threads:[~2016-09-14 14:29 UTC|newest]
Thread overview: 82+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-22 22:35 [RFC PATCH v2 00/20] x86: Secure Memory Encryption (AMD) Tom Lendacky
2016-08-22 22:35 ` [RFC PATCH v2 01/20] x86: Documentation for AMD Secure Memory Encryption (SME) Tom Lendacky
2016-09-02 8:50 ` Borislav Petkov
2016-09-07 14:02 ` Tom Lendacky
2016-09-07 15:23 ` Borislav Petkov
2016-08-22 22:35 ` [RFC PATCH v2 02/20] x86: Set the write-protect cache mode for full PAT support Tom Lendacky
2016-08-25 3:58 ` Borislav Petkov
2016-08-22 22:35 ` [RFC PATCH v2 03/20] x86: Secure Memory Encryption (SME) build enablement Tom Lendacky
2016-09-02 11:03 ` Borislav Petkov
2016-09-07 14:03 ` Tom Lendacky
2016-08-22 22:36 ` [RFC PATCH v2 04/20] x86: Secure Memory Encryption (SME) support Tom Lendacky
2016-08-25 13:04 ` Thomas Gleixner
2016-08-30 13:19 ` Tom Lendacky
2016-08-30 14:57 ` Andy Lutomirski
2016-08-31 13:26 ` Tom Lendacky
2016-08-22 22:36 ` [RFC PATCH v2 05/20] x86: Add the Secure Memory Encryption cpu feature Tom Lendacky
2016-09-02 14:09 ` Borislav Petkov
2016-09-07 14:07 ` Tom Lendacky
2016-08-22 22:36 ` [RFC PATCH v2 06/20] x86: Handle reduction in physical address size with SME Tom Lendacky
2016-08-22 22:36 ` [RFC PATCH v2 07/20] x86: Provide general kernel support for memory encryption Tom Lendacky
2016-09-02 18:14 ` Borislav Petkov
2016-09-07 14:11 ` Tom Lendacky
2016-09-05 8:48 ` Borislav Petkov
2016-09-07 14:16 ` Tom Lendacky
2016-09-05 15:22 ` Borislav Petkov
2016-09-07 14:19 ` Tom Lendacky
2016-09-06 9:31 ` Borislav Petkov
2016-09-07 14:30 ` Tom Lendacky
2016-09-07 15:55 ` Borislav Petkov
2016-09-08 13:26 ` Tom Lendacky
2016-09-08 13:55 ` Borislav Petkov
2016-09-12 13:43 ` Tom Lendacky
2016-08-22 22:37 ` [RFC PATCH v2 08/20] x86: Extend the early_memmap support with additional attrs Tom Lendacky
2016-08-22 22:37 ` [RFC PATCH v2 09/20] x86: Add support for early encryption/decryption of memory Tom Lendacky
2016-09-06 16:12 ` Borislav Petkov
2016-08-22 22:37 ` [RFC PATCH v2 10/20] x86: Insure that memory areas are encrypted when possible Tom Lendacky
2016-09-09 15:53 ` Borislav Petkov
2016-09-12 15:05 ` Tom Lendacky
2016-09-12 16:33 ` Borislav Petkov
2016-09-14 14:11 ` Tom Lendacky
2016-08-22 22:37 ` [RFC PATCH v2 11/20] mm: Access BOOT related data in the clear Tom Lendacky
2016-09-09 16:38 ` Borislav Petkov
2016-09-12 15:14 ` Tom Lendacky
2016-09-12 16:35 ` Borislav Petkov
2016-09-12 16:55 ` Andy Lutomirski
2016-09-14 14:20 ` Tom Lendacky
2016-09-15 9:57 ` Matt Fleming
2016-09-15 16:52 ` Tom Lendacky
2016-08-22 22:37 ` [RFC PATCH v2 12/20] x86: Add support for changing memory encryption attribute Tom Lendacky
2016-09-09 17:23 ` Borislav Petkov
2016-09-12 15:41 ` Tom Lendacky
2016-09-12 16:41 ` Borislav Petkov
2016-08-22 22:37 ` [RFC PATCH v2 13/20] x86: Decrypt trampoline area if memory encryption is active Tom Lendacky
2016-09-09 17:34 ` Borislav Petkov
2016-09-12 15:43 ` Tom Lendacky
2016-08-22 22:38 ` [RFC PATCH v2 14/20] x86: DMA support for memory encryption Tom Lendacky
2016-09-12 10:58 ` Borislav Petkov
2016-09-14 13:36 ` Tom Lendacky
2016-08-22 22:38 ` [RFC PATCH v2 15/20] iommu/amd: AMD IOMMU " Tom Lendacky
2016-09-12 11:45 ` Borislav Petkov
2016-09-14 13:45 ` Tom Lendacky
2016-09-14 14:41 ` Borislav Petkov
2016-09-15 16:57 ` Tom Lendacky
2016-09-16 7:08 ` Borislav Petkov
2016-08-22 22:38 ` [RFC PATCH v2 16/20] x86: Check for memory encryption on the APs Tom Lendacky
2016-09-12 12:17 ` Borislav Petkov
2016-09-14 13:50 ` Tom Lendacky
2016-09-12 16:43 ` Borislav Petkov
2016-09-14 14:12 ` Tom Lendacky
2016-08-22 22:38 ` [RFC PATCH v2 17/20] x86: Do not specify encrypted memory for VGA mapping Tom Lendacky
2016-08-22 22:38 ` [RFC PATCH v2 18/20] x86/kvm: Enable Secure Memory Encryption of nested page tables Tom Lendacky
2016-09-12 14:35 ` Borislav Petkov
2016-09-14 14:02 ` Tom Lendacky
2016-08-22 22:38 ` [RFC PATCH v2 19/20] x86: Access the setup data through debugfs un-encrypted Tom Lendacky
2016-09-12 16:59 ` Borislav Petkov
2016-09-14 14:29 ` Tom Lendacky [this message]
2016-09-14 14:51 ` Borislav Petkov
2016-09-15 17:08 ` Tom Lendacky
2016-09-16 7:11 ` Borislav Petkov
2016-08-22 22:39 ` [RFC PATCH v2 20/20] x86: Add support to make use of Secure Memory Encryption Tom Lendacky
2016-09-12 17:08 ` Borislav Petkov
2016-09-14 14:31 ` Tom Lendacky
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