From: Borislav Petkov <bp@suse.de>
To: Brijesh Singh <brijesh.singh@amd.com>,
Tom Lendacky <thomas.lendacky@amd.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>, "Arnd Bergmann" <arnd@arndb.de>,
"David Laight" <David.Laight@aculab.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"x86@kernel.org" <x86@kernel.org>,
"linux-efi@vger.kernel.org" <linux-efi@vger.kernel.org>,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"Fenghua Yu" <fenghua.yu@intel.com>,
"Matt Fleming" <matt@codeblueprint.co.uk>,
"David Howells" <dhowells@redhat.com>,
"Paul Mackerras" <paulus@samba.org>,
"Christoph Lameter" <cl@linux.com>,
"Jonathan Corbet" <corbet@lwn.net>,
"Radim Krcmár" <rkrcmar@redhat.com>,
"Piotr Luc" <piotr.luc@intel.com>,
"Ingo Molnar" <mingo@redhat.com>,
"Dave Airlie" <airlied@redhat.com>,
"Kees Cook" <keescook@chromium.org>,
"Konrad Rzeszutek Wilk" <konrad.wilk@oracle.com>,
"Reza Arbab" <arbab@linux.vnet.ibm.com>,
"Andy Lutomirski" <luto@kernel.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Laura Abbott" <labbott@redhat.com>,
"Tony Luck" <tony.luck@intel.com>,
Ard.Biesheuvel@zytor.com
Subject: Re: [RFC Part1 PATCH v3 13/17] x86/io: Unroll string I/O when SEV is active
Date: Fri, 15 Sep 2017 14:24:30 +0200 [thread overview]
Message-ID: <20170915122430.pnroy6vsg53warel@pd.tnic> (raw)
In-Reply-To: <20170822165248.rkbluikdgduu7ucy@pd.tnic>
On Tue, Aug 22, 2017 at 06:52:48PM +0200, Borislav Petkov wrote:
> As always, the devil is in the detail.
Ok, actually we can make this much simpler by using a static key. A
conceptual patch below - I only need to fix that crazy include hell I'm
stepping into with this.
In any case, we were talking about having a static branch already so
this fits the whole strategy.
---
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index d174b1c4a99e..e45369158632 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -45,6 +45,8 @@ EXPORT_SYMBOL_GPL(sme_me_mask);
unsigned int sev_enabled __section(.data) = 0;
EXPORT_SYMBOL_GPL(sev_enabled);
+DEFINE_STATIC_KEY_FALSE(__sev);
+
/* Buffer used for early in-place encryption by BSP, no locking needed */
static char sme_early_buffer[PAGE_SIZE] __aligned(PAGE_SIZE);
@@ -790,6 +792,7 @@ void __init __nostackprotector sme_enable(struct boot_params *bp)
/* SEV state cannot be controlled by a command line option */
sme_me_mask = me_mask;
sev_enabled = 1;
+ static_branch_enable(&__sev);
return;
}
diff --git a/include/linux/mem_encrypt.h b/include/linux/mem_encrypt.h
index ea0831a8dbe2..f3ab965a3d6a 100644
--- a/include/linux/mem_encrypt.h
+++ b/include/linux/mem_encrypt.h
@@ -13,6 +13,8 @@
#ifndef __MEM_ENCRYPT_H__
#define __MEM_ENCRYPT_H__
+#include <linux/jump_label.h>
+
#ifndef __ASSEMBLY__
#ifdef CONFIG_ARCH_HAS_MEM_ENCRYPT
@@ -26,6 +28,8 @@
#endif /* CONFIG_ARCH_HAS_MEM_ENCRYPT */
+extern struct static_key_false __sev;
+
static inline bool sme_active(void)
{
return (sme_me_mask && !sev_enabled);
@@ -33,7 +37,7 @@ static inline bool sme_active(void)
static inline bool sev_active(void)
{
- return (sme_me_mask && sev_enabled);
+ return static_branch_unlikely(&__sev);
}
static inline unsigned long sme_get_me_mask(void)
--
Regards/Gruss,
Boris.
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
--
next prev parent reply other threads:[~2017-09-15 12:24 UTC|newest]
Thread overview: 79+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-24 19:07 [RFC Part1 PATCH v3 00/17] x86: Secure Encrypted Virtualization (AMD) Brijesh Singh
2017-07-24 19:07 ` [RFC Part1 PATCH v3 01/17] Documentation/x86: Add AMD Secure Encrypted Virtualization (SEV) descrption Brijesh Singh
2017-07-25 5:45 ` Borislav Petkov
2017-07-25 14:59 ` Brijesh Singh
2017-07-24 19:07 ` [RFC Part1 PATCH v3 02/17] x86/CPU/AMD: Add the Secure Encrypted Virtualization CPU feature Brijesh Singh
2017-07-25 10:26 ` Borislav Petkov
2017-07-25 14:29 ` Tom Lendacky
2017-07-25 14:36 ` Borislav Petkov
2017-07-25 14:58 ` Tom Lendacky
2017-07-25 15:13 ` Borislav Petkov
2017-07-25 15:29 ` Tom Lendacky
2017-07-25 15:33 ` Borislav Petkov
2017-08-09 18:17 ` Tom Lendacky
2017-08-17 8:12 ` Borislav Petkov
2017-07-24 19:07 ` [RFC Part1 PATCH v3 03/17] x86/mm: Secure Encrypted Virtualization (SEV) support Brijesh Singh
2017-07-26 4:28 ` Borislav Petkov
2017-07-26 16:47 ` Tom Lendacky
2017-07-27 13:39 ` Borislav Petkov
2017-07-24 19:07 ` [RFC Part1 PATCH v3 04/17] x86/mm: Don't attempt to encrypt initrd under SEV Brijesh Singh
2017-07-26 14:44 ` Borislav Petkov
2017-07-24 19:07 ` [RFC Part1 PATCH v3 05/17] x86, realmode: Don't decrypt trampoline area " Brijesh Singh
2017-07-26 16:03 ` Borislav Petkov
2017-08-10 13:03 ` Tom Lendacky
2017-07-24 19:07 ` [RFC Part1 PATCH v3 06/17] x86/mm: Use encrypted access of boot related data with SEV Brijesh Singh
2017-07-27 13:31 ` Borislav Petkov
2017-08-17 18:05 ` Tom Lendacky
2017-07-24 19:07 ` [RFC Part1 PATCH v3 07/17] x86/mm: Include SEV for encryption memory attribute changes Brijesh Singh
2017-07-27 14:58 ` Borislav Petkov
2017-07-28 8:47 ` David Laight
2017-08-17 18:21 ` Tom Lendacky
2017-08-17 18:10 ` Tom Lendacky
2017-07-24 19:07 ` [RFC Part1 PATCH v3 08/17] x86/efi: Access EFI data as encrypted when SEV is active Brijesh Singh
2017-07-28 10:31 ` Borislav Petkov
2017-08-17 18:42 ` Tom Lendacky
2017-07-24 19:07 ` [RFC Part1 PATCH v3 09/17] resource: Consolidate resource walking code Brijesh Singh
2017-07-28 15:23 ` Borislav Petkov
2017-08-17 18:55 ` Tom Lendacky
2017-08-17 19:03 ` Tom Lendacky
2017-07-24 19:07 ` [RFC Part1 PATCH v3 10/17] resource: Provide resource struct in resource walk callback Brijesh Singh
2017-07-31 8:26 ` Borislav Petkov
2017-07-31 22:19 ` Kees Cook
2017-07-24 19:07 ` [RFC Part1 PATCH v3 11/17] x86/mm, resource: Use PAGE_KERNEL protection for ioremap of memory pages Brijesh Singh
2017-08-02 4:02 ` Borislav Petkov
2017-08-17 19:22 ` Tom Lendacky
2017-07-24 19:07 ` [RFC Part1 PATCH v3 12/17] x86/mm: DMA support for SEV memory encryption Brijesh Singh
2017-08-07 3:48 ` Borislav Petkov
2017-08-17 19:35 ` Tom Lendacky
2017-07-24 19:07 ` [RFC Part1 PATCH v3 13/17] x86/io: Unroll string I/O when SEV is active Brijesh Singh
2017-07-25 9:51 ` David Laight
2017-07-26 10:45 ` Arnd Bergmann
2017-07-26 19:24 ` Brijesh Singh
2017-07-26 19:26 ` H. Peter Anvin
2017-07-26 20:07 ` Brijesh Singh
2017-07-27 7:45 ` David Laight
2017-08-22 16:52 ` Borislav Petkov
2017-09-15 12:24 ` Borislav Petkov [this message]
2017-09-15 14:13 ` Brijesh Singh
2017-09-15 14:40 ` Borislav Petkov
2017-09-15 14:48 ` Brijesh Singh
2017-09-15 16:22 ` Borislav Petkov
2017-09-15 16:27 ` Brijesh Singh
2017-07-24 19:07 ` [RFC Part1 PATCH v3 14/17] x86/boot: Add early boot support when running with SEV active Brijesh Singh
2017-08-23 15:30 ` Borislav Petkov
2017-08-24 18:54 ` Tom Lendacky
2017-08-25 12:54 ` Borislav Petkov
2017-07-24 19:07 ` [RFC Part1 PATCH v3 15/17] x86: Add support for changing memory encryption attribute in early boot Brijesh Singh
2017-08-28 10:51 ` Borislav Petkov
2017-08-28 11:49 ` Brijesh Singh
2017-07-24 19:07 ` [RFC Part1 PATCH v3 16/17] X86/KVM: Provide support to create Guest and HV shared per-CPU variables Brijesh Singh
2017-08-29 10:22 ` Borislav Petkov
2017-08-30 16:18 ` Brijesh Singh
2017-08-30 17:46 ` Borislav Petkov
2017-09-01 22:52 ` Brijesh Singh
2017-09-02 3:21 ` Andy Lutomirski
2017-09-03 2:34 ` Brijesh Singh
2017-09-04 17:05 ` Borislav Petkov
2017-09-04 17:47 ` Brijesh Singh
2017-07-24 19:07 ` [RFC Part1 PATCH v3 17/17] X86/KVM: Clear encryption attribute when SEV is active Brijesh Singh
2017-08-31 15:06 ` Borislav Petkov
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