From: kaih.linux@gmail.com
To: jbeulich@suse.com, andrew.cooper3@citrix.com, xen-devel@lists.xen.org
Cc: Kai Huang <kai.huang@linux.intel.com>
Subject: [PATCH] xen: x86: remove duplicated MSR_IA32_FEATURE_CONTROL definition
Date: Wed, 22 Jun 2016 22:17:05 +1200 [thread overview]
Message-ID: <1466590625-9702-1-git-send-email-kai.huang@linux.intel.com> (raw)
From: Kai Huang <kai.huang@linux.intel.com>
MSR_IA32_FEATURE_CONTROL was introduced in below commit. Actually this MSR has
already been defined as IA32_FEATURE_CONTROL_MSR. Remove it as a duplication.
Also introduce a new macro for SGX_ENABLE bit in this MSR for better code and
further use. The code of below commit is changed accordingly.
commit 5a211704e8813c4890c8ce8dc4189d1dfb35ecd0
Author: Len Brown <len.brown@intel.com>
Date: Fri Apr 8 22:31:47 2016 +0200
mwait-idle: prevent SKL-H boot failure when C8+C9+C10 enabled
Some SKL-H configurations require "max_cstate=7" to boot.
While that is an effective workaround, it disables C10.
......
One more thinking: actually the SDM says 'Software is considered to have opted
into Intel SGX if and only if IA32_FEATURE_CONTROL.SGX_ENABLE and
IA32_FEATURE_CONTRORL.LOCK are set to 1', therefore maybe below change with the
lock bit checked is more reasonable, but existing code is safe anyway (and I
don't have machine to test).
/* if SGX is enabled */
if ((msr & IA32_FEATURE_CONTROL_SGX_ENABLE) &&
(msr & IA32_FEATURE_CONTROL_MSR_LOCK))
return;
Signed-off-by: Kai Huang <kai.huang@linux.intel.com>
---
xen/arch/x86/cpu/mwait-idle.c | 4 ++--
xen/include/asm-x86/msr-index.h | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/xen/arch/x86/cpu/mwait-idle.c b/xen/arch/x86/cpu/mwait-idle.c
index e062e21..946d598 100644
--- a/xen/arch/x86/cpu/mwait-idle.c
+++ b/xen/arch/x86/cpu/mwait-idle.c
@@ -1003,10 +1003,10 @@ static void __init sklh_idle_state_table_update(void)
/* if SGX is present */
if (boot_cpu_has(X86_FEATURE_SGX)) {
- rdmsrl(MSR_IA32_FEATURE_CONTROL, msr);
+ rdmsrl(IA32_FEATURE_CONTROL_MSR, msr);
/* if SGX is enabled */
- if (msr & (1 << 18))
+ if (msr & IA32_FEATURE_CONTROL_SGX_ENABLE)
return;
}
diff --git a/xen/include/asm-x86/msr-index.h b/xen/include/asm-x86/msr-index.h
index e0f7f8d..f539e24 100644
--- a/xen/include/asm-x86/msr-index.h
+++ b/xen/include/asm-x86/msr-index.h
@@ -139,6 +139,7 @@
#define IA32_FEATURE_CONTROL_MSR_ENABLE_VMXON_OUTSIDE_SMX 0x0004
#define IA32_FEATURE_CONTROL_MSR_SENTER_PARAM_CTL 0x7f00
#define IA32_FEATURE_CONTROL_MSR_ENABLE_SENTER 0x8000
+#define IA32_FEATURE_CONTROL_SGX_ENABLE 0x40000
/* K7/K8 MSRs. Not complete. See the architecture manual for a more
complete list. */
@@ -288,7 +289,6 @@
#define MSR_IA32_PLATFORM_ID 0x00000017
#define MSR_IA32_EBL_CR_POWERON 0x0000002a
#define MSR_IA32_EBC_FREQUENCY_ID 0x0000002c
-#define MSR_IA32_FEATURE_CONTROL 0x0000003a
#define MSR_IA32_TSC_ADJUST 0x0000003b
#define MSR_IA32_APICBASE 0x0000001b
--
2.7.4
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next reply other threads:[~2016-06-22 10:17 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-22 10:17 kaih.linux [this message]
2016-06-22 11:44 ` [PATCH] xen: x86: remove duplicated MSR_IA32_FEATURE_CONTROL definition Jan Beulich
2016-06-24 10:38 ` Huang, Kai
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