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From:   Fenghua Yu <fenghua.yu@intel.com>
To:     "Thomas Gleixner" <tglx@linutronix.de>,
        "Dave Hansen" <dave.hansen@linux.intel.com>,
        "Ingo Molnar" <mingo@redhat.com>, "Borislav Petkov" <bp@alien8.de>,
        "Peter Zijlstra" <peterz@infradead.org>,
        "Andy Lutomirski" <luto@kernel.org>,
        "Tony Luck" <tony.luck@intel.com>,
        "Lu Baolu" <baolu.lu@linux.intel.com>,
        "Joerg Roedel" <joro@8bytes.org>,
        Josh Poimboeuf <jpoimboe@redhat.com>,
        "Jacob Pan" <jacob.jun.pan@linux.intel.com>,
        "Ashok Raj" <ashok.raj@intel.com>,
        "Ravi V Shankar" <ravi.v.shankar@intel.com>
Cc:     iommu@lists.linux-foundation.org, "x86" <x86@kernel.org>,
        "linux-kernel" <linux-kernel@vger.kernel.org>,
        Fenghua Yu <fenghua.yu@intel.com>
Subject: [PATCH v3 09/11] x86/cpufeatures: Re-enable ENQCMD
Date:   Fri, 28 Jan 2022 12:29:03 -0800
Message-Id: <20220128202905.2274672-10-fenghua.yu@intel.com>
In-Reply-To: <20220128202905.2274672-1-fenghua.yu@intel.com>
References: <20220128202905.2274672-1-fenghua.yu@intel.com>
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Since ENQCMD is handled by #GP fix up, it can be re-enabled.

The ENQCMD feature can only be used if CONFIG_INTEL_IOMMU_SVM is set. Add
X86_FEATURE_ENQCMD to the disabled features mask as appropriate so that
cpu_feature_enabled() can be used to check the feature.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
---
v2:
- Update the commit message (Tony).

 arch/x86/include/asm/disabled-features.h | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h
index 8f28fafa98b3..1231d63f836d 100644
--- a/arch/x86/include/asm/disabled-features.h
+++ b/arch/x86/include/asm/disabled-features.h
@@ -56,8 +56,11 @@
 # define DISABLE_PTI		(1 << (X86_FEATURE_PTI & 31))
 #endif
 
-/* Force disable because it's broken beyond repair */
-#define DISABLE_ENQCMD		(1 << (X86_FEATURE_ENQCMD & 31))
+#ifdef CONFIG_INTEL_IOMMU_SVM
+# define DISABLE_ENQCMD		0
+#else
+# define DISABLE_ENQCMD		(1 << (X86_FEATURE_ENQCMD & 31))
+#endif
 
 #ifdef CONFIG_X86_SGX
 # define DISABLE_SGX	0
-- 
2.35.0