Message-ID: <a6090023-29d7-a190-d118-56b8e7acffc6@bytedance.com>
Date:   Wed, 8 Mar 2023 14:10:05 +0000
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Subject: Re: [External] Re: [PATCH v13 00/11] Parallel CPU bringup for x86_64
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To:     David Woodhouse <dwmw2@infradead.org>,
        Tom Lendacky <thomas.lendacky@amd.com>,
        "tglx@linutronix.de" <tglx@linutronix.de>,
        "Phillips, Kim" <kim.phillips@amd.com>,
        "brgerst@gmail.com" <brgerst@gmail.com>,
        "Rapan, Sabin" <sabrapan@amazon.com>
Cc:     "piotrgorski@cachyos.org" <piotrgorski@cachyos.org>,
        "oleksandr@natalenko.name" <oleksandr@natalenko.name>,
        "arjan@linux.intel.com" <arjan@linux.intel.com>,
        "mingo@redhat.com" <mingo@redhat.com>,
        "bp@alien8.de" <bp@alien8.de>,
        "dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
        "hpa@zytor.com" <hpa@zytor.com>, "x86@kernel.org" <x86@kernel.org>,
        "pbonzini@redhat.com" <pbonzini@redhat.com>,
        "paulmck@kernel.org" <paulmck@kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        "rcu@vger.kernel.org" <rcu@vger.kernel.org>,
        "mimoja@mimoja.de" <mimoja@mimoja.de>,
        "hewenliang4@huawei.com" <hewenliang4@huawei.com>,
        "seanjc@google.com" <seanjc@google.com>,
        "pmenzel@molgen.mpg.de" <pmenzel@molgen.mpg.de>,
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        "simon.evans@bytedance.com" <simon.evans@bytedance.com>,
        "liangma@liangbit.com" <liangma@liangbit.com>
References: <20230302111227.2102545-1-usama.arif@bytedance.com>
 <faa0eb3bb8ba0326d501516a057ab46eaf1f3c05.camel@infradead.org>
 <effbb6e2-c5a1-af7f-830d-8d7088f57477@amd.com>
 <269ed38b5eed9c3a259c183d59d4f1eb5128f132.camel@infradead.org>
 <0c56683a-c258-46f6-056e-e85da8a557db@amd.com>
 <3bfbbd92-b2ed-8189-7b57-0533f6c87ae7@amd.com>
 <1975308c952236895f2d8f0e56af9db288eaf330.camel@infradead.org>
 <39f23da7-1e77-4535-21a6-00f77a382ae5@amd.com>
 <ba8aae2eafdeb09ec1a41d45ab3c2e4cdaf7a28f.camel@infradead.org>
From:   Usama Arif <usama.arif@bytedance.com>
In-Reply-To: <ba8aae2eafdeb09ec1a41d45ab3c2e4cdaf7a28f.camel@infradead.org>
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> static bool prepare_parallel_bringup(void)
> {
> 	bool has_sev_es = IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT) &&
> 		static_branch_unlikely(&sev_es_enable_key);

sev_es_enable_key is only defined when CONFIG_AMD_MEM_ENCRYPT is 
enabled, so it gives a build error when AMD_MEM_ENCRYPT is disabled. 
maybe below is better?

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 282cca020777..e7df41436cfe 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1519,8 +1519,12 @@ void __init smp_prepare_cpus_common(void)
   */
  static bool prepare_parallel_bringup(void)
  {
-       bool has_sev_es = IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT) &&
-               static_branch_unlikely(&sev_es_enable_key);
+       bool has_sev_es;
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+       has_sev_es = static_branch_unlikely(&sev_es_enable_key);
+#else
+       has_sev_es = 0;
+#endif

         if (IS_ENABLED(CONFIG_X86_32))
                 return false;