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From:   isaku.yamahata@intel.com
To:     linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        Paolo Bonzini <pbonzini@redhat.com>,
        Sean Christopherson <seanjc@google.com>,
        Marc Zyngier <maz@kernel.org>, Will Deacon <will@kernel.org>,
        Yuan Yao <yuan.yao@linux.intel.com>
Cc:     isaku.yamahata@intel.com, isaku.yamahata@gmail.com,
        Kai Huang <kai.huang@intel.com>, Chao Gao <chao.gao@intel.com>,
        Atish Patra <atishp@atishpatra.org>,
        Shaokun Zhang <zhangshaokun@hisilicon.com>,
        Qi Liu <liuqi115@huawei.com>,
        John Garry <john.garry@huawei.com>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Huang Ying <ying.huang@intel.com>,
        Huacai Chen <chenhuacai@kernel.org>,
        linuxppc-dev@lists.ozlabs.org,
        Fabiano Rosas <farosas@linux.ibm.com>
Subject: [PATCH v4 23/26] RFC: KVM: powerpc: Move processor compatibility check to hardware setup
Date:   Thu,  8 Sep 2022 16:25:39 -0700
Message-Id: <b348201517333f52c570f359e0d94bc9d5afc4f2.1662679124.git.isaku.yamahata@intel.com>
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From: Isaku Yamahata <isaku.yamahata@intel.com>

Move processor compatibility check from kvm_arch_processor_compat() into
kvm_arch_hardware_setup().  The check does model name comparison with a
global variable, cur_cpu_spec.  There is no point to check it at run time
on all processors.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Fabiano Rosas <farosas@linux.ibm.com>
---
 arch/powerpc/kvm/powerpc.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 7b56d6ccfdfb..7e3a6659f107 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -444,12 +444,21 @@ int kvm_arch_hardware_enable(void)
 
 int kvm_arch_hardware_setup(void *opaque)
 {
-	return 0;
+	/*
+	 * kvmppc_core_check_processor_compat() checks the global variable.
+	 * No point to check on all processors or at runtime.
+	 * arch/powerpc/kvm/book3s.c: return 0
+	 * arch/powerpc/kvm/e500.c: strcmp(cur_cpu_spec->cpu_name, "e500v2")
+	 * arch/powerpc/kvm/e500mc.c: strcmp(cur_cpu_spec->cpu_name, "e500mc")
+	 *                            strcmp(cur_cpu_spec->cpu_name, "e5500")
+	 *                            strcmp(cur_cpu_spec->cpu_name, "e6500")
+	 */
+	return kvmppc_core_check_processor_compat();
 }
 
 int kvm_arch_check_processor_compat(void)
 {
-	return kvmppc_core_check_processor_compat();
+	return 0;
 }
 
 int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
-- 
2.25.1