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Reply-To: Sean Christopherson <seanjc@google.com>
Date: Fri,  8 Mar 2024 17:27:19 -0800
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Subject: [PATCH v6 3/9] KVM: x86: Stuff vCPU's PAT with default value at
 RESET, not creation
From: Sean Christopherson <seanjc@google.com>
To: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, 
	Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org, 
	Sean Christopherson <seanjc@google.com>, Paolo Bonzini <pbonzini@redhat.com>, 
	Andy Lutomirski <luto@kernel.org>, Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, 
	Shan Kang <shan.kang@intel.com>, Kai Huang <kai.huang@intel.com>, Xin Li <xin3.li@intel.com>
Content-Type: text/plain; charset="UTF-8"

Move the stuffing of the vCPU's PAT to the architectural "default" value
from kvm_arch_vcpu_create() to kvm_vcpu_reset(), guarded by !init_event,
to better capture that the default value is the value "Following Power-up
or Reset".  E.g. setting PAT only during creation would break if KVM were
to expose a RESET ioctl() to userspace (which is unlikely, but that's not
a good reason to have unintuitive code).

No functional change.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/kvm/x86.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 66c4381460dc..eac97b1b8379 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -12134,8 +12134,6 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
 	vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
 	vcpu->arch.reserved_gpa_bits = kvm_vcpu_reserved_gpa_bits_raw(vcpu);
 
-	vcpu->arch.pat = MSR_IA32_CR_PAT_DEFAULT;
-
 	kvm_async_pf_hash_reset(vcpu);
 
 	vcpu->arch.perf_capabilities = kvm_caps.supported_perf_cap;
@@ -12302,6 +12300,8 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
 	if (!init_event) {
 		vcpu->arch.smbase = 0x30000;
 
+		vcpu->arch.pat = MSR_IA32_CR_PAT_DEFAULT;
+
 		vcpu->arch.msr_misc_features_enables = 0;
 		vcpu->arch.ia32_misc_enable_msr = MSR_IA32_MISC_ENABLE_PEBS_UNAVAIL |
 						  MSR_IA32_MISC_ENABLE_BTS_UNAVAIL;
-- 
2.44.0.278.ge034bb2e1d-goog