linux-kernel - [PATCH v2 06/10] KVM: x86: Fold fx_init() into kvm_arch_vcpu

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Date:   Mon, 20 Sep 2021 17:02:59 -0700
From:   Sean Christopherson <seanjc@...gle.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, Reiji Watanabe <reijiw@...gle.com>
Subject: [PATCH v2 06/10] KVM: x86: Fold fx_init() into kvm_arch_vcpu_create()

Move the few bits of relevant fx_init() code into kvm_arch_vcpu_create(),
dropping the superfluous check on vcpu->arch.guest_fpu that was blindly
and wrongly added by commit ed02b213098a ("KVM: SVM: Guest FPU state
save/restore not needed for SEV-ES guest").

Note, KVM currently allocates and then frees FPU state for SEV-ES guests,
rather than avoid the allocation in the first place.  While that approach
is inarguably inefficient and unnecessary, it's a cleanup for the future.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/x86.c | 16 ++++------------
 1 file changed, 4 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6fd3fe21863e..ec61b90d9b73 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -10614,17 +10614,6 @@ static int sync_regs(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
-static void fx_init(struct kvm_vcpu *vcpu)
-{
-	if (!vcpu->arch.guest_fpu)
-		return;
-
-	fpstate_init(&vcpu->arch.guest_fpu->state);
-	if (boot_cpu_has(X86_FEATURE_XSAVES))
-		vcpu->arch.guest_fpu->state.xsave.header.xcomp_bv =
-			host_xcr0 | XSTATE_COMPACTION_ENABLED;
-}
-
 void kvm_free_guest_fpu(struct kvm_vcpu *vcpu)
 {
 	if (vcpu->arch.guest_fpu) {
@@ -10703,7 +10692,10 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
 		pr_err("kvm: failed to allocate vcpu's fpu\n");
 		goto free_user_fpu;
 	}
-	fx_init(vcpu);
+	fpstate_init(&vcpu->arch.guest_fpu->state);
+	if (boot_cpu_has(X86_FEATURE_XSAVES))
+		vcpu->arch.guest_fpu->state.xsave.header.xcomp_bv =
+			host_xcr0 | XSTATE_COMPACTION_ENABLED;
 
 	vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
 	vcpu->arch.reserved_gpa_bits = kvm_vcpu_reserved_gpa_bits_raw(vcpu);
-- 
2.33.0.464.g1972c5931b-goog