[PATCH v2 06/10] KVM: x86: Fold fx_init() into kvm_arch_vcpu_create()

From: Sean Christopherson
Date: Mon Sep 20 2021 - 22:09:02 EST


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@xxxxxxxxxx>
---
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