[PATCH v2 09/45] KVM: x86: Move allocation of pio_data page down a few lines

[Sean Christopherson]

Allocate the pio_data page after creating the MMU and local APIC so that
all direct memory allocations are grouped together.  This allows setting
the return value to -ENOMEM prior to starting the allocations instead of
setting it in the fail path for every allocation.

The pio_data page is only consumed when KVM_RUN is invoked, i.e. moving
its allocation has no real functional impact.

Signed-off-by: Sean Christopherson <sean.j.christopher...@intel.com>
---
 arch/x86/kvm/x86.c | 33 +++++++++++++--------------------
 1 file changed, 13 insertions(+), 20 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index e3f122dca5f8..b3e367963b08 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9420,18 +9420,11 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
        else
                vcpu->arch.mp_state = KVM_MP_STATE_UNINITIALIZED;
 
-       page = alloc_page(GFP_KERNEL | __GFP_ZERO);
-       if (!page) {
-               r = -ENOMEM;
-               goto fail;
-       }
-       vcpu->arch.pio_data = page_address(page);
-
        kvm_set_tsc_khz(vcpu, max_tsc_khz);
 
        r = kvm_mmu_create(vcpu);
        if (r < 0)
-               goto fail_free_pio_data;
+               return r;
 
        if (irqchip_in_kernel(vcpu->kvm)) {
                vcpu->arch.apicv_active = 
kvm_x86_ops->get_enable_apicv(vcpu->kvm);
@@ -9441,25 +9434,27 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
        } else
                static_key_slow_inc(&kvm_no_apic_vcpu);
 
+       r = -ENOMEM;
+
+       page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+       if (!page)
+               goto fail_free_lapic;
+       vcpu->arch.pio_data = page_address(page);
+
        vcpu->arch.mce_banks = kzalloc(KVM_MAX_MCE_BANKS * sizeof(u64) * 4,
                                       GFP_KERNEL_ACCOUNT);
-       if (!vcpu->arch.mce_banks) {
-               r = -ENOMEM;
-               goto fail_free_lapic;
-       }
+       if (!vcpu->arch.mce_banks)
+               goto fail_free_pio_data;
        vcpu->arch.mcg_cap = KVM_MAX_MCE_BANKS;
 
        if (!zalloc_cpumask_var(&vcpu->arch.wbinvd_dirty_mask,
-                               GFP_KERNEL_ACCOUNT)) {
-               r = -ENOMEM;
+                               GFP_KERNEL_ACCOUNT))
                goto fail_free_mce_banks;
-       }
 
        vcpu->arch.user_fpu = kmem_cache_zalloc(x86_fpu_cache,
                                                GFP_KERNEL_ACCOUNT);
        if (!vcpu->arch.user_fpu) {
                pr_err("kvm: failed to allocate userspace's fpu\n");
-               r = -ENOMEM;
                goto free_wbinvd_dirty_mask;
        }
 
@@ -9467,7 +9462,6 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
                                                 GFP_KERNEL_ACCOUNT);
        if (!vcpu->arch.guest_fpu) {
                pr_err("kvm: failed to allocate vcpu's fpu\n");
-               r = -ENOMEM;
                goto free_user_fpu;
        }
        fx_init(vcpu);
@@ -9494,13 +9488,12 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
        free_cpumask_var(vcpu->arch.wbinvd_dirty_mask);
 fail_free_mce_banks:
        kfree(vcpu->arch.mce_banks);
+fail_free_pio_data:
+       free_page((unsigned long)vcpu->arch.pio_data);
 fail_free_lapic:
        kvm_free_lapic(vcpu);
 fail_mmu_destroy:
        kvm_mmu_destroy(vcpu);
-fail_free_pio_data:
-       free_page((unsigned long)vcpu->arch.pio_data);
-fail:
        return r;
 }
 
-- 
2.24.1

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