[PATCH 08/45] KVM: x86: Move FPU allocation to common x86 code

Sean Christopherson
2019-10-22T01:58:48Z

The allocation of FPU structs is identical across VMX and SVM, move it
to common x86 code. Somewhat arbitrarily place the allocation so that
it resides directly above the associated initialization via fx_init(),
e.g. instead of retaining its position with respect to the overall vcpu
creation flow. Although the names names kvm_arch_vcpu_create() and
kvm_arch_vcpu_init() might suggest otherwise, x86 does not have a clean
split between 'create' and 'init'. Allocating the struct immediately
prior to the first use arguably improves readability *now*, and will
yield even bigger improvements when kvm_arch_vcpu_init() is removed in
a future patch.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/kvm/svm.c | 25 +------------------------
arch/x86/kvm/vmx/vmx.c | 25 +------------------------
arch/x86/kvm/x86.c | 21 +++++++++++++++++++++
3 files changed, 23 insertions(+), 48 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index bbc5dac9d400..dc4e835f7d46 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2151,25 +2151,9 @@ static int svm_create_vcpu(struct kvm *kvm, struct kvm_vcpu *vcpu,
BUILD_BUG_ON(offsetof(struct vcpu_svm, vcpu) != 0);
svm = to_svm(vcpu);

- vcpu->arch.user_fpu = kmem_cache_zalloc(x86_fpu_cache,
- GFP_KERNEL_ACCOUNT);
- if (!vcpu->arch.user_fpu) {
- printk(KERN_ERR "kvm: failed to allocate kvm userspace's fpu\n");
- err = -ENOMEM;
- goto out;
- }
-
- vcpu->arch.guest_fpu = kmem_cache_zalloc(x86_fpu_cache,
- GFP_KERNEL_ACCOUNT);
- if (!vcpu->arch.guest_fpu) {
- printk(KERN_ERR "kvm: failed to allocate vcpu's fpu\n");
- err = -ENOMEM;
- goto free_user_fpu;
- }
-
err = kvm_vcpu_init(vcpu, kvm, id);
if (err)
- goto free_guest_fpu;
+ return err;

err = -ENOMEM;
page = alloc_page(GFP_KERNEL_ACCOUNT);
@@ -2225,11 +2209,6 @@ static int svm_create_vcpu(struct kvm *kvm, struct kvm_vcpu *vcpu,
__free_page(page);
uninit:
kvm_vcpu_uninit(vcpu);
-free_guest_fpu:
- kmem_cache_free(x86_fpu_cache, vcpu->arch.guest_fpu);
-free_user_fpu:
- kmem_cache_free(x86_fpu_cache, vcpu->arch.user_fpu);
-out:
return err;
}

@@ -2257,8 +2236,6 @@ static void svm_free_vcpu(struct kvm_vcpu *vcpu)
__free_page(virt_to_page(svm->nested.hsave));
__free_pages(virt_to_page(svm->nested.msrpm), MSRPM_ALLOC_ORDER);
kvm_vcpu_uninit(vcpu);
- kmem_cache_free(x86_fpu_cache, vcpu->arch.user_fpu);
- kmem_cache_free(x86_fpu_cache, vcpu->arch.guest_fpu);
}

static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 832d8e38acd4..1973029c5c77 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6691,8 +6691,6 @@ static void vmx_free_vcpu(struct kvm_vcpu *vcpu)
free_loaded_vmcs(vmx->loaded_vmcs);
kfree(vmx->guest_msrs);
kvm_vcpu_uninit(vcpu);
- kmem_cache_free(x86_fpu_cache, vcpu->arch.user_fpu);
- kmem_cache_free(x86_fpu_cache, vcpu->arch.guest_fpu);
}

static int vmx_create_vcpu(struct kvm *kvm, struct kvm_vcpu *vcpu,
@@ -6705,25 +6703,9 @@ static int vmx_create_vcpu(struct kvm *kvm, struct kvm_vcpu *vcpu,
BUILD_BUG_ON(offsetof(struct vcpu_vmx, vcpu) != 0);
vmx = to_vmx(vcpu);

- vcpu->arch.user_fpu = kmem_cache_zalloc(x86_fpu_cache,
- GFP_KERNEL_ACCOUNT);
- if (!vcpu->arch.user_fpu) {
- printk(KERN_ERR "kvm: failed to allocate kvm userspace's fpu\n");
- err = -ENOMEM;
- goto out;
- }
-
- vcpu->arch.guest_fpu = kmem_cache_zalloc(x86_fpu_cache,
- GFP_KERNEL_ACCOUNT);
- if (!vcpu->arch.guest_fpu) {
- printk(KERN_ERR "kvm: failed to allocate vcpu's fpu\n");
- err = -ENOMEM;
- goto free_user_fpu;
- }
-
err = kvm_vcpu_init(vcpu, kvm, id);
if (err)
- goto free_vcpu;
+ return err;

err = -ENOMEM;

@@ -6819,11 +6801,6 @@ static int vmx_create_vcpu(struct kvm *kvm, struct kvm_vcpu *vcpu,
uninit_vcpu:
kvm_vcpu_uninit(vcpu);
free_vpid(vmx->vpid);
-free_vcpu:
- kmem_cache_free(x86_fpu_cache, vcpu->arch.guest_fpu);
-free_user_fpu:
- kmem_cache_free(x86_fpu_cache, vcpu->arch.user_fpu);
-out:
return err;
}

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 45b296a9fdbb..777a29b3c38b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9017,6 +9017,8 @@ void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
kvm_x86_ops->vcpu_free(vcpu);

free_cpumask_var(vcpu->arch.wbinvd_dirty_mask);
+ kmem_cache_free(x86_fpu_cache, vcpu->arch.user_fpu);
+ kmem_cache_free(x86_fpu_cache, vcpu->arch.guest_fpu);
kmem_cache_free(kvm_vcpu_cache, vcpu);
}

@@ -9371,6 +9373,21 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
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;
+ }
+
+ vcpu->arch.guest_fpu = kmem_cache_zalloc(x86_fpu_cache,
+ 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);

vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
@@ -9389,6 +9406,10 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)

return 0;

+free_user_fpu:
+ kmem_cache_free(x86_fpu_cache, vcpu->arch.user_fpu);
+free_wbinvd_dirty_mask:
+ free_cpumask_var(vcpu->arch.wbinvd_dirty_mask);
fail_free_mce_banks:
kfree(vcpu->arch.mce_banks);
fail_free_lapic:
--
2.22.0