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Message-Id: <20221109145156.84714-8-pbonzini@redhat.com>
Date: Wed, 9 Nov 2022 09:51:52 -0500
From: Paolo Bonzini <pbonzini@...hat.com>
To: linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc: thomas.lendacky@....com, jmattson@...gle.com, seanjc@...gle.com
Subject: [PATCH 07/11] KVM: SVM: do not allocate struct svm_cpu_data dynamically
The svm_data percpu variable is a pointer, but it is allocated when
KVM is loaded (via svm_hardware_setup), not at hardware_enable time.
Just allocate room for it statically, that is more efficient and
does not waste any memory compared to the status quo.
Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
---
arch/x86/kvm/svm/sev.c | 4 ++--
arch/x86/kvm/svm/svm.c | 41 +++++++++++++++--------------------------
arch/x86/kvm/svm/svm.h | 2 +-
3 files changed, 18 insertions(+), 29 deletions(-)
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 28064060413a..9b66ee34e264 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -196,7 +196,7 @@ static void sev_asid_free(struct kvm_sev_info *sev)
__set_bit(sev->asid, sev_reclaim_asid_bitmap);
for_each_possible_cpu(cpu) {
- sd = per_cpu(svm_data, cpu);
+ sd = per_cpu_ptr(&svm_data, cpu);
sd->sev_vmcbs[sev->asid] = NULL;
}
@@ -2600,7 +2600,7 @@ void sev_es_unmap_ghcb(struct vcpu_svm *svm)
void pre_sev_run(struct vcpu_svm *svm, int cpu)
{
- struct svm_cpu_data *sd = per_cpu(svm_data, cpu);
+ struct svm_cpu_data *sd = per_cpu_ptr(&svm_data, cpu);
int asid = sev_get_asid(svm->vcpu.kvm);
/* Assign the asid allocated with this SEV guest */
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 0f873b298931..48274c93d78b 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -245,7 +245,7 @@ struct kvm_ldttss_desc {
u32 zero1;
} __attribute__((packed));
-DEFINE_PER_CPU(struct svm_cpu_data *, svm_data);
+DEFINE_PER_CPU(struct svm_cpu_data, svm_data);
/*
* Only MSR_TSC_AUX is switched via the user return hook. EFER is switched via
@@ -581,12 +581,7 @@ static int svm_hardware_enable(void)
pr_err("%s: err EOPNOTSUPP on %d\n", __func__, me);
return -EINVAL;
}
- sd = per_cpu(svm_data, me);
- if (!sd) {
- pr_err("%s: svm_data is NULL on %d\n", __func__, me);
- return -EINVAL;
- }
-
+ sd = per_cpu_ptr(&svm_data, me);
sd->asid_generation = 1;
sd->max_asid = cpuid_ebx(SVM_CPUID_FUNC) - 1;
sd->next_asid = sd->max_asid + 1;
@@ -646,41 +641,35 @@ static int svm_hardware_enable(void)
static void svm_cpu_uninit(int cpu)
{
- struct svm_cpu_data *sd = per_cpu(svm_data, cpu);
+ struct svm_cpu_data *sd = per_cpu_ptr(&svm_data, cpu);
- if (!sd)
+ if (!sd->save_area)
return;
- per_cpu(svm_data, cpu) = NULL;
kfree(sd->sev_vmcbs);
__free_page(sd->save_area);
- kfree(sd);
+ sd->save_area = NULL;
}
static int svm_cpu_init(int cpu)
{
- struct svm_cpu_data *sd;
+ struct svm_cpu_data *sd = per_cpu_ptr(&svm_data, cpu);
int ret = -ENOMEM;
- sd = kzalloc(sizeof(struct svm_cpu_data), GFP_KERNEL);
- if (!sd)
- return ret;
+ memset(sd, 0, sizeof(struct svm_cpu_data));
sd->save_area = alloc_page(GFP_KERNEL | __GFP_ZERO);
if (!sd->save_area)
- goto free_cpu_data;
+ return ret;
ret = sev_cpu_init(sd);
if (ret)
goto free_save_area;
- per_cpu(svm_data, cpu) = sd;
-
return 0;
free_save_area:
__free_page(sd->save_area);
-free_cpu_data:
- kfree(sd);
+ sd->save_area = NULL;
return ret;
}
@@ -1424,7 +1413,7 @@ static void svm_clear_current_vmcb(struct vmcb *vmcb)
int i;
for_each_online_cpu(i)
- cmpxchg(&per_cpu(svm_data, i)->current_vmcb, vmcb, NULL);
+ cmpxchg(per_cpu_ptr(&svm_data.current_vmcb, i), vmcb, NULL);
}
static void svm_vcpu_free(struct kvm_vcpu *vcpu)
@@ -1449,7 +1438,7 @@ static void svm_vcpu_free(struct kvm_vcpu *vcpu)
static void svm_prepare_switch_to_guest(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
- struct svm_cpu_data *sd = per_cpu(svm_data, vcpu->cpu);
+ struct svm_cpu_data *sd = per_cpu_ptr(&svm_data, vcpu->cpu);
if (sev_es_guest(vcpu->kvm))
sev_es_unmap_ghcb(svm);
@@ -1486,7 +1475,7 @@ static void svm_prepare_host_switch(struct kvm_vcpu *vcpu)
static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
- struct svm_cpu_data *sd = per_cpu(svm_data, cpu);
+ struct svm_cpu_data *sd = per_cpu_ptr(&svm_data, cpu);
if (sd->current_vmcb != svm->vmcb) {
sd->current_vmcb = svm->vmcb;
@@ -3442,7 +3431,7 @@ static int svm_handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath)
static void reload_tss(struct kvm_vcpu *vcpu)
{
- struct svm_cpu_data *sd = per_cpu(svm_data, vcpu->cpu);
+ struct svm_cpu_data *sd = per_cpu_ptr(&svm_data, vcpu->cpu);
sd->tss_desc->type = 9; /* available 32/64-bit TSS */
load_TR_desc();
@@ -3450,7 +3439,7 @@ static void reload_tss(struct kvm_vcpu *vcpu)
static void pre_svm_run(struct kvm_vcpu *vcpu)
{
- struct svm_cpu_data *sd = per_cpu(svm_data, vcpu->cpu);
+ struct svm_cpu_data *sd = per_cpu_ptr(&svm_data, vcpu->cpu);
struct vcpu_svm *svm = to_svm(vcpu);
/*
@@ -3919,7 +3908,7 @@ static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu)
if (sev_es_guest(vcpu->kvm)) {
__svm_sev_es_vcpu_run(svm);
} else {
- struct svm_cpu_data *sd = per_cpu(svm_data, vcpu->cpu);
+ struct svm_cpu_data *sd = per_cpu_ptr(&svm_data, vcpu->cpu);
/*
* Use a single vmcb (vmcb01 because it's always valid) for
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 7540db9902a6..2af6a71126c1 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -293,7 +293,7 @@ struct svm_cpu_data {
struct vmcb **sev_vmcbs;
};
-DECLARE_PER_CPU(struct svm_cpu_data *, svm_data);
+DECLARE_PER_CPU(struct svm_cpu_data, svm_data);
void recalc_intercepts(struct vcpu_svm *svm);
--
2.31.1
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