[PATCH v5 13/15] KVM: SVM: Drop redundant svm_sev_enabled() helper

Sean Christopherson
2021-04-22T02:12:18Z

Replace calls to svm_sev_enabled() with direct checks on sev_enabled, or
in the case of svm_mem_enc_op, simply drop the call to svm_sev_enabled().
This effectively replaces checks against a valid max_sev_asid with checks
against sev_enabled. sev_enabled is forced off by sev_hardware_setup()
if max_sev_asid is invalid, all call sites are guaranteed to run after
sev_hardware_setup(), and all of the checks care about SEV being fully
enabled (as opposed to intentionally handling the scenario where
max_sev_asid is valid but SEV enabling fails due to OOM).

Reviewed by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/svm/sev.c | 6 +++---
arch/x86/kvm/svm/svm.h | 5 -----
2 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 68999085db6e..4440459cf8e3 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -1457,7 +1457,7 @@ int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
struct kvm_sev_cmd sev_cmd;
int r;

- if (!svm_sev_enabled() || !sev_enabled)
+ if (!sev_enabled)
return -ENOTTY;

if (!argp)
@@ -1844,7 +1844,7 @@ void __init sev_hardware_setup(void)

void sev_hardware_teardown(void)
{
- if (!svm_sev_enabled())
+ if (!sev_enabled)
return;

bitmap_free(sev_asid_bitmap);
@@ -1855,7 +1855,7 @@ void sev_hardware_teardown(void)

int sev_cpu_init(struct svm_cpu_data *sd)
{
- if (!svm_sev_enabled())
+ if (!sev_enabled)
return 0;

sd->sev_vmcbs = kcalloc(max_sev_asid + 1, sizeof(void *), GFP_KERNEL);
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 0af638f97b5f..f455784519d7 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -568,11 +568,6 @@ void svm_vcpu_unblocking(struct kvm_vcpu *vcpu);

extern unsigned int max_sev_asid;

-static inline bool svm_sev_enabled(void)
-{
- return IS_ENABLED(CONFIG_KVM_AMD_SEV) ? max_sev_asid : 0;
-}
-
void sev_vm_destroy(struct kvm *kvm);
int svm_mem_enc_op(struct kvm *kvm, void __user *argp);
int svm_register_enc_region(struct kvm *kvm,