[PATCH 3/5] KVM: arm64: Drop check_kvm_target_cpu() based percpu probe

From: Anshuman Khandual
Date: Tue Aug 10 2021 - 03:02:21 EST


kvm_target_cpu() never returns a negative error code, so check_kvm_target()
would never have 'ret' filled with a negative error code. Hence the percpu
probe via check_kvm_target_cpu() does not make sense as its never going to
find an unsupported CPU, forcing kvm_arch_init() to exit early. Hence lets
just drop this percpu probe (and also check_kvm_target_cpu()) altogether.

Cc: Marc Zyngier <maz@xxxxxxxxxx>
Cc: James Morse <james.morse@xxxxxxx>
Cc: Alexandru Elisei <alexandru.elisei@xxxxxxx>
Cc: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: kvmarm@xxxxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
---
arch/arm64/kvm/arm.c | 14 --------------
1 file changed, 14 deletions(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 19560e457c11..16f93678c17e 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -2010,11 +2010,6 @@ static int finalize_hyp_mode(void)
return 0;
}

-static void check_kvm_target_cpu(void *ret)
-{
- *(int *)ret = kvm_target_cpu();
-}
-
struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr)
{
struct kvm_vcpu *vcpu;
@@ -2074,7 +2069,6 @@ void kvm_arch_irq_bypass_start(struct irq_bypass_consumer *cons)
int kvm_arch_init(void *opaque)
{
int err;
- int ret, cpu;
bool in_hyp_mode;

if (!is_hyp_mode_available()) {
@@ -2089,14 +2083,6 @@ int kvm_arch_init(void *opaque)
kvm_info("Guests without required CPU erratum workarounds can deadlock system!\n" \
"Only trusted guests should be used on this system.\n");

- for_each_online_cpu(cpu) {
- smp_call_function_single(cpu, check_kvm_target_cpu, &ret, 1);
- if (ret < 0) {
- kvm_err("Error, CPU %d not supported!\n", cpu);
- return -ENODEV;
- }
- }
-
err = kvm_set_ipa_limit();
if (err)
return err;
--
2.20.1