[PATCH v5 28/30] KVM: Eliminate kvm_arch_check_processor_compat()

From: isaku . yamahata
Date: Thu Sep 22 2022 - 14:24:46 EST


From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>

Now all arch has "return 0" implementation. Eliminate it. If feature
compatibility check is needed, it should be done in
kvm_arch_hardware_setup(), kvm_arch_online_cpu(), and kvm_arch_resume().

Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
---
arch/arm64/kvm/arm.c | 5 -----
arch/mips/kvm/mips.c | 5 -----
arch/powerpc/kvm/powerpc.c | 5 -----
arch/riscv/kvm/main.c | 5 -----
arch/s390/kvm/kvm-s390.c | 5 -----
arch/x86/kvm/x86.c | 10 ----------
include/linux/kvm_host.h | 2 --
virt/kvm/kvm_arch.c | 22 ----------------------
virt/kvm/kvm_main.c | 4 ----
9 files changed, 63 deletions(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 7e83498b83aa..de0397bd7b18 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -68,11 +68,6 @@ int kvm_arch_hardware_setup(void *opaque)
return 0;
}

-int kvm_arch_check_processor_compat(void)
-{
- return 0;
-}
-
int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
struct kvm_enable_cap *cap)
{
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index 092d09fb6a7e..f4feae89075c 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -140,11 +140,6 @@ int kvm_arch_hardware_setup(void *opaque)
return 0;
}

-int kvm_arch_check_processor_compat(void)
-{
- return 0;
-}
-
extern void kvm_init_loongson_ipi(struct kvm *kvm);

int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 31dc4f231e9d..546ebbe16bfe 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -447,11 +447,6 @@ int kvm_arch_hardware_setup(void *opaque)
return kvmppc_core_check_processor_compat();
}

-int kvm_arch_check_processor_compat(void)
-{
- return 0;
-}
-
int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
{
struct kvmppc_ops *kvm_ops = NULL;
diff --git a/arch/riscv/kvm/main.c b/arch/riscv/kvm/main.c
index f8d6372d208f..ebabcb3dfb8c 100644
--- a/arch/riscv/kvm/main.c
+++ b/arch/riscv/kvm/main.c
@@ -20,11 +20,6 @@ long kvm_arch_dev_ioctl(struct file *filp,
return -EINVAL;
}

-int kvm_arch_check_processor_compat(void)
-{
- return 0;
-}
-
int kvm_arch_hardware_setup(void *opaque)
{
return 0;
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index e26d4dd85668..9c5d3e4b464f 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -254,11 +254,6 @@ int kvm_arch_hardware_enable(void)
return 0;
}

-int kvm_arch_check_processor_compat(void)
-{
- return 0;
-}
-
/* forward declarations */
static void kvm_gmap_notifier(struct gmap *gmap, unsigned long start,
unsigned long end);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 00cc74276819..1f791c93391b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -12035,11 +12035,6 @@ int kvm_arch_del_vm(int usage_count)
return 0;
}

-int kvm_arch_check_processor_compat_all(void)
-{
- return 0;
-}
-
int kvm_arch_online_cpu(unsigned int cpu, int usage_count)
{
int ret;
@@ -12203,11 +12198,6 @@ static int kvm_check_processor_compatibility(void)
return static_call(kvm_x86_check_processor_compatibility)();
}

-int kvm_arch_check_processor_compat(void)
-{
- return 0;
-}
-
bool kvm_vcpu_is_reset_bsp(struct kvm_vcpu *vcpu)
{
return vcpu->kvm->arch.bsp_vcpu_id == vcpu->vcpu_id;
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 7efc4792ff5f..87d4f42f3ff9 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1447,8 +1447,6 @@ void kvm_arch_hardware_disable(void);

int kvm_arch_hardware_setup(void *opaque);
void kvm_arch_hardware_unsetup(void);
-int kvm_arch_check_processor_compat(void);
-int kvm_arch_check_processor_compat_all(void);
int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu);
bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu);
int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu);
diff --git a/virt/kvm/kvm_arch.c b/virt/kvm/kvm_arch.c
index 2509c2777a49..076a55d59988 100644
--- a/virt/kvm/kvm_arch.c
+++ b/virt/kvm/kvm_arch.c
@@ -82,32 +82,10 @@ int __weak kvm_arch_del_vm(int usage_count)
return 0;
}

-static void check_processor_compat(void *rtn)
-{
- *(int *)rtn = kvm_arch_check_processor_compat();
-}
-
-int __weak kvm_arch_check_processor_compat_all(void)
-{
- int cpu;
- int r;
-
- for_each_online_cpu(cpu) {
- smp_call_function_single(cpu, check_processor_compat, &r, 1);
- if (r < 0)
- return r;
- }
- return 0;
-}
-
int __weak kvm_arch_online_cpu(unsigned int cpu, int usage_count)
{
int ret;

- ret = kvm_arch_check_processor_compat();
- if (ret)
- return ret;
-
if (!usage_count)
return 0;

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index d5f882fb9e0c..1c1a2b0630bc 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -5777,10 +5777,6 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
if (r < 0)
goto out_free_1;

- r = kvm_arch_check_processor_compat_all();
- if (r < 0)
- goto out_free_2;
-
r = cpuhp_setup_state_nocalls(CPUHP_AP_KVM_ONLINE, "kvm/cpu:online",
kvm_online_cpu, kvm_offline_cpu);
if (r)
--
2.25.1