[RFC PATCH v2 05/23] KVM: arm: Add arch vcpu uninit hook

[Dave.Martin@arm.com (Dave Martin)]

In preparation for adding support for SVE in guests on arm64, a
hook is needed for freeing additional per-vcpu memory when a vcpu
is freed.

x86 already uses the kvm_arch_vcpu_uninit() hook for a similar
purpose, so this patch populates the same hook for arm.  Since SVE
is specific to arm64, a subsidiary hook kvm_arm_arch_vcpu_uninit()
is added (with trivial implementations for now) to enable separate
specialisation for arm and arm64.

No functional change.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
---

Changes since RFCv1:

 * The vcpu _init_ hook that was added by the former version of this
   patch was never used for anything, so it is gone from this version.
---
 arch/arm/include/asm/kvm_host.h   | 3 ++-
 arch/arm64/include/asm/kvm_host.h | 3 ++-
 virt/kvm/arm/arm.c                | 5 +++++
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 3ad482d..c36760b 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -288,10 +288,11 @@ struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr);
 static inline bool kvm_arch_check_sve_has_vhe(void) { return true; }
 static inline void kvm_arch_hardware_unsetup(void) {}
 static inline void kvm_arch_sync_events(struct kvm *kvm) {}
-static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}
 static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
 static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {}
 
+static inline void kvm_arm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}
+
 static inline void kvm_arm_init_debug(void) {}
 static inline void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) {}
 static inline void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) {}
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 6316a57..d4b65414 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -425,10 +425,11 @@ static inline bool kvm_arch_check_sve_has_vhe(void)
 
 static inline void kvm_arch_hardware_unsetup(void) {}
 static inline void kvm_arch_sync_events(struct kvm *kvm) {}
-static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}
 static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
 static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {}
 
+static inline void kvm_arm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}
+
 void kvm_arm_init_debug(void);
 void kvm_arm_setup_debug(struct kvm_vcpu *vcpu);
 void kvm_arm_clear_debug(struct kvm_vcpu *vcpu);
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index c92053b..1418af9 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -358,6 +358,11 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
 	return kvm_vgic_vcpu_init(vcpu);
 }
 
+void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
+{
+	kvm_arm_arch_vcpu_uninit(vcpu);
+}
+
 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 {
 	int *last_ran;
-- 
2.1.4