[PATCH v4 04/13] KVM: arm64: Capture VM's first run

Raghavendra Rao Ananta rananta at google.com
Thu Feb 24 09:25:50 PST 2022


Capture the first run of the KVM VM, which is basically the
first KVM_RUN issued for any vCPU. This state of the VM is
helpful in the upcoming patches to prevent user-space from
configuring certain VM features, such as the feature bitmap
exposed by the psuedo-firmware registers, after the VM has
started running.

Signed-off-by: Raghavendra Rao Ananta <rananta at google.com>
---
 arch/arm64/include/asm/kvm_host.h | 9 +++++++++
 arch/arm64/kvm/arm.c              | 2 ++
 2 files changed, 11 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 657733554d98..e823571e50cc 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -139,6 +139,9 @@ struct kvm_arch {
 
 	/* Register scoping enabled for KVM registers */
 	bool reg_scope_enabled;
+
+	/* Capture first run of the VM */
+	bool has_run_once;
 };
 
 struct kvm_vcpu_fault_info {
@@ -796,6 +799,12 @@ bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu);
 int kvm_trng_call(struct kvm_vcpu *vcpu);
 int kvm_arm_reg_id_encode_scope(struct kvm_vcpu *vcpu, u64 *reg_id);
 void kvm_arm_reg_id_clear_scope(struct kvm_vcpu *vcpu, u64 *reg_id);
+
+static inline bool kvm_arm_vm_has_run_once(struct kvm_arch *kvm_arch)
+{
+	return kvm_arch->has_run_once;
+}
+
 #ifdef CONFIG_KVM
 extern phys_addr_t hyp_mem_base;
 extern phys_addr_t hyp_mem_size;
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 107977c82c6c..f61cd8d57eae 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -635,6 +635,8 @@ int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu)
 	if (kvm_vm_is_protected(kvm))
 		kvm_call_hyp_nvhe(__pkvm_vcpu_init_traps, vcpu);
 
+	kvm->arch.has_run_once = true;
+
 	return ret;
 }
 
-- 
2.35.1.473.g83b2b277ed-goog




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