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Date:   Thu, 24 Feb 2022 17:25:50 +0000
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Subject: [PATCH v4 04/13] KVM: arm64: Capture VM's first run
From:   Raghavendra Rao Ananta <rananta@google.com>
To:     Marc Zyngier <maz@kernel.org>, Andrew Jones <drjones@redhat.com>,
        James Morse <james.morse@arm.com>,
        Alexandru Elisei <alexandru.elisei@arm.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>
Cc:     Paolo Bonzini <pbonzini@redhat.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>, Peter Shier <pshier@google.com>,
        Ricardo Koller <ricarkol@google.com>,
        Oliver Upton <oupton@google.com>,
        Reiji Watanabe <reijiw@google.com>,
        Jing Zhang <jingzhangos@google.com>,
        Raghavendra Rao Anata <rananta@google.com>,
        linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu,
        linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

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@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