[PATCH v2 1/4] KVM: arm64: Make __vgic_v3_init_lrs HVC always available

[Vincent Donnefort]

The __vgic_v3_init_lrs hypercall only resets the vGIC LRs. Those
registers are expected to be 0 when the host is running. As a
consequence, it is completely safe to make it available at all times,
even when pKVM is enabled and the host was deprivileged.

Fixes: 057bed206f70 ("KVM: arm64: Disable privileged hypercalls after pKVM finalisation")
Signed-off-by: Vincent Donnefort <vdonnefort at google.com>
---
 arch/arm64/include/asm/kvm_asm.h   | 2 +-
 arch/arm64/kvm/hyp/nvhe/hyp-main.c | 5 +++--
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index e5b92ac09e69..ca7e55d8eec3 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -60,7 +60,6 @@ enum __kvm_host_smccc_func {
 	__KVM_HOST_SMCCC_FUNC___pkvm_create_private_mapping,
 	__KVM_HOST_SMCCC_FUNC___pkvm_cpu_set_vector,
 	__KVM_HOST_SMCCC_FUNC___kvm_enable_ssbs,
-	__KVM_HOST_SMCCC_FUNC___vgic_v3_init_lrs,
 	__KVM_HOST_SMCCC_FUNC___vgic_v3_get_gic_config,
 
 	MARKER(__KVM_HOST_SMCCC_FUNC_MIN_PKVM),
@@ -85,6 +84,7 @@ enum __kvm_host_smccc_func {
 	__KVM_HOST_SMCCC_FUNC___tracing_reset,
 	__KVM_HOST_SMCCC_FUNC___tracing_enable_event,
 	__KVM_HOST_SMCCC_FUNC___tracing_write_event,
+	__KVM_HOST_SMCCC_FUNC___vgic_v3_init_lrs,
 	__KVM_HOST_SMCCC_FUNC___vgic_v3_save_aprs,
 	__KVM_HOST_SMCCC_FUNC___vgic_v3_restore_vmcr_aprs,
 	__KVM_HOST_SMCCC_FUNC___vgic_v5_save_apr,
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index ac64a036b0a9..c1f0de3ec43f 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -627,7 +627,8 @@ static void handle___vgic_v3_get_gic_config(struct kvm_cpu_context *host_ctxt)
 
 static void handle___vgic_v3_init_lrs(struct kvm_cpu_context *host_ctxt)
 {
-	__vgic_v3_init_lrs();
+	if (hyp_gicv3_nr_lr)
+		__vgic_v3_init_lrs();
 }
 
 static void handle___vgic_v3_save_aprs(struct kvm_cpu_context *host_ctxt)
@@ -910,7 +911,6 @@ static const hcall_t host_hcall[] = {
 	HANDLE_FUNC(__pkvm_create_private_mapping),
 	HANDLE_FUNC(__pkvm_cpu_set_vector),
 	HANDLE_FUNC(__kvm_enable_ssbs),
-	HANDLE_FUNC(__vgic_v3_init_lrs),
 	HANDLE_FUNC(__vgic_v3_get_gic_config),
 	HANDLE_FUNC(__pkvm_prot_finalize),
 
@@ -931,6 +931,7 @@ static const hcall_t host_hcall[] = {
 	HANDLE_FUNC(__tracing_reset),
 	HANDLE_FUNC(__tracing_enable_event),
 	HANDLE_FUNC(__tracing_write_event),
+	HANDLE_FUNC(__vgic_v3_init_lrs),
 	HANDLE_FUNC(__vgic_v3_save_aprs),
 	HANDLE_FUNC(__vgic_v3_restore_vmcr_aprs),
 	HANDLE_FUNC(__vgic_v5_save_apr),
-- 
2.56.0.257.gf7497c7d27-goog