[PATCH 4/5] KVM: arm64: vgic-v3: Simplify initial GICv3 configuration sampling

[Marc Zyngier]

Now that we have our magic inline helper for ICH_VTR_EL2, we can
get rid of the hack that was reporting a combination of that
register and of the indication of the CPU interface supporting
GICv2 compatibility. We now only report the latter.

Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/kvm/hyp/vgic-v3-sr.c |  9 ++-------
 arch/arm64/kvm/vgic/vgic-v3.c   | 13 +++++++------
 arch/arm64/kvm/vgic/vgic-v5.c   |  2 +-
 3 files changed, 10 insertions(+), 14 deletions(-)

diff --git a/arch/arm64/kvm/hyp/vgic-v3-sr.c b/arch/arm64/kvm/hyp/vgic-v3-sr.c
index 3e5d5ddf35a19..8a15d6854d1bd 100644
--- a/arch/arm64/kvm/hyp/vgic-v3-sr.c
+++ b/arch/arm64/kvm/hyp/vgic-v3-sr.c
@@ -439,8 +439,6 @@ void __vgic_v3_init_lrs(void)
 
 /*
  * Return the GIC CPU configuration:
- * - [31:0]  ICH_VTR_EL2
- * - [62:32] RES0
  * - [63]    MMIO (GICv2) capable
  */
 u64 __vgic_v3_get_gic_config(void)
@@ -455,7 +453,7 @@ u64 __vgic_v3_get_gic_config(void)
 	 * system, so we first check if we have GICv5 support.
 	 */
 	if (cpus_have_final_cap(ARM64_HAS_GICV5_CPUIF))
-		return vgic_ich_vtr();
+		return 0;
 
 	sre = read_gicreg(ICC_SRE_EL1);
 	/*
@@ -497,10 +495,7 @@ u64 __vgic_v3_get_gic_config(void)
 		isb();
 	}
 
-	val  = (val & ICC_SRE_EL1_SRE) ? 0 : (1ULL << 63);
-	val |= vgic_ich_vtr();
-
-	return val;
+	return (val & ICC_SRE_EL1_SRE) ? 0 : (1ULL << 63);
 }
 
 static void __vgic_v3_compat_mode_enable(void)
diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c
index ef62dd498f5cf..68d4a486df0a1 100644
--- a/arch/arm64/kvm/vgic/vgic-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-v3.c
@@ -906,6 +906,9 @@ void noinstr kvm_patch_ich_vtr_el2(struct alt_instr *alt,
 
 	vtr = res.a1;
 
+	if (vgic_v3_broken_seis())
+		vtr &= ~ICH_VTR_EL2_SEIS;
+
 	/* Compute target register */
 	oinsn = le32_to_cpu(*origptr);
 	rd = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RD, oinsn);
@@ -950,12 +953,12 @@ void vgic_v3_enable_cpuif_traps(void)
  */
 int vgic_v3_probe(const struct gic_kvm_info *info)
 {
-	u64 ich_vtr_el2 = kvm_call_hyp_ret(__vgic_v3_get_gic_config);
+	u64 ich_vtr_el2;
 	bool has_v2;
 	int ret;
 
-	has_v2 = ich_vtr_el2 >> 63;
-	ich_vtr_el2 = (u32)ich_vtr_el2;
+	has_v2 = kvm_call_hyp_ret(__vgic_v3_get_gic_config) >> 63;
+	ich_vtr_el2 = vgic_ich_vtr();
 
 	/*
 	 * The ListRegs field is 5 bits, but there is an architectural
@@ -1010,10 +1013,8 @@ int vgic_v3_probe(const struct gic_kvm_info *info)
 	if (has_v2)
 		static_branch_enable(&vgic_v3_has_v2_compat);
 
-	if (vgic_v3_broken_seis()) {
+	if (vgic_v3_broken_seis())
 		kvm_info("GICv3 with broken locally generated SEI\n");
-		kvm_vgic_global_state.ich_vtr_el2 &= ~ICH_VTR_EL2_SEIS;
-	}
 
 	vgic_v3_enable_cpuif_traps();
 
diff --git a/arch/arm64/kvm/vgic/vgic-v5.c b/arch/arm64/kvm/vgic/vgic-v5.c
index d4789ff3e7402..16bc0a670d3e5 100644
--- a/arch/arm64/kvm/vgic/vgic-v5.c
+++ b/arch/arm64/kvm/vgic/vgic-v5.c
@@ -83,7 +83,7 @@ int vgic_v5_probe(const struct gic_kvm_info *info)
 	}
 
 	kvm_vgic_global_state.has_gcie_v3_compat = true;
-	ich_vtr_el2 =  kvm_call_hyp_ret(__vgic_v3_get_gic_config);
+	ich_vtr_el2 = vgic_ich_vtr();
 	kvm_vgic_global_state.ich_vtr_el2 = (u32)ich_vtr_el2;
 
 	/*
-- 
2.47.3