[PATCH v6 22/25] KVM: arm64: Trap disabled features of ID_AA64MMFR1_EL1

[Reiji Watanabe]

Add feature_config_ctrl for LORegions, which is indicated in
ID_AA64MMFR1_EL1, to program configuration register to trap
guest's using the feature when it is not exposed to the guest.

Change trap_loregion() to use vcpu_feature_is_available()
to simplify checking of the feature's availability.

Signed-off-by: Reiji Watanabe <reijiw at google.com>
---
 arch/arm64/kvm/sys_regs.c | 27 ++++++++++++++++++++++++---
 1 file changed, 24 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 677815030d44..f3661881cbed 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -374,6 +374,11 @@ static void feature_tracefilt_trap_activate(struct kvm_vcpu *vcpu)
 	feature_trap_activate(vcpu, VCPU_MDCR_EL2, MDCR_EL2_TTRF, 0);
 }
 
+static void feature_lor_trap_activate(struct kvm_vcpu *vcpu)
+{
+	feature_trap_activate(vcpu, VCPU_HCR_EL2, HCR_TLOR, 0);
+}
+
 /* For ID_AA64PFR0_EL1 */
 static struct feature_config_ctrl ftr_ctrl_ras = {
 	.ftr_reg = SYS_ID_AA64PFR0_EL1,
@@ -433,6 +438,15 @@ static struct feature_config_ctrl ftr_ctrl_tracefilt = {
 	.trap_activate = feature_tracefilt_trap_activate,
 };
 
+/* For ID_AA64MMFR1_EL1 */
+static struct feature_config_ctrl ftr_ctrl_lor = {
+	.ftr_reg = SYS_ID_AA64MMFR1_EL1,
+	.ftr_shift = ID_AA64MMFR1_LOR_SHIFT,
+	.ftr_min = 1,
+	.ftr_signed = FTR_UNSIGNED,
+	.trap_activate = feature_lor_trap_activate,
+};
+
 /* id_reg_desc flags field values */
 #define ID_DESC_REG_UNALLOC	(1UL << 0)
 #define ID_DESC_REG_HIDDEN	(1UL << 1)
@@ -1003,10 +1017,9 @@ static bool trap_loregion(struct kvm_vcpu *vcpu,
 			  struct sys_reg_params *p,
 			  const struct sys_reg_desc *r)
 {
-	u64 val = read_id_reg_with_encoding(vcpu, SYS_ID_AA64MMFR1_EL1);
 	u32 sr = reg_to_encoding(r);
 
-	if (!(val & (0xfUL << ID_AA64MMFR1_LOR_SHIFT))) {
+	if (!vcpu_feature_is_available(vcpu, &ftr_ctrl_lor)) {
 		kvm_inject_undefined(vcpu);
 		return false;
 	}
@@ -3785,6 +3798,14 @@ static struct id_reg_desc id_aa64mmfr0_el1_desc = {
 	.validate = validate_id_aa64mmfr0_el1,
 };
 
+static struct id_reg_desc id_aa64mmfr1_el1_desc = {
+	.reg_desc = ID_SANITISED(ID_AA64MMFR1_EL1),
+	.trap_features = &(const struct feature_config_ctrl *[]) {
+		&ftr_ctrl_lor,
+		NULL,
+	},
+};
+
 static struct id_reg_desc id_aa64dfr0_el1_desc = {
 	.reg_desc = ID_SANITISED(ID_AA64DFR0_EL1),
 	.init = init_id_aa64dfr0_el1_desc,
@@ -3901,7 +3922,7 @@ static struct id_reg_desc *id_reg_desc_table[KVM_ARM_ID_REG_MAX_NUM] = {
 
 	/* CRm=7 */
 	ID_DESC(ID_AA64MMFR0_EL1, &id_aa64mmfr0_el1_desc),
-	ID_DESC_DEFAULT(ID_AA64MMFR1_EL1),
+	ID_DESC(ID_AA64MMFR1_EL1, &id_aa64mmfr1_el1_desc),
 	ID_DESC_DEFAULT(ID_AA64MMFR2_EL1),
 	ID_DESC_UNALLOC(7, 3),
 	ID_DESC_UNALLOC(7, 4),
-- 
2.35.1.723.g4982287a31-goog