Describe the CNTHCTL_EL2 register, and associate it with all the sysregs
it allows to trap.
Reviewed-by: Eric Auger <eric.auger@xxxxxxxxxx>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
---
arch/arm64/kvm/emulate-nested.c | 50 ++++++++++++++++++++++++++++++++-
1 file changed, 49 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/emulate-nested.c b/arch/arm64/kvm/emulate-nested.c
index 241e44eeed6d..860910386b5b 100644
--- a/arch/arm64/kvm/emulate-nested.c
+++ b/arch/arm64/kvm/emulate-nested.c
@@ -100,9 +100,11 @@ enum cgt_group_id {
/*
* Anything after this point requires a callback evaluating a
- * complex trap condition. Hopefully we'll never need this...
+ * complex trap condition. Ugly stuff.
*/
__COMPLEX_CONDITIONS__,
+ CGT_CNTHCTL_EL1PCTEN = __COMPLEX_CONDITIONS__,
+ CGT_CNTHCTL_EL1PTEN,
/* Must be last */
__NR_CGT_GROUP_IDS__
@@ -369,10 +371,51 @@ static const enum cgt_group_id *coarse_control_combo[] = {
typedef enum trap_behaviour (*complex_condition_check)(struct kvm_vcpu *);
+/*
+ * Warning, maximum confusion ahead.
+ *
+ * When E2H=0, CNTHCTL_EL2[1:0] are defined as EL1PCEN:EL1PCTEN
+ * When E2H=1, CNTHCTL_EL2[11:10] are defined as EL1PTEN:EL1PCTEN
+ *
+ * Note the single letter difference? Yet, the bits have the same
+ * function despite a different layout and a different name.
+ *
+ * We don't try to reconcile this mess. We just use the E2H=0 bits
+ * to generate something that is in the E2H=1 format, and live with
+ * it. You're welcome.
+ */
+static u64 get_sanitized_cnthctl(struct kvm_vcpu *vcpu)
+{
+ u64 val = __vcpu_sys_reg(vcpu, CNTHCTL_EL2);
+
+ if (!vcpu_el2_e2h_is_set(vcpu))
+ val = (val & (CNTHCTL_EL1PCEN | CNTHCTL_EL1PCTEN)) << 10;
+
+ return val & ((CNTHCTL_EL1PCEN | CNTHCTL_EL1PCTEN) << 10);
+}
+
+static enum trap_behaviour check_cnthctl_el1pcten(struct kvm_vcpu *vcpu)
+{
+ if (get_sanitized_cnthctl(vcpu) & (CNTHCTL_EL1PCTEN << 10))
+ return BEHAVE_HANDLE_LOCALLY;
+
+ return BEHAVE_FORWARD_ANY;
+}
+
+static enum trap_behaviour check_cnthctl_el1pten(struct kvm_vcpu *vcpu)
+{
+ if (get_sanitized_cnthctl(vcpu) & (CNTHCTL_EL1PCEN << 10))
+ return BEHAVE_HANDLE_LOCALLY;
+
+ return BEHAVE_FORWARD_ANY;
+}
+
#define CCC(id, fn) \
[id - __COMPLEX_CONDITIONS__] = fn
static const complex_condition_check ccc[] = {
+ CCC(CGT_CNTHCTL_EL1PCTEN, check_cnthctl_el1pcten),
+ CCC(CGT_CNTHCTL_EL1PTEN, check_cnthctl_el1pten),
};
/*
@@ -877,6 +920,11 @@ static const struct encoding_to_trap_config encoding_to_cgt[] __initconst = {
SR_TRAP(SYS_TRBPTR_EL1, CGT_MDCR_E2TB),
SR_TRAP(SYS_TRBSR_EL1, CGT_MDCR_E2TB),
SR_TRAP(SYS_TRBTRG_EL1, CGT_MDCR_E2TB),
+ SR_TRAP(SYS_CNTP_TVAL_EL0, CGT_CNTHCTL_EL1PTEN),
+ SR_TRAP(SYS_CNTP_CVAL_EL0, CGT_CNTHCTL_EL1PTEN),
+ SR_TRAP(SYS_CNTP_CTL_EL0, CGT_CNTHCTL_EL1PTEN),
+ SR_TRAP(SYS_CNTPCT_EL0, CGT_CNTHCTL_EL1PCTEN),
+ SR_TRAP(SYS_CNTPCTSS_EL0, CGT_CNTHCTL_EL1PCTEN),
};
static DEFINE_XARRAY(sr_forward_xa);
--
2.34.1
