[RFC 5/8] KVM: arm64: Add the EL1 physical timer access handler

From: Jintack Lim
Date: Mon Dec 26 2016 - 12:47:05 EST


KVM traps on the EL1 phys timer accesses from VMs, but it doesn't handle
those traps. This results in terminating VMs. Instead, set a handler for
the EL1 phys timer access, and inject an undefined exception as an
intermediate step.

Signed-off-by: Jintack Lim <jintack@xxxxxxxxxxxxxxx>
---
arch/arm64/kvm/sys_regs.c | 34 ++++++++++++++++++++++++++++++++++
1 file changed, 34 insertions(+)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 87e7e66..fd9e747 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -820,6 +820,30 @@ static bool access_pmuserenr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
CRm((0b1100 | (((n) >> 3) & 0x3))), Op2(((n) & 0x7)), \
access_pmu_evtyper, reset_unknown, (PMEVTYPER0_EL0 + n), }

+static bool access_cntp_tval(struct kvm_vcpu *vcpu,
+ struct sys_reg_params *p,
+ const struct sys_reg_desc *r)
+{
+ kvm_inject_undefined(vcpu);
+ return true;
+}
+
+static bool access_cntp_ctl(struct kvm_vcpu *vcpu,
+ struct sys_reg_params *p,
+ const struct sys_reg_desc *r)
+{
+ kvm_inject_undefined(vcpu);
+ return true;
+}
+
+static bool access_cntp_cval(struct kvm_vcpu *vcpu,
+ struct sys_reg_params *p,
+ const struct sys_reg_desc *r)
+{
+ kvm_inject_undefined(vcpu);
+ return true;
+}
+
/*
* Architected system registers.
* Important: Must be sorted ascending by Op0, Op1, CRn, CRm, Op2
@@ -1029,6 +1053,16 @@ static bool access_pmuserenr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
{ Op0(0b11), Op1(0b011), CRn(0b1101), CRm(0b0000), Op2(0b011),
NULL, reset_unknown, TPIDRRO_EL0 },

+ /* CNTP_TVAL_EL0 */
+ { Op0(0b11), Op1(0b011), CRn(0b1110), CRm(0b0010), Op2(0b000),
+ access_cntp_tval },
+ /* CNTP_CTL_EL0 */
+ { Op0(0b11), Op1(0b011), CRn(0b1110), CRm(0b0010), Op2(0b001),
+ access_cntp_ctl },
+ /* CNTP_CVAL_EL0 */
+ { Op0(0b11), Op1(0b011), CRn(0b1110), CRm(0b0010), Op2(0b010),
+ access_cntp_cval },
+
/* PMEVCNTRn_EL0 */
PMU_PMEVCNTR_EL0(0),
PMU_PMEVCNTR_EL0(1),
--
1.9.1