Re: [RFC v3 09/10] KVM: arm64: Add the EL1 physical timer access handler

[Christoffer Dall]

On Wed, Feb 01, 2017 at 12:43:09PM -0500, Jintack Lim wrote:
> 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 

Reviewed-by: Christoffer Dall 
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[RFC v3 09/10] KVM: arm64: Add the EL1 physical timer access handler

[Jintack Lim]

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 
---
 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 caa47ce..1cd3464 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(0b), 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


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