[RFC v2 10/10] KVM: arm/arm64: Emulate the EL1 phys timer register access
From: Jintack Lim <hidden>
Date: 2017-01-27 01:07:02
Also in:
kvm, kvmarm, lkml
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine (kvm), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Paolo Bonzini, Marc Zyngier, Oliver Upton, Linus Torvalds
Emulate read and write operations to CNTP_TVAL, CNTP_CVAL and CNTP_CTL. Now VMs are able to use the EL1 physical timer. Signed-off-by: Jintack Lim <redacted> --- arch/arm64/kvm/sys_regs.c | 32 +++++++++++++++++++++++++++++--- include/kvm/arm_arch_timer.h | 2 ++ virt/kvm/arm/arch_timer.c | 2 +- 3 files changed, 32 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index fd9e747..adf009f 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c@@ -824,7 +824,14 @@ static bool access_cntp_tval(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) { - kvm_inject_undefined(vcpu); + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); + u64 now = kvm_phys_timer_read(); + + if (p->is_write) + ptimer->cnt_cval = p->regval + now; + else + p->regval = ptimer->cnt_cval - now; + return true; }
@@ -832,7 +839,20 @@ static bool access_cntp_ctl(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) { - kvm_inject_undefined(vcpu); + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); + + if (p->is_write) { + /* ISTATUS bit is read-only */ + ptimer->cnt_ctl = p->regval & ~ARCH_TIMER_CTRL_IT_STAT; + } else { + u64 now = kvm_phys_timer_read(); + + p->regval = ptimer->cnt_ctl; + /* Set ISTATUS bit if it's expired */ + if (ptimer->cnt_cval <= now) + p->regval |= ARCH_TIMER_CTRL_IT_STAT; + } + return true; }
@@ -840,7 +860,13 @@ static bool access_cntp_cval(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) { - kvm_inject_undefined(vcpu); + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); + + if (p->is_write) + ptimer->cnt_cval = p->regval; + else + p->regval = ptimer->cnt_cval; + return true; }
diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h
index a364593..fec99f2 100644
--- a/include/kvm/arm_arch_timer.h
+++ b/include/kvm/arm_arch_timer.h@@ -74,6 +74,8 @@ bool kvm_timer_should_fire(struct kvm_vcpu *vcpu, void kvm_timer_schedule(struct kvm_vcpu *vcpu); void kvm_timer_unschedule(struct kvm_vcpu *vcpu); +u64 kvm_phys_timer_read(void); + void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu); void kvm_timer_init_vhe(void);
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
index b366bb2..9eec063 100644
--- a/virt/kvm/arm/arch_timer.c
+++ b/virt/kvm/arm/arch_timer.c@@ -40,7 +40,7 @@ void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu) vcpu_vtimer(vcpu)->active_cleared_last = false; } -static u64 kvm_phys_timer_read(void) +u64 kvm_phys_timer_read(void) { return timecounter->cc->read(timecounter->cc); }
--
1.9.1