[RFC 8/8] KVM: arm/arm64: Emulate the EL1 phys timer register access
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STALE3562d
SUPERSEDED
From: Jintack Lim <hidden>
Date: 2016-12-26 17:48:31
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
Revision rfc of 4 in this series.
Revisions (4)
- rfc current
- v2 [diff vs current]
- v3 [diff vs current]
- v4 [diff vs current]
Emulate read and write operations to CNTP_TVAL, CNTP_CVAL and CNTP_CTL. Now the VM is able to use the EL1 physical timer. Signed-off-by: Jintack Lim <redacted> --- arch/arm64/kvm/sys_regs.c | 35 ++++++++++++++++++++++++++++++++--- include/kvm/arm_arch_timer.h | 3 +++ virt/kvm/arm/arch_timer.c | 4 ++-- 3 files changed, 37 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index fd9e747..7cef94f 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c@@ -824,7 +824,15 @@ 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); + cycle_t now = kvm_phys_timer_read(); + + if (p->is_write) { + ptimer->cnt_cval = p->regval + now; + kvm_timer_emulate(vcpu, ptimer); + } else + p->regval = ptimer->cnt_cval - now; + return true; }
@@ -832,7 +840,21 @@ 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; + kvm_timer_emulate(vcpu, ptimer); + } else { + cycle_t 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 +862,14 @@ 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; + kvm_timer_emulate(vcpu, ptimer); + } 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 04ed9c1..776579b 100644
--- a/include/kvm/arm_arch_timer.h
+++ b/include/kvm/arm_arch_timer.h@@ -75,6 +75,9 @@ bool kvm_timer_should_fire(struct kvm_vcpu *vcpu, struct arch_timer_context *timer_ctx); void kvm_timer_schedule(struct kvm_vcpu *vcpu); void kvm_timer_unschedule(struct kvm_vcpu *vcpu); +void kvm_timer_emulate(struct kvm_vcpu *vcpu, struct arch_timer_context *timer); + +cycle_t kvm_phys_timer_read(void); void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu);
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
index be8d953..7a161f8 100644
--- a/virt/kvm/arm/arch_timer.c
+++ b/virt/kvm/arm/arch_timer.c@@ -39,7 +39,7 @@ void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu) vcpu_vtimer(vcpu)->active_cleared_last = false; } -static cycle_t kvm_phys_timer_read(void) +cycle_t kvm_phys_timer_read(void) { return timecounter->cc->read(timecounter->cc); }
@@ -258,7 +258,7 @@ static int kvm_timer_update_state(struct kvm_vcpu *vcpu) * Schedule the background timer for the emulated timer. The background timer * runs whenever vcpu is runnable and the timer is not expired. */ -static void kvm_timer_emulate(struct kvm_vcpu *vcpu, +void kvm_timer_emulate(struct kvm_vcpu *vcpu, struct arch_timer_context *timer_ctx) { struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
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1.9.1