From mboxrd@z Thu Jan 1 00:00:00 1970 From: jintack@cs.columbia.edu (Jintack Lim) Date: Thu, 26 Jan 2017 20:05:00 -0500 Subject: [RFC v2 10/10] KVM: arm/arm64: Emulate the EL1 phys timer register access In-Reply-To: <1485479100-4966-1-git-send-email-jintack@cs.columbia.edu> References: <1485479100-4966-1-git-send-email-jintack@cs.columbia.edu> Message-ID: <1485479100-4966-11-git-send-email-jintack@cs.columbia.edu> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 --- 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