From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoffer Dall Subject: [PATCH v3 16/20] KVM: arm/arm64: Use kvm_arm_timer_set/get_reg for guest register traps Date: Sat, 23 Sep 2017 02:42:03 +0200 Message-ID: <20170923004207.22356-17-cdall@linaro.org> References: <20170923004207.22356-1-cdall@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id AF06E49C52 for ; Fri, 22 Sep 2017 20:42:18 -0400 (EDT) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 9UONdKqYQfc9 for ; Fri, 22 Sep 2017 20:42:18 -0400 (EDT) Received: from mail-wm0-f42.google.com (mail-wm0-f42.google.com [74.125.82.42]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id CD61249C69 for ; Fri, 22 Sep 2017 20:42:17 -0400 (EDT) Received: by mail-wm0-f42.google.com with SMTP id q124so7623550wmb.0 for ; Fri, 22 Sep 2017 17:42:29 -0700 (PDT) In-Reply-To: <20170923004207.22356-1-cdall@linaro.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Cc: Marc Zyngier , Catalin Marinas , Will Deacon , kvm@vger.kernel.org, Christoffer Dall List-Id: kvmarm@lists.cs.columbia.edu When trapping on a guest access to one of the timer registers, we were messing with the internals of the timer state from the sysregs handling code, and that logic was about to receive more added complexity when optimizing the timer handling code. Therefore, since we already have timer register access functions (to access registers from userspace), reuse those for the timer register traps from a VM and let the timer code maintain its own consistency. Signed-off-by: Christoffer Dall --- arch/arm64/kvm/sys_regs.c | 41 ++++++++++++++--------------------------- 1 file changed, 14 insertions(+), 27 deletions(-) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 2e070d3..bb0e41b 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -841,13 +841,16 @@ static bool access_cntp_tval(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) { - struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); u64 now = kvm_phys_timer_read(); + u64 cval; - if (p->is_write) - ptimer->cnt_cval = p->regval + now; - else - p->regval = ptimer->cnt_cval - now; + if (p->is_write) { + kvm_arm_timer_set_reg(vcpu, KVM_REG_ARM_PTIMER_CVAL, + p->regval + now); + } else { + cval = kvm_arm_timer_get_reg(vcpu, KVM_REG_ARM_PTIMER_CVAL); + p->regval = cval - now; + } return true; } @@ -856,24 +859,10 @@ static bool access_cntp_ctl(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) { - 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. - * Note that according to ARMv8 ARM Issue A.k, ISTATUS bit is - * UNKNOWN when ENABLE bit is 0, so we chose to set ISTATUS bit - * regardless of ENABLE bit for our implementation convenience. - */ - if (ptimer->cnt_cval <= now) - p->regval |= ARCH_TIMER_CTRL_IT_STAT; - } + if (p->is_write) + kvm_arm_timer_set_reg(vcpu, KVM_REG_ARM_PTIMER_CTL, p->regval); + else + p->regval = kvm_arm_timer_get_reg(vcpu, KVM_REG_ARM_PTIMER_CTL); return true; } @@ -882,12 +871,10 @@ static bool access_cntp_cval(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) { - struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); - if (p->is_write) - ptimer->cnt_cval = p->regval; + kvm_arm_timer_set_reg(vcpu, KVM_REG_ARM_PTIMER_CVAL, p->regval); else - p->regval = ptimer->cnt_cval; + p->regval = kvm_arm_timer_get_reg(vcpu, KVM_REG_ARM_PTIMER_CVAL); return true; } -- 2.9.0