On Sat, Sep 23 2017 at 2:42:03 am BST, Christoffer Dall <[email protected]> wrote: > 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 <[email protected]> > --- > 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; > }
Acked-by: Marc Zyngier <[email protected]> M. -- Jazz is not dead, it just smell funny. _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
