On Tue, Jun 11, 2013 at 05:16:59PM +0200, Andre Przywara wrote: > For migration to work we need to save (and later restore) the state of > each core's virtual generic timer. > Since this is per VCPU, we can use the [gs]et_one_reg ioctl and export > the three needed registers (control, counter, compare value). > Though they live in cp15 space, we don't use the existing list, since > they need special accessor functions and also the arch timer is > optional. > > Changes from v1: > - move code out of coproc.c and into guest.c and arch_timer.c > - present the registers with their native CP15 addresses, but without > using space in the VCPU's cp15 array > - do the user space copying in the accessor functions > > Signed-off-by: Andre Przywara <andre.przywara@xxxxxxxxxx> > --- > arch/arm/include/asm/kvm_host.h | 5 ++++ > arch/arm/include/uapi/asm/kvm.h | 16 ++++++++++ > arch/arm/kvm/arch_timer.c | 65 +++++++++++++++++++++++++++++++++++++++++ > arch/arm/kvm/guest.c | 26 ++++++++++++++++- > 4 files changed, 111 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h > index 57cb786..1096e33 100644 > --- a/arch/arm/include/asm/kvm_host.h > +++ b/arch/arm/include/asm/kvm_host.h > @@ -224,4 +224,9 @@ static inline int kvm_arch_dev_ioctl_check_extension(long ext) > int kvm_perf_init(void); > int kvm_perf_teardown(void); > > +int kvm_arm_num_timer_regs(void); > +int kvm_arm_copy_timer_indices(struct kvm_vcpu *, u64 __user *); > +int kvm_arm_timer_get_reg(struct kvm_vcpu *, const struct kvm_one_reg *); > +int kvm_arm_timer_set_reg(struct kvm_vcpu *, const struct kvm_one_reg *); > + > #endif /* __ARM_KVM_HOST_H__ */ > diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h > index c1ee007..e3b0115 100644 > --- a/arch/arm/include/uapi/asm/kvm.h > +++ b/arch/arm/include/uapi/asm/kvm.h > @@ -118,6 +118,22 @@ struct kvm_arch_memory_slot { > #define KVM_REG_ARM_32_CRN_MASK 0x0000000000007800 > #define KVM_REG_ARM_32_CRN_SHIFT 11 > > +#define KVM_REG_ARM_32_CP15 (KVM_REG_ARM | KVM_REG_SIZE_U32 | \ > + (15ULL << KVM_REG_ARM_COPROC_SHIFT)) > +#define KVM_REG_ARM_64_CP15 (KVM_REG_ARM | KVM_REG_SIZE_U64 | \ > + (15ULL << KVM_REG_ARM_COPROC_SHIFT)) > +#define KVM_REG_ARM_TIMER_CTL (KVM_REG_ARM_32_CP15 | \ > + ( 3ULL << KVM_REG_ARM_CRM_SHIFT) | \ > + (14ULL << KVM_REG_ARM_32_CRN_SHIFT) | \ > + ( 0ULL << KVM_REG_ARM_OPC1_SHIFT) | \ > + ( 1ULL << KVM_REG_ARM_32_OPC2_SHIFT)) > +#define KVM_REG_ARM_TIMER_CNT (KVM_REG_ARM_64_CP15 | \ > + (14ULL << KVM_REG_ARM_CRM_SHIFT) | \ > + ( 1ULL << KVM_REG_ARM_OPC1_SHIFT)) > +#define KVM_REG_ARM_TIMER_CVAL (KVM_REG_ARM_64_CP15 | \ > + (14ULL << KVM_REG_ARM_CRM_SHIFT) | \ > + ( 3ULL << KVM_REG_ARM_OPC1_SHIFT)) > + > /* Normal registers are mapped as coprocessor 16. */ > #define KVM_REG_ARM_CORE (0x0010 << KVM_REG_ARM_COPROC_SHIFT) > #define KVM_REG_ARM_CORE_REG(name) (offsetof(struct kvm_regs, name) / 4) > diff --git a/arch/arm/kvm/arch_timer.c b/arch/arm/kvm/arch_timer.c > index c55b608..8d709eb 100644 > --- a/arch/arm/kvm/arch_timer.c > +++ b/arch/arm/kvm/arch_timer.c > @@ -18,6 +18,7 @@ > > #include <linux/cpu.h> > #include <linux/of_irq.h> > +#include <linux/uaccess.h> > #include <linux/kvm.h> > #include <linux/kvm_host.h> > #include <linux/interrupt.h> > @@ -171,6 +172,70 @@ static void kvm_timer_init_interrupt(void *info) > enable_percpu_irq(timer_irq.irq, 0); > } > > +int kvm_arm_num_timer_regs(void) > +{ > + return 3; > +} > + > +int kvm_arm_copy_timer_indices(struct kvm_vcpu *vcpu, u64 __user *uindices) > +{ > + if (put_user(KVM_REG_ARM_TIMER_CTL, uindices)) > + return -EFAULT; > + uindices++; > + if (put_user(KVM_REG_ARM_TIMER_CNT, uindices)) > + return -EFAULT; > + uindices++; > + if (put_user(KVM_REG_ARM_TIMER_CVAL, uindices)) > + return -EFAULT; > + > + return 0; > +} > + > +int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) > +{ > + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; > + void __user *uaddr = (void __user *)(long)reg->addr; > + u64 val; > + int ret; > + > + ret = copy_from_user(&val, uaddr, KVM_REG_SIZE(reg->id)); > + if (ret != 0) > + return ret; > + > + switch (reg->id) { > + case KVM_REG_ARM_TIMER_CTL: > + timer->cntv_ctl = val; > + break; > + case KVM_REG_ARM_TIMER_CNT: > + vcpu->kvm->arch.timer.cntvoff = kvm_phys_timer_read() - val; > + break; > + case KVM_REG_ARM_TIMER_CVAL: > + timer->cntv_cval = val; > + break; > + } > + > + return 0; > +} > + > +int kvm_arm_timer_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) > +{ > + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; > + void __user *uaddr = (void __user *)(long)reg->addr; > + u64 val; > + > + switch (reg->id) { > + case KVM_REG_ARM_TIMER_CTL: > + val = timer->cntv_ctl; > + break; > + case KVM_REG_ARM_TIMER_CNT: > + val = kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff; > + break; > + case KVM_REG_ARM_TIMER_CVAL: > + val = timer->cntv_cval; > + break; > + } > + return copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id)); > +} > > static int kvm_timer_cpu_notify(struct notifier_block *self, > unsigned long action, void *cpu) > diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c > index 152d036..a50ffb6 100644 > --- a/arch/arm/kvm/guest.c > +++ b/arch/arm/kvm/guest.c > @@ -121,7 +121,8 @@ static unsigned long num_core_regs(void) > */ > unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu) > { > - return num_core_regs() + kvm_arm_num_coproc_regs(vcpu); > + return num_core_regs() + kvm_arm_num_coproc_regs(vcpu) > + + kvm_arm_num_timer_regs(); > } > > /** > @@ -133,6 +134,7 @@ int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices) > { > unsigned int i; > const u64 core_reg = KVM_REG_ARM | KVM_REG_SIZE_U32 | KVM_REG_ARM_CORE; > + int ret; > > for (i = 0; i < sizeof(struct kvm_regs)/sizeof(u32); i++) { > if (put_user(core_reg | i, uindices)) > @@ -140,9 +142,25 @@ int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices) > uindices++; > } > > + ret = kvm_arm_copy_timer_indices(vcpu, uindices); > + if (ret) > + return ret; > + uindices += kvm_arm_num_timer_regs(); > + > return kvm_arm_copy_coproc_indices(vcpu, uindices); > } > > +static bool is_timer_reg(u64 index) > +{ > + switch (index) { > + case KVM_REG_ARM_TIMER_CTL: > + case KVM_REG_ARM_TIMER_CNT: > + case KVM_REG_ARM_TIMER_CVAL: > + return true; > + } > + return false; > +} > + > int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) > { > /* We currently use nothing arch-specific in upper 32 bits */ > @@ -153,6 +171,9 @@ int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) > if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE) > return get_core_reg(vcpu, reg); > > + if (is_timer_reg(reg->id)) > + return kvm_arm_timer_get_reg(vcpu, reg); > + > return kvm_arm_coproc_get_reg(vcpu, reg); > } > > @@ -166,6 +187,9 @@ int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) > if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE) > return set_core_reg(vcpu, reg); > > + if (is_timer_reg(reg->id)) > + return kvm_arm_timer_set_reg(vcpu, reg); > + > return kvm_arm_coproc_set_reg(vcpu, reg); > } > > -- This looks good to me! Thanks, -Christoffer _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm