| Message ID | 20120915153657.21545.3972.stgit@ubuntu (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
> -----Original Message----- > From: kvm-owner@vger.kernel.org [mailto:kvm-owner@vger.kernel.org] On > Behalf Of Christoffer Dall > Sent: Sunday, September 16, 2012 12:37 AM > To: kvm@vger.kernel.org; linux-arm-kernel@lists.infradead.org; > kvmarm@lists.cs.columbia.edu > Subject: [PATCH 01/10] ARM: KVM: Keep track of currently running vcpus > > From: Marc Zyngier <marc.zyngier@arm.com> > > When an interrupt occurs for the guest, it is sometimes necessary to find > out which vcpu was running at that point. > > Keep track of which vcpu is being tun in kvm_arch_vcpu_ioctl_run(), and > allow the data to be retrived using either: > - kvm_arm_get_running_vcpu(): returns the vcpu running at this point > on the current CPU. Can only be used in a non-preemptable context. What's the purpose of kvm_arm_get_running_vcpu? It seems to be enough to pass vcpu struct through function argument, and there is no caller by now. > - kvm_arm_get_running_vcpus(): returns the per-CPU variable holding > the the running vcpus, useable for per-CPU interrupts. > > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> > Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com> > --- > arch/arm/include/asm/kvm_host.h | 9 +++++++++ > arch/arm/kvm/arm.c | 30 ++++++++++++++++++++++++++++++ > 2 files changed, 39 insertions(+) > > diff --git a/arch/arm/include/asm/kvm_host.h > b/arch/arm/include/asm/kvm_host.h index 3fec9ad..2e3ac1c 100644 > --- a/arch/arm/include/asm/kvm_host.h > +++ b/arch/arm/include/asm/kvm_host.h > @@ -208,4 +208,13 @@ static inline int kvm_test_age_hva(struct kvm *kvm, > unsigned long hva) { > return 0; > } > + > +struct kvm_vcpu *kvm_arm_get_running_vcpu(void); struct kvm_vcpu > +__percpu **kvm_get_running_vcpus(void); > + > +int kvm_arm_copy_coproc_indices(struct kvm_vcpu *vcpu, u64 __user > +*uindices); unsigned long kvm_arm_num_coproc_regs(struct kvm_vcpu > +*vcpu); struct kvm_one_reg; int kvm_arm_coproc_get_reg(struct kvm_vcpu > +*vcpu, const struct kvm_one_reg *); int kvm_arm_coproc_set_reg(struct > +kvm_vcpu *vcpu, const struct kvm_one_reg *); > #endif /* __ARM_KVM_HOST_H__ */ > diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index > 64fbec7..e6c3743 100644 > --- a/arch/arm/kvm/arm.c > +++ b/arch/arm/kvm/arm.c > @@ -54,11 +54,38 @@ static DEFINE_PER_CPU(unsigned long, > kvm_arm_hyp_stack_page); static struct vfp_hard_struct __percpu > *kvm_host_vfp_state; static unsigned long hyp_default_vectors; > > +/* Per-CPU variable containing the currently running vcpu. */ static > +DEFINE_PER_CPU(struct kvm_vcpu *, kvm_arm_running_vcpu); > + > /* The VMID used in the VTTBR */ > static atomic64_t kvm_vmid_gen = ATOMIC64_INIT(1); static u8 > kvm_next_vmid; static DEFINE_SPINLOCK(kvm_vmid_lock); > > +static void kvm_arm_set_running_vcpu(struct kvm_vcpu *vcpu) { > + BUG_ON(preemptible()); > + __get_cpu_var(kvm_arm_running_vcpu) = vcpu; } > + > +/** > + * kvm_arm_get_running_vcpu - get the vcpu running on the current CPU. > + * Must be called from non-preemptible context */ struct kvm_vcpu > +*kvm_arm_get_running_vcpu(void) { > + BUG_ON(preemptible()); > + return __get_cpu_var(kvm_arm_running_vcpu); > +} > + > +/** > + * kvm_arm_get_running_vcpus - get the per-CPU array on currently running > vcpus. > + */ > +struct kvm_vcpu __percpu **kvm_get_running_vcpus(void) { > + return &kvm_arm_running_vcpu; > +} > + > int kvm_arch_hardware_enable(void *garbage) { > return 0; > @@ -293,10 +320,13 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int > cpu) > cpumask_clear_cpu(cpu, &vcpu->arch.require_dcache_flush); > flush_cache_all(); /* We'd really want v7_flush_dcache_all() > */ > } > + > + kvm_arm_set_running_vcpu(vcpu); > } > > void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) { > + kvm_arm_set_running_vcpu(NULL); > } > > int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in the body > of a message to majordomo@vger.kernel.org More majordomo info at > http://vger.kernel.org/majordomo-info.html
On Thu, 20 Sep 2012 21:53:33 +0900, Min-gyu Kim <mingyu84.kim@samsung.com> wrote: >> -----Original Message----- >> From: kvm-owner@vger.kernel.org [mailto:kvm-owner@vger.kernel.org] On >> Behalf Of Christoffer Dall >> Sent: Sunday, September 16, 2012 12:37 AM >> To: kvm@vger.kernel.org; linux-arm-kernel@lists.infradead.org; >> kvmarm@lists.cs.columbia.edu >> Subject: [PATCH 01/10] ARM: KVM: Keep track of currently running vcpus >> >> From: Marc Zyngier <marc.zyngier@arm.com> >> >> When an interrupt occurs for the guest, it is sometimes necessary to find >> out which vcpu was running at that point. >> >> Keep track of which vcpu is being tun in kvm_arch_vcpu_ioctl_run(), and >> allow the data to be retrived using either: >> - kvm_arm_get_running_vcpu(): returns the vcpu running at this point >> on the current CPU. Can only be used in a non-preemptable context. > > What's the purpose of kvm_arm_get_running_vcpu? > It seems to be enough to pass vcpu struct through function argument, > and there is no caller by now. This is also designed to be used in an interrupt handler, and is used by the (currently out of tree) perf code: https://lists.cs.columbia.edu/pipermail/kvmarm/2012-September/003192.html Basically, you need this infrastructure when handling interrupts. M.
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 3fec9ad..2e3ac1c 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -208,4 +208,13 @@ static inline int kvm_test_age_hva(struct kvm *kvm, unsigned long hva) { return 0; } + +struct kvm_vcpu *kvm_arm_get_running_vcpu(void); +struct kvm_vcpu __percpu **kvm_get_running_vcpus(void); + +int kvm_arm_copy_coproc_indices(struct kvm_vcpu *vcpu, u64 __user *uindices); +unsigned long kvm_arm_num_coproc_regs(struct kvm_vcpu *vcpu); +struct kvm_one_reg; +int kvm_arm_coproc_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *); +int kvm_arm_coproc_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *); #endif /* __ARM_KVM_HOST_H__ */ diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 64fbec7..e6c3743 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -54,11 +54,38 @@ static DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page); static struct vfp_hard_struct __percpu *kvm_host_vfp_state; static unsigned long hyp_default_vectors; +/* Per-CPU variable containing the currently running vcpu. */ +static DEFINE_PER_CPU(struct kvm_vcpu *, kvm_arm_running_vcpu); + /* The VMID used in the VTTBR */ static atomic64_t kvm_vmid_gen = ATOMIC64_INIT(1); static u8 kvm_next_vmid; static DEFINE_SPINLOCK(kvm_vmid_lock); +static void kvm_arm_set_running_vcpu(struct kvm_vcpu *vcpu) +{ + BUG_ON(preemptible()); + __get_cpu_var(kvm_arm_running_vcpu) = vcpu; +} + +/** + * kvm_arm_get_running_vcpu - get the vcpu running on the current CPU. + * Must be called from non-preemptible context + */ +struct kvm_vcpu *kvm_arm_get_running_vcpu(void) +{ + BUG_ON(preemptible()); + return __get_cpu_var(kvm_arm_running_vcpu); +} + +/** + * kvm_arm_get_running_vcpus - get the per-CPU array on currently running vcpus. + */ +struct kvm_vcpu __percpu **kvm_get_running_vcpus(void) +{ + return &kvm_arm_running_vcpu; +} + int kvm_arch_hardware_enable(void *garbage) { return 0; @@ -293,10 +320,13 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) cpumask_clear_cpu(cpu, &vcpu->arch.require_dcache_flush); flush_cache_all(); /* We'd really want v7_flush_dcache_all() */ } + + kvm_arm_set_running_vcpu(vcpu); } void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) { + kvm_arm_set_running_vcpu(NULL); } int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,