On 09.02.2012, at 23:33, Christoffer Dall wrote:
> From: Christoffer Dall <c.dall@xxxxxxxxxxxxxxxxxxxxxx>
>
> The kvm_vcpu_kick function performs roughly the same funcitonality on
> most all architectures, so we shouldn't have separate copies.
>
> PowerPC keeps a pointer to interchanging waitqueues on the vcpu_arch
> structure and to accomodate this special need a
> __KVM_HAVE_ARCH_VCPU_GET_WQ define and accompanying function
> kvm_arch_vcpu_wq have been defined. For all other architectures this
> is a generic inline that just returns &vcpu->wq;
>
> This patch applies to Linus' tree on the Linux 3.3-rc1 tag.
Please work against kvm.git for kvm patches :). Makes life easier for everyone involved. It takes a while for patches to land in Linus' tree. I don't think it matters for this patch, but it might in the future.
>
> Changes since v2:
> - Restore arch-specific vcpu->cpu assignment to arch-specific code
> - Set vcpu mode in PowerPC arch-specific kvm code
>
> Changes since v1:
> - Abstact CPU mode check into arch-specific function
> - Remove redundant vcpu->cpu assignment
>
> Signed-off-by: Christoffer Dall <c.dall@xxxxxxxxxxxxxxxxxxxxxx>
> ---
> arch/ia64/include/asm/kvm_host.h | 1 +
> arch/ia64/kvm/kvm-ia64.c | 15 ---------------
> arch/powerpc/include/asm/kvm_host.h | 6 ++++++
> arch/powerpc/kvm/book3s_pr.c | 4 ++++
> arch/powerpc/kvm/booke.c | 2 ++
> arch/powerpc/kvm/powerpc.c | 17 +++++++----------
> arch/s390/kvm/kvm-s390.c | 8 ++++++++
> arch/x86/kvm/x86.c | 16 ++--------------
> include/linux/kvm_host.h | 9 +++++++++
> virt/kvm/kvm_main.c | 22 ++++++++++++++++++++++
> 10 files changed, 61 insertions(+), 39 deletions(-)
>
> diff --git a/arch/ia64/include/asm/kvm_host.h b/arch/ia64/include/asm/kvm_host.h
> index 2689ee5..06a5e91 100644
> --- a/arch/ia64/include/asm/kvm_host.h
> +++ b/arch/ia64/include/asm/kvm_host.h
> @@ -365,6 +365,7 @@ struct thash_cb {
> };
>
> struct kvm_vcpu_stat {
> + u32 halt_wakeup;
> };
>
> struct kvm_vcpu_arch {
> diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
> index 4050520..3f6a3cc 100644
> --- a/arch/ia64/kvm/kvm-ia64.c
> +++ b/arch/ia64/kvm/kvm-ia64.c
> @@ -1849,21 +1849,6 @@ void kvm_arch_hardware_unsetup(void)
> {
> }
>
> -void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
> -{
> - int me;
> - int cpu = vcpu->cpu;
> -
> - if (waitqueue_active(&vcpu->wq))
> - wake_up_interruptible(&vcpu->wq);
> -
> - me = get_cpu();
> - if (cpu != me && (unsigned) cpu < nr_cpu_ids && cpu_online(cpu))
> - if (!test_and_set_bit(KVM_REQ_KICK, &vcpu->requests))
> - smp_send_reschedule(cpu);
> - put_cpu();
> -}
> -
> int kvm_apic_set_irq(struct kvm_vcpu *vcpu, struct kvm_lapic_irq *irq)
> {
> return __apic_accept_irq(vcpu, irq->vector);
> diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
> index bf8af5d..b687444 100644
> --- a/arch/powerpc/include/asm/kvm_host.h
> +++ b/arch/powerpc/include/asm/kvm_host.h
> @@ -438,4 +438,10 @@ struct kvm_vcpu_arch {
> #define KVMPPC_VCPU_BUSY_IN_HOST 1
> #define KVMPPC_VCPU_RUNNABLE 2
>
> +#define __KVM_HAVE_ARCH_VCPU_GET_WQ 1
> +static inline wait_queue_head *kvm_arch_vcpu_wq(struct kvm_vcpu *vcpu)
> +{
> + return vcpu->arch.wqp;
> +}
> +
> #endif /* __POWERPC_KVM_HOST_H__ */
> diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
> index e2cfb9e..43466aa 100644
> --- a/arch/powerpc/kvm/book3s_pr.c
> +++ b/arch/powerpc/kvm/book3s_pr.c
> @@ -968,6 +968,8 @@ int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
> if (vcpu->arch.shared->msr & MSR_FP)
> kvmppc_handle_ext(vcpu, BOOK3S_INTERRUPT_FP_UNAVAIL, MSR_FP);
>
> + vcpu->mode = IN_GUEST_MODE;
This is racy. I'll just write a patch myself then :)
> +
> kvm_guest_enter();
>
> ret = __kvmppc_vcpu_run(kvm_run, vcpu);
> @@ -976,6 +978,8 @@ int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
>
> local_irq_disable();
>
> + vcpu->mode = OUTSIDE_GUEST_MODE;
> +
> current->thread.regs->msr = ext_msr;
>
> /* Make sure we save the guest FPU/Altivec/VSX state */
> diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
> index bb6c988..f909289 100644
> --- a/arch/powerpc/kvm/booke.c
> +++ b/arch/powerpc/kvm/booke.c
> @@ -321,11 +321,13 @@ int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
> return -EINVAL;
> }
>
> + vcpu->mode = IN_GUEST_MODE;
> local_irq_disable();
> kvm_guest_enter();
> ret = __kvmppc_vcpu_run(kvm_run, vcpu);
> kvm_guest_exit();
> local_irq_enable();
> + vcpu->mode = OUTSIDE_GUEST_MODE;
>
> return ret;
> }
> diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
> index 607fbdf..3b9b5cd 100644
> --- a/arch/powerpc/kvm/powerpc.c
> +++ b/arch/powerpc/kvm/powerpc.c
> @@ -42,6 +42,11 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
> !!(v->arch.pending_exceptions);
> }
>
> +int kvm_arch_vcpu_in_guest_mode(struct kvm_vcpu *vcpu)
> +{
> + return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
> +}
> +
> int kvmppc_kvm_pv(struct kvm_vcpu *vcpu)
> {
> int nr = kvmppc_get_gpr(vcpu, 11);
> @@ -311,10 +316,7 @@ static void kvmppc_decrementer_func(unsigned long data)
>
> kvmppc_core_queue_dec(vcpu);
>
> - if (waitqueue_active(vcpu->arch.wqp)) {
> - wake_up_interruptible(vcpu->arch.wqp);
> - vcpu->stat.halt_wakeup++;
> - }
> + kvm_vcpu_kick(vcpu);
> }
>
> /*
> @@ -572,12 +574,7 @@ int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq)
>
> kvmppc_core_queue_external(vcpu, irq);
>
> - if (waitqueue_active(vcpu->arch.wqp)) {
> - wake_up_interruptible(vcpu->arch.wqp);
> - vcpu->stat.halt_wakeup++;
> - } else if (vcpu->cpu != -1) {
> - smp_send_reschedule(vcpu->cpu);
> - }
> + kvm_vcpu_kick(vcpu);
>
> return 0;
> }
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index d1c44573..5e2217f 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -380,6 +380,14 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)
> return 0;
> }
>
> +int kvm_arch_vcpu_in_guest_mode(struct kvm_vcpu *vcpu)
> +{
> + /* kvm common code refers to this, but never calls it */
> + BUG();
> + return 0;
> +}
> +
> +
> static int kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu)
> {
> kvm_s390_vcpu_initial_reset(vcpu);
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 43c4dab..57d13a6 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -6135,21 +6135,9 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)
> kvm_cpu_has_interrupt(vcpu));
> }
>
> -void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
> +int kvm_arch_vcpu_in_guest_mode(struct kvm_vcpu *vcpu)
> {
> - int me;
> - int cpu = vcpu->cpu;
> -
> - if (waitqueue_active(&vcpu->wq)) {
> - wake_up_interruptible(&vcpu->wq);
> - ++vcpu->stat.halt_wakeup;
> - }
> -
> - me = get_cpu();
> - if (cpu != me && (unsigned)cpu < nr_cpu_ids && cpu_online(cpu))
> - if (kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE)
> - smp_send_reschedule(cpu);
> - put_cpu();
> + return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
> }
>
> int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu)
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index 41973e2..638fa64 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -440,6 +440,7 @@ void mark_page_dirty_in_slot(struct kvm *kvm, struct kvm_memory_slot *memslot,
> gfn_t gfn);
>
> void kvm_vcpu_block(struct kvm_vcpu *vcpu);
> +void kvm_vcpu_kick(struct kvm_vcpu *vcpu);
> void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu);
> void kvm_resched(struct kvm_vcpu *vcpu);
> void kvm_load_guest_fpu(struct kvm_vcpu *vcpu);
> @@ -507,6 +508,7 @@ int kvm_arch_hardware_setup(void);
> void kvm_arch_hardware_unsetup(void);
> void kvm_arch_check_processor_compat(void *rtn);
> int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu);
> +int kvm_arch_vcpu_in_guest_mode(struct kvm_vcpu *vcpu);
>
> void kvm_free_physmem(struct kvm *kvm);
>
> @@ -522,6 +524,13 @@ static inline void kvm_arch_free_vm(struct kvm *kvm)
> }
> #endif
>
> +#ifndef __KVM_HAVE_ARCH_VCPU_GET_WQ
> +static inline wait_queue_head_t *kvm_arch_vcpu_wq(struct kvm_vcpu *vcpu)
> +{
> + return &vcpu->wq;
> +}
> +#endif
> +
> int kvm_arch_init_vm(struct kvm *kvm);
> void kvm_arch_destroy_vm(struct kvm *kvm);
> void kvm_free_all_assigned_devices(struct kvm *kvm);
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 7287bf5..3d72008 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -1581,6 +1581,28 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
> finish_wait(&vcpu->wq, &wait);
> }
>
> +/*
> + * Kick a sleeping VCPU, or a guest VCPU in guest mode, into host kernel mode.
> + */
> +void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
> +{
> + int me;
> + int cpu = vcpu->cpu;
> + wait_queue_head_t *wqp;
> +
> + wqp = kvm_arch_vcpu_wq(vcpu);
> + if (waitqueue_active(wqp)) {
> + wake_up_interruptible(wqp);
> + ++vcpu->stat.halt_wakeup;
> + }
> +
> + me = get_cpu();
> + if (cpu != me && (unsigned)cpu < nr_cpu_ids && cpu_online(cpu))
> + if (kvm_arch_vcpu_in_guest_mode(vcpu))
Didn't the last version did an atomic cmpxchg here? Also, that check certainly wasn't there for ia64 before. Are you sure it's happy with it? :)
Alex
> + smp_send_reschedule(cpu);
> + put_cpu();
> +}
> +
> void kvm_resched(struct kvm_vcpu *vcpu)
> {
> if (!need_resched())
>
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