[10/10] KVM: switch vcpu context to use SRCU

Message ID	20090921234124.924808866@amt.cnet (mailing list archive)
State	New, archived
Headers	show Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n8LNgYod002832 for <patchwork-kvm@patchwork.kernel.org>; Mon, 21 Sep 2009 23:42:34 GMT Message-Id: <20090921234124.924808866@amt.cnet> User-Agent: quilt/0.47-1 Date: Mon, 21 Sep 2009 20:37:21 -0300 From: Marcelo Tosatti <mtosatti@redhat.com> To: kvm@vger.kernel.org Cc: avi@redhat.com, Marcelo Tosatti <mtosatti@redhat.com> Subject: [patch 10/10] KVM: switch vcpu context to use SRCU References: <20090921233711.213665413@amt.cnet> Content-Disposition: inline; filename=switch-to-memslot-srcu Sender: kvm-owner@vger.kernel.org Precedence: bulk

Index: kvm-slotslock/arch/x86/kvm/x86.c =================================================================== --- kvm-slotslock.orig/arch/x86/kvm/x86.c +++ kvm-slotslock/arch/x86/kvm/x86.c @@ -1140,15 +1140,15 @@ static int __msr_io(struct kvm_vcpu *vcp int (*do_msr)(struct kvm_vcpu *vcpu, unsigned index, u64 *data)) { - int i; + int i, idx; vcpu_load(vcpu); - down_read(&vcpu->kvm->slots_lock); + idx = srcu_read_lock(&vcpu->kvm->srcu); for (i = 0; i < msrs->nmsrs; ++i) if (do_msr(vcpu, entries[i].index, &entries[i].data)) break; - up_read(&vcpu->kvm->slots_lock); + srcu_read_unlock(&vcpu->kvm->srcu, idx); vcpu_put(vcpu); @@ -3531,16 +3531,17 @@ static void vapic_enter(struct kvm_vcpu static void vapic_exit(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->arch.apic; + int idx; if (!apic || !apic->vapic_addr) return; - down_read(&vcpu->kvm->slots_lock); + idx = srcu_read_lock(&vcpu->kvm->srcu); kvm_release_page_dirty(apic->vapic_page); spin_lock(&vcpu->kvm->mmu_lock); mark_page_dirty(vcpu->kvm, apic->vapic_addr >> PAGE_SHIFT); spin_unlock(&vcpu->kvm->mmu_lock); - up_read(&vcpu->kvm->slots_lock); + srcu_read_unlock(&vcpu->kvm->srcu, idx); } static void update_cr8_intercept(struct kvm_vcpu *vcpu) @@ -3669,7 +3670,7 @@ static int vcpu_enter_guest(struct kvm_v kvm_lapic_sync_to_vapic(vcpu); } - up_read(&vcpu->kvm->slots_lock); + srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx); kvm_guest_enter(); @@ -3710,7 +3711,7 @@ static int vcpu_enter_guest(struct kvm_v preempt_enable(); - down_read(&vcpu->kvm->slots_lock); + vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu); /* * Profile KVM exit RIPs: @@ -3732,6 +3733,7 @@ out: static int __vcpu_run(struct kvm_vcpu *vcpu) { int r; + struct kvm *kvm = vcpu->kvm; if (unlikely(vcpu->arch.mp_state == KVM_MP_STATE_SIPI_RECEIVED)) { pr_debug("vcpu %d received sipi with vector # %x\n", @@ -3743,7 +3745,7 @@ static int __vcpu_run(struct kvm_vcpu *v vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE; } - down_read(&vcpu->kvm->slots_lock); + vcpu->srcu_idx = srcu_read_lock(&kvm->srcu); vapic_enter(vcpu); r = 1; @@ -3751,9 +3753,9 @@ static int __vcpu_run(struct kvm_vcpu *v if (vcpu->arch.mp_state == KVM_MP_STATE_RUNNABLE) r = vcpu_enter_guest(vcpu); else { - up_read(&vcpu->kvm->slots_lock); + srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx); kvm_vcpu_block(vcpu); - down_read(&vcpu->kvm->slots_lock); + vcpu->srcu_idx = srcu_read_lock(&kvm->srcu); if (test_and_clear_bit(KVM_REQ_UNHALT, &vcpu->requests)) { switch(vcpu->arch.mp_state) { @@ -3788,13 +3790,13 @@ static int __vcpu_run(struct kvm_vcpu *v ++vcpu->stat.signal_exits; } if (need_resched()) { - up_read(&vcpu->kvm->slots_lock); + srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx); kvm_resched(vcpu); - down_read(&vcpu->kvm->slots_lock); + vcpu->srcu_idx = srcu_read_lock(&kvm->srcu); } } - up_read(&vcpu->kvm->slots_lock); + srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx); post_kvm_run_save(vcpu); vapic_exit(vcpu); @@ -3834,10 +3836,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_v vcpu->mmio_read_completed = 1; vcpu->mmio_needed = 0; - down_read(&vcpu->kvm->slots_lock); + vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu); r = emulate_instruction(vcpu, vcpu->arch.mmio_fault_cr2, 0, EMULTYPE_NO_DECODE); - up_read(&vcpu->kvm->slots_lock); + srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx); if (r == EMULATE_DO_MMIO) { /* * Read-modify-write. Back to userspace. @@ -4575,11 +4577,12 @@ int kvm_arch_vcpu_ioctl_translate(struct { unsigned long vaddr = tr->linear_address; gpa_t gpa; + int idx; vcpu_load(vcpu); - down_read(&vcpu->kvm->slots_lock); + idx = srcu_read_lock(&vcpu->kvm->srcu); gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, vaddr); - up_read(&vcpu->kvm->slots_lock); + srcu_read_unlock(&vcpu->kvm->srcu, idx); tr->physical_address = gpa; tr->valid = gpa != UNMAPPED_GVA; tr->writeable = 1; @@ -4818,10 +4821,12 @@ fail: void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) { + int idx; + kvm_free_lapic(vcpu); - down_read(&vcpu->kvm->slots_lock); + idx = srcu_read_lock(&vcpu->kvm->srcu); kvm_mmu_destroy(vcpu); - up_read(&vcpu->kvm->slots_lock); + srcu_read_unlock(&vcpu->kvm->srcu, idx); free_page((unsigned long)vcpu->arch.pio_data); } Index: kvm-slotslock/include/linux/kvm_host.h =================================================================== --- kvm-slotslock.orig/include/linux/kvm_host.h +++ kvm-slotslock/include/linux/kvm_host.h @@ -84,6 +84,8 @@ struct kvm_vcpu { struct kvm_run *run; unsigned long requests; unsigned long guest_debug; + int srcu_idx; + int fpu_active; int guest_fpu_loaded; wait_queue_head_t wq; Index: kvm-slotslock/arch/x86/kvm/mmu.c =================================================================== --- kvm-slotslock.orig/arch/x86/kvm/mmu.c +++ kvm-slotslock/arch/x86/kvm/mmu.c @@ -2883,10 +2883,9 @@ static int mmu_shrink(int nr_to_scan, gf spin_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) { - int npages; + int npages, idx; - if (!down_read_trylock(&kvm->slots_lock)) - continue; + idx = srcu_read_lock(&kvm->srcu); spin_lock(&kvm->mmu_lock); npages = kvm->arch.n_alloc_mmu_pages - kvm->arch.n_free_mmu_pages; @@ -2899,7 +2898,7 @@ static int mmu_shrink(int nr_to_scan, gf nr_to_scan--; spin_unlock(&kvm->mmu_lock); - up_read(&kvm->slots_lock); + srcu_read_unlock(&kvm->srcu, idx); } if (kvm_freed) list_move_tail(&kvm_freed->vm_list, &vm_list); Index: kvm-slotslock/arch/x86/kvm/vmx.c =================================================================== --- kvm-slotslock.orig/arch/x86/kvm/vmx.c +++ kvm-slotslock/arch/x86/kvm/vmx.c @@ -2429,10 +2429,10 @@ static int vmx_vcpu_reset(struct kvm_vcp { struct vcpu_vmx *vmx = to_vmx(vcpu); u64 msr; - int ret; + int ret, idx; vcpu->arch.regs_avail = ~((1 << VCPU_REGS_RIP) | (1 << VCPU_REGS_RSP)); - down_read(&vcpu->kvm->slots_lock); + idx = srcu_read_lock(&vcpu->kvm->srcu); if (!init_rmode(vmx->vcpu.kvm)) { ret = -ENOMEM; goto out; @@ -2540,7 +2540,7 @@ static int vmx_vcpu_reset(struct kvm_vcp vmx->emulation_required = 0; out: - up_read(&vcpu->kvm->slots_lock); + srcu_read_unlock(&vcpu->kvm->srcu, idx); return ret; } Index: kvm-slotslock/arch/ia64/kvm/kvm-ia64.c =================================================================== --- kvm-slotslock.orig/arch/ia64/kvm/kvm-ia64.c +++ kvm-slotslock/arch/ia64/kvm/kvm-ia64.c @@ -636,12 +636,9 @@ static void kvm_vcpu_post_transition(str static int __vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) { union context *host_ctx, *guest_ctx; - int r; + int r, idx; - /* - * down_read() may sleep and return with interrupts enabled - */ - down_read(&vcpu->kvm->slots_lock); + idx = srcu_read_lock(&vcpu->kvm->srcu); again: if (signal_pending(current)) { @@ -663,7 +660,7 @@ again: if (r < 0) goto vcpu_run_fail; - up_read(&vcpu->kvm->slots_lock); + srcu_read_unlock(&vcpu->kvm->srcu, idx); kvm_guest_enter(); /* @@ -687,7 +684,7 @@ again: kvm_guest_exit(); preempt_enable(); - down_read(&vcpu->kvm->slots_lock); + idx = srcu_read_lock(&vcpu->kvm->srcu); r = kvm_handle_exit(kvm_run, vcpu); @@ -697,10 +694,10 @@ again: } out: - up_read(&vcpu->kvm->slots_lock); + srcu_read_unlock(&vcpu->kvm->srcu, idx); if (r > 0) { kvm_resched(vcpu); - down_read(&vcpu->kvm->slots_lock); + idx = srcu_read_lock(&vcpu->kvm->srcu); goto again; }

[10/10] KVM: switch vcpu context to use SRCU

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