First patch in a series which enables the relocation of the PIC/IOAPIC to userspace. Adds capability KVM_CAP_SPLIT_IRQCHIP; KVM_CAP_SPLIT_IRQCHIP enables the construction of LAPICs without the rest of the irqchip. Compile tested for x86. Signed-off-by: Steve Rutherford <srutherford@xxxxxxxxxx> Suggested-by: Andrew Honig <ahonig@xxxxxxxxxx> --- Documentation/virtual/kvm/api.txt | 15 +++++++++++++++ arch/x86/include/asm/kvm_host.h | 2 ++ arch/x86/kvm/i8254.c | 5 ++++- arch/x86/kvm/ioapic.h | 8 ++++++++ arch/x86/kvm/irq.h | 6 ++++++ arch/x86/kvm/irq_comm.c | 9 ++++++++- arch/x86/kvm/lapic.c | 9 ++++++--- arch/x86/kvm/vmx.c | 4 ++-- arch/x86/kvm/x86.c | 22 ++++++++++++++++++++-- include/linux/kvm_host.h | 1 + include/uapi/linux/kvm.h | 1 + 11 files changed, 73 insertions(+), 9 deletions(-) diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index a4ebcb7..b655024 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -3620,6 +3620,21 @@ struct { KVM handlers should exit to userspace with rc = -EREMOTE. +7.5 KVM_SPLIT_IRQCHIP + +Architectures: x86 +Parameters: None +Returns: 0 on success, -1 on error + +Create a local apic for each processor in the kernel. With this capability +enabled, the userspace VMM is expected to emulate the IOAPIC and PIC. + +This supersedes KVM_CREATE_IRQCHIP, creating only local APICs, but no in kernel +IOAPIC or PIC. This also enables in kernel routing of interrupt requests. + +Fails if VCPU has already been created, or if the irqchip is already in the +kernel (i.e. KVM_CREATE_IRQCHIP has already been called). + 8. Other capabilities. ---------------------- diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index fa32b53..18a110b 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -669,6 +669,8 @@ struct kvm_arch { bool boot_vcpu_runs_old_kvmclock; u64 disabled_quirks; + + bool irqchip_split; }; struct kvm_vm_stat { diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c index f90952f..5708850 100644 --- a/arch/x86/kvm/i8254.c +++ b/arch/x86/kvm/i8254.c @@ -35,6 +35,7 @@ #include <linux/kvm_host.h> #include <linux/slab.h> +#include "ioapic.h" #include "irq.h" #include "i8254.h" #include "x86.h" @@ -333,7 +334,9 @@ static void create_pit_timer(struct kvm *kvm, u32 val, int is_period) struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state; s64 interval; - if (!irqchip_in_kernel(kvm) || ps->flags & KVM_PIT_FLAGS_HPET_LEGACY) + if (!irqchip_in_kernel(kvm) || + !ioapic_in_kernel(kvm) || + ps->flags & KVM_PIT_FLAGS_HPET_LEGACY) return; interval = muldiv64(val, NSEC_PER_SEC, KVM_PIT_FREQ); diff --git a/arch/x86/kvm/ioapic.h b/arch/x86/kvm/ioapic.h index ca0b0b4..3ce56f8 100644 --- a/arch/x86/kvm/ioapic.h +++ b/arch/x86/kvm/ioapic.h @@ -98,6 +98,14 @@ static inline struct kvm_ioapic *ioapic_irqchip(struct kvm *kvm) return kvm->arch.vioapic; } +static inline int ioapic_in_kernel(struct kvm *kvm) +{ + int ret; + + ret = (ioapic_irqchip(kvm) != NULL); + return ret; +} + static inline bool kvm_ioapic_handles_vector(struct kvm *kvm, int vector) { struct kvm_ioapic *ioapic = kvm->arch.vioapic; diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h index ad68c73..2f13dd5 100644 --- a/arch/x86/kvm/irq.h +++ b/arch/x86/kvm/irq.h @@ -83,11 +83,17 @@ static inline struct kvm_pic *pic_irqchip(struct kvm *kvm) return kvm->arch.vpic; } +static inline int irqchip_split(struct kvm *kvm) +{ + return kvm->arch.irqchip_split; +} + static inline int irqchip_in_kernel(struct kvm *kvm) { int ret; ret = (pic_irqchip(kvm) != NULL); + ret |= irqchip_split(kvm); smp_rmb(); return ret; } diff --git a/arch/x86/kvm/irq_comm.c b/arch/x86/kvm/irq_comm.c index 9efff9e..67f6b62 100644 --- a/arch/x86/kvm/irq_comm.c +++ b/arch/x86/kvm/irq_comm.c @@ -208,7 +208,7 @@ void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id) goto unlock; } clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap); - if (!irqchip_in_kernel(kvm)) + if (!ioapic_in_kernel(kvm)) goto unlock; kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id); @@ -328,3 +328,10 @@ int kvm_setup_default_irq_routing(struct kvm *kvm) return kvm_set_irq_routing(kvm, default_routing, ARRAY_SIZE(default_routing), 0); } + +static const struct kvm_irq_routing_entry empty_routing[] = {}; + +int kvm_setup_empty_irq_routing(struct kvm *kvm) +{ + return kvm_set_irq_routing(kvm, empty_routing, 0, 0); +} diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 2a5ca97..536b79e 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -209,7 +209,8 @@ out: if (old) kfree_rcu(old, rcu); - kvm_vcpu_request_scan_ioapic(kvm); + if (!irqchip_split(kvm)) + kvm_vcpu_request_scan_ioapic(kvm); } static inline void apic_set_spiv(struct kvm_lapic *apic, u32 val) @@ -1838,7 +1839,8 @@ void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu, kvm_x86_ops->hwapic_isr_update(vcpu->kvm, apic_find_highest_isr(apic)); kvm_make_request(KVM_REQ_EVENT, vcpu); - kvm_rtc_eoi_tracking_restore_one(vcpu); + if (!irqchip_split(vcpu->kvm)) + kvm_rtc_eoi_tracking_restore_one(vcpu); } void __kvm_migrate_apic_timer(struct kvm_vcpu *vcpu) @@ -1921,7 +1923,8 @@ static void apic_sync_pv_eoi_to_guest(struct kvm_vcpu *vcpu, /* Cache not set: could be safe but we don't bother. */ apic->highest_isr_cache == -1 || /* Need EOI to update ioapic. */ - kvm_ioapic_handles_vector(vcpu->kvm, apic->highest_isr_cache)) { + kvm_ioapic_handles_vector(vcpu->kvm, apic->highest_isr_cache) || + irqchip_split(vcpu->kvm)) { /* * PV EOI was disabled by apic_sync_pv_eoi_from_guest * so we need not do anything here. diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 4014a82..08203a1 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -948,7 +948,7 @@ static inline bool cpu_has_vmx_tpr_shadow(void) static inline bool vm_need_tpr_shadow(struct kvm *kvm) { - return (cpu_has_vmx_tpr_shadow()) && (irqchip_in_kernel(kvm)); + return (cpu_has_vmx_tpr_shadow()) && irqchip_in_kernel(kvm); } static inline bool cpu_has_secondary_exec_ctrls(void) @@ -9485,7 +9485,7 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) /* vmcs12's VM_ENTRY_LOAD_IA32_EFER and VM_ENTRY_IA32E_MODE are * emulated by vmx_set_efer(), below. */ - vm_entry_controls_init(vmx, + vm_entry_controls_init(vmx, (vmcs12->vm_entry_controls & ~VM_ENTRY_LOAD_IA32_EFER & ~VM_ENTRY_IA32E_MODE) | (vmcs_config.vmentry_ctrl & ~VM_ENTRY_IA32E_MODE)); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 28076c2..985c99f 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2461,6 +2461,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_TSC_DEADLINE_TIMER: case KVM_CAP_ENABLE_CAP_VM: case KVM_CAP_DISABLE_QUIRKS: + case KVM_CAP_SPLIT_IRQCHIP: #ifdef CONFIG_KVM_DEVICE_ASSIGNMENT case KVM_CAP_ASSIGN_DEV_IRQ: case KVM_CAP_PCI_2_3: @@ -3568,6 +3569,23 @@ static int kvm_vm_ioctl_enable_cap(struct kvm *kvm, kvm->arch.disabled_quirks = cap->args[0]; r = 0; break; + case KVM_CAP_SPLIT_IRQCHIP: { + mutex_lock(&kvm->lock); + r = -EEXIST; + if (irqchip_in_kernel(kvm)) + goto split_irqchip_unlock; + r = -EINVAL; + if (atomic_read(&kvm->online_vcpus)) + goto split_irqchip_unlock; + r = kvm_setup_empty_irq_routing(kvm); + if (r) + goto split_irqchip_unlock; + kvm->arch.irqchip_split = true; + r = 0; +split_irqchip_unlock: + mutex_unlock(&kvm->lock); + break; + } default: r = -EINVAL; break; @@ -3686,7 +3704,7 @@ long kvm_arch_vm_ioctl(struct file *filp, } r = -ENXIO; - if (!irqchip_in_kernel(kvm)) + if (!irqchip_in_kernel(kvm) || !ioapic_in_kernel(kvm)) goto get_irqchip_out; r = kvm_vm_ioctl_get_irqchip(kvm, chip); if (r) @@ -3710,7 +3728,7 @@ long kvm_arch_vm_ioctl(struct file *filp, } r = -ENXIO; - if (!irqchip_in_kernel(kvm)) + if (!irqchip_in_kernel(kvm) || !ioapic_in_kernel(kvm)) goto set_irqchip_out; r = kvm_vm_ioctl_set_irqchip(kvm, chip); if (r) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 51103f0..f7eab09 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1000,6 +1000,7 @@ static inline int mmu_notifier_retry(struct kvm *kvm, unsigned long mmu_seq) #endif int kvm_setup_default_irq_routing(struct kvm *kvm); +int kvm_setup_empty_irq_routing(struct kvm *kvm); int kvm_set_irq_routing(struct kvm *kvm, const struct kvm_irq_routing_entry *entries, unsigned nr, diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 9ef19eb..e4304d0 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -818,6 +818,7 @@ struct kvm_ppc_smmu_info { #define KVM_CAP_DISABLE_QUIRKS 116 #define KVM_CAP_X86_SMM 117 #define KVM_CAP_MULTI_ADDRESS_SPACE 118 +#define KVM_CAP_SPLIT_IRQCHIP 119 #ifdef KVM_CAP_IRQ_ROUTING -- 2.5.0.rc2.392.g76e840b -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html