From 73880c80aa9c8dc353cd0ad26579023213cd5314 Mon Sep 17 00:00:00 2001 From: Gleb Natapov Date: Tue, 9 Jun 2009 15:56:28 +0300 Subject: KVM: Break dependency between vcpu index in vcpus array and vcpu_id. Archs are free to use vcpu_id as they see fit. For x86 it is used as vcpu's apic id. New ioctl is added to configure boot vcpu id that was assumed to be 0 till now. Signed-off-by: Gleb Natapov Signed-off-by: Avi Kivity --- virt/kvm/Kconfig | 3 +++ virt/kvm/kvm_main.c | 64 ++++++++++++++++++++++++++++++++--------------------- 2 files changed, 42 insertions(+), 25 deletions(-) (limited to 'virt') diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig index 56c6848d2df8..daece36c0a57 100644 --- a/virt/kvm/Kconfig +++ b/virt/kvm/Kconfig @@ -9,3 +9,6 @@ config HAVE_KVM_IRQCHIP config HAVE_KVM_EVENTFD bool select EVENTFD + +config KVM_APIC_ARCHITECTURE + bool diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 0d54edecbc70..25e1f9c97b1a 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -689,11 +689,6 @@ out: } #endif -static inline int valid_vcpu(int n) -{ - return likely(n >= 0 && n < KVM_MAX_VCPUS); -} - inline int kvm_is_mmio_pfn(pfn_t pfn) { if (pfn_valid(pfn)) { @@ -1714,24 +1709,18 @@ static struct file_operations kvm_vcpu_fops = { */ static int create_vcpu_fd(struct kvm_vcpu *vcpu) { - int fd = anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, 0); - if (fd < 0) - kvm_put_kvm(vcpu->kvm); - return fd; + return anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, 0); } /* * Creates some virtual cpus. Good luck creating more than one. */ -static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n) +static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id) { int r; struct kvm_vcpu *vcpu; - if (!valid_vcpu(n)) - return -EINVAL; - - vcpu = kvm_arch_vcpu_create(kvm, n); + vcpu = kvm_arch_vcpu_create(kvm, id); if (IS_ERR(vcpu)) return PTR_ERR(vcpu); @@ -1742,25 +1731,38 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n) return r; mutex_lock(&kvm->lock); - if (kvm->vcpus[n]) { - r = -EEXIST; + if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) { + r = -EINVAL; goto vcpu_destroy; } - kvm->vcpus[n] = vcpu; - if (n == 0) - kvm->bsp_vcpu = vcpu; - mutex_unlock(&kvm->lock); + + for (r = 0; r < atomic_read(&kvm->online_vcpus); r++) + if (kvm->vcpus[r]->vcpu_id == id) { + r = -EEXIST; + goto vcpu_destroy; + } + + BUG_ON(kvm->vcpus[atomic_read(&kvm->online_vcpus)]); /* Now it's all set up, let userspace reach it */ kvm_get_kvm(kvm); r = create_vcpu_fd(vcpu); - if (r < 0) - goto unlink; + if (r < 0) { + kvm_put_kvm(kvm); + goto vcpu_destroy; + } + + kvm->vcpus[atomic_read(&kvm->online_vcpus)] = vcpu; + smp_wmb(); + atomic_inc(&kvm->online_vcpus); + +#ifdef CONFIG_KVM_APIC_ARCHITECTURE + if (kvm->bsp_vcpu_id == id) + kvm->bsp_vcpu = vcpu; +#endif + mutex_unlock(&kvm->lock); return r; -unlink: - mutex_lock(&kvm->lock); - kvm->vcpus[n] = NULL; vcpu_destroy: mutex_unlock(&kvm->lock); kvm_arch_vcpu_destroy(vcpu); @@ -2233,6 +2235,15 @@ static long kvm_vm_ioctl(struct file *filp, r = kvm_irqfd(kvm, data.fd, data.gsi, data.flags); break; } +#ifdef CONFIG_KVM_APIC_ARCHITECTURE + case KVM_SET_BOOT_CPU_ID: + r = 0; + if (atomic_read(&kvm->online_vcpus) != 0) + r = -EBUSY; + else + kvm->bsp_vcpu_id = arg; + break; +#endif default: r = kvm_arch_vm_ioctl(filp, ioctl, arg); } @@ -2299,6 +2310,9 @@ static long kvm_dev_ioctl_check_extension_generic(long arg) case KVM_CAP_USER_MEMORY: case KVM_CAP_DESTROY_MEMORY_REGION_WORKS: case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS: +#ifdef CONFIG_KVM_APIC_ARCHITECTURE + case KVM_CAP_SET_BOOT_CPU_ID: +#endif return 1; #ifdef CONFIG_HAVE_KVM_IRQCHIP case KVM_CAP_IRQ_ROUTING: -- cgit v1.2.3