From 07975ad3b30579ca27d880491ad992326b930c63 Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Thu, 29 Mar 2012 21:14:12 +0200 Subject: [PATCH] KVM: Introduce direct MSI message injection for in-kernel irqchips Currently, MSI messages can only be injected to in-kernel irqchips by defining a corresponding IRQ route for each message. This is not only unhandy if the MSI messages are generated "on the fly" by user space, IRQ routes are a limited resource that user space has to manage carefully. By providing a direct injection path, we can both avoid using up limited resources and simplify the necessary steps for user land. Signed-off-by: Jan Kiszka Signed-off-by: Avi Kivity --- Documentation/virtual/kvm/api.txt | 21 +++++++++++++++++++++ arch/x86/kvm/Kconfig | 1 + include/linux/kvm.h | 11 +++++++++++ include/linux/kvm_host.h | 2 ++ virt/kvm/Kconfig | 3 +++ virt/kvm/irq_comm.c | 14 ++++++++++++++ virt/kvm/kvm_main.c | 14 ++++++++++++++ 7 files changed, 66 insertions(+) diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 81ff39f6248d..a1552210b16d 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -1689,6 +1689,27 @@ where the guest will clear the flag: when the soft lockup watchdog timer resets itself or when a soft lockup is detected. This ioctl can be called any time after pausing the vcpu, but before it is resumed. +4.71 KVM_SIGNAL_MSI + +Capability: KVM_CAP_SIGNAL_MSI +Architectures: x86 +Type: vm ioctl +Parameters: struct kvm_msi (in) +Returns: >0 on delivery, 0 if guest blocked the MSI, and -1 on error + +Directly inject a MSI message. Only valid with in-kernel irqchip that handles +MSI messages. + +struct kvm_msi { + __u32 address_lo; + __u32 address_hi; + __u32 data; + __u32 flags; + __u8 pad[16]; +}; + +No flags are defined so far. The corresponding field must be 0. + 5. The kvm_run structure Application code obtains a pointer to the kvm_run structure by diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig index 1a7fe868f375..a28f338843ea 100644 --- a/arch/x86/kvm/Kconfig +++ b/arch/x86/kvm/Kconfig @@ -36,6 +36,7 @@ config KVM select TASKSTATS select TASK_DELAY_ACCT select PERF_EVENTS + select HAVE_KVM_MSI ---help--- Support hosting fully virtualized guest machines using hardware virtualization extensions. You will need a fairly recent diff --git a/include/linux/kvm.h b/include/linux/kvm.h index 7a9dd4b3dede..225b452e1d1d 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -590,6 +590,7 @@ struct kvm_ppc_pvinfo { #define KVM_CAP_SYNC_REGS 74 #define KVM_CAP_PCI_2_3 75 #define KVM_CAP_KVMCLOCK_CTRL 76 +#define KVM_CAP_SIGNAL_MSI 77 #ifdef KVM_CAP_IRQ_ROUTING @@ -715,6 +716,14 @@ struct kvm_one_reg { __u64 addr; }; +struct kvm_msi { + __u32 address_lo; + __u32 address_hi; + __u32 data; + __u32 flags; + __u8 pad[16]; +}; + /* * ioctls for VM fds */ @@ -789,6 +798,8 @@ struct kvm_s390_ucas_mapping { /* Available with KVM_CAP_PCI_2_3 */ #define KVM_ASSIGN_SET_INTX_MASK _IOW(KVMIO, 0xa4, \ struct kvm_assigned_pci_dev) +/* Available with KVM_CAP_SIGNAL_MSI */ +#define KVM_SIGNAL_MSI _IOW(KVMIO, 0xa5, struct kvm_msi) /* * ioctls for vcpu fds diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 186ffab0b9f0..6f343307d72b 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -802,6 +802,8 @@ int kvm_set_irq_routing(struct kvm *kvm, unsigned flags); void kvm_free_irq_routing(struct kvm *kvm); +int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi); + #else static inline void kvm_free_irq_routing(struct kvm *kvm) {} diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig index f63ccb0a5982..28694f4a9139 100644 --- a/virt/kvm/Kconfig +++ b/virt/kvm/Kconfig @@ -18,3 +18,6 @@ config KVM_MMIO config KVM_ASYNC_PF bool + +config HAVE_KVM_MSI + bool diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c index 9f614b4e365f..a6a0365475ed 100644 --- a/virt/kvm/irq_comm.c +++ b/virt/kvm/irq_comm.c @@ -138,6 +138,20 @@ int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e, return kvm_irq_delivery_to_apic(kvm, NULL, &irq); } +int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi) +{ + struct kvm_kernel_irq_routing_entry route; + + if (!irqchip_in_kernel(kvm) || msi->flags != 0) + return -EINVAL; + + route.msi.address_lo = msi->address_lo; + route.msi.address_hi = msi->address_hi; + route.msi.data = msi->data; + + return kvm_set_msi(&route, kvm, KVM_USERSPACE_IRQ_SOURCE_ID, 1); +} + /* * Return value: * < 0 Interrupt was ignored (masked or not delivered for other reasons) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 9eb7936e491d..1847c762d8d9 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2059,6 +2059,17 @@ static long kvm_vm_ioctl(struct file *filp, kvm->bsp_vcpu_id = arg; mutex_unlock(&kvm->lock); break; +#endif +#ifdef CONFIG_HAVE_KVM_MSI + case KVM_SIGNAL_MSI: { + struct kvm_msi msi; + + r = -EFAULT; + if (copy_from_user(&msi, argp, sizeof msi)) + goto out; + r = kvm_send_userspace_msi(kvm, &msi); + break; + } #endif default: r = kvm_arch_vm_ioctl(filp, ioctl, arg); @@ -2188,6 +2199,9 @@ static long kvm_dev_ioctl_check_extension_generic(long arg) case KVM_CAP_SET_BOOT_CPU_ID: #endif case KVM_CAP_INTERNAL_ERROR_DATA: +#ifdef CONFIG_HAVE_KVM_MSI + case KVM_CAP_SIGNAL_MSI: +#endif return 1; #ifdef CONFIG_HAVE_KVM_IRQCHIP case KVM_CAP_IRQ_ROUTING: -- 2.34.1