From 3401d54696f992edf036f00f46c8c399d1b75c2a Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Wed, 23 Jan 2013 13:18:04 -0500 Subject: [PATCH] KVM: ARM: Introduce KVM_ARM_SET_DEVICE_ADDR ioctl On ARM some bits are specific to the model being emulated for the guest and user space needs a way to tell the kernel about those bits. An example is mmio device base addresses, where KVM must know the base address for a given device to properly emulate mmio accesses within a certain address range or directly map a device with virtualiation extensions into the guest address space. We make this API ARM-specific as we haven't yet reached a consensus for a generic API for all KVM architectures that will allow us to do something like this. Reviewed-by: Will Deacon Signed-off-by: Christoffer Dall Signed-off-by: Marc Zyngier --- Documentation/virtual/kvm/api.txt | 37 +++++++++++++++++++++++++++++++ arch/arm/include/uapi/asm/kvm.h | 13 +++++++++++ arch/arm/kvm/arm.c | 23 ++++++++++++++++++- include/uapi/linux/kvm.h | 8 +++++++ 4 files changed, 80 insertions(+), 1 deletion(-) diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index c25439a58274..4505f869e450 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -2210,6 +2210,43 @@ This ioctl returns the guest registers that are supported for the KVM_GET_ONE_REG/KVM_SET_ONE_REG calls. +4.80 KVM_ARM_SET_DEVICE_ADDR + +Capability: KVM_CAP_ARM_SET_DEVICE_ADDR +Architectures: arm +Type: vm ioctl +Parameters: struct kvm_arm_device_address (in) +Returns: 0 on success, -1 on error +Errors: + ENODEV: The device id is unknown + ENXIO: Device not supported on current system + EEXIST: Address already set + E2BIG: Address outside guest physical address space + +struct kvm_arm_device_addr { + __u64 id; + __u64 addr; +}; + +Specify a device address in the guest's physical address space where guests +can access emulated or directly exposed devices, which the host kernel needs +to know about. The id field is an architecture specific identifier for a +specific device. + +ARM divides the id field into two parts, a device id and an address type id +specific to the individual device. + +  bits: | 63 ... 32 | 31 ... 16 | 15 ... 0 | + field: | 0x00000000 | device id | addr type id | + +ARM currently only require this when using the in-kernel GIC support for the +hardware VGIC features, using KVM_ARM_DEVICE_VGIC_V2 as the device id. When +setting the base address for the guest's mapping of the VGIC virtual CPU +and distributor interface, the ioctl must be called after calling +KVM_CREATE_IRQCHIP, but before calling KVM_RUN on any of the VCPUs. Calling +this ioctl twice for any of the base addresses will return -EEXIST. + + 5. The kvm_run structure ------------------------ diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h index 3303ff5adbf3..346ac3f4a2b8 100644 --- a/arch/arm/include/uapi/asm/kvm.h +++ b/arch/arm/include/uapi/asm/kvm.h @@ -65,6 +65,19 @@ struct kvm_regs { #define KVM_ARM_TARGET_CORTEX_A15 0 #define KVM_ARM_NUM_TARGETS 1 +/* KVM_ARM_SET_DEVICE_ADDR ioctl id encoding */ +#define KVM_ARM_DEVICE_TYPE_SHIFT 0 +#define KVM_ARM_DEVICE_TYPE_MASK (0xffff << KVM_ARM_DEVICE_TYPE_SHIFT) +#define KVM_ARM_DEVICE_ID_SHIFT 16 +#define KVM_ARM_DEVICE_ID_MASK (0xffff << KVM_ARM_DEVICE_ID_SHIFT) + +/* Supported device IDs */ +#define KVM_ARM_DEVICE_VGIC_V2 0 + +/* Supported VGIC address types */ +#define KVM_VGIC_V2_ADDR_TYPE_DIST 0 +#define KVM_VGIC_V2_ADDR_TYPE_CPU 1 + #define KVM_ARM_VCPU_POWER_OFF 0 /* CPU is started in OFF state */ struct kvm_vcpu_init { diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 2d30e3afdaf9..523f77a44e44 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -167,6 +167,8 @@ int kvm_dev_ioctl_check_extension(long ext) case KVM_CAP_COALESCED_MMIO: r = KVM_COALESCED_MMIO_PAGE_OFFSET; break; + case KVM_CAP_ARM_SET_DEVICE_ADDR: + r = 1; case KVM_CAP_NR_VCPUS: r = num_online_cpus(); break; @@ -827,10 +829,29 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log) return -EINVAL; } +static int kvm_vm_ioctl_set_device_addr(struct kvm *kvm, + struct kvm_arm_device_addr *dev_addr) +{ + return -ENODEV; +} + long kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { - return -EINVAL; + struct kvm *kvm = filp->private_data; + void __user *argp = (void __user *)arg; + + switch (ioctl) { + case KVM_ARM_SET_DEVICE_ADDR: { + struct kvm_arm_device_addr dev_addr; + + if (copy_from_user(&dev_addr, argp, sizeof(dev_addr))) + return -EFAULT; + return kvm_vm_ioctl_set_device_addr(kvm, &dev_addr); + } + default: + return -EINVAL; + } } static void cpu_init_hyp_mode(void *vector) diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 7f2360a46fc2..c70577cf67bc 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -637,6 +637,7 @@ struct kvm_ppc_smmu_info { #define KVM_CAP_PPC_BOOKE_WATCHDOG 83 #define KVM_CAP_PPC_HTAB_FD 84 #define KVM_CAP_ARM_PSCI 87 +#define KVM_CAP_ARM_SET_DEVICE_ADDR 88 #ifdef KVM_CAP_IRQ_ROUTING @@ -784,6 +785,11 @@ struct kvm_msi { __u8 pad[16]; }; +struct kvm_arm_device_addr { + __u64 id; + __u64 addr; +}; + /* * ioctls for VM fds */ @@ -869,6 +875,8 @@ struct kvm_s390_ucas_mapping { #define KVM_ALLOCATE_RMA _IOR(KVMIO, 0xa9, struct kvm_allocate_rma) /* Available with KVM_CAP_PPC_HTAB_FD */ #define KVM_PPC_GET_HTAB_FD _IOW(KVMIO, 0xaa, struct kvm_get_htab_fd) +/* Available with KVM_CAP_ARM_SET_DEVICE_ADDR */ +#define KVM_ARM_SET_DEVICE_ADDR _IOW(KVMIO, 0xab, struct kvm_arm_device_addr) /* * ioctls for vcpu fds -- GitLab