diff options
| -rw-r--r-- | Documentation/virtual/kvm/devices/xive.txt | 23 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/xive.h | 1 | ||||
| -rw-r--r-- | arch/powerpc/include/uapi/asm/kvm.h | 2 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_xive_native.c | 39 | ||||
| -rw-r--r-- | arch/powerpc/sysdev/xive/native.c | 11 |
5 files changed, 76 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/devices/xive.txt b/Documentation/virtual/kvm/devices/xive.txt index 525d1eebcf34..0cd7847ec38a 100644 --- a/Documentation/virtual/kvm/devices/xive.txt +++ b/Documentation/virtual/kvm/devices/xive.txt @@ -13,6 +13,29 @@ requires a POWER9 host and the guest OS should have support for the XIVE native exploitation interrupt mode. If not, it should run using the legacy interrupt mode, referred as XICS (POWER7/8). +* Device Mappings + + The KVM device exposes different MMIO ranges of the XIVE HW which + are required for interrupt management. These are exposed to the + guest in VMAs populated with a custom VM fault handler. + + 1. Thread Interrupt Management Area (TIMA) + + Each thread has an associated Thread Interrupt Management context + composed of a set of registers. These registers let the thread + handle priority management and interrupt acknowledgment. The most + important are : + + - Interrupt Pending Buffer (IPB) + - Current Processor Priority (CPPR) + - Notification Source Register (NSR) + + They are exposed to software in four different pages each proposing + a view with a different privilege. The first page is for the + physical thread context and the second for the hypervisor. Only the + third (operating system) and the fourth (user level) are exposed the + guest. + * Groups: 1. KVM_DEV_XIVE_GRP_CTRL diff --git a/arch/powerpc/include/asm/xive.h b/arch/powerpc/include/asm/xive.h index c4e88abd3b67..eaf76f57023a 100644 --- a/arch/powerpc/include/asm/xive.h +++ b/arch/powerpc/include/asm/xive.h @@ -23,6 +23,7 @@ * same offset regardless of where the code is executing */ extern void __iomem *xive_tima; +extern unsigned long xive_tima_os; /* * Offset in the TM area of our current execution level (provided by diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h index cd3f16b70a2e..0998e8edc91a 100644 --- a/arch/powerpc/include/uapi/asm/kvm.h +++ b/arch/powerpc/include/uapi/asm/kvm.h @@ -720,4 +720,6 @@ struct kvm_ppc_xive_eq { #define KVM_XIVE_EQ_ALWAYS_NOTIFY 0x00000001 +#define KVM_XIVE_TIMA_PAGE_OFFSET 0 + #endif /* __LINUX_KVM_POWERPC_H */ diff --git a/arch/powerpc/kvm/book3s_xive_native.c b/arch/powerpc/kvm/book3s_xive_native.c index 2f9d5e9439a6..f5314da0cb45 100644 --- a/arch/powerpc/kvm/book3s_xive_native.c +++ b/arch/powerpc/kvm/book3s_xive_native.c @@ -165,6 +165,44 @@ bail: return rc; } +static vm_fault_t xive_native_tima_fault(struct vm_fault *vmf) +{ + struct vm_area_struct *vma = vmf->vma; + + switch (vmf->pgoff - vma->vm_pgoff) { + case 0: /* HW - forbid access */ + case 1: /* HV - forbid access */ + return VM_FAULT_SIGBUS; + case 2: /* OS */ + vmf_insert_pfn(vma, vmf->address, xive_tima_os >> PAGE_SHIFT); + return VM_FAULT_NOPAGE; + case 3: /* USER - TODO */ + default: + return VM_FAULT_SIGBUS; + } +} + +static const struct vm_operations_struct xive_native_tima_vmops = { + .fault = xive_native_tima_fault, +}; + +static int kvmppc_xive_native_mmap(struct kvm_device *dev, + struct vm_area_struct *vma) +{ + /* We only allow mappings at fixed offset for now */ + if (vma->vm_pgoff == KVM_XIVE_TIMA_PAGE_OFFSET) { + if (vma_pages(vma) > 4) + return -EINVAL; + vma->vm_ops = &xive_native_tima_vmops; + } else { + return -EINVAL; + } + + vma->vm_flags |= VM_IO | VM_PFNMAP; + vma->vm_page_prot = pgprot_noncached_wc(vma->vm_page_prot); + return 0; +} + static int kvmppc_xive_native_set_source(struct kvmppc_xive *xive, long irq, u64 addr) { @@ -1050,6 +1088,7 @@ struct kvm_device_ops kvm_xive_native_ops = { .set_attr = kvmppc_xive_native_set_attr, .get_attr = kvmppc_xive_native_get_attr, .has_attr = kvmppc_xive_native_has_attr, + .mmap = kvmppc_xive_native_mmap, }; void kvmppc_xive_native_init_module(void) diff --git a/arch/powerpc/sysdev/xive/native.c b/arch/powerpc/sysdev/xive/native.c index 0c037e933e55..7782201e5fe8 100644 --- a/arch/powerpc/sysdev/xive/native.c +++ b/arch/powerpc/sysdev/xive/native.c @@ -521,6 +521,9 @@ u32 xive_native_default_eq_shift(void) } EXPORT_SYMBOL_GPL(xive_native_default_eq_shift); +unsigned long xive_tima_os; +EXPORT_SYMBOL_GPL(xive_tima_os); + bool __init xive_native_init(void) { struct device_node *np; @@ -573,6 +576,14 @@ bool __init xive_native_init(void) for_each_possible_cpu(cpu) kvmppc_set_xive_tima(cpu, r.start, tima); + /* Resource 2 is OS window */ + if (of_address_to_resource(np, 2, &r)) { + pr_err("Failed to get thread mgmnt area resource\n"); + return false; + } + + xive_tima_os = r.start; + /* Grab size of provisionning pages */ xive_parse_provisioning(np); |