This will let the guest create a memory mapping to expose the ESB MMIO
regions used to control the interrupt sources, to trigger events, to
EOI or to turn off the sources.
Signed-off-by: Cédric Le Goater <clg@xxxxxxxx>
---
arch/powerpc/include/uapi/asm/kvm.h | 4 ++
arch/powerpc/kvm/book3s_xive_native.c | 97 +++++++++++++++++++++++++++
2 files changed, 101 insertions(+)
diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h
index 8c876c166ef2..6bb61ba141c2 100644
--- a/arch/powerpc/include/uapi/asm/kvm.h
+++ b/arch/powerpc/include/uapi/asm/kvm.h
@@ -675,4 +675,8 @@ struct kvm_ppc_cpu_char {
#define KVM_XICS_PRESENTED (1ULL << 43)
#define KVM_XICS_QUEUED (1ULL << 44)
+/* POWER9 XIVE Native Interrupt Controller */
+#define KVM_DEV_XIVE_GRP_CTRL 1
+#define KVM_DEV_XIVE_GET_ESB_FD 1
+
#endif /* __LINUX_KVM_POWERPC_H */
diff --git a/arch/powerpc/kvm/book3s_xive_native.c b/arch/powerpc/kvm/book3s_xive_native.c
index 115143e76c45..e20081f0c8d4 100644
--- a/arch/powerpc/kvm/book3s_xive_native.c
+++ b/arch/powerpc/kvm/book3s_xive_native.c
@@ -153,6 +153,85 @@ int kvmppc_xive_native_connect_vcpu(struct kvm_device *dev,
return rc;
}
+static int xive_native_esb_fault(struct vm_fault *vmf)
+{
+ struct vm_area_struct *vma = vmf->vma;
+ struct kvmppc_xive *xive = vma->vm_file->private_data;
+ struct kvmppc_xive_src_block *sb;
+ struct kvmppc_xive_irq_state *state;
+ struct xive_irq_data *xd;
+ u32 hw_num;
+ u16 src;
+ u64 page;
+ unsigned long irq;
+
+ /*
+ * Linux/KVM uses a two pages ESB setting, one for trigger and
+ * one for EOI
+ */
+ irq = vmf->pgoff / 2;
+
+ sb = kvmppc_xive_find_source(xive, irq, &src);
+ if (!sb) {
+ pr_err("%s: source %lx not found !\n", __func__, irq);
+ return VM_FAULT_SIGBUS;
+ }
+
+ state = &sb->irq_state[src];
+ kvmppc_xive_select_irq(state, &hw_num, &xd);
+
+ arch_spin_lock(&sb->lock);
+
+ /*
+ * first/even page is for trigger
+ * second/odd page is for EOI and management.
+ */
+ page = vmf->pgoff % 2 ? xd->eoi_page : xd->trig_page;
+ arch_spin_unlock(&sb->lock);
+
+ if (!page) {
+ pr_err("%s: acessing invalid ESB page for source %lx !\n",
+ __func__, irq);
+ return VM_FAULT_SIGBUS;
+ }
+
+ vmf_insert_pfn(vma, vmf->address, page >> PAGE_SHIFT);
+ return VM_FAULT_NOPAGE;
+}
+
+static const struct vm_operations_struct xive_native_esb_vmops = {
+ .fault = xive_native_esb_fault,
+};
+
+static int xive_native_esb_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ /* There are two ESB pages (trigger and EOI) per IRQ */
+ if (vma_pages(vma) + vma->vm_pgoff > KVMPPC_XIVE_NR_IRQS * 2)
+ return -EINVAL;
+
+ vma->vm_flags |= VM_IO | VM_PFNMAP;
+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+ vma->vm_ops = &xive_native_esb_vmops;
+ return 0;
+}
+
+static const struct file_operations xive_native_esb_fops = {
+ .mmap = xive_native_esb_mmap,
+};
+
+static int kvmppc_xive_native_get_esb_fd(struct kvmppc_xive *xive, u64 addr)
+{
+ u64 __user *ubufp = (u64 __user *) addr;
+ int ret;
+
+ ret = anon_inode_getfd("[xive-esb]", &xive_native_esb_fops, xive,
+ O_RDWR | O_CLOEXEC);
+ if (ret < 0)
+ return ret;
+
+ return put_user(ret, ubufp);
+}
+
static int kvmppc_xive_native_set_attr(struct kvm_device *dev,
struct kvm_device_attr *attr)
{
@@ -162,12 +241,30 @@ static int kvmppc_xive_native_set_attr(struct kvm_device *dev,
static int kvmppc_xive_native_get_attr(struct kvm_device *dev,
struct kvm_device_attr *attr)
{
+ struct kvmppc_xive *xive = dev->private;
+
+ switch (attr->group) {
+ case KVM_DEV_XIVE_GRP_CTRL:
+ switch (attr->attr) {
+ case KVM_DEV_XIVE_GET_ESB_FD:
+ return kvmppc_xive_native_get_esb_fd(xive, attr->addr);
+ }
+ break;
+ }
return -ENXIO;
}
static int kvmppc_xive_native_has_attr(struct kvm_device *dev,
struct kvm_device_attr *attr)
{
+ switch (attr->group) {
+ case KVM_DEV_XIVE_GRP_CTRL:
+ switch (attr->attr) {
+ case KVM_DEV_XIVE_GET_ESB_FD:
+ return 0;
+ }
+ break;
+ }
return -ENXIO;
}
--
2.20.1
