diff options
| -rw-r--r-- | Documentation/virtual/kvm/devices/xive.txt | 19 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_xive.c | 15 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_xive.h | 9 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_xive_native.c | 41 |
4 files changed, 84 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/devices/xive.txt b/Documentation/virtual/kvm/devices/xive.txt index 69ee62d3d4dc..9a24a4525253 100644 --- a/Documentation/virtual/kvm/devices/xive.txt +++ b/Documentation/virtual/kvm/devices/xive.txt @@ -43,6 +43,25 @@ the legacy interrupt mode, referred as XICS (POWER7/8). manage the source: to trigger, to EOI, to turn off the source for instance. + 3. Device pass-through + + When a device is passed-through into the guest, the source + interrupts are from a different HW controller (PHB4) and the ESB + pages exposed to the guest should accommadate this change. + + The passthru_irq helpers, kvmppc_xive_set_mapped() and + kvmppc_xive_clr_mapped() are called when the device HW irqs are + mapped into or unmapped from the guest IRQ number space. The KVM + device extends these helpers to clear the ESB pages of the guest IRQ + number being mapped and then lets the VM fault handler repopulate. + The handler will insert the ESB page corresponding to the HW + interrupt of the device being passed-through or the initial IPI ESB + page if the device has being removed. + + The ESB remapping is fully transparent to the guest and the OS + device driver. All handling is done within VFIO and the above + helpers in KVM-PPC. + * Groups: 1. KVM_DEV_XIVE_GRP_CTRL diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c index c1b7aa7dbc28..480a3fc6b9fd 100644 --- a/arch/powerpc/kvm/book3s_xive.c +++ b/arch/powerpc/kvm/book3s_xive.c @@ -937,6 +937,13 @@ int kvmppc_xive_set_mapped(struct kvm *kvm, unsigned long guest_irq, /* Turn the IPI hard off */ xive_vm_esb_load(&state->ipi_data, XIVE_ESB_SET_PQ_01); + /* + * Reset ESB guest mapping. Needed when ESB pages are exposed + * to the guest in XIVE native mode + */ + if (xive->ops && xive->ops->reset_mapped) + xive->ops->reset_mapped(kvm, guest_irq); + /* Grab info about irq */ state->pt_number = hw_irq; state->pt_data = irq_data_get_irq_handler_data(host_data); @@ -1022,6 +1029,14 @@ int kvmppc_xive_clr_mapped(struct kvm *kvm, unsigned long guest_irq, state->pt_number = 0; state->pt_data = NULL; + /* + * Reset ESB guest mapping. Needed when ESB pages are exposed + * to the guest in XIVE native mode + */ + if (xive->ops && xive->ops->reset_mapped) { + xive->ops->reset_mapped(kvm, guest_irq); + } + /* Reconfigure the IPI */ xive_native_configure_irq(state->ipi_number, kvmppc_xive_vp(xive, state->act_server), diff --git a/arch/powerpc/kvm/book3s_xive.h b/arch/powerpc/kvm/book3s_xive.h index 622f594d93e1..e011622dc038 100644 --- a/arch/powerpc/kvm/book3s_xive.h +++ b/arch/powerpc/kvm/book3s_xive.h @@ -94,6 +94,11 @@ struct kvmppc_xive_src_block { struct kvmppc_xive_irq_state irq_state[KVMPPC_XICS_IRQ_PER_ICS]; }; +struct kvmppc_xive; + +struct kvmppc_xive_ops { + int (*reset_mapped)(struct kvm *kvm, unsigned long guest_irq); +}; struct kvmppc_xive { struct kvm *kvm; @@ -132,6 +137,10 @@ struct kvmppc_xive { /* Flags */ u8 single_escalation; + + struct kvmppc_xive_ops *ops; + struct address_space *mapping; + struct mutex mapping_lock; }; #define KVMPPC_XIVE_Q_COUNT 8 diff --git a/arch/powerpc/kvm/book3s_xive_native.c b/arch/powerpc/kvm/book3s_xive_native.c index 465eb90ff23e..62648f833adf 100644 --- a/arch/powerpc/kvm/book3s_xive_native.c +++ b/arch/powerpc/kvm/book3s_xive_native.c @@ -11,6 +11,7 @@ #include <linux/gfp.h> #include <linux/spinlock.h> #include <linux/delay.h> +#include <linux/file.h> #include <asm/uaccess.h> #include <asm/kvm_book3s.h> #include <asm/kvm_ppc.h> @@ -165,6 +166,35 @@ bail: return rc; } +/* + * Device passthrough support + */ +static int kvmppc_xive_native_reset_mapped(struct kvm *kvm, unsigned long irq) +{ + struct kvmppc_xive *xive = kvm->arch.xive; + + if (irq >= KVMPPC_XIVE_NR_IRQS) + return -EINVAL; + + /* + * Clear the ESB pages of the IRQ number being mapped (or + * unmapped) into the guest and let the the VM fault handler + * repopulate with the appropriate ESB pages (device or IC) + */ + pr_debug("clearing esb pages for girq 0x%lx\n", irq); + mutex_lock(&xive->mapping_lock); + if (xive->mapping) + unmap_mapping_range(xive->mapping, + irq * (2ull << PAGE_SHIFT), + 2ull << PAGE_SHIFT, 1); + mutex_unlock(&xive->mapping_lock); + return 0; +} + +static struct kvmppc_xive_ops kvmppc_xive_native_ops = { + .reset_mapped = kvmppc_xive_native_reset_mapped, +}; + static vm_fault_t xive_native_esb_fault(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; @@ -242,6 +272,8 @@ static const struct vm_operations_struct xive_native_tima_vmops = { static int kvmppc_xive_native_mmap(struct kvm_device *dev, struct vm_area_struct *vma) { + struct kvmppc_xive *xive = dev->private; + /* We only allow mappings at fixed offset for now */ if (vma->vm_pgoff == KVM_XIVE_TIMA_PAGE_OFFSET) { if (vma_pages(vma) > 4) @@ -257,6 +289,13 @@ static int kvmppc_xive_native_mmap(struct kvm_device *dev, vma->vm_flags |= VM_IO | VM_PFNMAP; vma->vm_page_prot = pgprot_noncached_wc(vma->vm_page_prot); + + /* + * Grab the KVM device file address_space to be able to clear + * the ESB pages mapping when a device is passed-through into + * the guest. + */ + xive->mapping = vma->vm_file->f_mapping; return 0; } @@ -971,6 +1010,7 @@ static int kvmppc_xive_native_create(struct kvm_device *dev, u32 type) xive->dev = dev; xive->kvm = kvm; kvm->arch.xive = xive; + mutex_init(&xive->mapping_lock); /* * Allocate a bunch of VPs. KVM_MAX_VCPUS is a large value for @@ -984,6 +1024,7 @@ static int kvmppc_xive_native_create(struct kvm_device *dev, u32 type) ret = -ENXIO; xive->single_escalation = xive_native_has_single_escalation(); + xive->ops = &kvmppc_xive_native_ops; if (ret) kfree(xive); |