3 files changed, 65 insertions, 0 deletions

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);