[PATCH 1/3] KVM: PPC: Book3S HV: XIVE: clear file mapping when device is released

["Cédric Le Goater" <clg@kaod.org>]

Improve the release of the XIVE KVM device by clearing the file
address_space which is used to unmap the interrupt ESB pages when a
device is passed-through.

Suggested-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
 arch/powerpc/kvm/book3s_xive_native.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/powerpc/kvm/book3s_xive_native.c b/arch/powerpc/kvm/book3s_xive_native.c
index 6a8e698c4b6e..796d86549cfe 100644
--- a/arch/powerpc/kvm/book3s_xive_native.c
+++ b/arch/powerpc/kvm/book3s_xive_native.c
@@ -979,6 +979,14 @@ static void kvmppc_xive_native_release(struct kvm_device *dev)
 
 	pr_devel("Releasing xive native device\n");
 
+	/*
+	 * Clear the KVM device file address_space which is used to
+	 * unmap the ESB pages when a device is passed-through.
+	 */
+	mutex_lock(&xive->mapping_lock);
+	xive->mapping = NULL;
+	mutex_unlock(&xive->mapping_lock);
+
 	/*
 	 * Clearing mmu_ready temporarily while holding kvm->lock
 	 * is a way of ensuring that no vcpus can enter the guest
-- 
2.20.1