[PATCH 1/6] KVM: PPC: Book3S HV: XIVE: initialize private pointer when VPs are allocated

[Greg Kurz]

From: Cédric Le Goater <c...@kaod.org>

Do not assign the device private pointer before making sure the XIVE
VPs are allocated in OPAL and test pointer validity when releasing
the device.

Fixes: 5422e95103cf ("KVM: PPC: Book3S HV: XIVE: Replace the 'destroy' method 
by a 'release' method")
Signed-off-by: Cédric Le Goater <c...@kaod.org>
Signed-off-by: Greg Kurz <gr...@kaod.org>
---
 arch/powerpc/kvm/book3s_xive.c        |   13 +++++++++++--
 arch/powerpc/kvm/book3s_xive_native.c |   13 +++++++++++--
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c
index 591bfb4bfd0f..cd2006bfcd3e 100644
--- a/arch/powerpc/kvm/book3s_xive.c
+++ b/arch/powerpc/kvm/book3s_xive.c
@@ -1897,12 +1897,21 @@ void kvmppc_xive_free_sources(struct 
kvmppc_xive_src_block *sb)
 static void kvmppc_xive_release(struct kvm_device *dev)
 {
        struct kvmppc_xive *xive = dev->private;
-       struct kvm *kvm = xive->kvm;
+       struct kvm *kvm;
        struct kvm_vcpu *vcpu;
        int i;
 
        pr_devel("Releasing xive device\n");
 
+       /*
+        * In case of failure (OPAL) at device creation, the device
+        * can be partially initialized.
+        */
+       if (!xive)
+               return;
+
+       kvm = xive->kvm;
+
        /*
         * Since this is the device release function, we know that
         * userspace does not have any open fd referring to the
@@ -2001,7 +2010,6 @@ static int kvmppc_xive_create(struct kvm_device *dev, u32 
type)
        if (!xive)
                return -ENOMEM;
 
-       dev->private = xive;
        xive->dev = dev;
        xive->kvm = kvm;
        mutex_init(&xive->lock);
@@ -2031,6 +2039,7 @@ static int kvmppc_xive_create(struct kvm_device *dev, u32 
type)
        if (ret)
                return ret;
 
+       dev->private = xive;
        return 0;
 }
 
diff --git a/arch/powerpc/kvm/book3s_xive_native.c 
b/arch/powerpc/kvm/book3s_xive_native.c
index 248c1ea9e788..e9cbb42de424 100644
--- a/arch/powerpc/kvm/book3s_xive_native.c
+++ b/arch/powerpc/kvm/book3s_xive_native.c
@@ -987,12 +987,21 @@ static int kvmppc_xive_native_has_attr(struct kvm_device 
*dev,
 static void kvmppc_xive_native_release(struct kvm_device *dev)
 {
        struct kvmppc_xive *xive = dev->private;
-       struct kvm *kvm = xive->kvm;
+       struct kvm *kvm;
        struct kvm_vcpu *vcpu;
        int i;
 
        pr_devel("Releasing xive native device\n");
 
+       /*
+        * In case of failure (OPAL) at device creation, the device
+        * can be partially initialized.
+        */
+       if (!xive)
+               return;
+
+       kvm = xive->kvm;
+
        /*
         * Clear the KVM device file address_space which is used to
         * unmap the ESB pages when a device is passed-through.
@@ -1076,7 +1085,6 @@ static int kvmppc_xive_native_create(struct kvm_device 
*dev, u32 type)
        if (!xive)
                return -ENOMEM;
 
-       dev->private = xive;
        xive->dev = dev;
        xive->kvm = kvm;
        kvm->arch.xive = xive;
@@ -1100,6 +1108,7 @@ static int kvmppc_xive_native_create(struct kvm_device 
*dev, u32 type)
        if (ret)
                return ret;
 
+       dev->private = xive;
        return 0;
 }