[PATCH v5 01/10] KVM: arm/arm64: vgic-its: Fix return value for device table restore

Eric Auger
2017-10-23T14:07:34Z

From: wanghaibin <wanghaibin.wang@huawei.com>

If ITT only contains invalid entries, vgic_its_restore_itt
returns 1 and this is considered as an an error in
vgic_its_restore_dte.

Also in case the device table only contains invalid entries,
the table restore fails and this is not correct.

This patch fixes those 2 issues:
- vgic_its_restore_itt now returns <= 0 values. If all
ITEs are invalid, this is considered as successful.
- vgic_its_restore_device_tables also returns <= 0 values.

We also simplify the returned value computation in
handle_l1_dte.

Signed-off-by: wanghaibin <wanghaibin.wang@huawei.com>
Signed-off-by: Eric Auger <eric.auger@redhat.com>

---

need to CC'ed stable

v2 -> v3:
- add comments
- vgic_its_restore_itt don't return +1 anymore
- reword the commit message

v1 -> v2:
- if (ret > 0) ret = 0
---
virt/kvm/arm/vgic/vgic-its.c | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index f51c1e1..d27a301 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -1940,6 +1940,14 @@ static int vgic_its_save_itt(struct vgic_its *its, struct its_device *device)
return 0;
}

+/**
+ * vgic_its_restore_itt - restore the ITT of a device
+ *
+ * @its: its handle
+ * @dev: device handle
+ *
+ * Return 0 on success, < 0 on error
+ */
static int vgic_its_restore_itt(struct vgic_its *its, struct its_device *dev)
{
const struct vgic_its_abi *abi = vgic_its_get_abi(its);
@@ -1951,6 +1959,10 @@ static int vgic_its_restore_itt(struct vgic_its *its, struct its_device *dev)
ret = scan_its_table(its, base, max_size, ite_esz, 0,
vgic_its_restore_ite, dev);

+ /* scan_its_table returns +1 if all ITEs are invalid */
+ if (ret > 0)
+ ret = 0;
+
return ret;
}

@@ -2107,10 +2119,7 @@ static int handle_l1_dte(struct vgic_its *its, u32 id, void *addr,
ret = scan_its_table(its, gpa, SZ_64K, dte_esz,
l2_start_id, vgic_its_restore_dte, NULL);

- if (ret <= 0)
- return ret;
-
- return 1;
+ return ret;
}

/**
@@ -2140,8 +2149,9 @@ static int vgic_its_restore_device_tables(struct vgic_its *its)
vgic_its_restore_dte, NULL);
}

+ /* scan_its_table returns +1 if all entries are invalid */
if (ret > 0)
- ret = -EINVAL;
+ ret = 0;

return ret;
}
--
2.5.5