[Qemu-devel] [PULL V4 05/31] pci: fix unaligned access in pci_xxx_quad()

[Jason Wang <jasowang@redhat.com>]

From: Dmitry Fleytman <dmitry.fleytman@ravellosystems.com>

Replace legacy cpu_to_le64w()/le64_to_cpup()
calls with stq_le_p()/ldq_le_p().

Motivation for this modification is that
follow up patches add utility function
pcie_dev_ser_num_init() for PCIe DSN
capability creation which uses
pci_set_quad() with a misaligned offset.

Signed-off-by: Dmitry Fleytman <dmitry.fleytman@ravellosystems.com>
Signed-off-by: Leonid Bloch <leonid.bloch@ravellosystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 include/hw/pci/pci.h | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index ef6ba51..4420f47 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -465,16 +465,23 @@ pci_get_long(const uint8_t *config)
     return ldl_le_p(config);
 }
 
+/*
+ * PCI capabilities and/or their fields
+ * are generally DWORD aligned only so
+ * mechanism used by pci_set/get_quad()
+ * must be tolerant to unaligned pointers
+ *
+ */
 static inline void
 pci_set_quad(uint8_t *config, uint64_t val)
 {
-    cpu_to_le64w((uint64_t *)config, val);
+    stq_le_p(config, val);
 }
 
 static inline uint64_t
 pci_get_quad(const uint8_t *config)
 {
-    return le64_to_cpup((const uint64_t *)config);
+    return ldq_le_p(config);
 }
 
 static inline void
-- 
2.7.4