[Qemu-devel] [PATCH] pcnet: Fix sign extension: make ipxe work with >2G RAM

[Alex Williamson <alex.williamson@redhat.com>]

From: Michael Brown <mcb30@ipxe.org>

The problem is with definitions in hw/pcnet.c such as:

  #define CSR_CRDA(S)      ((S)->csr[28] | ((S)->csr[29] << 16))

"(S)->csr[29]" is a uint16_t, but "(S)->csr[29] << 16" gets promoted to
int, so the overall CSR_CRDA(s) is a (signed) int rather than a uint32_t.

This then gets assigned to a uint64_t using

  target_phys_addr_t crda = CSR_CRDA(s);

so when (S)->csr[29] has the high bit set, we end up with
crda=0xffffffffxxxxxxxx.

From: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---

 hw/pcnet.c |   30 +++++++++++++++---------------
 1 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/hw/pcnet.c b/hw/pcnet.c
index 6dfdcc4..e961d14 100644
--- a/hw/pcnet.c
+++ b/hw/pcnet.c
@@ -113,23 +113,23 @@ struct qemu_ether_header {
 #define CSR_XMTRL(S)     ((S)->csr[78])
 #define CSR_MISSC(S)     ((S)->csr[112])
 
-#define CSR_IADR(S)      ((S)->csr[ 1] | ((S)->csr[ 2] << 16))
-#define CSR_CRBA(S)      ((S)->csr[18] | ((S)->csr[19] << 16))
-#define CSR_CXBA(S)      ((S)->csr[20] | ((S)->csr[21] << 16))
-#define CSR_NRBA(S)      ((S)->csr[22] | ((S)->csr[23] << 16))
-#define CSR_BADR(S)      ((S)->csr[24] | ((S)->csr[25] << 16))
-#define CSR_NRDA(S)      ((S)->csr[26] | ((S)->csr[27] << 16))
-#define CSR_CRDA(S)      ((S)->csr[28] | ((S)->csr[29] << 16))
-#define CSR_BADX(S)      ((S)->csr[30] | ((S)->csr[31] << 16))
-#define CSR_NXDA(S)      ((S)->csr[32] | ((S)->csr[33] << 16))
-#define CSR_CXDA(S)      ((S)->csr[34] | ((S)->csr[35] << 16))
-#define CSR_NNRD(S)      ((S)->csr[36] | ((S)->csr[37] << 16))
-#define CSR_NNXD(S)      ((S)->csr[38] | ((S)->csr[39] << 16))
-#define CSR_PXDA(S)      ((S)->csr[60] | ((S)->csr[61] << 16))
-#define CSR_NXBA(S)      ((S)->csr[64] | ((S)->csr[65] << 16))
+#define CSR_IADR(S)      ((S)->csr[ 1] | ((uint32_t)(S)->csr[ 2] << 16))
+#define CSR_CRBA(S)      ((S)->csr[18] | ((uint32_t)(S)->csr[19] << 16))
+#define CSR_CXBA(S)      ((S)->csr[20] | ((uint32_t)(S)->csr[21] << 16))
+#define CSR_NRBA(S)      ((S)->csr[22] | ((uint32_t)(S)->csr[23] << 16))
+#define CSR_BADR(S)      ((S)->csr[24] | ((uint32_t)(S)->csr[25] << 16))
+#define CSR_NRDA(S)      ((S)->csr[26] | ((uint32_t)(S)->csr[27] << 16))
+#define CSR_CRDA(S)      ((S)->csr[28] | ((uint32_t)(S)->csr[29] << 16))
+#define CSR_BADX(S)      ((S)->csr[30] | ((uint32_t)(S)->csr[31] << 16))
+#define CSR_NXDA(S)      ((S)->csr[32] | ((uint32_t)(S)->csr[33] << 16))
+#define CSR_CXDA(S)      ((S)->csr[34] | ((uint32_t)(S)->csr[35] << 16))
+#define CSR_NNRD(S)      ((S)->csr[36] | ((uint32_t)(S)->csr[37] << 16))
+#define CSR_NNXD(S)      ((S)->csr[38] | ((uint32_t)(S)->csr[39] << 16))
+#define CSR_PXDA(S)      ((S)->csr[60] | ((uint32_t)(S)->csr[61] << 16))
+#define CSR_NXBA(S)      ((S)->csr[64] | ((uint32_t)(S)->csr[65] << 16))
 
 #define PHYSADDR(S,A) \
-  (BCR_SSIZE32(S) ? (A) : (A) | ((0xff00 & (uint32_t)(s)->csr[2])<<16))
+  (BCR_SSIZE32(S) ? (A) : (A) | ((0xff00 & (uint32_t)(S)->csr[2])<<16))
 
 struct pcnet_initblk16 {
     uint16_t mode;