[PATCH 2/2] acpi/crs: Support ranges > 32b for hosts

[Ben Widawsky]

According to PCIe spec 5.0 Type 1 header space Base Address Registers
are defined by 7.5.1.2.1 Base Address Registers (same as Type 0). The
_CRS region should allow for the same range (up to 64b). Prior to this
change, any host bridge utilizing more than 32b for the BAR would have
the address truncated and likely lead to conflicts when the operating
systems reads the _CRS object.

Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>

---
I don't think this effects any code currently in QEMU. You'd need to
have a host bridge which has a BAR, and that BAR wants to be > 32b. I've
hit this because I have a modified PXB device that does advertise a 64b
BAR. Also, you'd need a platform that cares about ACPI, which, many do
not.
---
 hw/i386/acpi-build.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index df13abecf4..75604bdc74 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -789,8 +789,14 @@ static Aml *build_crs(PCIHostState *host, CrsRangeSet 
*range_set)
                 crs_range_insert(temp_range_set.io_ranges,
                                  range_base, range_limit);
             } else { /* "memory" */
-                crs_range_insert(temp_range_set.mem_ranges,
-                                 range_base, range_limit);
+                uint64_t length = range_limit - range_base + 1;
+                if (range_limit <= UINT32_MAX && length <= UINT32_MAX) {
+                    crs_range_insert(temp_range_set.mem_ranges, range_base,
+                                     range_limit);
+                } else {
+                    crs_range_insert(temp_range_set.mem_64bit_ranges,
+                                     range_base, range_limit);
+                }
             }
         }
 
-- 
2.29.1