On 29/07/2017 2:34, Aleksandr Bezzubikov wrote:
On PCI init PCI bridge devices may need some
extra info about bus number to reserve, IO, memory and
prefetchable memory limits. QEMU can provide this
with special vendor-specific PCI capability.
This capability is intended to be used only
for Red Hat PCI bridges, i.e. QEMU cooperation.
Signed-off-by: Aleksandr Bezzubikov <zuban...@gmail.com>
---
src/fw/dev-pci.h | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 62 insertions(+)
create mode 100644 src/fw/dev-pci.h
diff --git a/src/fw/dev-pci.h b/src/fw/dev-pci.h
new file mode 100644
index 0000000..fbd49ed
--- /dev/null
+++ b/src/fw/dev-pci.h
@@ -0,0 +1,62 @@
+#ifndef _PCI_CAP_H
+#define _PCI_CAP_H
+
+#include "types.h"
+
+/*
+
Hi Aleksander,
+QEMU-specific vendor(Red Hat)-specific capability.
+It's intended to provide some hints for firmware to init PCI devices.
+
+Its is shown below:
+
+Header:
+
+u8 id; Standard PCI Capability Header field
+u8 next; Standard PCI Capability Header field
+u8 len; Standard PCI Capability Header field
+u8 type; Red Hat vendor-specific capability type:
+ now only REDHAT_QEMU_CAP 1 exists
+Data:
+
+u16 non_prefetchable_16; non-prefetchable memory limit
+
Maybe we should name it "mem". And if I remember right Gerd
suggested keeping them all 32 bits:
u32 mem_res
+u8 bus_res; minimum bus number to reserve;
+ this is necessary for PCI Express Root Ports
+ to support PCIE-to-PCI bridge hotplug
+
+u8 io_8; IO limit in case of 8-bit limit value
I must have missed it, but why do we need io_8 field?
+u32 io_32; IO limit in case of 16-bit limit value
+ io_8 and io_16 are mutually exclusive, in other words,
+ they can't be non-zero simultaneously
I don't see any io_16 field.
Maybe only one field:
u32 io_res
+
+u32 prefetchable_32; non-prefetchable memory limit
+ in case of 32-bit limit value
Name and comment mismatch
+u64 prefetchable_64; non-prefetchable memory limit
+ in case of 64-bit limit value
+ prefetachable_32 and prefetchable_64 are
+ mutually exclusive, in other words,
+ they can't be non-zero simultaneously
Name and comment mismatch
It should look like:
- u32 bus_res
- u32 io_res
- u32 mem_res,
- u32 mem_prefetchable_32,
- u64 mem_prefetchable_64, (mutually exclusive with the above)
Does it look right to all?
+If any field in Data section is 0,
+it means that such kind of reservation
+is not needed.
+
+*/
+
+/* Offset of vendor-specific capability type field */
+#define PCI_CAP_VNDR_SPEC_TYPE 3
+
+/* List of valid Red Hat vendor-specific capability types */
+#define REDHAT_CAP_TYPE_QEMU 1
Maybe we should be more concrete:
REDHAT_CAP_TYPE_RES_RESERVE
+
+
+/* Offsets of QEMU capability fields */
+#define QEMU_PCI_CAP_NON_PREF 4
+#define QEMU_PCI_CAP_BUS_RES 6
+#define QEMU_PCI_CAP_IO_8 7
+#define QEMU_PCI_CAP_IO_32 8
+#define QEMU_PCI_CAP_PREF_32 12
+#define QEMU_PCI_CAP_PREF_64 16
+#define QEMU_PCI_CAP_SIZE 24
+
+#endif /* _PCI_CAP_H */
I know the exact layout is less important for your current
project, but is important to get it right the first time.
Thanks,
Marcel