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[Qemu-devel] [PATCH RFC v2 2/2] hw/pci: handle unassigned pci addresses
From: |
Marcel Apfelbaum |
Subject: |
[Qemu-devel] [PATCH RFC v2 2/2] hw/pci: handle unassigned pci addresses |
Date: |
Mon, 9 Sep 2013 14:11:54 +0300 |
Created a MemoryRegion with negative priority that
spans over all the pci address space.
It "intercepts" the accesses to unassigned pci
address space and will follow the pci spec:
1. returns -1 on read
2. does nothing on write
3. sets the RECEIVED MASTER ABORT bit in the STATUS register
of the device that initiated the transaction
Note: This implementation assumes that all the reads/writes to
the pci address space are done by the cpu.
Signed-off-by: Marcel Apfelbaum <address@hidden>
---
Changes from v1:
- "pci-unassigned-mem" MemoryRegion resides now in PCIBus and not on
various Host Bridges
- "pci-unassgined-mem" does not have a ".valid.accept" field and
implements read write methods
hw/pci/pci.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
include/hw/pci/pci_bus.h | 1 +
2 files changed, 47 insertions(+)
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index d00682e..b6a8026 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -283,6 +283,43 @@ const char *pci_root_bus_path(PCIDevice *dev)
return rootbus->qbus.name;
}
+static void unassigned_mem_access(PCIBus *bus)
+{
+ /* FIXME assumption: memory access to the pci address
+ * space is always initiated by the host bridge
+ * (device 0 on the bus) */
+ PCIDevice *d = bus->devices[0];
+ if (!d) {
+ return;
+ }
+
+ pci_word_test_and_set_mask(d->config + PCI_STATUS,
+ PCI_STATUS_REC_MASTER_ABORT);
+}
+
+static uint64_t unassigned_mem_read(void *opaque, hwaddr addr, unsigned size)
+{
+ PCIBus *bus = opaque;
+ unassigned_mem_access(bus);
+
+ return -1ULL;
+}
+
+static void unassigned_mem_write(void *opaque, hwaddr addr, uint64_t val,
+ unsigned size)
+{
+ PCIBus *bus = opaque;
+ unassigned_mem_access(bus);
+}
+
+static const MemoryRegionOps unassigned_mem_ops = {
+ .read = unassigned_mem_read,
+ .write = unassigned_mem_write,
+ .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+#define UNASSIGNED_MEM_PRIORITY -1
+
static void pci_bus_init(PCIBus *bus, DeviceState *parent,
const char *name,
MemoryRegion *address_space_mem,
@@ -294,6 +331,15 @@ static void pci_bus_init(PCIBus *bus, DeviceState *parent,
bus->address_space_mem = address_space_mem;
bus->address_space_io = address_space_io;
+
+ memory_region_init_io(&bus->unassigned_mem, OBJECT(bus),
+ &unassigned_mem_ops, bus, "pci-unassigned",
+ memory_region_size(bus->address_space_mem));
+ memory_region_add_subregion_overlap(bus->address_space_mem,
+ bus->address_space_mem->addr,
+ &bus->unassigned_mem,
+ UNASSIGNED_MEM_PRIORITY);
+
/* host bridge */
QLIST_INIT(&bus->child);
diff --git a/include/hw/pci/pci_bus.h b/include/hw/pci/pci_bus.h
index 9df1788..4cc25a3 100644
--- a/include/hw/pci/pci_bus.h
+++ b/include/hw/pci/pci_bus.h
@@ -23,6 +23,7 @@ struct PCIBus {
PCIDevice *parent_dev;
MemoryRegion *address_space_mem;
MemoryRegion *address_space_io;
+ MemoryRegion unassigned_mem;
QLIST_HEAD(, PCIBus) child; /* this will be replaced by qdev later */
QLIST_ENTRY(PCIBus) sibling;/* this will be replaced by qdev later */
--
1.8.3.1
- [Qemu-devel] [PATCH RFC v2 0/3] pci: complete master abort protocol, Marcel Apfelbaum, 2013/09/09
- [Qemu-devel] [PATCH RFC v2 1/2] memory: allow MemoryRegion's priority field to accept negative values, Marcel Apfelbaum, 2013/09/09
- [Qemu-devel] [PATCH RFC v2 2/2] hw/pci: handle unassigned pci addresses,
Marcel Apfelbaum <=
- Re: [Qemu-devel] [PATCH RFC v2 2/2] hw/pci: handle unassigned pci addresses, Michael S. Tsirkin, 2013/09/09
- Re: [Qemu-devel] [PATCH RFC v2 2/2] hw/pci: handle unassigned pci addresses, Marcel Apfelbaum, 2013/09/09
- Re: [Qemu-devel] [PATCH RFC v2 2/2] hw/pci: handle unassigned pci addresses, Michael S. Tsirkin, 2013/09/09
- Re: [Qemu-devel] [PATCH RFC v2 2/2] hw/pci: handle unassigned pci addresses, Marcel Apfelbaum, 2013/09/09
- Re: [Qemu-devel] [PATCH RFC v2 2/2] hw/pci: handle unassigned pci addresses, Peter Maydell, 2013/09/09
- Re: [Qemu-devel] [PATCH RFC v2 2/2] hw/pci: handle unassigned pci addresses, Michael S. Tsirkin, 2013/09/09
- Re: [Qemu-devel] [PATCH RFC v2 2/2] hw/pci: handle unassigned pci addresses, Peter Maydell, 2013/09/09
- Re: [Qemu-devel] [PATCH RFC v2 2/2] hw/pci: handle unassigned pci addresses, Marcel Apfelbaum, 2013/09/09
- Re: [Qemu-devel] [PATCH RFC v2 2/2] hw/pci: handle unassigned pci addresses, Peter Maydell, 2013/09/09
- Re: [Qemu-devel] [PATCH RFC v2 2/2] hw/pci: handle unassigned pci addresses, Marcel Apfelbaum, 2013/09/09