pci: allow 0 address for PCI IO/MEM regions

Some kernels program a 0 address for io regions. PCI 3.0 spec
section 6.2.5.1 doesn't seem to disallow this.

based on patch by Michael Roth <mdroth@linux.vnet.ibm.com>

Add pci_allow_0_addr in MachineClass to conditionally
allow addr 0 for pseries, as this can break other architectures.

This patch allows to hotplug PCI card in pseries machine, as the first
added card BAR0 is always set to 0 address.

This as a temporary hack, waiting to fix PCI memory priorities for more
machine types...

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Laurent Vivier 2015-07-24 10:35:13 +02:00 committed by Michael S. Tsirkin
parent c8d163bc9e
commit e402463073
3 changed files with 12 additions and 4 deletions

View File

@ -38,6 +38,7 @@
#include "hw/pci/msix.h" #include "hw/pci/msix.h"
#include "exec/address-spaces.h" #include "exec/address-spaces.h"
#include "hw/hotplug.h" #include "hw/hotplug.h"
#include "hw/boards.h"
//#define DEBUG_PCI //#define DEBUG_PCI
#ifdef DEBUG_PCI #ifdef DEBUG_PCI
@ -1065,6 +1066,10 @@ static pcibus_t pci_bar_address(PCIDevice *d,
pcibus_t new_addr, last_addr; pcibus_t new_addr, last_addr;
int bar = pci_bar(d, reg); int bar = pci_bar(d, reg);
uint16_t cmd = pci_get_word(d->config + PCI_COMMAND); uint16_t cmd = pci_get_word(d->config + PCI_COMMAND);
Object *machine = qdev_get_machine();
ObjectClass *oc = object_get_class(machine);
MachineClass *mc = MACHINE_CLASS(oc);
bool allow_0_address = mc->pci_allow_0_address;
if (type & PCI_BASE_ADDRESS_SPACE_IO) { if (type & PCI_BASE_ADDRESS_SPACE_IO) {
if (!(cmd & PCI_COMMAND_IO)) { if (!(cmd & PCI_COMMAND_IO)) {
@ -1075,7 +1080,8 @@ static pcibus_t pci_bar_address(PCIDevice *d,
/* Check if 32 bit BAR wraps around explicitly. /* Check if 32 bit BAR wraps around explicitly.
* TODO: make priorities correct and remove this work around. * TODO: make priorities correct and remove this work around.
*/ */
if (last_addr <= new_addr || new_addr == 0 || last_addr >= UINT32_MAX) { if (last_addr <= new_addr || last_addr >= UINT32_MAX ||
(!allow_0_address && new_addr == 0)) {
return PCI_BAR_UNMAPPED; return PCI_BAR_UNMAPPED;
} }
return new_addr; return new_addr;
@ -1099,8 +1105,8 @@ static pcibus_t pci_bar_address(PCIDevice *d,
/* XXX: as we cannot support really dynamic /* XXX: as we cannot support really dynamic
mappings, we handle specific values as invalid mappings, we handle specific values as invalid
mappings. */ mappings. */
if (last_addr <= new_addr || new_addr == 0 || if (last_addr <= new_addr || last_addr == PCI_BAR_UNMAPPED ||
last_addr == PCI_BAR_UNMAPPED) { (!allow_0_address && new_addr == 0)) {
return PCI_BAR_UNMAPPED; return PCI_BAR_UNMAPPED;
} }

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@ -1835,6 +1835,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
mc->default_ram_size = 512 * M_BYTE; mc->default_ram_size = 512 * M_BYTE;
mc->kvm_type = spapr_kvm_type; mc->kvm_type = spapr_kvm_type;
mc->has_dynamic_sysbus = true; mc->has_dynamic_sysbus = true;
mc->pci_allow_0_address = true;
fwc->get_dev_path = spapr_get_fw_dev_path; fwc->get_dev_path = spapr_get_fw_dev_path;
nc->nmi_monitor_handler = spapr_nmi; nc->nmi_monitor_handler = spapr_nmi;

View File

@ -100,7 +100,8 @@ struct MachineClass {
no_cdrom:1, no_cdrom:1,
no_sdcard:1, no_sdcard:1,
has_dynamic_sysbus:1, has_dynamic_sysbus:1,
no_tco:1; no_tco:1,
pci_allow_0_address:1;
int is_default; int is_default;
const char *default_machine_opts; const char *default_machine_opts;
const char *default_boot_order; const char *default_boot_order;