[PATCH-for-10.0,3/8] hw/pci-host/gpex: Allow machines to set PCI_BUS_IO_ADDR0_ALLOWED flag

Commit Message

Philippe Mathieu-Daudé Nov. 25, 2024, 2:05 p.m. UTC

Expose the "allow-io-addr0-accesses" property so machines
using a GPEX host bridge can set this flag on the bus.

Signed-off-by: Philippe Mathieu-Daudé <[e-mail]>
---
 include/hw/pci-host/gpex.h | 1 +
 hw/pci-host/gpex.c         | 6 ++++++
 2 files changed, 7 insertions(+)

Comments

Peter Maydell Nov. 25, 2024, 2:34 p.m. UTC | #1

On Mon, 25 Nov 2024 at 14:06, Philippe Mathieu-Daudé <[e-mail]> wrote:
>
> Expose the "allow-io-addr0-accesses" property so machines
> using a GPEX host bridge can set this flag on the bus.
>
> Signed-off-by: Philippe Mathieu-Daudé <[e-mail]>
> ---
>  include/hw/pci-host/gpex.h | 1 +
>  hw/pci-host/gpex.c         | 6 ++++++
>  2 files changed, 7 insertions(+)

Given the way the gpex controller handles its MMIO regions,
I rather suspect that none of its users really need to set
"no address 0 accesses", though of course this is a behaviour
change for some machines so would need testing.

-- PMM

Patch

diff --git a/include/hw/pci-host/gpex.h b/include/hw/pci-host/gpex.h
index dce883573b..8c990bff5f 100644
--- a/include/hw/pci-host/gpex.h
+++ b/include/hw/pci-host/gpex.h
@@ -64,6 +64,7 @@  struct GPEXHost {
     int irq_num[GPEX_NUM_IRQS];
 
     bool allow_unmapped_accesses;
+    bool allow_io_addr0_accesses;
 
     struct GPEXConfig gpex_cfg;
 };
diff --git a/hw/pci-host/gpex.c b/hw/pci-host/gpex.c
index e9cf455bf5..635467016f 100644
--- a/hw/pci-host/gpex.c
+++ b/hw/pci-host/gpex.c
@@ -32,6 +32,7 @@ 
 #include "qemu/osdep.h"
 #include "qapi/error.h"
 #include "hw/irq.h"
+#include "hw/pci/pci_bus.h"
 #include "hw/pci-host/gpex.h"
 #include "hw/qdev-properties.h"
 #include "migration/vmstate.h"
@@ -136,6 +137,9 @@  static void gpex_host_realize(DeviceState *dev, Error **errp)
     pci->bus = pci_register_root_bus(dev, "pcie.0", gpex_set_irq,
                                      pci_swizzle_map_irq_fn, s, &s->io_mmio,
                                      &s->io_ioport, 0, 4, TYPE_PCIE_BUS);
+    if (s->allow_io_addr0_accesses) {
+        pci->bus->flags |= PCI_BUS_IO_ADDR0_ALLOWED;
+    }
 
     pci_bus_set_route_irq_fn(pci->bus, gpex_route_intx_pin_to_irq);
     qdev_realize(DEVICE(&s->gpex_root), BUS(pci->bus), &error_fatal);
@@ -154,6 +158,8 @@  static Property gpex_host_properties[] = {
      */
     DEFINE_PROP_BOOL("allow-unmapped-accesses", GPEXHost,
                      allow_unmapped_accesses, true),
+    DEFINE_PROP_BOOL("allow-io-addr0-accesses", GPEXHost,
+                     allow_io_addr0_accesses, false),
     DEFINE_PROP_UINT64(PCI_HOST_ECAM_BASE, GPEXHost, gpex_cfg.ecam.base, 0),
     DEFINE_PROP_SIZE(PCI_HOST_ECAM_SIZE, GPEXHost, gpex_cfg.ecam.size, 0),
     DEFINE_PROP_UINT64(PCI_HOST_PIO_BASE, GPEXHost, gpex_cfg.pio.base, 0),