Merge tag 'pull-xen-20230306' of https://xenbits.xen.org/git-http/people/aperard/qemu-dm into staging

Xen queue:

- fix for graphic passthrough with 'xenfv' machine
- fix uninitialized variable

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# gpg: Signature made Mon 06 Mar 2023 14:00:24 GMT
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# gpg: Good signature from "Anthony PERARD <anthony.perard@gmail.com>" [marginal]
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* tag 'pull-xen-20230306' of https://xenbits.xen.org/git-http/people/aperard/qemu-dm:
  hw/xen/xen_pt: fix uninitialized variable
  xen/pt: reserve PCI slot 2 for Intel igd-passthru

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

5 files changed, 79 insertions, 12 deletions

diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 2f16011..4bf15f9 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -422,6 +422,7 @@ static void pc_xen_hvm_init(MachineState *machine)
     }
 
     pc_xen_hvm_init_pci(machine);
+    xen_igd_reserve_slot(pcms->bus);
     pci_create_simple(pcms->bus, -1, "xen-platform");
 }
 #endif
diff --git a/hw/xen/xen_pt.c b/hw/xen/xen_pt.c
index 8db0532..85c93cf 100644
--- a/hw/xen/xen_pt.c
+++ b/hw/xen/xen_pt.c
@@ -57,6 +57,7 @@
 #include <sys/ioctl.h>
 
 #include "hw/pci/pci.h"
+#include "hw/pci/pci_bus.h"
 #include "hw/qdev-properties.h"
 #include "hw/qdev-properties-system.h"
 #include "hw/xen/xen.h"
@@ -780,15 +781,6 @@ static void xen_pt_realize(PCIDevice *d, Error **errp)
                s->hostaddr.bus, s->hostaddr.slot, s->hostaddr.function,
                s->dev.devfn);
 
-    xen_host_pci_device_get(&s->real_device,
-                            s->hostaddr.domain, s->hostaddr.bus,
-                            s->hostaddr.slot, s->hostaddr.function,
-                            errp);
-    if (*errp) {
-        error_append_hint(errp, "Failed to \"open\" the real pci device");
-        return;
-    }
-
     s->is_virtfn = s->real_device.is_virtfn;
     if (s->is_virtfn) {
         XEN_PT_LOG(d, "%04x:%02x:%02x.%d is a SR-IOV Virtual Function\n",
@@ -803,8 +795,10 @@ static void xen_pt_realize(PCIDevice *d, Error **errp)
     s->io_listener = xen_pt_io_listener;
 
     /* Setup VGA bios for passthrough GFX */
-    if ((s->real_device.domain == 0) && (s->real_device.bus == 0) &&
-        (s->real_device.dev == 2) && (s->real_device.func == 0)) {
+    if ((s->real_device.domain == XEN_PCI_IGD_DOMAIN) &&
+        (s->real_device.bus == XEN_PCI_IGD_BUS) &&
+        (s->real_device.dev == XEN_PCI_IGD_DEV) &&
+        (s->real_device.func == XEN_PCI_IGD_FN)) {
         if (!is_igd_vga_passthrough(&s->real_device)) {
             error_setg(errp, "Need to enable igd-passthru if you're trying"
                     " to passthrough IGD GFX");
@@ -950,11 +944,58 @@ static void xen_pci_passthrough_instance_init(Object *obj)
     PCI_DEVICE(obj)->cap_present |= QEMU_PCI_CAP_EXPRESS;
 }
 
+void xen_igd_reserve_slot(PCIBus *pci_bus)
+{
+    if (!xen_igd_gfx_pt_enabled()) {
+        return;
+    }
+
+    XEN_PT_LOG(0, "Reserving PCI slot 2 for IGD\n");
+    pci_bus->slot_reserved_mask |= XEN_PCI_IGD_SLOT_MASK;
+}
+
+static void xen_igd_clear_slot(DeviceState *qdev, Error **errp)
+{
+    ERRP_GUARD();
+    PCIDevice *pci_dev = (PCIDevice *)qdev;
+    XenPCIPassthroughState *s = XEN_PT_DEVICE(pci_dev);
+    XenPTDeviceClass *xpdc = XEN_PT_DEVICE_GET_CLASS(s);
+    PCIBus *pci_bus = pci_get_bus(pci_dev);
+
+    xen_host_pci_device_get(&s->real_device,
+                            s->hostaddr.domain, s->hostaddr.bus,
+                            s->hostaddr.slot, s->hostaddr.function,
+                            errp);
+    if (*errp) {
+        error_append_hint(errp, "Failed to \"open\" the real pci device");
+        return;
+    }
+
+    if (!(pci_bus->slot_reserved_mask & XEN_PCI_IGD_SLOT_MASK)) {
+        xpdc->pci_qdev_realize(qdev, errp);
+        return;
+    }
+
+    if (is_igd_vga_passthrough(&s->real_device) &&
+        s->real_device.domain == XEN_PCI_IGD_DOMAIN &&
+        s->real_device.bus == XEN_PCI_IGD_BUS &&
+        s->real_device.dev == XEN_PCI_IGD_DEV &&
+        s->real_device.func == XEN_PCI_IGD_FN &&
+        s->real_device.vendor_id == PCI_VENDOR_ID_INTEL) {
+        pci_bus->slot_reserved_mask &= ~XEN_PCI_IGD_SLOT_MASK;
+        XEN_PT_LOG(pci_dev, "Intel IGD found, using slot 2\n");
+    }
+    xpdc->pci_qdev_realize(qdev, errp);
+}
+
 static void xen_pci_passthrough_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
 
+    XenPTDeviceClass *xpdc = XEN_PT_DEVICE_CLASS(klass);
+    xpdc->pci_qdev_realize = dc->realize;
+    dc->realize = xen_igd_clear_slot;
     k->realize = xen_pt_realize;
     k->exit = xen_pt_unregister_device;
     k->config_read = xen_pt_pci_read_config;
@@ -977,6 +1018,7 @@ static const TypeInfo xen_pci_passthrough_info = {
     .instance_size = sizeof(XenPCIPassthroughState),
     .instance_finalize = xen_pci_passthrough_finalize,
     .class_init = xen_pci_passthrough_class_init,
+    .class_size = sizeof(XenPTDeviceClass),
     .instance_init = xen_pci_passthrough_instance_init,
     .interfaces = (InterfaceInfo[]) {
         { INTERFACE_CONVENTIONAL_PCI_DEVICE },
diff --git a/hw/xen/xen_pt.h b/hw/xen/xen_pt.h
index cf10fc7..e184699 100644
--- a/hw/xen/xen_pt.h
+++ b/hw/xen/xen_pt.h
@@ -40,7 +40,20 @@ typedef struct XenPTReg XenPTReg;
 #define TYPE_XEN_PT_DEVICE "xen-pci-passthrough"
 OBJECT_DECLARE_SIMPLE_TYPE(XenPCIPassthroughState, XEN_PT_DEVICE)
 
+#define XEN_PT_DEVICE_CLASS(klass) \
+    OBJECT_CLASS_CHECK(XenPTDeviceClass, klass, TYPE_XEN_PT_DEVICE)
+#define XEN_PT_DEVICE_GET_CLASS(obj) \
+    OBJECT_GET_CLASS(XenPTDeviceClass, obj, TYPE_XEN_PT_DEVICE)
+
+typedef void (*XenPTQdevRealize)(DeviceState *qdev, Error **errp);
+
+typedef struct XenPTDeviceClass {
+    PCIDeviceClass parent_class;
+    XenPTQdevRealize pci_qdev_realize;
+} XenPTDeviceClass;
+
 uint32_t igd_read_opregion(XenPCIPassthroughState *s);
+void xen_igd_reserve_slot(PCIBus *pci_bus);
 void igd_write_opregion(XenPCIPassthroughState *s, uint32_t val);
 void xen_igd_passthrough_isa_bridge_create(XenPCIPassthroughState *s,
                                            XenHostPCIDevice *dev);
@@ -75,6 +88,13 @@ typedef int (*xen_pt_conf_byte_read)
 
 #define XEN_PCI_INTEL_OPREGION 0xfc
 
+#define XEN_PCI_IGD_DOMAIN 0
+#define XEN_PCI_IGD_BUS 0
+#define XEN_PCI_IGD_DEV 2
+#define XEN_PCI_IGD_FN 0
+#define XEN_PCI_IGD_SLOT_MASK \
+    (1UL << PCI_SLOT(PCI_DEVFN(XEN_PCI_IGD_DEV, XEN_PCI_IGD_FN)))
+
 typedef enum {
     XEN_PT_GRP_TYPE_HARDWIRED = 0,  /* 0 Hardwired reg group */
     XEN_PT_GRP_TYPE_EMU,            /* emul reg group */
diff --git a/hw/xen/xen_pt_config_init.c b/hw/xen/xen_pt_config_init.c
index cde898b..8b9b554 100644
--- a/hw/xen/xen_pt_config_init.c
+++ b/hw/xen/xen_pt_config_init.c
@@ -1924,7 +1924,7 @@ static void xen_pt_config_reg_init(XenPCIPassthroughState *s,
     if (reg->init) {
         uint32_t host_mask, size_mask;
         unsigned int offset;
-        uint32_t val;
+        uint32_t val = 0;
 
         /* initialize emulate register */
         rc = reg->init(s, reg_entry->reg,
diff --git a/hw/xen/xen_pt_stub.c b/hw/xen/xen_pt_stub.c
index 2d8cac8..5c10844 100644
--- a/hw/xen/xen_pt_stub.c
+++ b/hw/xen/xen_pt_stub.c
@@ -20,3 +20,7 @@ void xen_igd_gfx_pt_set(bool value, Error **errp)
         error_setg(errp, "Xen PCI passthrough support not built in");
     }
 }
+
+void xen_igd_reserve_slot(PCIBus *pci_bus)
+{
+}