xen: fix build without pci passthrough

Xen PCI passthrough support may not be available and thus the global
variable "has_igd_gfx_passthru" might be compiled out. Common code
should not access it in that case.

Unfortunately, we can't use CONFIG_XEN_PCI_PASSTHROUGH directly in
xen-common.c so this patch instead move access to the
has_igd_gfx_passthru variable via function and those functions are
also implemented as stubs. The stubs will be used when QEMU is built
without passthrough support.

Now, when one will want to enable igd-passthru via the -machine
property, they will get an error message if QEMU is built without
passthrough support.

Fixes: 46472d82322d0 ('xen: convert "-machine igd-passthru" to an accelerator property')
Reported-by: Roger Pau Monné <[email protected]>
Signed-off-by: Anthony PERARD <[email protected]>
Message-Id: <20200603160442.3151170[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

diff --git a/accel/xen/xen-all.c b/accel/xen/xen-all.c
index f3edc65ec9a00694607d9056ad1b739edc330e50..0c24d4b191a4f270c06aa23991d4ae8517b7702c 100644 (file)
--- a/accel/xen/xen-all.c
+++ b/accel/xen/xen-all.c
@@ -137,12 +137,12 @@ static void xen_change_state_handler(void *opaque, int running,
 
 static bool xen_get_igd_gfx_passthru(Object *obj, Error **errp)
 {
-    return has_igd_gfx_passthru;
+    return xen_igd_gfx_pt_enabled();
 }
 
 static void xen_set_igd_gfx_passthru(Object *obj, bool value, Error **errp)
 {
-    has_igd_gfx_passthru = value;
+    xen_igd_gfx_pt_set(value, errp);
 }
 
 static void xen_setup_post(MachineState *ms, AccelState *accel)

diff --git a/hw/Makefile.objs b/hw/Makefile.objs
index 660e2b43734817910a836a1279514554616cdc89..4cbe5e4e57d62d5311690d82b7523b3a28929491 100644 (file)
--- a/hw/Makefile.objs
+++ b/hw/Makefile.objs
@@ -35,7 +35,7 @@ devices-dirs-y += usb/
 devices-dirs-$(CONFIG_VFIO) += vfio/
 devices-dirs-y += virtio/
 devices-dirs-y += watchdog/
-devices-dirs-y += xen/
+devices-dirs-$(CONFIG_XEN) += xen/
 devices-dirs-$(CONFIG_MEM_DEVICE) += mem/
 devices-dirs-$(CONFIG_NUBUS) += nubus/
 devices-dirs-y += semihosting/

diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index eea964e72b89aa316d55b65d925f3f6cd2f6d9f0..054d3aa9f7aec4d243ffa2dda6df0700b4fbc0f0 100644 (file)
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -377,7 +377,7 @@ static void pc_init_isa(MachineState *machine)
 #ifdef CONFIG_XEN
 static void pc_xen_hvm_init_pci(MachineState *machine)
 {
-    const char *pci_type = has_igd_gfx_passthru ?
+    const char *pci_type = xen_igd_gfx_pt_enabled() ?
                 TYPE_IGD_PASSTHROUGH_I440FX_PCI_DEVICE : TYPE_I440FX_PCI_DEVICE;
 
     pc_init1(machine,

diff --git a/hw/xen/Makefile.objs b/hw/xen/Makefile.objs
index 340b2c5096192385bc3828580bb231709fed398e..3fc715e5954d04e8192e124ebdbaf5bb5c45b80f 100644 (file)
--- a/hw/xen/Makefile.objs
+++ b/hw/xen/Makefile.objs
@@ -1,6 +1,7 @@
 # xen backend driver support
-common-obj-$(CONFIG_XEN) += xen-legacy-backend.o xen_devconfig.o xen_pvdev.o xen-bus.o xen-bus-helper.o xen-backend.o
+common-obj-y += xen-legacy-backend.o xen_devconfig.o xen_pvdev.o xen-bus.o xen-bus-helper.o xen-backend.o
 
 obj-$(CONFIG_XEN_PCI_PASSTHROUGH) += xen-host-pci-device.o
 obj-$(CONFIG_XEN_PCI_PASSTHROUGH) += xen_pt.o xen_pt_config_init.o xen_pt_graphics.o xen_pt_msi.o
 obj-$(CONFIG_XEN_PCI_PASSTHROUGH) += xen_pt_load_rom.o
+obj-$(call $(lnot, $(CONFIG_XEN_PCI_PASSTHROUGH))) += xen_pt_stub.o

diff --git a/hw/xen/xen_pt.c b/hw/xen/xen_pt.c
index 81d5ad8da7f0519744b10db74fd270608015c85c..ab84443d5ec8e5dec48bc21ad0633b38b32d4905 100644 (file)
--- a/hw/xen/xen_pt.c
+++ b/hw/xen/xen_pt.c
@@ -65,7 +65,17 @@
 #include "qemu/range.h"
 #include "exec/address-spaces.h"
 
-bool has_igd_gfx_passthru;
+static bool has_igd_gfx_passthru;
+
+bool xen_igd_gfx_pt_enabled(void)
+{
+    return has_igd_gfx_passthru;
+}
+
+void xen_igd_gfx_pt_set(bool value, Error **errp)
+{
+    has_igd_gfx_passthru = value;
+}
 
 #define XEN_PT_NR_IRQS (256)
 static uint8_t xen_pt_mapped_machine_irq[XEN_PT_NR_IRQS] = {0};

diff --git a/hw/xen/xen_pt.h b/hw/xen/xen_pt.h
index 179775db7b220796334bd0f964eb9b8b0747d80e..6e9cec95f3b762b08a259679bd96c1120ee6dfdc 100644 (file)
--- a/hw/xen/xen_pt.h
+++ b/hw/xen/xen_pt.h
@@ -5,6 +5,9 @@
 #include "hw/pci/pci.h"
 #include "xen-host-pci-device.h"
 
+bool xen_igd_gfx_pt_enabled(void);
+void xen_igd_gfx_pt_set(bool value, Error **errp);
+
 void xen_pt_log(const PCIDevice *d, const char *f, ...) GCC_FMT_ATTR(2, 3);
 
 #define XEN_PT_ERR(d, _f, _a...) xen_pt_log(d, "%s: Error: "_f, __func__, ##_a)
@@ -322,10 +325,9 @@ extern void *pci_assign_dev_load_option_rom(PCIDevice *dev,
                                             unsigned int domain,
                                             unsigned int bus, unsigned int slot,
                                             unsigned int function);
-extern bool has_igd_gfx_passthru;
 static inline bool is_igd_vga_passthrough(XenHostPCIDevice *dev)
 {
-    return (has_igd_gfx_passthru
+    return (xen_igd_gfx_pt_enabled()
             && ((dev->class_code >> 0x8) == PCI_CLASS_DISPLAY_VGA));
 }
 int xen_pt_register_vga_regions(XenHostPCIDevice *dev);

diff --git a/hw/xen/xen_pt_stub.c b/hw/xen/xen_pt_stub.c
new file mode 100644 (file)
index 0000000..2d8cac8
--- /dev/null
+++ b/hw/xen/xen_pt_stub.c
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2020       Citrix Systems UK Ltd.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/xen/xen_pt.h"
+#include "qapi/error.h"
+
+bool xen_igd_gfx_pt_enabled(void)
+{
+    return false;
+}
+
+void xen_igd_gfx_pt_set(bool value, Error **errp)
+{
+    if (value) {
+        error_setg(errp, "Xen PCI passthrough support not built in");
+    }
+}