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 <roger.pau@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Message-Id: <20200603160442.3151170-1-anthony.perard@citrix.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit acd0c9416d4846afc541605ee0e75ca163773e6c)
[fix conflict in hw/xen/Makefile.objs]
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>

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 22dee0e76c628512c9c389224f8a81da846a3b0d..0440e655e24d556d434fa5d7abb764f8f2415b94 100644 (file)
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -373,7 +373,7 @@ 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 84df60a9281a261b4f19ac54d30419c3621f0677..8f3048a1db6769a89f5d9eb01a57932f3608b1f5 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-common.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-common.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-common.c b/hw/xen/xen-common.c
index a15070f7f6c908a387d644ab8ca2bb11de638266..05e5fa17b2be0f3d50f0654722c598b606618a7d 100644 (file)
--- a/hw/xen/xen-common.c
+++ b/hw/xen/xen-common.c
@@ -129,12 +129,12 @@ 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/xen/xen_pt.c b/hw/xen/xen_pt.c
index b91082cb8bc1d6f4a2166edc6b8acc33de219f76..12a8232dc27f7413c30af85f38f1786a1ccdc133 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");
+    }
+}