vga: misc fixes and cleanups.

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Merge remote-tracking branch 'remotes/kraxel/tags/vga-20210901-pull-request' into staging

vga: misc fixes and cleanups.

# gpg: Signature made Wed 01 Sep 2021 05:18:46 BST
# gpg:                using RSA key A0328CFFB93A17A79901FE7D4CB6D8EED3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>" [full]
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>" [full]
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>" [full]
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* remotes/kraxel/tags/vga-20210901-pull-request:
  hw/display/artist: Fix bug in coordinate extraction in artist_vram_read() and artist_vram_write()
  hw/display/xlnx_dp: fix an out-of-bounds read in xlnx_dp_read
  vga: don't abort when adding a duplicate isa-vga device
  ui/console: Restrict udmabuf_fd() to Linux
  hw/display: Restrict virtio-gpu-udmabuf stubs to !Linux
  virtio-gpu: no point of checking res->iov

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

hw/display/artist.c

@@ -1170,8 +1170,8 @@ static void artist_vram_write(void *opaque, hwaddr addr, uint64_t val,
     }
 
     buf = vram_write_buffer(s);
-    posy = ADDR_TO_Y(addr);
-    posx = ADDR_TO_X(addr);
+    posy = ADDR_TO_Y(addr >> 2);
+    posx = ADDR_TO_X(addr >> 2);
 
     if (!buf->size) {
         return;
@@ -1232,8 +1232,8 @@ static uint64_t artist_vram_read(void *opaque, hwaddr addr, unsigned size)
         return 0;
     }
 
-    posy = ADDR_TO_Y(addr);
-    posx = ADDR_TO_X(addr);
+    posy = ADDR_TO_Y(addr >> 2);
+    posx = ADDR_TO_X(addr >> 2);
 
     if (posy > buf->height || posx > buf->width) {
         return 0;

hw/display/meson.build

@@ -56,7 +56,8 @@ if config_all_devices.has_key('CONFIG_VIRTIO_GPU')
   virtio_gpu_ss = ss.source_set()
   virtio_gpu_ss.add(when: 'CONFIG_VIRTIO_GPU',
                     if_true: [files('virtio-gpu-base.c', 'virtio-gpu.c'), pixman])
-  virtio_gpu_ss.add(when: 'CONFIG_LINUX', if_true: files('virtio-gpu-udmabuf.c'))
+  virtio_gpu_ss.add(when: 'CONFIG_LINUX', if_true: files('virtio-gpu-udmabuf.c'),
+                                          if_false: files('virtio-gpu-udmabuf-stubs.c'))
   virtio_gpu_ss.add(when: 'CONFIG_VHOST_USER_GPU', if_true: files('vhost-user-gpu.c'))
   hw_display_modules += {'virtio-gpu': virtio_gpu_ss}
 

hw/display/vga-isa.c

@@ -33,6 +33,7 @@
 #include "hw/loader.h"
 #include "hw/qdev-properties.h"
 #include "qom/object.h"
+#include "qapi/error.h"
 
 #define TYPE_ISA_VGA "isa-vga"
 OBJECT_DECLARE_SIMPLE_TYPE(ISAVGAState, ISA_VGA)
@@ -61,6 +62,15 @@ static void vga_isa_realizefn(DeviceState *dev, Error **errp)
     MemoryRegion *vga_io_memory;
     const MemoryRegionPortio *vga_ports, *vbe_ports;
 
+    /*
+     * make sure this device is not being added twice, if so
+     * exit without crashing qemu
+     */
+    if (object_resolve_path_type("", TYPE_ISA_VGA, NULL)) {
+        error_setg(errp, "at most one %s device is permitted", TYPE_ISA_VGA);
+        return;
+    }
+
     s->global_vmstate = true;
     vga_common_init(s, OBJECT(dev));
     s->legacy_address_space = isa_address_space(isadev);

hw/display/virtio-gpu.c

@@ -362,7 +362,7 @@ static void virtio_gpu_resource_create_blob(VirtIOGPU *g,
     ret = virtio_gpu_create_mapping_iov(g, cblob.nr_entries, sizeof(cblob),
                                         cmd, &res->addrs, &res->iov,
                                         &res->iov_cnt);
-    if (ret != 0 || res->iov) {
+    if (ret != 0) {
         cmd->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
         g_free(res);
         return;

hw/display/xlnx_dp.c

@@ -714,7 +714,11 @@ static uint64_t xlnx_dp_read(void *opaque, hwaddr offset, unsigned size)
         break;
     default:
         assert(offset <= (0x3AC >> 2));
-        ret = s->core_registers[offset];
+        if (offset == (0x3A8 >> 2) || offset == (0x3AC >> 2)) {
+            ret = s->core_registers[DP_INT_MASK];
+        } else {
+            ret = s->core_registers[offset];
+        }
         break;
     }
 

include/ui/console.h

@@ -471,7 +471,9 @@ bool vnc_display_reload_certs(const char *id,  Error **errp);
 /* input.c */
 int index_from_key(const char *key, size_t key_length);
 
+#ifdef CONFIG_LINUX
 /* udmabuf.c */
 int udmabuf_fd(void);
+#endif
 
 #endif

stubs/meson.build

@@ -52,7 +52,6 @@ if have_system
   stub_ss.add(files('semihost.c'))
   stub_ss.add(files('usb-dev-stub.c'))
   stub_ss.add(files('xen-hw-stub.c'))
-  stub_ss.add(files('virtio-gpu-udmabuf.c'))
 else
   stub_ss.add(files('qdev.c'))
 endif

tests/qtest/fuzz-xlnx-dp-test.c

@@ -0,0 +1,33 @@
+/*
+ * QTest fuzzer-generated testcase for xlnx-dp display device
+ *
+ * Copyright (c) 2021 Qiang Liu <cyruscyliu@gmail.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "libqos/libqtest.h"
+
+/*
+ * This used to trigger the out-of-bounds read in xlnx_dp_read
+ */
+static void test_fuzz_xlnx_dp_0x3ac(void)
+{
+    QTestState *s = qtest_init("-M xlnx-zcu102 -display none ");
+    qtest_readl(s, 0xfd4a03ac);
+    qtest_quit(s);
+}
+
+int main(int argc, char **argv)
+{
+    const char *arch = qtest_get_arch();
+
+    g_test_init(&argc, &argv, NULL);
+
+   if (strcmp(arch, "aarch64") == 0) {
+        qtest_add_func("fuzz/test_fuzz_xlnx_dp/3ac", test_fuzz_xlnx_dp_0x3ac);
+   }
+
+   return g_test_run();
+}

tests/qtest/meson.build

@@ -187,6 +187,7 @@ qtests_aarch64 = \
    'numa-test',
    'boot-serial-test',
    'xlnx-can-test',
+   'fuzz-xlnx-dp-test',
    'migration-test']
 
 qtests_s390x = \

ui/meson.build

@@ -12,12 +12,14 @@ softmmu_ss.add(files(
   'kbd-state.c',
   'keymaps.c',
   'qemu-pixman.c',
-  'udmabuf.c',
 ))
 softmmu_ss.add([spice_headers, files('spice-module.c')])
 softmmu_ss.add(when: spice_protocol, if_true: files('vdagent.c'))
 
-softmmu_ss.add(when: 'CONFIG_LINUX', if_true: files('input-linux.c'))
+softmmu_ss.add(when: 'CONFIG_LINUX', if_true: files(
+  'input-linux.c',
+  'udmabuf.c',
+))
 softmmu_ss.add(when: cocoa, if_true: files('cocoa.m'))
 
 vnc_ss = ss.source_set()

ui/udmabuf.c

@@ -8,8 +8,6 @@
 #include "qapi/error.h"
 #include "ui/console.h"
 
-#ifdef CONFIG_LINUX
-
 #include <fcntl.h>
 #include <sys/ioctl.h>
 
@@ -29,12 +27,3 @@ int udmabuf_fd(void)
     }
     return udmabuf;
 }
-
-#else
-
-int udmabuf_fd(void)
-{
-    return -1;
-}
-
-#endif