virtio-gpu: fix crashes upon warm reboot with vga mode

With vga=775 on the Linux command line a first boot of the VM running
Linux works fine. After a warm reboot it crashes during Linux boot.

Before that, valgrind points out bad memory write to console
surface. The VGA code is not aware that virtio-gpu got a message
surface scanout when the display is disabled. Let's reset VGA graphic
mode when it is the case, so that a new display surface is created
when doing further VGA operations.

https://bugs.launchpad.net/qemu/+bug/1784900/

Reported-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Tested-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Message-id: 20180803153235.4134-1-marcandre.lureau@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Marc-André Lureau 2018-08-03 17:32:35 +02:00 committed by Peter Maydell
parent 09b94ac0f2
commit 93f874fe9d
3 changed files with 17 additions and 0 deletions

View File

@ -421,6 +421,11 @@ static void virtio_gpu_disable_scanout(VirtIOGPU *g, int scanout_id)
scanout->height ?: 480,
"Guest disabled display.");
}
if (g->disable_scanout) {
g->disable_scanout(g, scanout_id);
}
dpy_gfx_replace_surface(scanout->con, ds);
scanout->resource_id = 0;
scanout->ds = NULL;

View File

@ -75,6 +75,16 @@ static void virtio_vga_gl_block(void *opaque, bool block)
}
}
static void virtio_vga_disable_scanout(VirtIOGPU *g, int scanout_id)
{
VirtIOVGA *vvga = container_of(g, VirtIOVGA, vdev);
if (scanout_id == 0) {
/* reset surface if needed */
vvga->vga.graphic_mode = -1;
}
}
static const GraphicHwOps virtio_vga_ops = {
.invalidate = virtio_vga_invalidate_display,
.gfx_update = virtio_vga_update_display,
@ -156,6 +166,7 @@ static void virtio_vga_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
vvga->vga_mrs, true);
vga->con = g->scanout[0].con;
g->disable_scanout = virtio_vga_disable_scanout;
graphic_console_set_hwops(vga->con, &virtio_vga_ops, vvga);
for (i = 0; i < g->conf.max_outputs; i++) {

View File

@ -125,6 +125,7 @@ typedef struct VirtIOGPU {
uint32_t bytes_3d;
} stats;
void (*disable_scanout)(struct VirtIOGPU *g, int scanout_id);
Error *migration_blocker;
} VirtIOGPU;