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 <stef...@linux.vnet.ibm.com> Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com> --- include/hw/virtio/virtio-gpu.h | 1 + hw/display/virtio-gpu.c | 5 +++++ hw/display/virtio-vga.c | 11 +++++++++++ 3 files changed, 17 insertions(+) diff --git a/include/hw/virtio/virtio-gpu.h b/include/hw/virtio/virtio-gpu.h index 9780f755ef..d0321672f4 100644 --- a/include/hw/virtio/virtio-gpu.h +++ b/include/hw/virtio/virtio-gpu.h @@ -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; diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c index ec366f4c35..3ddd29c0de 100644 --- a/hw/display/virtio-gpu.c +++ b/hw/display/virtio-gpu.c @@ -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; diff --git a/hw/display/virtio-vga.c b/hw/display/virtio-vga.c index 2b36f2899a..672b7f9ce2 100644 --- a/hw/display/virtio-vga.c +++ b/hw/display/virtio-vga.c @@ -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++) { -- 2.18.0.547.g1d89318c48
