| Message ID | 20210813233619.32178-1-jziviani@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | vga: don't abort when adding a duplicate isa-vga device | expand |
On 14/08/2021 01.36, Jose R. Ziviani wrote: > If users try to add an isa-vga device that was already registered, > still in command line, qemu will crash: > > $ qemu-system-mips64el -M pica61 -device isa-vga > RAMBlock "vga.vram" already registered, abort! > Aborted (core dumped) > > That particular board registers such device automaticaly, so it's > not obvious that a VGA device already exists. This patch changes > this behavior by displaying a message and ignoring that device, > starting qemu normally. > > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/44 > Signed-off-by: Jose R. Ziviani <jziviani@suse.de> > --- > hw/display/vga-isa.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/hw/display/vga-isa.c b/hw/display/vga-isa.c > index 90851e730b..69db502dde 100644 > --- a/hw/display/vga-isa.c > +++ b/hw/display/vga-isa.c > @@ -61,6 +61,15 @@ static void vga_isa_realizefn(DeviceState *dev, Error **errp) > MemoryRegion *vga_io_memory; > const MemoryRegionPortio *vga_ports, *vbe_ports; > > + /* > + * some machines register VGA by default, so instead of aborting > + * it, show a message and ignore this device. > + */ > + if (qemu_ram_block_by_name("vga.vram")) { > + error_report("vga.vram is already registered, ignoring this device"); > + return; > + } I think we should not ignore the error, but rather turn this into a proper error (instead of aborting). So if you replace error_report(...) with error_setg(errp, ...), the patch should be fine. Thomas
Hi, > > + if (qemu_ram_block_by_name("vga.vram")) { > > + error_report("vga.vram is already registered, ignoring this device"); > > + return; > > + } > > I think we should not ignore the error, but rather turn this into a proper > error (instead of aborting). Yes. Silently fixing up things automatically tends to be worse long-term. take care, Gerd
Hello Thomas and Gerd, Thank you for reviewing it. Sending a v2 soon. Thank you very much! On 16/08/2021 02:05, Gerd Hoffmann wrote: > Hi, > >>> + if (qemu_ram_block_by_name("vga.vram")) { >>> + error_report("vga.vram is already registered, ignoring this device"); >>> + return; >>> + } >> I think we should not ignore the error, but rather turn this into a proper >> error (instead of aborting). > Yes. Silently fixing up things automatically tends to be worse long-term. > > take care, > Gerd >
Thomas Huth <thuth@redhat.com> writes: > On 14/08/2021 01.36, Jose R. Ziviani wrote: >> If users try to add an isa-vga device that was already registered, >> still in command line, qemu will crash: >> $ qemu-system-mips64el -M pica61 -device isa-vga >> RAMBlock "vga.vram" already registered, abort! >> Aborted (core dumped) >> That particular board registers such device automaticaly, so it's >> not obvious that a VGA device already exists. This patch changes >> this behavior by displaying a message and ignoring that device, >> starting qemu normally. >> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/44 >> Signed-off-by: Jose R. Ziviani <jziviani@suse.de> >> --- >> hw/display/vga-isa.c | 9 +++++++++ >> 1 file changed, 9 insertions(+) >> diff --git a/hw/display/vga-isa.c b/hw/display/vga-isa.c >> index 90851e730b..69db502dde 100644 >> --- a/hw/display/vga-isa.c >> +++ b/hw/display/vga-isa.c >> @@ -61,6 +61,15 @@ static void vga_isa_realizefn(DeviceState *dev, Error **errp) >> MemoryRegion *vga_io_memory; >> const MemoryRegionPortio *vga_ports, *vbe_ports; >> + /* >> + * some machines register VGA by default, so instead of aborting >> + * it, show a message and ignore this device. >> + */ >> + if (qemu_ram_block_by_name("vga.vram")) { >> + error_report("vga.vram is already registered, ignoring this device"); >> + return; >> + } > > I think we should not ignore the error, but rather turn this into a > proper error (instead of aborting). > > So if you replace error_report(...) with error_setg(errp, ...), the > patch should be fine. Agreed. error_report() in a function with an Error **errp parameter is almost always wrong.
diff --git a/hw/display/vga-isa.c b/hw/display/vga-isa.c index 90851e730b..69db502dde 100644 --- a/hw/display/vga-isa.c +++ b/hw/display/vga-isa.c @@ -61,6 +61,15 @@ static void vga_isa_realizefn(DeviceState *dev, Error **errp) MemoryRegion *vga_io_memory; const MemoryRegionPortio *vga_ports, *vbe_ports; + /* + * some machines register VGA by default, so instead of aborting + * it, show a message and ignore this device. + */ + if (qemu_ram_block_by_name("vga.vram")) { + error_report("vga.vram is already registered, ignoring this device"); + return; + } + s->global_vmstate = true; vga_common_init(s, OBJECT(dev)); s->legacy_address_space = isa_address_space(isadev);
If users try to add an isa-vga device that was already registered, still in command line, qemu will crash: $ qemu-system-mips64el -M pica61 -device isa-vga RAMBlock "vga.vram" already registered, abort! Aborted (core dumped) That particular board registers such device automaticaly, so it's not obvious that a VGA device already exists. This patch changes this behavior by displaying a message and ignoring that device, starting qemu normally. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/44 Signed-off-by: Jose R. Ziviani <jziviani@suse.de> --- hw/display/vga-isa.c | 9 +++++++++ 1 file changed, 9 insertions(+)