[Qemu-devel] [PATCH] add support for higher screen resolutions

[Qemu-devel] [PATCH] add support for higher screen resolutions

[Andreas Winkelbauer]

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This patch introduces changes which are necessary for using qemu with
higher screen resolutions than 1600x1200 (with -std-vga).

In addition to this patch, the vgabios needs to be regenerated to
support higher resolutions too. A corresponding patch for the vgabios
has been submitted to Volker Ruppert.

kvm carries this patch since kvm-62 (commit
aaf6c43f811309b3f0546dd74b2543af2fad7f02).

Signed-off-by: Andreas Winkelbauer <andreas.winkelbauer@gmx.at>
---

Since I do not know how you usually generate the vgabios I will send the
 patch for it also to the qemu list. I hope Volker Ruppert will pick up
the patch, so that one could use the upstream version of vgabios directly.

bye,
Andi

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diff -uNrp trunk.orig/hw/pc.h trunk/hw/pc.h
--- trunk.orig/hw/pc.h	2008-09-17 02:11:50.000000000 +0200
+++ trunk/hw/pc.h	2008-09-17 02:22:03.000000000 +0200
@@ -110,9 +110,9 @@ int piix4_init(PCIBus *bus, int devfn);
 /* vga.c */
 
 #ifndef TARGET_SPARC
-#define VGA_RAM_SIZE (8192 * 1024)
+#define VGA_RAM_SIZE (16 * 1024 * 1024)
 #else
-#define VGA_RAM_SIZE (9 * 1024 * 1024)
+#define VGA_RAM_SIZE (17 * 1024 * 1024)
 #endif
 
 int isa_vga_init(DisplayState *ds, uint8_t *vga_ram_base,
diff -uNrp trunk.orig/hw/vga_int.h trunk/hw/vga_int.h
--- trunk.orig/hw/vga_int.h	2008-09-17 02:11:49.000000000 +0200
+++ trunk/hw/vga_int.h	2008-09-17 02:21:43.000000000 +0200
@@ -30,8 +30,8 @@
 /* bochs VBE support */
 #define CONFIG_BOCHS_VBE
 
-#define VBE_DISPI_MAX_XRES              1600
-#define VBE_DISPI_MAX_YRES              1200
+#define VBE_DISPI_MAX_XRES              2560
+#define VBE_DISPI_MAX_YRES              1600
 #define VBE_DISPI_MAX_BPP               32
 
 #define VBE_DISPI_INDEX_ID              0x0

Re: [Qemu-devel] [PATCH] add support for higher screen resolutions

[Jamie Lokier]

Andreas Winkelbauer wrote:
> This patch introduces changes which are necessary for using qemu with
> higher screen resolutions than 1600x1200 (with -std-vga).
> 
> In addition to this patch, the vgabios needs to be regenerated to
> support higher resolutions too. A corresponding patch for the vgabios
> has been submitted to Volker Ruppert.

Speaking of resolutions, it would be quite nice to support EDID
(information from a monitor about its capabilities) and monitor
hotplug emulation.  In particular, that would make it possible to run
QEMU in full-screen mode on any screen size, without borders or
scaling.  There is a VGA BIOS call to get EDID info, although I'm not
sure if it supports monitor hotplug, or which guests use it.  Any
thoughts on that?

-- Jamie

Re: [Qemu-devel] [PATCH] add support for higher screen resolutions

[Samuel Thibault]

Andreas Winkelbauer, le Wed 17 Sep 2008 18:50:24 +0200, a écrit :
>  /* vga.c */
>  
>  #ifndef TARGET_SPARC
> -#define VGA_RAM_SIZE (8192 * 1024)
> +#define VGA_RAM_SIZE (16 * 1024 * 1024)
>  #else

Mmm, did you check that save/restore works between before and after the
change?

Samuel

[Qemu-devel] Re: [PATCH] add support for higher screen resolutions

[Andreas Winkelbauer]

Samuel Thibault <samuel.thibault <at> ens-lyon.org> writes:

> Andreas Winkelbauer, le Wed 17 Sep 2008 18:50:24 +0200, a écrit :
> >  /* vga.c */
> >  
> >  #ifndef TARGET_SPARC
> > -#define VGA_RAM_SIZE (8192 * 1024)
> > +#define VGA_RAM_SIZE (16 * 1024 * 1024)
> >  #else
> 
> Mmm, did you check that save/restore works between before and after the
> change?

No I did not check this, because I usually don't use save/restore.

Are there some problems due to this change? If so, have you also increased the
vga memory in vgabios to 16MB?

I would be very surprised if this change breaks save/restore, since kvm uses
this patch for quite a long time now and there were no complaints about
save/restore not working.

bye,
andi

Re: [Qemu-devel] Re: [PATCH] add support for higher screen resolutions

[Samuel Thibault]

Andreas Winkelbauer, le Thu 18 Sep 2008 01:17:20 +0000, a écrit :
> Samuel Thibault <samuel.thibault <at> ens-lyon.org> writes:
> > Andreas Winkelbauer, le Wed 17 Sep 2008 18:50:24 +0200, a écrit :
> > >  /* vga.c */
> > >  
> > >  #ifndef TARGET_SPARC
> > > -#define VGA_RAM_SIZE (8192 * 1024)
> > > +#define VGA_RAM_SIZE (16 * 1024 * 1024)
> > >  #else
> > 
> > Mmm, did you check that save/restore works between before and after the
> > change?
> 
> Are there some problems due to this change?

I haven't tested myself with plain qemu, but with xen ioemu I had
troubles when I tried to change the video memory size.

> I would be very surprised if this change breaks save/restore, since kvm uses
> this patch for quite a long time now and there were no complaints about
> save/restore not working.

Including on upgrade?

Samuel

Re: [Qemu-devel] Re: [PATCH] add support for higher screen resolutions

[Anthony Liguori]

Samuel Thibault wrote:
> Andreas Winkelbauer, le Thu 18 Sep 2008 01:17:20 +0000, a écrit :
>   
>> Samuel Thibault <samuel.thibault <at> ens-lyon.org> writes:
>>     
>>> Andreas Winkelbauer, le Wed 17 Sep 2008 18:50:24 +0200, a écrit :
>>>       
>>>>  /* vga.c */
>>>>  
>>>>  #ifndef TARGET_SPARC
>>>> -#define VGA_RAM_SIZE (8192 * 1024)
>>>> +#define VGA_RAM_SIZE (16 * 1024 * 1024)
>>>>  #else
>>>>         
>>> Mmm, did you check that save/restore works between before and after the
>>> change?
>>>       
>> Are there some problems due to this change?
>>     
>
> I haven't tested myself with plain qemu, but with xen ioemu I had
> troubles when I tried to change the video memory size.
>
>   
>> I would be very surprised if this change breaks save/restore, since kvm uses
>> this patch for quite a long time now and there were no complaints about
>> save/restore not working.
>>     

The problem is that a patch like this will break save/restore across 
different versions of QEMU.  The fact that this isn't easily detected is 
a problem that would be nice to fix.

Has vgabios cut a release with the patch required for this?  Does the 
KVM version of vgabios contain any other patches?

Regards,

Anthony Liguori


> Including on upgrade?
>
> Samuel
>
>
>