Re: [PATCH] align vga rom to 4k boundary.

Avi Kivity
2009-04-11T11:14:46Z

Glauber Costa wrote:
> Instead of aligning to 2k boundary, as required by the bios,
> align to 4k boundary, as required by kvm memory functions. Without
> this patch, starting kvm with -vga std option fails with:
>
> create_userspace_phys_mem: Invalid argument
> kvm_cpu_register_physical_memory: failed
>
> as described by: https://bugzilla.redhat.com/show_bug.cgi?id=494376
>
> It does not fail with cirrus vga, because it is naturally aligned.
> This problem does not seem to affect upstream qemu.
>
> exit(1);
> }
> /* Round up vga bios size to the next 2k boundary */
> - vga_bios_size = (vga_bios_size + 2047) & ~2047;
> + vga_bios_size = (vga_bios_size + 4095) & ~4095;
> option_rom_start = 0xc0000 + vga_bios_size;
>
> /* setup basic memory access */
>

Comment needs updating.

--
Do not meddle in the internals of kernels, for they are subtle and quick to panic.