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Re: [Qemu-devel] [PATCH v7 1/4] isapc: Fix non-KVM qemu boot (read/write
Re: [Qemu-devel] [PATCH v7 1/4] isapc: Fix non-KVM qemu boot (read/write memory for isapc BIOS)
Fri, 31 May 2013 23:44:58 -0400
On Fri, May 31, 2013 at 02:48:17PM +0200, Paolo Bonzini wrote:
> Il 31/05/2013 04:06, Kevin O'Connor ha scritto:
> > On Wed, May 29, 2013 at 01:27:24AM -0700, Jordan Justen wrote:
> >> > The isapc machine with seabios currently requires the BIOS region
> >> > to be read/write memory rather than read-only memory.
> >> >
> >> > KVM currently cannot support the BIOS as a ROM region, but qemu
> >> > in non-KVM mode can. Based on this, isapc machine currently only
> >> > works with KVM.
> >> >
> >> > To work-around this isapc issue, this change avoids marking the
> >> > BIOS as readonly for isapc.
> > How about changing the code to always make the ROM read/write (instead
> > of doing it only on isapc). Currently, if the rom is marked as
> > read-only, then SeaBIOS makes it read/write as the first thing it
> > does. So, making it read-only doesn't really serve any purpose.
> I don't think SeaBIOS can rely on the value of the PAM registers when it
> is started via a CPU reset (INIT), can it?
SeaBIOS currently detects the PAM registers at startup - if it is in
read-only mode it makes it read/write. If it's in read/write mode it
leaves it there. That's why I think it is silly to start in read-only
mode - the first thing the guest does is make it read/write.
[Qemu-devel] [PATCH v7 4/4] pc_sysfw: allow flash (-pflash) memory to be used with KVM, Jordan Justen, 2013/05/29
[Qemu-devel] [PATCH v7 3/4] kvm: support using KVM_MEM_READONLY flag for regions, Jordan Justen, 2013/05/29
[Qemu-devel] [PATCH v7 2/4] kvm: add kvm_readonly_mem_enabled, Jordan Justen, 2013/05/29
Re: [Qemu-devel] [PATCH v7 0/4] KVM flash memory support, Anthony Liguori, 2013/05/31