[SeaBIOS] ohci bulk?
kevin at koconnor.net
Mon Nov 22 14:47:23 CET 2010
On Mon, Nov 22, 2010 at 11:52:56AM +0100, Gerd Hoffmann wrote:
> >I suppose one could implement a simple SMM gateway - write a magic IO
> >bit to invoke the SMM handler, have the SMM handler backup the cpu
> >state somewhere in BIOS owned memory, and then leave SMM mode with
> >execution at a BIOS handler running in 32bit flat mode.
> Hmm, how about having a virtual "I/O bounce" device? Allocate two
> dwords in I/O space. One dword for the address, one for the data.
> reads and writes to the data register will be bounced to the address
> written into the address register.
It could work. However, having the ability to go into full 32bit mode
would be more flexible.
> On real hardware seabios could emulate this using SMM.
> On virtual hardware qemu could emulate this so we don't need SMM
> support in kvm.
How hard would it be to add SMM support into kvm?
> From a security point of view it might not be the best idea though.
If a program has access to iospace, it's basically fully privileged
anyway, so I don't think this is a problem. (For example, the old
16bit DMA registers are fully programmed from iospace.)
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