On 05/02/2012 06:54 PM, Gerd Hoffmann wrote: > On 05/02/12 17:33, Avi Kivity wrote: > > On 05/02/2012 05:02 PM, Gerd Hoffmann wrote: > >> Hi, > >> > >> seabios (master branch) just got 64bit pci support. When running out of > >> address space in the pci memory window below 4G (0xe0000000+) seabios > >> will map 64bit pci bars above 4G to make room below 4G. > >> > >> This patch series carries two little patches for qemu to adapt it to the > >> seabios changes. First patch creates a memory window for the 64bit pci > >> bars. Second patch adds a 64bit option to the ivshmem driver, which > >> allows to use huge shared memory chunks. > > > > What happens if a pre-64-bit-pci guest boots on such a setup? > > If it worked before it should continue to work just fine. Note that the > 64bit bars are only mapped above 4G in case there is not enough address > space below 4G, so existing setups should never ever see bars mapped high.
I see. I guess it depends on the algorithm for selecting the BAR to be evicted, but if everything fitted before, it should fit now as well. If it didn't, then a different device may break in each of the two cases. -- error compiling committee.c: too many arguments to function
