On 2014-05-15 07:54, Arthur Chunqi Li wrote: > Hi Jan and there, > > I want to disable IDE BMDMA in Qemu/KVM and let guest OS uses only PIO > mode. Are there any configurations in Qemu or KVM to disable the > hardware support of DMA? Not that I know. These features are built into the chipsets we emulate, and there seems to be no option to disable them. Maybe the isapc will not expose DMA capabilities - but will also lack a lot of other things like PCI... Jan > > I have tried to disable IDE DMA in guest OS booting params as follows: > ide-core.nodma=0.0 libata.dma=0 ide=nodma ide0=nodma > > But I can also get the followings in dmesg: > [0.533276] ata1: PATA max MWDMA2 cmd 0x1f0 ctl 0x3f6 bmdma 0xc040 irq 14 > [0.533641] ata2: PATA max MWDMA2 cmd 0x170 ctl 0x376 bmdma 0xc048 irq 15 > > and I do tracked irq 14 and irq 15 in ioapic_deliver when read/write disk. > > How could I totally disable IDE BMDMA from guest's boot time? > > Thanks, > Arthur >
Attachment:
signature.asc
Description: OpenPGP digital signature
