On 2/22/21 6:59 AM, David Gibson wrote: > On Fri, Feb 19, 2021 at 06:38:42PM +0100, Philippe Mathieu-Daudé wrote: >> Restrit KVM to the following PPC machines: >> - 40p >> - bamboo >> - g3beige >> - mac99 >> - mpc8544ds >> - ppce500 >> - pseries >> - sam460ex >> - virtex-ml507 > > Hrm. > > The reason this list is kind of surprising is because there are 3 > different "flavours" of KVM on ppc: KVM HV ("pseries" only), KVM PR > (almost any combination, theoretically, but kind of buggy in > practice), and the Book E specific KVM (Book-E systems with HV > extensions only). > > But basically, qemu explicitly managing what accelerators are > available for each machine seems the wrong way around to me. The > approach we've generally taken is that qemu requests the specific > features it needs of KVM, and KVM tells us whether it can supply those > or not (which may involve selecting between one of the several > flavours). > > That way we can extend KVM to cover more situations without needing > corresponding changes in qemu every time. OK thanks for the information. I'll wait the other patches get reviewed (in particular the most important ones, 2 and 10) before respining including this information. Regards, Phil.