Il 11/12/2013 14:35, Alexander Graf ha scritto:
>>> >> + if (kvm_enabled()) {
>>> >> + /*
>>> >> + * The guest may want to directly execute from the rom
>>> >> region,
>>> >> + * so we better invalidate its icache
>>> >> + */
>>> >> + flush_icache_range((uintptr_t)ptr, (uintptr_t)ptr + l);
>>> >> + }
>> >
>> > Shouldn't KVM itself do that when a memslot is registered? There should
>> > be no reason for non-TCG QEMU to flush the icache.
> How would KVM know when things changed inside of a memory region? It's up to
> user space to manage the contents of a memory region, no?
Yeah, that is true. BTW, shouldn't the same happen when you do migration?
I'd prefer the above snippet to be replaced by a function in
kvm-stub.c/kvm-all.c (kvm_flush_icache_range).
I wonder if there would be a reason to add a KVM_FLUSH_ICACHE ioctl
though. Could a virtually-indexed/virtually-tagged icache require
flushing by guest address instead of host address?
Paolo
