On 2011-08-05 06:02, David Gibson wrote:
> At present, an explicit test disallows use of -mem-path when kvm is enabled
> but KVM_CAP_SYNC_MMU is not set. In particular, this prevents the user
> from using hugetlbfs to back the guest memory.
>
> I can see no reason for this check, and when I asked about it previously,
> the only theory offered was that this was a limitation of the very early
> days of kvm which only happened to match the SYNC_MMU flag by accident.
>
> This patch, therefore, removes the check. This is of particular use to
> us on POWER, where we haven't yet implement SYNC_MMU, but where backing
> the guest with hugepages is possible, and in fact mandatory (for now).
>
> Signed-off-by: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>
> ---
> exec.c | 5 -----
> 1 files changed, 0 insertions(+), 5 deletions(-)
>
> diff --git a/exec.c b/exec.c
> index 476b507..041637c 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -2818,11 +2818,6 @@ static void *file_ram_alloc(RAMBlock *block,
> return NULL;
> }
>
> - if (kvm_enabled() && !kvm_has_sync_mmu()) {
> - fprintf(stderr, "host lacks kvm mmu notifiers, -mem-path unsupported\n");
> - return NULL;
> - }
> -
> if (asprintf(&filename, "%s/qemu_back_mem.XXXXXX", path) == -1) {
> return NULL;
> }
This is nothing trivial, see ce9a92411d in qemu-kvm or
http://thread.gmane.org/gmane.comp.emulators.kvm.devel/27380. And it
should rather target uq/master. CCing Avi, Marcelo, and the kvm list.
Jan
Attachment:
signature.asc
Description: OpenPGP digital signature
