Re: [libvirt] Memory access API
On Wed, Jun 19, 2013 at 04:29:48AM +0200, Marek Marczykowski-Górecki wrote:
Hi,
Is there any zero-copy VM memory access API in libvirt? I see only
virDomainMemoryPeek function, which copy some memory from VM and do not permit
VM memory modifications.
What I'm looking for is xen xc_map_foreign_pages or
xc_gnttab_map_domain_grant_refs equivalent/wrapper. IOW map memory pages to
dom0 address space, without copy. I know that not every hypervisor supports
it, but it is useful to build a high-performance communication channel on top
of it.
The only way to access memory from libvirt is via virDomainMemoryPeek
currently.
QEMU has an 'ivshm' device for doing shared memory segments between
VMs and/or host, which would be zero-copy but support for this has
not yet been integrated in libvirt. Patches are welcome if anyone
wants to add this though.
Daniel
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