Avi Kivity
2012-Jul-17 13:37 UTC
Re: [Qemu-devel] [PATCH 3/4] exec, memory: Call to xen_modified_memory.
On 07/17/2012 04:30 PM, Anthony PERARD wrote:> This patch add some calls to xen_modified_memory to notify Xen about dirtybits > during migration. > > diff --git a/exec.c b/exec.c > index c9fa17d..9f7a4f7 100644 > --- a/exec.c > +++ b/exec.c > @@ -3438,6 +3438,7 @@ void cpu_physical_memory_rw(target_phys_addr_t addr, uint8_t *buf, > cpu_physical_memory_set_dirty_flags( > addr1, (0xff & ~CODE_DIRTY_FLAG)); > } > + xen_modified_memory(addr1, TARGET_PAGE_SIZE); > qemu_put_ram_ptr(ptr); > } > } else {This is pretty ugly. An alternative is to set up a periodic bitmap scan that looks at the qemu dirty bitmap and calls xen_modified_memory() for dirty page ranges, and clears the bitmap for the next pass. Is it workable? (is xen_modified_memory a hypercall, or does it maintain an in-memory structure?) -- error compiling committee.c: too many arguments to function