On 11/14/2011 05:56 AM, zanghongy...@huawei.com wrote: > From: Hongyong Zang <zanghongy...@huawei.com> > > Ivshmem(nahanni) is a mechanism for sharing host memory with VMs running on > the same host. Currently, guest notifies qemu by reading or writing ivshmem > device's PCI MMIO BAR0(Doorbell). > > This patch, changes this PCI MMIO BAR0(Doorbell) to PIO. And we find guest > accesses PIO BAR 30% faster than MMIO BAR. > > CharDriverState **eventfd_chr; > CharDriverState *server_chr; > - MemoryRegion ivshmem_mmio; > + MemoryRegion ivshmem_pio; > > - pcibus_t mmio_addr; > + pcibus_t pio_addr;
This is a backwards incompatible change. The way to accomplish this is to add a new BAR which aliases the old one. The new BAR should not be visible on guests created with -M pc-1.0 and below. Please also update the spec so that driver authors can make use of the new feature. -- error compiling committee.c: too many arguments to function
