On Tue, Oct 10, 2023 at 08:42:13AM +0000, Tian, Kevin wrote: > > From: ankita@xxxxxxxxxx <ankita@xxxxxxxxxx> > > Sent: Sunday, October 8, 2023 4:23 AM > > > > PCI BAR are aligned to the power-of-2, but the actual memory on the > > device may not. A read or write access to the physical address from the > > last device PFN up to the next power-of-2 aligned physical address > > results in reading ~0 and dropped writes. > > > > my question to v10 was not answered. posted again: > -- > Though the variant driver emulates the access to the offset beyond > the available memory size, how does the userspace driver or the guest > learn to know the actual size and avoid using the invalid hole to hold > valid data? The device FW knows and tells the VM. Jason
