On Tue, Mar 03, 2020 at 12:00:00PM +0100, Jan Beulich wrote: > On 03.03.2020 11:29, Roger Pau Monné wrote: > > On Tue, Mar 03, 2020 at 10:14:50AM +0100, Jan Beulich wrote: > >> On 02.03.2020 16:55, Roger Pau Monne wrote: > >>> + /* Truncate the start of the region */ > >>> + start = ROUNDUP(kernel_end, PAGE_SIZE); > >>> + else if ( kernel_start <= end && kernel_end >= end ) > >> > >> and < on the left side of the && here. Furthermore - can this > >> really be "else if()" here, i.e. doesn't it need to be plain > >> "if()"? > > > > I don't think so, as the region where the kernel has been loaded must > > always be a single RAM region. Ie: [kernel_start, kernel_end) is > > always going to be a subset of a RAM region. > > I this true even with the page size alignment getting done? > IOW are all E820 ranges we produce exact multiples of 4k in > size and aligned to 4k boundaries?
Yes, pvh_setup_e820 guarantees that, as the EPT/NPT cannot handle anything smaller than a page. The RAM regions in the native e820 are adjusted to that effect. > >> Also, do both regions need to be adjacent? If not, wouldn't it be > >> better to find slots for them one by one? > > > > That's going to be much more complicated, as you would have to account > > for previous regions while searching for empty spaces. If we want to > > go that route we would have to use a rangeset or some such in order to > > keep track of used areas. > > I accept this being more complicated, and hence not really > wanting doing now and here. But perhaps you could leave a > comment to the effect that the choice of using a single > region is for simplicity reasons? Sure. Thanks, Roger. _______________________________________________ Xen-devel mailing list [email protected] https://lists.xenproject.org/mailman/listinfo/xen-devel
