[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [RFC 0 PATCH 3/3] PVH dom0: construct_dom0 changes
On Thu, 26 Sep 2013 09:02:41 +0100 "Jan Beulich" <JBeulich@xxxxxxxx> wrote: > >>> On 25.09.13 at 23:03, Mukesh Rathor <mukesh.rathor@xxxxxxxxxx> > >>> wrote: > > @@ -307,6 +308,136 @@ static void __init > > process_dom0_ioports_disable(void) } > > } > > > > +/* > > + * Set the 1:1 map for all non-RAM regions for dom 0. Thus, dom0 > > will have > > + * the entire io region mapped in the EPT/NPT. > > + * > > + * PVH FIXME: The following doesn't map MMIO ranges when they sit > > above the > > + * highest E820 covered address. > > This absolutely needs fixing before this can go in. Any suggestions on how to fix it? Mapping all the way to end could result in a huge hap table. > > + const struct e820entry *entry; > > + unsigned int i, nump; > > + int rc; > > + > > + for ( i = 0, entry = e820.map; i < e820.nr_map; i++, entry++ ) > > + { > > + end = entry->addr + entry->size; > > + > > + if ( entry->type == E820_RAM || entry->type == > > E820_UNUSABLE || > > The inclusion of E820_UNUSABLE here clearly needs an explanation > (ideally in the shape of a code comment). > > > + i == e820.nr_map - 1 ) > > + { > > + start_pfn = PFN_DOWN(start); > > + end_pfn = PFN_UP(end); > > + > > + if ( entry->type == E820_RAM || entry->type == > > E820_UNUSABLE ) > > + end_pfn = PFN_UP(entry->addr); > > Better coded as if/else construct (making more obvious what the > intention here is - it took me quite some time to see that what > you're doing here is correct, because the general case really is > what sits in the if() body, and the exception is what gets done > before the if(), which is counter intuitive). Based on xen_set_identity_and_release linux function. Took me a while to figure that one too. So, I tried simplifying it, but in the end came back to this. Not sure where I would the else. thanks Mukesh _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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