On Wed, Oct 17, 2012 at 04:51:17PM -0700, H. Peter Anvin wrote: > On 10/17/2012 06:49 AM, Konrad Rzeszutek Wilk wrote: > >In the past it used to point to 'sidt' (native_store_idt) operation > >which is a non-privileged operation. This resulted in the > >'struct desc_ptr' value containing the address of Xen's IDT table, > >instead of the IDT table that Linux thinks its using. The end result > >is that doing: > > > > store_idt(&desc); > > load_idt(&desc); > > > >would blow up b/c xen_load_idt would try to parse the IDT contents > >(desc) and de-reference a virtual address that is outside Linux's > >__va (it is in Xen's virtual address). > > > >With this patch we are providing the last written IDT address. > > > > OK... this seems like another excellent set of pvops calls that > should be nukable to Kingdom Come. There is no reason, ever, to > read the IDT and GDT from the kernel... the kernel already knows > what they should be! Even during suspend and resume cycle? There are the sequence of sidt/lidt calls being done there. And we do need to filter at least the sidt call - and in the case of ACPI suspend path, the lidt. > > -hpa > > > -- > H. Peter Anvin, Intel Open Source Technology Center > I work for Intel. I don't speak on their behalf. > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
