On Tue, Aug 28, 2012 at 8:12 AM, Peter Maydell <peter.maydell@xxxxxxxxxx> wrote:
> On 28 August 2012 16:00, Christoffer Dall <c.dall@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>> On Thu, Aug 23, 2012 at 7:20 AM, Christoffer Dall
>> <c.dall@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>>> On Thu, Aug 23, 2012 at 3:19 AM, Rusty Russell <rusty.russell@xxxxxxxxxx> wrote:
>>>> + if (par & (1U << 11)) {
>>>> + /* LPAE PAR format */
>>>> + /*
>>>> + * TODO: Check if this ever happens
>>>> + * - called from Hyp mode
>>>> + */
>>>
>>> Getting a chance to revisit this, surely it has to happen if the guest
>>> uses LPAE - otherwise you wouldn't be able to get the top bits from
>>> the VA to PA operation executed from Hyp mode.
>>>
>>> Peter/Marc, can you verify?
>
> __kvm_va_to_pa always switches to hyp mode to do the translation,
> right?
yes
> ATS1Cxx operations from Hyp mode always return the answer
> using the 64-bit PAR format (see ARM ARM B3.14.3). So bit 11 is
> always set. (If you do the operation from PL1 then the format of
> the PAR depends on whether the TTBR.EAE bit is set, but this isn't
> true for operations done from Hyp mode, to avoid the hypervisor
> having to care whether the guest is using long format descriptor
> or not.)
>
ok, cool, thanks.
-Christoffer
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