On 12/12/2019 10:11, Jan Beulich wrote:
> On 11.12.2019 21:57, Andrew Cooper wrote:
>> On 11/12/2019 09:28, Jan Beulich wrote:
>>> AMD and friends explicitly specify that 64-bit operands aren't possible
>>> for these insns. Nevertheless REX.W isn't fully ignored: It still
>>> cancels a possible operand size override (0x66). Intel otoh explicitly
>>> provides for 64-bit operands on the respective insn page of the SDM.
>>>
>>> Signed-off-by: Jan Beulich <[email protected]>
>> It is definitely more than just these.  Near jumps have per-vendor
>> behaviour on how long the instruction is, whereas far jump/calls are in
>> the same category as these by the looks of things.
> But you don't expect me to fold all of these into one patch, do
> you?

short jmp certainly not, but far jmp/call is just two extra case
statements in this new code block, no?

> We have _some_ vendor dependent behavior already, and I'm
> slowly adding to it. Our far call/jmp support is rather
> incomplete in other ways anyway.

There is different truncation behaviour for %rip which needs altering,
but that is a separate area of code.  Anything else?

~Andrew

_______________________________________________
Xen-devel mailing list
[email protected]
https://lists.xenproject.org/mailman/listinfo/xen-devel

Reply via email to