On Fri, Sep 21, 2018 at 10:36:17AM -0700, Jim Mattson wrote:
> According to volume 3 of the SDM, bits 63:15 and 12:4 of the exit
> qualification field for debug exceptions are reserved (cleared to
> 0). However, the SDM is incorrect about bit 16 (corresponding to
> DR6.RTM). This bit should be set if a debug exception (#DB) or a
> breakpoint exception (#BP) occurred inside an RTM region while
> advanced debugging of RTM transactional regions was enabled. Note that
> this is the opposite of DR6.RTM, which "indicates (when clear) that a
> debug exception (#DB) or breakpoint exception (#BP) occurred inside an
> RTM region while advanced debugging of RTM transactional regions was
> enabled."
>
> There is still an issue with stale DR6 bits potentially being
> misreported for the current debug exception. DR6 should not have been
> modified before vectoring the #DB exception, and the "new DR6 bits"
> should be available somewhere, but it was and they aren't.
>
> Fixes: b96fb439774e1 ("KVM: nVMX: fixes to nested virt interrupt injection")
> Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
Reviewed-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
