Yes, I'm only seeing the BSOD since 077fc1c04d. 0e251a837 is still fine and
I can boot my win7 domU.

My bisection process is pretty basic. I have a script which checks out the
git staging tree, does a hard reset on the git commit I want to test,
applies some custom patches (only changes in vif-nat and mkdeb to put some
git build info into the package description so i can use dpkg -I to see
what commit the package is on) and does a make world and make debball:

git clone -b staging git://xenbits.xen.org/xen.git xen-unstable-staging
git reset --hard 077fc1c04d70ef1748ac2daa6622b3320a1a004c
// add custom patches
./configure  --disable-kernels --disable-stubdom --disable-docs
make -j4 world
make -j4 debball

Then I save the created .deb into a folder for storage / later testing and
install it if I want. And with that, I did the usual bisection: use a
previous commit if something goes wrong and a later commit if everything
works, until I arrived at your commit and wrote the mail..

> Also, the original problem I am trying to fix only related to EPT and
VT-d page table sharing. So have you tried to not share them?

Sorry, can you explain this a little more? I don't know how to influence
VT-d page table sharing since I don't know much about the deeper mechanics
of XEN.

But I am very grateful for your help and therefor would like to help with
the testing of your patches.

For my last test I once again used your 077fc1c commit and applied both
your first (printing out if log dirty mode is enabled) and second (the
latest) patch and it actually workd: no BSOD and the domU came up fine and
was usable. Also logs seem fine and there were no VT-d page faults. I
attached qemu log and xl dmesg log never the less.

Hope this helps!