guest-diag: strict-anchor pagemap window fallback un-deadlocks the GL setup-push family

A strict demand anchor (the host's exact [entry_va,+len) read window, e.g.
the 60 216 B setup push) whose full-window content parse fails on every
candidate used to set strict_pending, and the pend_bases rule then skipped
every loose demand VA of the same GL family for as long as the anchor was
pending - the host demanded the push's pages individually, the guest
suppressed them, and the entry stayed unreadable for the whole generation
(r1396: entry 8 unreadable=1 on all generations while its sibling entries
read fine; generations churn every ~12 s, the content sweeps take longer).

Add _pagemap_window_pin(): on a failed strict resolve, pin the anchor
window's pages directly from the client's /proc/pid/pagemap (the r586
mechanism already proven for the non-family draws). The anchor VA is the
host's own GPFIFO entry VA, so a present client page is by definition its
translation; no content gate and no family learn, so no k/(area,adj) risk.
Partial presence heals on the ~2 s anchor resend. A 'strict-pagemap:' log
line reports present/total pages either way (0 present => kernel-resident,
the fallback cannot help).

SESSION 153 r1397; scan: r1397 offline brief Change 1.

0 files changed, 0 insertions, 0 deletions