On Tue, Feb 6, 2024 at 5:08 AM Petr Beneš <w1be...@gmail.com> wrote: > > From: Petr Beneš <w1be...@gmail.com> > > This patch addresses a behavior discrepancy in the handling of altp2m views, > where upon the creation and subsequent EPT violation, the page access > permissions were incorrectly inherited from the hostp2m instead of respecting > the altp2m default_access. > > Previously, when a new altp2m view was established with restrictive > default_access permissions and activated via xc_altp2m_switch_to_view(), > it failed to trigger an event on the first access violation. This behavior > diverged from the intended mechanism, where the altp2m's default_access > should dictate the initial permissions, ensuring proper event triggering on > access violations. > > The correction involves modifying the handling mechanism to respect the > altp2m view's default_access upon its activation, eliminating the need for > setting memory access permissions for the entire altp2m range (e.g. within > xen-access.c). This change not only aligns the behavior with the expected > access control logic but also results in a significant performance improvement > by reducing the overhead associated with setting memory access permissions > across the altp2m range. > > Signed-off-by: Petr Beneš <w1be...@gmail.com>
Acked-by: Tamas K Lengyel <ta...@tklengyel.com>
