[PATCH v2 0/2] xen/x86: alternative fix for XSA-369

From: Roger Pau Monne
Date: Wed Mar 24 2021 - 08:25:38 EST


Hello,

This is a proposal for an alternative fix for XSA-369 that instead of
special casing XEN_UNPOPULATED_ALLOC to size the p2m relies on making
XEN_BALLOON_MEMORY_HOTPLUG_LIMIT depend on the generic MEMORY_HOTPLUG
option rather than XEN_BALLOON_MEMORY_HOTPLUG.

I think this is safer, as we don't want to be special casing any option
that pulls in generic MEMORY_HOTPLUG without XEN_BALLOON_MEMORY_HOTPLUG.
Without this we would also need to at least special case ZONE_DEVICE
which also relies on MEMORY_HOTPLUG, and is what pulls the generic
MEMORY_HOTPLUG option even when XEN_BALLOON_MEMORY_HOTPLUG is disabled
with XEN_UNPOPULATED_ALLOC.

Thanks, Roger.

Roger Pau Monne (2):
xen/x86: make XEN_BALLOON_MEMORY_HOTPLUG_LIMIT depend on
MEMORY_HOTPLUG
Revert "xen: fix p2m size in dom0 for disabled memory hotplug case"

arch/x86/include/asm/xen/page.h | 12 ------------
arch/x86/xen/p2m.c | 7 ++-----
arch/x86/xen/setup.c | 16 ++++++++++++++--
drivers/xen/Kconfig | 4 ++--
4 files changed, 18 insertions(+), 21 deletions(-)

--
2.30.1