| Message ID | 20230109150922.10578-1-jgross@suse.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 26ce6ec364f18d2915923bc05784084e54a5c4cc |
| Headers | show |
| Series | x86/mm: fix poking_init() for Xen PV guests | expand |
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index d3987359d441..5f8ba537d9d3 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -804,6 +804,9 @@ void __init poking_init(void) poking_mm = mm_alloc(); BUG_ON(!poking_mm); + /* Xen PV guests need the PGD to be pinned. */ + paravirt_arch_dup_mmap(NULL, poking_mm); + /* * Randomize the poking address, but make sure that the following page * will be mapped at the same PMD. We need 2 pages, so find space for 3,
Commit 3f4c8211d982 ("x86/mm: Use mm_alloc() in poking_init()") broke the kernel for running as Xen PV guest. It seems as if the new address space is never activated before being used, resulting in Xen rejecting to accept the new CR3 value (the PGD isn't pinned). Fix that by adding the now missing call of paravirt_arch_dup_mmap() to poking_init(). That call was previously done by dup_mm()->dup_mmap() and it is a NOP for all cases but for Xen PV, where it is just doing the pinning of the PGD. Fixes: 3f4c8211d982 ("x86/mm: Use mm_alloc() in poking_init()") Signed-off-by: Juergen Gross <jgross@suse.com> --- arch/x86/mm/init.c | 3 +++ 1 file changed, 3 insertions(+)