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authorJuergen Gross2023-01-09 16:09:22 +0100
committerPeter Zijlstra2023-01-12 11:22:20 +0100
commit26ce6ec364f18d2915923bc05784084e54a5c4cc (patch)
tree8af8622ce3f5137c36a488a9e337869e40cad13a /arch
parent2a81160d29d65b5876ab3f824fda99ae0219f05e (diff)
x86/mm: fix poking_init() for Xen PV guests
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> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20230109150922.10578-1-jgross@suse.com
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/mm/init.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index d3987359d441..cb258f58fdc8 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -26,6 +26,7 @@
#include <asm/pti.h>
#include <asm/text-patching.h>
#include <asm/memtype.h>
+#include <asm/paravirt.h>
/*
* We need to define the tracepoints somewhere, and tlb.c
@@ -804,6 +805,9 @@ 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,