Commit ad6c00283163 ("swiotlb: Free tbl memory in swiotlb_exit()")
introduced a set_memory_encrypted() call to swiotlb_exit() so that the
buffer pages are returned to an encrypted state prior to being freed.
Sachin reports that this leads to the following crash on a Power server:
[ 0.010799] software IO TLB: tearing down default memory pool
[ 0.010805] ------------[ cut here ]------------
[ 0.010808] kernel BUG at arch/powerpc/kernel/interrupt.c:98!
Nick spotted that this is because set_memory_encrypted() is issuing an
ultracall which doesn't exist for the processor, and should therefore
be gated by mem_encrypt_active() to mirror the x86 implementation.
Cc: Konrad Rzeszutek Wilk <konrad.w...@oracle.com>
Cc: Claire Chang <tien...@chromium.org>
Cc: Christoph Hellwig <h...@lst.de>
Cc: Robin Murphy <robin.mur...@arm.com>
Fixes: ad6c00283163 ("swiotlb: Free tbl memory in swiotlb_exit()")
Suggested-by: Nicholas Piggin <npig...@gmail.com>
Reported-by: Sachin Sant <sach...@linux.vnet.ibm.com>
Tested-by: Sachin Sant <sach...@linux.vnet.ibm.com>
Tested-by: Nathan Chancellor <nat...@kernel.org>
Link:
https://lore.kernel.org/r/1905cd70-7656-42ae-99e2-a31fc3812...@linux.vnet.ibm.com/
Signed-off-by: Will Deacon <w...@kernel.org>
---
arch/powerpc/platforms/pseries/svm.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/arch/powerpc/platforms/pseries/svm.c
b/arch/powerpc/platforms/pseries/svm.c
index 1d829e257996..87f001b4c4e4 100644
--- a/arch/powerpc/platforms/pseries/svm.c
+++ b/arch/powerpc/platforms/pseries/svm.c
@@ -63,6 +63,9 @@ void __init svm_swiotlb_init(void)
int set_memory_encrypted(unsigned long addr, int numpages)
{
+ if (!mem_encrypt_active())
+ return 0;
+
if (!PAGE_ALIGNED(addr))
return -EINVAL;
@@ -73,6 +76,9 @@ int set_memory_encrypted(unsigned long addr, int numpages)
int set_memory_decrypted(unsigned long addr, int numpages)
{
+ if (!mem_encrypt_active())
+ return 0;
+
if (!PAGE_ALIGNED(addr))
return -EINVAL;
--
2.32.0.554.ge1b32706d8-goog
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