| Message ID | 20210730114231.23445-1-will@kernel.org (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Headers | show |
| Series | powerpc/svm: Don't issue ultracalls if !mem_encrypt_active() | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/github-powerpc_selftests | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_ppctests | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_clang | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_sparse | success | Successfully ran 4 jobs. |
| snowpatch_ozlabs/github-powerpc_kernel_qemu | success | Successfully ran 25 jobs. |
Excerpts from Will Deacon's message of July 30, 2021 9:42 pm: > 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.wilk@oracle.com> > Cc: Claire Chang <tientzu@chromium.org> > Cc: Christoph Hellwig <hch@lst.de> > Cc: Robin Murphy <robin.murphy@arm.com> > Fixes: ad6c00283163 ("swiotlb: Free tbl memory in swiotlb_exit()") > Suggested-by: Nicholas Piggin <npiggin@gmail.com> > Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com> > Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com> > Tested-by: Nathan Chancellor <nathan@kernel.org> > Link: https://lore.kernel.org/r/1905CD70-7656-42AE-99E2-A31FC3812EAC@linux.vnet.ibm.com/ > Signed-off-by: Will Deacon <will@kernel.org> > --- Thanks for writing it. Acked-by: Nicholas Piggin <npiggin@gmail.com> > 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 > >
Will Deacon <will@kernel.org> writes: > 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.wilk@oracle.com> > Cc: Claire Chang <tientzu@chromium.org> > Cc: Christoph Hellwig <hch@lst.de> > Cc: Robin Murphy <robin.murphy@arm.com> > Fixes: ad6c00283163 ("swiotlb: Free tbl memory in swiotlb_exit()") > Suggested-by: Nicholas Piggin <npiggin@gmail.com> > Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com> > Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com> > Tested-by: Nathan Chancellor <nathan@kernel.org> > Link: https://lore.kernel.org/r/1905CD70-7656-42AE-99E2-A31FC3812EAC@linux.vnet.ibm.com/ > Signed-off-by: Will Deacon <will@kernel.org> > --- > arch/powerpc/platforms/pseries/svm.c | 6 ++++++ > 1 file changed, 6 insertions(+) Thanks. Acked-by: Michael Ellerman <mpe@ellerman.id.au> I assume Konrad will take this via the swiotlb tree? cheers
On Mon, Aug 02, 2021 at 09:20:30PM +1000, Michael Ellerman wrote: > Will Deacon <will@kernel.org> writes: > > 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.wilk@oracle.com> > > Cc: Claire Chang <tientzu@chromium.org> > > Cc: Christoph Hellwig <hch@lst.de> > > Cc: Robin Murphy <robin.murphy@arm.com> > > Fixes: ad6c00283163 ("swiotlb: Free tbl memory in swiotlb_exit()") > > Suggested-by: Nicholas Piggin <npiggin@gmail.com> > > Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com> > > Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com> > > Tested-by: Nathan Chancellor <nathan@kernel.org> > > Link: https://lore.kernel.org/r/1905CD70-7656-42AE-99E2-A31FC3812EAC@linux.vnet.ibm.com/ > > Signed-off-by: Will Deacon <will@kernel.org> > > --- > > arch/powerpc/platforms/pseries/svm.c | 6 ++++++ > > 1 file changed, 6 insertions(+) > > Thanks. > > Acked-by: Michael Ellerman <mpe@ellerman.id.au> > > > I assume Konrad will take this via the swiotlb tree? Btw, we're currently reworking that whole "am I running as a confidential guest" querying, see: https://lkml.kernel.org/r/029791b24c6412f9427cfe6ec598156c64395964.1627424774.git.thomas.lendacky@amd.com for example. I see Konrad has queued this for 5.15 in his devel/for-linus-5.15 branch so if he sends it to Linus in the upcoming merge window (right Konrad?) then I can base the rework ontop, once 5.15-rc1 releases, so that there are no build breakages... Thx.
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;
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.wilk@oracle.com> Cc: Claire Chang <tientzu@chromium.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Robin Murphy <robin.murphy@arm.com> Fixes: ad6c00283163 ("swiotlb: Free tbl memory in swiotlb_exit()") Suggested-by: Nicholas Piggin <npiggin@gmail.com> Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com> Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/1905CD70-7656-42AE-99E2-A31FC3812EAC@linux.vnet.ibm.com/ Signed-off-by: Will Deacon <will@kernel.org> --- arch/powerpc/platforms/pseries/svm.c | 6 ++++++ 1 file changed, 6 insertions(+)