Excerpts from Christian Zigotzky's message of June 12, 2020 11:01 pm:
On 11 June 2020 at 04:47 pm, Christian Zigotzky wrote:
On 10 June 2020 at 01:23 pm, Christian Zigotzky wrote:
On 10 June 2020 at 11:06 am, Christian Zigotzky wrote:
On 10 June 2020 at 00:18 am, Christian Zigotzky wrote:
Hello,
KVM-PR doesn't work anymore on my Nemo board [1]. I figured out
that the Git kernels and the kernel 5.7 are affected.
Error message: Fienix kernel: kvmppc_exit_pr_progint: emulation at
700 failed (00000000)
I can boot virtual QEMU PowerPC machines with KVM-PR with the
kernel 5.6 without any problems on my Nemo board.
I tested it with QEMU 2.5.0 and QEMU 5.0.0 today.
Could you please check KVM-PR on your PowerPC machine?
Thanks,
Christian
[1] https://en.wikipedia.org/wiki/AmigaOne_X1000
I figured out that the PowerPC updates 5.7-1 [1] are responsible
for
the KVM-PR issue. Please test KVM-PR on your PowerPC machines and
check the PowerPC updates 5.7-1 [1].
Thanks
[1]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d38c07afc356ddebaa3ed8ecb3f553340e05c969
I tested the latest Git kernel with Mac-on-Linux/KVM-PR today.
Unfortunately I can't use KVM-PR with MoL anymore because of this
issue (see screenshots [1]). Please check the PowerPC updates 5.7-1.
Thanks
[1]
-
https://i.pinimg.com/originals/0c/b3/64/0cb364a40241fa2b7f297d4272bbb8b7.png
-
https://i.pinimg.com/originals/9a/61/d1/9a61d170b1c9f514f7a78a3014ffd18f.png
Hi All,
I bisected today because of the KVM-PR issue.
Result:
9600f261acaaabd476d7833cec2dd20f2919f1a0 is the first bad commit
commit 9600f261acaaabd476d7833cec2dd20f2919f1a0
Author: Nicholas Piggin <npiggin@xxxxxxxxx>
Date: Wed Feb 26 03:35:21 2020 +1000
powerpc/64s/exception: Move KVM test to common code
This allows more code to be moved out of unrelocated regions.
The
system call KVMTEST is changed to be open-coded and remain in
the
tramp area to avoid having to move it to entry_64.S. The custom
nature
of the system call entry code means the hcall case can be
made more
streamlined than regular interrupt handlers.
mpe: Incorporate fix from Nick:
Moving KVM test to the common entry code missed the case of
HMI and
MCE, which do not do __GEN_COMMON_ENTRY (because they don't
want to
switch to virt mode).
This means a MCE or HMI exception that is taken while KVM is
running a
guest context will not be switched out of that context, and
KVM won't
be notified. Found by running sigfuz in guest with patched
host on
POWER9 DD2.3, which causes some TM related HMI interrupts
(which are
expected and supposed to be handled by KVM).
This fix adds a __GEN_REALMODE_COMMON_ENTRY for those
handlers to add
the KVM test. This makes them look a little more like other
handlers
that all use __GEN_COMMON_ENTRY.
Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link:
https://lore.kernel.org/r/20200225173541.1549955-13-npiggin@xxxxxxxxx
:040000 040000 ec21cec22d165f8696d69532734cb2985d532cb0
87dd49a9cd7202ec79350e8ca26cea01f1dbd93d M arch
-----
The following commit is the problem: powerpc/64s/exception: Move KVM
test to common code [1]
These changes were included in the PowerPC updates 5.7-1. [2]
Another test:
git checkout d38c07afc356ddebaa3ed8ecb3f553340e05c969 (PowerPC
updates
5.7-1 [2] ) -> KVM-PR doesn't work.
After that: git revert d38c07afc356ddebaa3ed8ecb3f553340e05c969 -m 1
-> KVM-PR works.
Could you please check the first bad commit? [1]
Thanks,
Christian
[1]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9600f261acaaabd476d7833cec2dd20f2919f1a0
[2]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d38c07afc356ddebaa3ed8ecb3f553340e05c969
Hi All,
I tried to revert the __GEN_REALMODE_COMMON_ENTRY fix for the
latest Git
kernel and for the stable kernel 5.7.2 but without any success. There
was lot of restructuring work during the kernel 5.7 development
time in
the PowerPC area so it isn't possible reactivate the old code. That
means we have lost the whole KVM-PR support. I also reported this
issue
to Alexander Graf two days ago. He wrote: "Howdy :). It looks pretty
broken. Have you ever made a bisect to see where the problem comes
from?"
Please check the KVM-PR code.
Does this patch fix it for you?
The CTR register reload in the KVM interrupt path used the wrong save
area for SLB (and NMI) interrupts.
Fixes: 9600f261acaaa ("powerpc/64s/exception: Move KVM test to
common code")
Reported-by: Christian Zigotzky <chzigotzky@xxxxxxxxxxx>
Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
---
arch/powerpc/kernel/exceptions-64s.S | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/exceptions-64s.S
b/arch/powerpc/kernel/exceptions-64s.S
index e70ebb5c318c..fa080694e581 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -270,7 +270,7 @@ BEGIN_FTR_SECTION
END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
.endif
- ld r10,PACA_EXGEN+EX_CTR(r13)
+ ld r10,IAREA+EX_CTR(r13)
mtctr r10
BEGIN_FTR_SECTION
ld r10,IAREA+EX_PPR(r13)
@@ -298,7 +298,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
.if IKVM_SKIP
89: mtocrf 0x80,r9
- ld r10,PACA_EXGEN+EX_CTR(r13)
+ ld r10,IAREA+EX_CTR(r13)
mtctr r10
ld r9,IAREA+EX_R9(r13)
ld r10,IAREA+EX_R10(r13)
