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| author | Christian Borntraeger <borntraeger@linux.ibm.com> | 2022-01-17 20:40:32 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-02-01 19:26:59 +0300 |
| commit | cfd2a7f8deaa6c86bcb12dad82a8b8a871d8aff2 (patch) | |
| tree | fa2a4238d9f7bff711db6cc762a574f882c8e39f /arch/s390 | |
| parent | c058e1ae9dd516cbc8b6a38dc6d67d70479dfbbf (diff) | |
| download | linux-cfd2a7f8deaa6c86bcb12dad82a8b8a871d8aff2.tar.xz | |
s390/nmi: handle vector validity failures for KVM guests
commit f094a39c6ba168f2df1edfd1731cca377af5f442 upstream.
The machine check validity bit tells about the context. If a KVM guest
was running the bit tells about the guest validity and the host state is
not affected. As a guest can disable the guest validity this might
result in unwanted host errors on machine checks.
Cc: stable@vger.kernel.org
Fixes: c929500d7a5a ("s390/nmi: s390: New low level handling for machine check happening in guest")
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/kernel/nmi.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c index dffc65d8064c..a50f2ff1b00e 100644 --- a/arch/s390/kernel/nmi.c +++ b/arch/s390/kernel/nmi.c @@ -273,7 +273,14 @@ static int notrace s390_validate_registers(union mci mci, int umode) /* Validate vector registers */ union ctlreg0 cr0; - if (!mci.vr) { + /* + * The vector validity must only be checked if not running a + * KVM guest. For KVM guests the machine check is forwarded by + * KVM and it is the responsibility of the guest to take + * appropriate actions. The host vector or FPU values have been + * saved by KVM and will be restored by KVM. + */ + if (!mci.vr && !test_cpu_flag(CIF_MCCK_GUEST)) { /* * Vector registers can't be restored. If the kernel * currently uses vector registers the system is |