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| author | Christian Borntraeger <borntraeger@de.ibm.com> | 2018-11-09 09:21:47 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-31 08:14:35 +0100 |
| commit | e0d573a08f234722fe21a5729d2e945b775c5201 (patch) | |
| tree | 0582ba4413ea89a421963a68b9021f187caade78 /arch/s390/kernel | |
| parent | b563764443a302aab197550870ca57fda65662b8 (diff) | |
| download | linux-stable-e0d573a08f234722fe21a5729d2e945b775c5201.tar.gz linux-stable-e0d573a08f234722fe21a5729d2e945b775c5201.tar.bz2 linux-stable-e0d573a08f234722fe21a5729d2e945b775c5201.zip | |
s390/early: improve machine detection
commit 03aa047ef2db4985e444af6ee1c1dd084ad9fb4c upstream.
Right now the early machine detection code check stsi 3.2.2 for "KVM"
and set MACHINE_IS_VM if this is different. As the console detection
uses diagnose 8 if MACHINE_IS_VM returns true this will crash Linux
early for any non z/VM system that sets a different value than KVM.
So instead of assuming z/VM, do not set any of MACHINE_IS_LPAR,
MACHINE_IS_VM, or MACHINE_IS_KVM.
CC: stable@vger.kernel.org
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/s390/kernel')
| -rw-r--r-- | arch/s390/kernel/early.c | 4 | ||||
| -rw-r--r-- | arch/s390/kernel/setup.c | 2 |
2 files changed, 4 insertions, 2 deletions
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c index 5b28b434f8a1..e7e6608b996c 100644 --- a/arch/s390/kernel/early.c +++ b/arch/s390/kernel/early.c @@ -64,10 +64,10 @@ static noinline __init void detect_machine_type(void) if (stsi(vmms, 3, 2, 2) || !vmms->count) return; - /* Running under KVM? If not we assume z/VM */ + /* Detect known hypervisors */ if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3)) S390_lowcore.machine_flags |= MACHINE_FLAG_KVM; - else + else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4)) S390_lowcore.machine_flags |= MACHINE_FLAG_VM; } diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index c637c12f9e37..a0097f8bada8 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -882,6 +882,8 @@ void __init setup_arch(char **cmdline_p) pr_info("Linux is running under KVM in 64-bit mode\n"); else if (MACHINE_IS_LPAR) pr_info("Linux is running natively in 64-bit mode\n"); + else + pr_info("Linux is running as a guest in 64-bit mode\n"); /* Have one command line that is parsed and saved in /proc/cmdline */ /* boot_command_line has been already set up in early.c */ |