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| author | Christian Borntraeger <borntraeger@de.ibm.com> | 2018-11-09 09:21:47 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2019-05-02 21:41:19 +0100 |
| commit | 7804d76c3675b4b1e442e3a89834665bcac45645 (patch) | |
| tree | 8f764ac8e871e57ca88d16fa4942f5d567406eeb /arch/s390/kernel | |
| parent | cce7cb83976e0413f0b1e77f70e1d0aa508e7d20 (diff) | |
| download | linux-stable-7804d76c3675b4b1e442e3a89834665bcac45645.tar.gz linux-stable-7804d76c3675b4b1e442e3a89834665bcac45645.tar.bz2 linux-stable-7804d76c3675b4b1e442e3a89834665bcac45645.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.
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>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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 ec372dd54c7f..94aab1c8d0ef 100644 --- a/arch/s390/kernel/early.c +++ b/arch/s390/kernel/early.c @@ -232,10 +232,10 @@ 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 1e2264b46e4c..9539c86684c1 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -831,6 +831,8 @@ 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"); #endif /* CONFIG_64BIT */ /* Have one command line that is parsed and saved in /proc/cmdline */ |