| Message ID | 20190527063931.16303-2-po-hsu.lin@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | s390/early: improve machine detection | expand |
On 5/26/19 11:39 PM, Po-Hsu Lin wrote: > From: Christian Borntraeger <borntraeger@de.ibm.com> > > BugLink: https://bugs.launchpad.net/bugs/1829972 > > 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> > (cherry picked from commit 03aa047ef2db4985e444af6ee1c1dd084ad9fb4c) > Signed-off-by: Po-Hsu Lin <po-hsu.lin@canonical.com> Acked-by: Connor Kuehl <connor.kuehl@canonical.com> > --- > arch/s390/kernel/early.c | 4 ++-- > 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 ac707a9..77f162b 100644 > --- a/arch/s390/kernel/early.c > +++ b/arch/s390/kernel/early.c > @@ -90,10 +90,10 @@ 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 0786a6b..c69f3a3 100644 > --- a/arch/s390/kernel/setup.c > +++ b/arch/s390/kernel/setup.c > @@ -880,6 +880,8 @@ 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 */ >
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c index ac707a9..77f162b 100644 --- a/arch/s390/kernel/early.c +++ b/arch/s390/kernel/early.c @@ -90,10 +90,10 @@ 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 0786a6b..c69f3a3 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -880,6 +880,8 @@ 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 */