| Message ID | 20180621150645.GB8203@flask (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Jun 21, 2018 at 05:06:48PM +0200, Radim Krčmář wrote: > 2018-06-21 08:13-0400, mpagano@gentoo.org: > > From: Mike Pagano <mpagano@gentoo.org> > > > > Please check that the following patch fixes your problem as well, > > thanks. > Thank-you. Our user reports this patch as fixing his issue. See: https://bugs.gentoo.org/show_bug.cgi?id=658544
On 21/06/2018 17:06, Radim Krčmář wrote: >> Signed-off-by: Andreas Steinmetz <ast@domdv.de> >> --- >> arch/x86/kernel/kvmclock.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c >> index bf8d1eb7fca3..6aee5c6265b3 100644 >> --- a/arch/x86/kernel/kvmclock.c >> +++ b/arch/x86/kernel/kvmclock.c >> @@ -350,7 +350,7 @@ void __init kvmclock_init(void) >> >> int __init kvm_setup_vsyscall_timeinfo(void) >> { >> -#ifdef CONFIG_X86_64 >> +#ifdef CONFIG_X86_64 || defined(CONFIG_X86_32) > > The code should actually read "#if defined(...", or be omitted as we > have only these two x86 variants. The correct variant might cause > unexpected bugs by enabling the vsyscall on 32 bit kernels. > > Please check that the following patch fixes your problem as well, > > thanks. Thanks Radim, I queued your patch. Paolo > ---8<--- > pvti_cpu0_va is the address of shared kvmclock data structure. > > pvti_cpu0_va is currently kept unset (1) on 32 bit systems, (2) when > kvmclock vsyscall is disabled, and (3) if kvmclock is not stable. > This poses a problem, because kvm_ptp needs pvti_cpu0_va, but (1) can > work on 32 bit, (2) has little relation to the vsyscall, and (3) does > not need stable kvmclock (although kvmclock won't be used for system > clock if it's not stable, so kvm_ptp is pointless in that case). > > Expose pvti_cpu0_va whenever kvmclock is enabled to allow all users to > work with it. > > This fixes a regression found on Gentoo: https://bugs.gentoo.org/658544. > > Fixes: 9f08890ab906 ("x86/pvclock: add setter for pvclock_pvti_cpu0_va") > Reported-by: Andreas Steinmetz <ast@domdv.de> > Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> > --- > arch/x86/kernel/kvmclock.c | 11 +++++------ > 1 file changed, 5 insertions(+), 6 deletions(-) > > diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c > index bf8d1eb7fca3..46ffa8327563 100644 > --- a/arch/x86/kernel/kvmclock.c > +++ b/arch/x86/kernel/kvmclock.c > @@ -319,6 +319,8 @@ void __init kvmclock_init(void) > printk(KERN_INFO "kvm-clock: Using msrs %x and %x", > msr_kvm_system_time, msr_kvm_wall_clock); > > + pvclock_set_pvti_cpu0_va(hv_clock); > + > if (kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE_STABLE_BIT)) > pvclock_set_flags(PVCLOCK_TSC_STABLE_BIT); > > @@ -366,14 +368,11 @@ int __init kvm_setup_vsyscall_timeinfo(void) > vcpu_time = &hv_clock[cpu].pvti; > flags = pvclock_read_flags(vcpu_time); > > - if (!(flags & PVCLOCK_TSC_STABLE_BIT)) { > - put_cpu(); > - return 1; > - } > - > - pvclock_set_pvti_cpu0_va(hv_clock); > put_cpu(); > > + if (!(flags & PVCLOCK_TSC_STABLE_BIT)) > + return 1; > + > kvm_clock.archdata.vclock_mode = VCLOCK_PVCLOCK; > #endif > return 0; >
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index bf8d1eb7fca3..46ffa8327563 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -319,6 +319,8 @@ void __init kvmclock_init(void) printk(KERN_INFO "kvm-clock: Using msrs %x and %x", msr_kvm_system_time, msr_kvm_wall_clock); + pvclock_set_pvti_cpu0_va(hv_clock); + if (kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE_STABLE_BIT)) pvclock_set_flags(PVCLOCK_TSC_STABLE_BIT); @@ -366,14 +368,11 @@ int __init kvm_setup_vsyscall_timeinfo(void) vcpu_time = &hv_clock[cpu].pvti; flags = pvclock_read_flags(vcpu_time); - if (!(flags & PVCLOCK_TSC_STABLE_BIT)) { - put_cpu(); - return 1; - } - - pvclock_set_pvti_cpu0_va(hv_clock); put_cpu(); + if (!(flags & PVCLOCK_TSC_STABLE_BIT)) + return 1; + kvm_clock.archdata.vclock_mode = VCLOCK_PVCLOCK; #endif return 0;