[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [Patch v2] x86/time: Correctly update the domain wallclock in the shared info page
For a normal HVM domain on 64bit Xen, the shared info switches to 32bit for hvmloader, then to the native size for the HVM guest. This guarantees at least one transition during which the wallclock information will be updated. The wallclock for each domain gets updated when dom0 issues a XENPF_settime hypercall to updated the wallclock base time. However, for a 64bit domain on 64bit Xen which is resuming from S4, (i.e. bypassing hvmloader), there are no transitions in the size of the shared info page, meaning that before the next XENPF_settime from dom0, the domU PV drivers will find the Unix Epoch in the wallclock rather than the correct time. Therefore, manually set the wallclock when creating the domain, so it is set right from the start of the domain, and when manually adjusting the domain time offset, as it depends on the same value which has just been adjusted. Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> CC: Keir Fraser <keir@xxxxxxx> CC: Jan Beulich <JBeulich@xxxxxxxx> CC: Paul Durrant <Paul.Durrant@xxxxxxxxxx> --- This fixes a bug presence since Xen gained 64bit support, which had been hacked around in a gross way in XenServer. It should be backported to all stable releases. Changes since v1: * s/watchdog/wallclock/ - Stupid typo. --- xen/arch/x86/domain.c | 1 + xen/arch/x86/time.c | 1 + 2 files changed, 2 insertions(+) diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c index 874742c..664d598 100644 --- a/xen/arch/x86/domain.c +++ b/xen/arch/x86/domain.c @@ -546,6 +546,7 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags) clear_page(d->shared_info); share_xen_page_with_guest( virt_to_page(d->shared_info), d, XENSHARE_writable); + update_domain_wallclock_time(d); if ( (rc = init_domain_irq_mapping(d)) != 0 ) goto fail; diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c index cf8bc78..f047cb3 100644 --- a/xen/arch/x86/time.c +++ b/xen/arch/x86/time.c @@ -931,6 +931,7 @@ void domain_set_time_offset(struct domain *d, int32_t time_offset_seconds) d->time_offset_seconds = time_offset_seconds; if ( is_hvm_domain(d) ) rtc_update_clock(d); + update_domain_wallclock_time(d); } int cpu_frequency_change(u64 freq) -- 1.7.10.4 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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