aha/arch/x86
Glauber Costa afbcf7ab8d KVM: allow userspace to adjust kvmclock offset
When we migrate a kvm guest that uses pvclock between two hosts, we may
suffer a large skew. This is because there can be significant differences
between the monotonic clock of the hosts involved. When a new host with
a much larger monotonic time starts running the guest, the view of time
will be significantly impacted.

Situation is much worse when we do the opposite, and migrate to a host with
a smaller monotonic clock.

This proposed ioctl will allow userspace to inform us what is the monotonic
clock value in the source host, so we can keep the time skew short, and
more importantly, never goes backwards. Userspace may also need to trigger
the current data, since from the first migration onwards, it won't be
reflected by a simple call to clock_gettime() anymore.

[marcelo: future-proof abi with a flags field]
[jan: fix KVM_GET_CLOCK by clearing flags field instead of checking it]

Signed-off-by: Glauber Costa <glommer@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:19 +02:00
..
boot x86: Document linker script ASSERT() quirk 2009-10-16 07:18:46 +02:00
configs tracing: Rename FTRACE_SYSCALLS for tracepoints 2009-08-26 00:17:35 +02:00
crypto crypto: aesni-intel - Fix irq_fpu_usable usage 2009-10-20 16:20:47 +09:00
ia32 x86-64: Fix register leak in 32-bit syscall audting 2009-10-26 16:23:26 +01:00
include/asm KVM: allow userspace to adjust kvmclock offset 2009-12-03 09:32:19 +02:00
kernel Merge remote branch 'tip/x86/entry' into kvm-updates/2.6.33 2009-12-03 09:30:06 +02:00
kvm KVM: allow userspace to adjust kvmclock offset 2009-12-03 09:32:19 +02:00
lguest lguest: move panic notifier registration to its expected place. 2009-09-23 22:26:44 +09:30
lib x86: Don't generate cmpxchg8b_emu if CONFIG_X86_CMPXCHG64=y 2009-10-01 08:42:24 +02:00
math-emu
mm x86: Fix error return sequence in __ioremap_caller() 2009-11-08 12:48:58 +01:00
oprofile perf: Do the big rename: Performance Counters -> Performance Events 2009-09-21 14:28:04 +02:00
pci const: mark struct vm_struct_operations 2009-09-27 11:39:25 -07:00
power x86: Remove final bits of CONFIG_X86_OLD_MCE 2009-09-18 08:31:23 +02:00
vdso kbuild: rename ld-option to cc-ldoption 2009-09-20 12:27:42 +02:00
video
xen xen: mask extended topology info in cpuid 2009-11-03 11:09:12 -08:00
Kbuild
Kconfig Merge remote branch 'tip/x86/entry' into kvm-updates/2.6.33 2009-12-03 09:30:06 +02:00
Kconfig.cpu x86: Side-step lguest problem by only building cmpxchg8b_emu for pre-Pentium 2009-10-26 12:33:02 +01:00
Kconfig.debug kmemcheck: make kconfig accessible for other architectures 2009-06-15 15:49:17 +02:00
Makefile x86: Remove STACKPROTECTOR_ALL 2009-10-23 16:35:23 +02:00
Makefile_32.cpu x86: add specific support for Intel Atom architecture 2009-08-23 11:20:02 +02:00