path: root/kernel
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authorRadim Krčmář <rkrcmar@redhat.com>2015-03-25 12:08:14 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2015-04-27 15:48:59 +0200
commit5dca0d9147458be9b9363b8a484aa77d710b412a (patch)
treec1614d2156f3d2b28ecc003e81cee39e8513f023 /kernel
parentb787f68c36d49bb1d9236f403813641efa74a031 (diff)
kvm: x86: fix kvmclock update protocol
The kvmclock spec says that the host will increment a version field to an odd number, then update stuff, then increment it to an even number. The host is buggy and doesn't do this, and the result is observable when one vcpu reads another vcpu's kvmclock data. There's no good way for a guest kernel to keep its vdso from reading a different vcpu's kvmclock data, but we don't need to care about changing VCPUs as long as we read a consistent data from kvmclock. (VCPU can change outside of this loop too, so it doesn't matter if we return a value not fit for this VCPU.) Based on a patch by Radim Krčmář. Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Acked-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'kernel')
0 files changed, 0 insertions, 0 deletions

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