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4d25a066b6
Unlike all of the other cpuid bits, the TSC deadline timer bit is set unconditionally, regardless of what userspace wants. This is broken in several ways: - if userspace doesn't use KVM_CREATE_IRQCHIP, and doesn't emulate the TSC deadline timer feature, a guest that uses the feature will break - live migration to older host kernels that don't support the TSC deadline timer will cause the feature to be pulled from under the guest's feet; breaking it - guests that are broken wrt the feature will fail. Fix by not enabling the feature automatically; instead report it to userspace. Because the feature depends on KVM_CREATE_IRQCHIP, which we cannot guarantee will be called, we expose it via a KVM_CAP_TSC_DEADLINE_TIMER and not KVM_GET_SUPPORTED_CPUID. Fixes the Illumos guest kernel, which uses the TSC deadline timer feature. [avi: add the KVM_CAP + documentation] Reported-by: Alexey Zaytsev <alexey.zaytsev@gmail.com> Tested-by: Alexey Zaytsev <alexey.zaytsev@gmail.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com> |
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.. | ||
boot | ||
configs | ||
crypto | ||
ia32 | ||
include/asm | ||
kernel | ||
kvm | ||
lguest | ||
lib | ||
math-emu | ||
mm | ||
net | ||
oprofile | ||
pci | ||
platform | ||
power | ||
tools | ||
um | ||
vdso | ||
video | ||
xen | ||
.gitignore | ||
Kbuild | ||
Kconfig | ||
Kconfig.cpu | ||
Kconfig.debug | ||
Makefile | ||
Makefile_32.cpu | ||
Makefile.um |