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author | Michael Kelley <mhkelley@outlook.com> | 2018-03-04 22:17:18 -0700 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-03-06 09:57:17 -0800 |
commit | 248e742a396e7f00b283f1c56e14b1bef6e3ec56 (patch) | |
tree | 7c4976f72e563b771ac6b53094cab1e91fe3849c /arch/x86/include/uapi | |
parent | ce767047b1b731a1899a528338644f2bfdab8b36 (diff) | |
download | op-kernel-dev-248e742a396e7f00b283f1c56e14b1bef6e3ec56.zip op-kernel-dev-248e742a396e7f00b283f1c56e14b1bef6e3ec56.tar.gz |
Drivers: hv: vmbus: Implement Direct Mode for stimer0
The 2016 version of Hyper-V offers the option to operate the guest VM
per-vcpu stimer's in Direct Mode, which means the timer interupts on its
own vector rather than queueing a VMbus message. Direct Mode reduces
timer processing overhead in both the hypervisor and the guest, and
avoids having timer interrupts pollute the VMbus interrupt stream for
the synthetic NIC and storage. This patch enables Direct Mode by
default on stimer0 when running on a version of Hyper-V that supports
it.
In prep for coming support of Hyper-V on ARM64, the arch independent
portion of the code contains calls to routines that will be populated
on ARM64 but are not needed and do nothing on x86.
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/include/uapi')
-rw-r--r-- | arch/x86/include/uapi/asm/hyperv.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h index 0994143..6c0c3a3 100644 --- a/arch/x86/include/uapi/asm/hyperv.h +++ b/arch/x86/include/uapi/asm/hyperv.h @@ -77,6 +77,9 @@ /* Crash MSR available */ #define HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE (1 << 10) +/* stimer Direct Mode is available */ +#define HV_X64_STIMER_DIRECT_MODE_AVAILABLE (1 << 19) + /* * Feature identification: EBX indicates which flags were specified at * partition creation. The format is the same as the partition creation |