Acked: [bionic:linux-azure][PATCH 1/1] Drivers: hv: vmbus: Implement Direct Mode for stimer0
Krzysztof Kozlowski
krzysztof.kozlowski at canonical.com
Wed Jul 28 07:28:57 UTC 2021
On 23/07/2021 20:14, Guilherme G. Piccoli wrote:
> From: Michael Kelley <mhkelley at outlook.com>
>
> BugLink: https://bugs.launchpad.net/bugs/1882623
>
> 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 at microsoft.com>
> Signed-off-by: K. Y. Srinivasan <kys at microsoft.com>
> Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> (backported from commit 248e742a396e7f00b283f1c56e14b1bef6e3ec56)
> [gpiccoli: context adjustments, specially due to the lack of the
> following commits in our kernel:
> - commit 51d4e5daa328 ("x86/irq: Count Hyper-V reenlightenment interrupts")
> - commit 5a4858032217 ("x86/hyper-v: move hyperv.h out of uapi")
> Note that the hyperv.h uapi file changed to hyperv-tlfs.h not in uapi.]
> Signed-off-by: Guilherme G. Piccoli <gpiccoli at canonical.com>
> ---
> arch/x86/entry/entry_32.S | 3 ++
> arch/x86/entry/entry_64.S | 3 ++
> arch/x86/include/asm/hardirq.h | 3 ++
> arch/x86/include/asm/hyperv-tlfs.h | 3 ++
> arch/x86/include/asm/irq_vectors.h | 3 +-
> arch/x86/include/asm/mshyperv.h | 13 +++++++
> arch/x86/kernel/cpu/mshyperv.c | 40 ++++++++++++++++++++
> arch/x86/kernel/irq.c | 7 ++++
> drivers/hv/hv.c | 59 ++++++++++++++++++++++++++++--
> drivers/hv/hyperv_vmbus.h | 4 +-
> 10 files changed, 133 insertions(+), 5 deletions(-)
>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski at canonical.com>
Best regards,
Krzysztof
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