The KVM_KVMCLOCK_CTRL ioctl signals to supported KVM guests
that the hypervisor has paused it. Update the documentation to
reflect that the guest is notified by this API.
Signed-off-by: Joshua Abraham <[email protected]>
---
Changes in v2:
- Re-word documentation to be clearer. Also fix a small grammar
error.
Documentation/virt/kvm/api.rst | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index efbbe570aa9b..d2c1cbce1018 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -2572,13 +2572,15 @@ list in 4.68.
:Parameters: None
:Returns: 0 on success, -1 on error
-This signals to the host kernel that the specified guest is being paused by
-userspace. The host will set a flag in the pvclock structure that is checked
-from the soft lockup watchdog. The flag is part of the pvclock structure that
-is shared between guest and host, specifically the second bit of the flags
+This ioctl sets a flag accessible to the guest indicating that the specified
+vCPU has been paused by the host userspace.
+
+The host will set a flag in the pvclock structure that is checked from the
+soft lockup watchdog. The flag is part of the pvclock structure that is
+shared between guest and host, specifically the second bit of the flags
field of the pvclock_vcpu_time_info structure. It will be set exclusively by
the host and read/cleared exclusively by the guest. The guest operation of
-checking and clearing the flag must an atomic operation so
+checking and clearing the flag must be an atomic operation so
load-link/store-conditional, or equivalent must be used. There are two cases
where the guest will clear the flag: when the soft lockup watchdog timer resets
itself or when a soft lockup is detected. This ioctl can be called any time
--
2.17.1
On Fri, 1 May 2020 18:36:24 -0400
Joshua Abraham <[email protected]> wrote:
> The KVM_KVMCLOCK_CTRL ioctl signals to supported KVM guests
> that the hypervisor has paused it. Update the documentation to
> reflect that the guest is notified by this API.
>
> Signed-off-by: Joshua Abraham <[email protected]>
> ---
> Changes in v2:
> - Re-word documentation to be clearer. Also fix a small grammar
> error.
>
> Documentation/virt/kvm/api.rst | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
Applied, thanks.
jon