From 34e30ebbe48cc43c14276f863f0d2995c8f13186 Mon Sep 17 00:00:00 2001 From: David Matlack Date: Thu, 1 Dec 2022 11:52:49 -0800 Subject: KVM: Document the interaction between KVM_CAP_HALT_POLL and halt_poll_ns Clarify the existing documentation about how KVM_CAP_HALT_POLL and halt_poll_ns interact to make it clear that VMs using KVM_CAP_HALT_POLL ignore halt_poll_ns. Signed-off-by: David Matlack Message-Id: <20221201195249.3369720-3-dmatlack@google.com> Signed-off-by: Paolo Bonzini --- Documentation/virt/kvm/api.rst | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) (limited to 'Documentation/virt/kvm/api.rst') diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index eee9f857a986..896914e3a847 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -7213,14 +7213,13 @@ veto the transition. :Parameters: args[0] is the maximum poll time in nanoseconds :Returns: 0 on success; -1 on error -This capability overrides the kvm module parameter halt_poll_ns for the -target VM. - -VCPU polling allows a VCPU to poll for wakeup events instead of immediately -scheduling during guest halts. The maximum time a VCPU can spend polling is -controlled by the kvm module parameter halt_poll_ns. This capability allows -the maximum halt time to specified on a per-VM basis, effectively overriding -the module parameter for the target VM. +KVM_CAP_HALT_POLL overrides the kvm.halt_poll_ns module parameter to set the +maximum halt-polling time for all vCPUs in the target VM. This capability can +be invoked at any time and any number of times to dynamically change the +maximum halt-polling time. + +See Documentation/virt/kvm/halt-polling.rst for more information on halt +polling. 7.21 KVM_CAP_X86_USER_SPACE_MSR ------------------------------- -- cgit v1.2.3