Re: [PATCH 13/14] KVM: x86: Directly block (instead of "halting") UNINITIALIZED vCPUs
From: David Matlack <dmatlack@google.com>
Date: 2021-09-28 22:13:00
Also in:
kvm, kvmarm, linux-arm-kernel, lkml
On Fri, Sep 24, 2021 at 05:55:27PM -0700, Sean Christopherson wrote:
Go directly to kvm_vcpu_block() when handling the case where userspace attempts to run an UNINITIALIZED vCPU. The vCPU isn't halted and its time spent in limbo arguably should not be factored into halt-polling as the behavior of the VM at this point is not at all indicative of the behavior of the VM once it is up and running, i.e. executing HLT in idle tasks. Note, because this case is encountered only on the first run of an AP vCPU, vcpu->halt_poll_ns is guaranteed to be '0', and so KVM will not attempt halt-polling, i.e. this really only affects the post-block bookkeeping. Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: David Matlack <dmatlack@google.com>
quoted hunk ↗ jump to hunk
--- arch/x86/kvm/x86.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 0d71c73a61bb..b444f9315766 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c@@ -10127,7 +10127,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) r = -EINTR; goto out; } - kvm_vcpu_halt(vcpu); + kvm_vcpu_block(vcpu); if (kvm_apic_accept_events(vcpu) < 0) { r = 0; goto out;-- 2.33.0.685.g46640cef36-goog