Re: [PATCH v2 16/16] KVM: PPC: Book3S HV: XIVE: clear the vCPU interrupt presenters

[David Gibson <david@gibson.dropbear.id.au>]

[-- Attachment #1: Type: text/plain, Size: 3263 bytes --]

On Wed, Mar 13, 2019 at 09:17:17AM +0100, Cédric Le Goater wrote:
> On 2/25/19 5:18 AM, David Gibson wrote:
> > On Fri, Feb 22, 2019 at 12:28:40PM +0100, Cédric Le Goater wrote:
> >> When the VM boots, the CAS negotiation process determines which
> >> interrupt mode to use and invokes a machine reset. At that time, the
> >> previous KVM interrupt device is 'destroyed' before the chosen one is
> >> created. Upon destruction, the vCPU interrupt presenters using the KVM
> >> device should be cleared first, the machine will reconnect them later
> >> to the new device after it is created.
> >>
> >> When using the KVM device, there is still a race window with the early
> >> checks in kvmppc_native_connect_vcpu(). Yet to be fixed.
> >>
> >> Signed-off-by: Cédric Le Goater <clg@kaod.org>
> >> ---
> >>  arch/powerpc/kvm/book3s_xics.c        | 19 +++++++++++++
> >>  arch/powerpc/kvm/book3s_xive.c        | 39 +++++++++++++++++++++++++--
> >>  arch/powerpc/kvm/book3s_xive_native.c | 16 +++++++++++
> >>  3 files changed, 72 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/arch/powerpc/kvm/book3s_xics.c b/arch/powerpc/kvm/book3s_xics.c
> >> index f27ee57ab46e..81cdabf4295f 100644
> >> --- a/arch/powerpc/kvm/book3s_xics.c
> >> +++ b/arch/powerpc/kvm/book3s_xics.c
> >> @@ -1342,6 +1342,25 @@ static void kvmppc_xics_free(struct kvm_device *dev)
> >>  	struct kvmppc_xics *xics = dev->private;
> >>  	int i;
> >>  	struct kvm *kvm = xics->kvm;
> >> +	struct kvm_vcpu *vcpu;
> >> +
> >> +	/*
> >> +	 * When destroying the VM, the vCPUs are destroyed first and
> >> +	 * the vCPU list should be empty. If this is not the case,
> >> +	 * then we are simply destroying the device and we should
> >> +	 * clean up the vCPU interrupt presenters first.
> >> +	 */
> >> +	if (atomic_read(&kvm->online_vcpus) != 0) {
> >> +		/*
> >> +		 * call kick_all_cpus_sync() to ensure that all CPUs
> >> +		 * have executed any pending interrupts
> >> +		 */
> >> +		if (is_kvmppc_hv_enabled(kvm))
> >> +			kick_all_cpus_sync();
> >> +
> >> +		kvm_for_each_vcpu(i, vcpu, kvm)
> >> +			kvmppc_xics_free_icp(vcpu);
> >> +	}
> >>  
> >>  	debugfs_remove(xics->dentry);
> >>  
> >> diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c
> >> index 7a14512b8944..0a1c11d6881c 100644
> >> --- a/arch/powerpc/kvm/book3s_xive.c
> >> +++ b/arch/powerpc/kvm/book3s_xive.c
> >> @@ -1105,11 +1105,19 @@ void kvmppc_xive_disable_vcpu_interrupts(struct kvm_vcpu *vcpu)
> >>  void kvmppc_xive_cleanup_vcpu(struct kvm_vcpu *vcpu)
> >>  {
> >>  	struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
> >> -	struct kvmppc_xive *xive = xc->xive;
> >> +	struct kvmppc_xive *xive;
> >>  	int i;
> >>  
> >> +	if (!kvmppc_xics_enabled(vcpu))
> > 
> > This should be kvmppc_xive_enabled(), no?
> 
> This is the KVM XICS-on-XIVE device and its IRQ type is KVMPPC_IRQ_XICS.
> So this is correct :/ 

Ah, right, sorry.

> May be we should introduce a KVMPPC_IRQ_XICS_ON_XIVE macro to
> clarify.

Yeah, maybe.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]