arm/arm64: KVM: Allow a VCPU to fully reset itself

The current kvm_psci_vcpu_on implementation will directly try to
manipulate the state of the VCPU to reset it.  However, since this is
not done on the thread that runs the VCPU, we can end up in a strangely
corrupted state when the source and target VCPUs are running at the same
time.

Fix this by factoring out all reset logic from the PSCI implementation
and forwarding the required information along with a request to the
target VCPU.

Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
This commit is contained in:
Marc Zyngier
2018-12-20 11:36:07 +00:00
parent e761a927bc
commit 358b28f09f
6 changed files with 95 additions and 20 deletions

View File

@@ -626,6 +626,13 @@ static void vcpu_req_sleep(struct kvm_vcpu *vcpu)
/* Awaken to handle a signal, request we sleep again later. */
kvm_make_request(KVM_REQ_SLEEP, vcpu);
}
/*
* Make sure we will observe a potential reset request if we've
* observed a change to the power state. Pairs with the smp_wmb() in
* kvm_psci_vcpu_on().
*/
smp_rmb();
}
static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu)
@@ -639,6 +646,9 @@ static void check_vcpu_requests(struct kvm_vcpu *vcpu)
if (kvm_check_request(KVM_REQ_SLEEP, vcpu))
vcpu_req_sleep(vcpu);
if (kvm_check_request(KVM_REQ_VCPU_RESET, vcpu))
kvm_reset_vcpu(vcpu);
/*
* Clear IRQ_PENDING requests that were made to guarantee
* that a VCPU sees new virtual interrupts.