KVM: PPC: Book3S HV: Tunable to disable KVM IRQ bypass

Add a  module parameter kvm_irq_bypass for kvm_hv.ko to
disable IRQ bypass for passthrough interrupts. The default
value of this tunable is 1 - that is enable the feature.

Since the tunable is used by built-in kernel code, we use
the module_param_cb macro to achieve this.

Signed-off-by: Suresh Warrier <warrier@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This commit is contained in:
Suresh Warrier 2016-08-19 15:35:54 +10:00 committed by Paul Mackerras
parent af893c7dc9
commit 644abbb254
4 changed files with 14 additions and 1 deletions

View File

@ -227,6 +227,7 @@ extern void kvmppc_copy_to_svcpu(struct kvmppc_book3s_shadow_vcpu *svcpu,
struct kvm_vcpu *vcpu);
extern void kvmppc_copy_from_svcpu(struct kvm_vcpu *vcpu,
struct kvmppc_book3s_shadow_vcpu *svcpu);
extern int kvm_irq_bypass;
static inline struct kvmppc_vcpu_book3s *to_book3s(struct kvm_vcpu *vcpu)
{

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@ -461,7 +461,7 @@ static inline int kvmppc_xics_enabled(struct kvm_vcpu *vcpu)
static inline struct kvmppc_passthru_irqmap *kvmppc_get_passthru_irqmap(
struct kvm *kvm)
{
if (kvm)
if (kvm && kvm_irq_bypass)
return kvm->arch.pimap;
return NULL;
}

View File

@ -95,6 +95,10 @@ static struct kernel_param_ops module_param_ops = {
.get = param_get_int,
};
module_param_cb(kvm_irq_bypass, &module_param_ops, &kvm_irq_bypass,
S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(kvm_irq_bypass, "Bypass passthrough interrupt optimization");
module_param_cb(h_ipi_redirect, &module_param_ops, &h_ipi_redirect,
S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(h_ipi_redirect, "Redirect H_IPI wakeup to a free host core");
@ -3443,6 +3447,9 @@ static int kvmppc_set_passthru_irq(struct kvm *kvm, int host_irq, int guest_gsi)
struct irq_chip *chip;
int i;
if (!kvm_irq_bypass)
return 1;
desc = irq_to_desc(host_irq);
if (!desc)
return -EIO;
@ -3519,6 +3526,9 @@ static int kvmppc_clr_passthru_irq(struct kvm *kvm, int host_irq, int guest_gsi)
struct kvmppc_passthru_irqmap *pimap;
int i;
if (!kvm_irq_bypass)
return 0;
desc = irq_to_desc(host_irq);
if (!desc)
return -EIO;

View File

@ -27,6 +27,8 @@
int h_ipi_redirect = 1;
EXPORT_SYMBOL(h_ipi_redirect);
int kvm_irq_bypass = 1;
EXPORT_SYMBOL(kvm_irq_bypass);
static void icp_rm_deliver_irq(struct kvmppc_xics *xics, struct kvmppc_icp *icp,
u32 new_irq);