KVM: arm64: pvtime: Ensure task delay accounting is enabled

Ensure we're actually accounting run_delay before we claim that we'll
expose it to the guest. If we're not, then we just pretend like steal
time isn't supported in order to avoid any confusion.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200622142710.18677-1-drjones@redhat.com
This commit is contained in:
Andrew Jones 2020-06-22 16:27:10 +02:00 committed by Marc Zyngier
parent 66b7e05dc0
commit a25e91028a

View File

@ -3,6 +3,7 @@
#include <linux/arm-smccc.h>
#include <linux/kvm_host.h>
#include <linux/sched/stat.h>
#include <asm/kvm_mmu.h>
#include <asm/pvclock-abi.h>
@ -73,6 +74,11 @@ gpa_t kvm_init_stolen_time(struct kvm_vcpu *vcpu)
return base;
}
static bool kvm_arm_pvtime_supported(void)
{
return !!sched_info_on();
}
int kvm_arm_pvtime_set_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr)
{
@ -82,7 +88,8 @@ int kvm_arm_pvtime_set_attr(struct kvm_vcpu *vcpu,
int ret = 0;
int idx;
if (attr->attr != KVM_ARM_VCPU_PVTIME_IPA)
if (!kvm_arm_pvtime_supported() ||
attr->attr != KVM_ARM_VCPU_PVTIME_IPA)
return -ENXIO;
if (get_user(ipa, user))
@ -110,7 +117,8 @@ int kvm_arm_pvtime_get_attr(struct kvm_vcpu *vcpu,
u64 __user *user = (u64 __user *)attr->addr;
u64 ipa;
if (attr->attr != KVM_ARM_VCPU_PVTIME_IPA)
if (!kvm_arm_pvtime_supported() ||
attr->attr != KVM_ARM_VCPU_PVTIME_IPA)
return -ENXIO;
ipa = vcpu->arch.steal.base;
@ -125,7 +133,8 @@ int kvm_arm_pvtime_has_attr(struct kvm_vcpu *vcpu,
{
switch (attr->attr) {
case KVM_ARM_VCPU_PVTIME_IPA:
return 0;
if (kvm_arm_pvtime_supported())
return 0;
}
return -ENXIO;
}