Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fix from Paolo Bonzini:
"Fix SRCU bug introduced in the merge window"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: x86/xen: Take srcu lock when accessing kvm_memslots()
+9
-11
+9
-11
arch/x86/kvm/x86.c
+9
-11
arch/x86/kvm/x86.c
···
4025
4025
{
4026
4026
struct kvm_host_map map;
4027
4027
struct kvm_steal_time *st;
4028
-
int idx;
4029
4028
4030
4029
if (!(vcpu->arch.st.msr_val & KVM_MSR_ENABLED))
4031
4030
return;
···
4032
4033
if (vcpu->arch.st.preempted)
4033
4034
return;
4034
4035
4035
-
/*
4036
-
* Take the srcu lock as memslots will be accessed to check the gfn
4037
-
* cache generation against the memslots generation.
4038
-
*/
4039
-
idx = srcu_read_lock(&vcpu->kvm->srcu);
4040
-
4041
4036
if (kvm_map_gfn(vcpu, vcpu->arch.st.msr_val >> PAGE_SHIFT, &map,
4042
4037
&vcpu->arch.st.cache, true))
4043
-
goto out;
4038
+
return;
4044
4039
4045
4040
st = map.hva +
4046
4041
offset_in_page(vcpu->arch.st.msr_val & KVM_STEAL_VALID_BITS);
···
4042
4049
st->preempted = vcpu->arch.st.preempted = KVM_VCPU_PREEMPTED;
4043
4050
4044
4051
kvm_unmap_gfn(vcpu, &map, &vcpu->arch.st.cache, true, true);
4045
-
4046
-
out:
4047
-
srcu_read_unlock(&vcpu->kvm->srcu, idx);
4048
4052
}
4049
4053
4050
4054
void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
4051
4055
{
4056
+
int idx;
4057
+
4052
4058
if (vcpu->preempted && !vcpu->arch.guest_state_protected)
4053
4059
vcpu->arch.preempted_in_kernel = !static_call(kvm_x86_get_cpl)(vcpu);
4054
4060
4061
+
/*
4062
+
* Take the srcu lock as memslots will be accessed to check the gfn
4063
+
* cache generation against the memslots generation.
4064
+
*/
4065
+
idx = srcu_read_lock(&vcpu->kvm->srcu);
4055
4066
if (kvm_xen_msr_enabled(vcpu->kvm))
4056
4067
kvm_xen_runstate_set_preempted(vcpu);
4057
4068
else
4058
4069
kvm_steal_time_set_preempted(vcpu);
4070
+
srcu_read_unlock(&vcpu->kvm->srcu, idx);
4059
4071
4060
4072
static_call(kvm_x86_vcpu_put)(vcpu);
4061
4073
vcpu->arch.last_host_tsc = rdtsc();