diff options
| author | Wanpeng Li <wanpengli@tencent.com> | 2021-04-23 16:23:20 +0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-04-23 17:00:50 -0400 |
| commit | 9c1a07442c95f6e64dc8de099e9f35ea73db7852 (patch) | |
| tree | 071c9494694a03f93f60f50364ad3a096ddd5016 | |
| parent | bf05bf16c76bb44ab5156223e1e58e26dfe30a88 (diff) | |
| download | linux-9c1a07442c95f6e64dc8de099e9f35ea73db7852.tar.bz2 | |
KVM: x86/xen: Take srcu lock when accessing kvm_memslots()
kvm_memslots() will be called by kvm_write_guest_offset_cached() so we should
take the srcu lock. Let's pull the srcu lock operation from kvm_steal_time_set_preempted()
again to fix xen part.
Fixes: 30b5c851af7 ("KVM: x86/xen: Add support for vCPU runstate information")
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1619166200-9215-1-git-send-email-wanpengli@tencent.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/x86.c | 20 |
1 files changed, 9 insertions, 11 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index eca63625aee4..ee0dc58ac3a5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4025,7 +4025,6 @@ static void kvm_steal_time_set_preempted(struct kvm_vcpu *vcpu) { struct kvm_host_map map; struct kvm_steal_time *st; - int idx; if (!(vcpu->arch.st.msr_val & KVM_MSR_ENABLED)) return; @@ -4033,15 +4032,9 @@ static void kvm_steal_time_set_preempted(struct kvm_vcpu *vcpu) if (vcpu->arch.st.preempted) return; - /* - * Take the srcu lock as memslots will be accessed to check the gfn - * cache generation against the memslots generation. - */ - idx = srcu_read_lock(&vcpu->kvm->srcu); - if (kvm_map_gfn(vcpu, vcpu->arch.st.msr_val >> PAGE_SHIFT, &map, &vcpu->arch.st.cache, true)) - goto out; + return; st = map.hva + offset_in_page(vcpu->arch.st.msr_val & KVM_STEAL_VALID_BITS); @@ -4049,20 +4042,25 @@ static void kvm_steal_time_set_preempted(struct kvm_vcpu *vcpu) st->preempted = vcpu->arch.st.preempted = KVM_VCPU_PREEMPTED; kvm_unmap_gfn(vcpu, &map, &vcpu->arch.st.cache, true, true); - -out: - srcu_read_unlock(&vcpu->kvm->srcu, idx); } void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) { + int idx; + if (vcpu->preempted && !vcpu->arch.guest_state_protected) vcpu->arch.preempted_in_kernel = !static_call(kvm_x86_get_cpl)(vcpu); + /* + * Take the srcu lock as memslots will be accessed to check the gfn + * cache generation against the memslots generation. + */ + idx = srcu_read_lock(&vcpu->kvm->srcu); if (kvm_xen_msr_enabled(vcpu->kvm)) kvm_xen_runstate_set_preempted(vcpu); else kvm_steal_time_set_preempted(vcpu); + srcu_read_unlock(&vcpu->kvm->srcu, idx); static_call(kvm_x86_vcpu_put)(vcpu); vcpu->arch.last_host_tsc = rdtsc(); |