diff options
| author | Michal Luczaj <mhal@rbox.co> | 2023-01-07 01:12:52 +0100 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2023-02-03 15:30:17 -0800 |
| commit | 708f799d22fe6b69d2e6e3e0625c30666d5e798a (patch) | |
| tree | d8c5d7356311c60c71776cd9fac0f42a05a6092c | |
| parent | 95744a90db18437410aa94620b8a330311bd9cf6 (diff) | |
KVM: x86: Optimize kvm->lock and SRCU interaction (KVM_X86_SET_MSR_FILTER)
Reduce time spent holding kvm->lock: unlock mutex before calling
synchronize_srcu(). There is no need to hold kvm->lock until all vCPUs
have been kicked, KVM only needs to guarantee that all vCPUs will switch
to the new filter before exiting to userspace.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Link: https://lore.kernel.org/r/20230107001256.2365304-3-mhal@rbox.co
[sean: expand changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | arch/x86/kvm/x86.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index d7d5bca00294..4f8e78d49585 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6497,12 +6497,12 @@ static int kvm_vm_ioctl_set_msr_filter(struct kvm *kvm, old_filter = srcu_dereference_check(kvm->arch.msr_filter, &kvm->srcu, 1); rcu_assign_pointer(kvm->arch.msr_filter, new_filter); + mutex_unlock(&kvm->lock); synchronize_srcu(&kvm->srcu); kvm_free_msr_filter(old_filter); kvm_make_all_cpus_request(kvm, KVM_REQ_MSR_FILTER_CHANGED); - mutex_unlock(&kvm->lock); return 0; } |