From: Radim Krčmář <[email protected]> A first step in vcpu->requests encapsulation. Additionally, we now use READ_ONCE() when accessing vcpu->requests, which ensures we always load vcpu->requests when it's accessed. This is important as other threads can change it any time. Also, READ_ONCE() documents that vcpu->requests is used with other threads, likely requiring memory barriers, which it does.
Signed-off-by: Radim Krčmář <[email protected]> [ Documented the new use of READ_ONCE() and converted another check in arch/mips/kvm/vz.c ] Signed-off-by: Andrew Jones <[email protected]> --- arch/mips/kvm/trap_emul.c | 2 +- arch/mips/kvm/vz.c | 2 +- arch/powerpc/kvm/booke.c | 2 +- arch/powerpc/kvm/powerpc.c | 5 ++--- arch/s390/kvm/kvm-s390.c | 2 +- arch/x86/kvm/x86.c | 4 ++-- include/linux/kvm_host.h | 5 +++++ 7 files changed, 13 insertions(+), 9 deletions(-) diff --git a/arch/mips/kvm/trap_emul.c b/arch/mips/kvm/trap_emul.c index a563759fd142..6a0d7040d882 100644 --- a/arch/mips/kvm/trap_emul.c +++ b/arch/mips/kvm/trap_emul.c @@ -1094,7 +1094,7 @@ static void kvm_trap_emul_check_requests(struct kvm_vcpu *vcpu, int cpu, struct mm_struct *mm; int i; - if (likely(!vcpu->requests)) + if (likely(!kvm_request_pending(vcpu))) return; if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu)) { diff --git a/arch/mips/kvm/vz.c b/arch/mips/kvm/vz.c index 71d8856ade64..74805035edc8 100644 --- a/arch/mips/kvm/vz.c +++ b/arch/mips/kvm/vz.c @@ -2337,7 +2337,7 @@ static int kvm_vz_check_requests(struct kvm_vcpu *vcpu, int cpu) int ret = 0; int i; - if (!vcpu->requests) + if (!kvm_request_pending(vcpu)) return 0; if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu)) { diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index 3eaac3809977..071b87ee682f 100644 --- a/arch/powerpc/kvm/booke.c +++ b/arch/powerpc/kvm/booke.c @@ -687,7 +687,7 @@ int kvmppc_core_prepare_to_enter(struct kvm_vcpu *vcpu) kvmppc_core_check_exceptions(vcpu); - if (vcpu->requests) { + if (kvm_request_pending(vcpu)) { /* Exception delivery raised request; start over */ return 1; } diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index f7cf2cd564ef..fd64f087737c 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -55,8 +55,7 @@ EXPORT_SYMBOL_GPL(kvmppc_pr_ops); int kvm_arch_vcpu_runnable(struct kvm_vcpu *v) { - return !!(v->arch.pending_exceptions) || - v->requests; + return !!(v->arch.pending_exceptions) || kvm_request_pending(v); } int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu) @@ -108,7 +107,7 @@ int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu) */ smp_mb(); - if (vcpu->requests) { + if (kvm_request_pending(vcpu)) { /* Make sure we process requests preemptable */ local_irq_enable(); trace_kvm_check_requests(vcpu); diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 689ac48361c6..ad41e0fa3a21 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -2440,7 +2440,7 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu) { retry: kvm_s390_vcpu_request_handled(vcpu); - if (!vcpu->requests) + if (!kvm_request_pending(vcpu)) return 0; /* * We use MMU_RELOAD just to re-arm the ipte notifier for the diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 464da936c53d..f81060518635 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6710,7 +6710,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) bool req_immediate_exit = false; - if (vcpu->requests) { + if (kvm_request_pending(vcpu)) { if (kvm_check_request(KVM_REQ_MMU_RELOAD, vcpu)) kvm_mmu_unload(vcpu); if (kvm_check_request(KVM_REQ_MIGRATE_TIMER, vcpu)) @@ -6874,7 +6874,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) kvm_x86_ops->sync_pir_to_irr(vcpu); } - if (vcpu->mode == EXITING_GUEST_MODE || vcpu->requests + if (vcpu->mode == EXITING_GUEST_MODE || kvm_request_pending(vcpu) || need_resched() || signal_pending(current)) { vcpu->mode = OUTSIDE_GUEST_MODE; smp_wmb(); diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 3724b51aab64..0b50e7b35ed4 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1105,6 +1105,11 @@ static inline void kvm_make_request(int req, struct kvm_vcpu *vcpu) set_bit(req & KVM_REQUEST_MASK, &vcpu->requests); } +static inline bool kvm_request_pending(struct kvm_vcpu *vcpu) +{ + return READ_ONCE(vcpu->requests); +} + static inline bool kvm_test_request(int req, struct kvm_vcpu *vcpu) { return test_bit(req & KVM_REQUEST_MASK, &vcpu->requests); -- 2.9.3 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
