[PATCH 2/5] KVM: add KVM request variants without barrier

Radim Krčmář
2017-02-16T16:04:46Z

The leading underscores mean that the call is just a bitop wrapper.

Switch all users of open-coded set/check/test to kvm_request ones.
Automated by coccinelle script:
@@
expression VCPU, REQ;
@@
-set_bit(REQ, &VCPU->requests)
+__kvm_request_set(REQ, VCPU)

@@
expression VCPU, REQ;
@@
-clear_bit(REQ, &VCPU->requests)
+__kvm_request_clear(REQ, VCPU)

@@
expression VCPU, REQ;
@@
-test_bit(REQ, &VCPU->requests)
+__kvm_request_test(REQ, VCPU)

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
---
arch/mips/kvm/emulate.c | 2 +-
arch/powerpc/kvm/book3s_pr.c | 2 +-
arch/powerpc/kvm/book3s_pr_papr.c | 2 +-
arch/powerpc/kvm/booke.c | 4 ++--
arch/powerpc/kvm/powerpc.c | 2 +-
arch/s390/kvm/kvm-s390.c | 2 +-
arch/x86/kvm/vmx.c | 2 +-
arch/x86/kvm/x86.c | 14 +++++++-------
include/linux/kvm_host.h | 22 +++++++++++++++++++---
9 files changed, 34 insertions(+), 18 deletions(-)

diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c
index ee4af898bcf6..552ae2b5e911 100644
--- a/arch/mips/kvm/emulate.c
+++ b/arch/mips/kvm/emulate.c
@@ -865,7 +865,7 @@ enum emulation_result kvm_mips_emul_wait(struct kvm_vcpu *vcpu)
* check if any I/O interrupts are pending.
*/
if (kvm_request_test_and_clear(KVM_REQ_UNHALT, vcpu)) {
- clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
+ __kvm_request_clear(KVM_REQ_UNHALT, vcpu);
vcpu->run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
}
}
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index 7af5154e848b..f5894d27a8a9 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -349,7 +349,7 @@ static void kvmppc_set_msr_pr(struct kvm_vcpu *vcpu, u64 msr)
if (msr & MSR_POW) {
if (!vcpu->arch.pending_exceptions) {
kvm_vcpu_block(vcpu);
- clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
+ __kvm_request_clear(KVM_REQ_UNHALT, vcpu);
vcpu->stat.halt_wakeup++;

/* Unset POW bit after we woke up */
diff --git a/arch/powerpc/kvm/book3s_pr_papr.c b/arch/powerpc/kvm/book3s_pr_papr.c
index f102616febc7..86847220811a 100644
--- a/arch/powerpc/kvm/book3s_pr_papr.c
+++ b/arch/powerpc/kvm/book3s_pr_papr.c
@@ -344,7 +344,7 @@ int kvmppc_h_pr(struct kvm_vcpu *vcpu, unsigned long cmd)
case H_CEDE:
kvmppc_set_msr_fast(vcpu, kvmppc_get_msr(vcpu) | MSR_EE);
kvm_vcpu_block(vcpu);
- clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
+ __kvm_request_clear(KVM_REQ_UNHALT, vcpu);
vcpu->stat.halt_wakeup++;
return EMULATE_DONE;
case H_LOGICAL_CI_LOAD:
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 806caaf60e10..e9098af0ab2a 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -579,7 +579,7 @@ static void arm_next_watchdog(struct kvm_vcpu *vcpu)
* userspace, so clear the KVM_REQ_WATCHDOG request.
*/
if ((vcpu->arch.tsr & (TSR_ENW | TSR_WIS)) != (TSR_ENW | TSR_WIS))
- clear_bit(KVM_REQ_WATCHDOG, &vcpu->requests);
+ __kvm_request_clear(KVM_REQ_WATCHDOG, vcpu);

spin_lock_irqsave(&vcpu->arch.wdt_lock, flags);
nr_jiffies = watchdog_next_timeout(vcpu);
@@ -690,7 +690,7 @@ int kvmppc_core_prepare_to_enter(struct kvm_vcpu *vcpu)
if (vcpu->arch.shared->msr & MSR_WE) {
local_irq_enable();
kvm_vcpu_block(vcpu);
- clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
+ __kvm_request_clear(KVM_REQ_UNHALT, vcpu);
hard_irq_disable();

kvmppc_set_exit_type(vcpu, EMULATED_MTMSRWE_EXITS);
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 19e89419a843..f570ca9cd8c6 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -231,7 +231,7 @@ int kvmppc_kvm_pv(struct kvm_vcpu *vcpu)
case EV_HCALL_TOKEN(EV_IDLE):
r = EV_SUCCESS;
kvm_vcpu_block(vcpu);
- clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
+ __kvm_request_clear(KVM_REQ_UNHALT, vcpu);
break;
default:
r = EV_UNIMPLEMENTED;
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index db3c742a5dc9..0fa77e6fdfaf 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -2443,7 +2443,7 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu)
}

/* nothing to do, just clear the request */
- clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
+ __kvm_request_clear(KVM_REQ_UNHALT, vcpu);

return 0;
}
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index b183b4ac3ea5..7ab638f2189b 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6352,7 +6352,7 @@ static int handle_invalid_guest_state(struct kvm_vcpu *vcpu)
if (intr_window_requested && vmx_interrupt_allowed(vcpu))
return handle_interrupt_window(&vmx->vcpu);

- if (test_bit(KVM_REQ_EVENT, &vcpu->requests))
+ if (__kvm_request_test(KVM_REQ_EVENT, vcpu))
return 1;

err = emulate_instruction(vcpu, EMULTYPE_NO_REEXECUTE);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index da125323682a..6e8c62c29a5a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1767,7 +1767,7 @@ static void kvm_gen_update_masterclock(struct kvm *kvm)

/* guest entries allowed */
kvm_for_each_vcpu(i, vcpu, kvm)
- clear_bit(KVM_REQ_MCLOCK_INPROGRESS, &vcpu->requests);
+ __kvm_request_clear(KVM_REQ_MCLOCK_INPROGRESS, vcpu);

spin_unlock(&ka->pvclock_gtod_sync_lock);
#endif
@@ -2228,8 +2228,8 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
bool tmp = (msr == MSR_KVM_SYSTEM_TIME);

if (ka->boot_vcpu_runs_old_kvmclock != tmp)
- set_bit(KVM_REQ_MASTERCLOCK_UPDATE,
- &vcpu->requests);
+ __kvm_request_set(KVM_REQ_MASTERCLOCK_UPDATE,
+ vcpu);

ka->boot_vcpu_runs_old_kvmclock = tmp;
}
@@ -2816,7 +2816,7 @@ static bool need_emulate_wbinvd(struct kvm_vcpu *vcpu)

static inline void kvm_migrate_timers(struct kvm_vcpu *vcpu)
{
- set_bit(KVM_REQ_MIGRATE_TIMER, &vcpu->requests);
+ __kvm_request_set(KVM_REQ_MIGRATE_TIMER, vcpu);
}

void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
@@ -7048,7 +7048,7 @@ static int vcpu_run(struct kvm_vcpu *vcpu)
if (r <= 0)
break;

- clear_bit(KVM_REQ_PENDING_TIMER, &vcpu->requests);
+ __kvm_request_clear(KVM_REQ_PENDING_TIMER, vcpu);
if (kvm_cpu_has_pending_timer(vcpu))
kvm_inject_pending_timer_irqs(vcpu);

@@ -7176,7 +7176,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
if (unlikely(vcpu->arch.mp_state == KVM_MP_STATE_UNINITIALIZED)) {
kvm_vcpu_block(vcpu);
kvm_apic_accept_events(vcpu);
- clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
+ __kvm_request_clear(KVM_REQ_UNHALT, vcpu);
r = -EAGAIN;
goto out;
}
@@ -8381,7 +8381,7 @@ static inline bool kvm_vcpu_has_events(struct kvm_vcpu *vcpu)
if (atomic_read(&vcpu->arch.nmi_queued))
return true;

- if (test_bit(KVM_REQ_SMI, &vcpu->requests))
+ if (__kvm_request_test(KVM_REQ_SMI, vcpu))
return true;

if (kvm_arch_interrupt_allowed(vcpu) &&
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 21f91de3098b..d899473859d3 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1100,6 +1100,12 @@ static inline int kvm_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
* TODO: the API is inconsistent -- a request doesn't call kvm_vcpu_kick(), but
* forces smp_wmb() for all requests.
*/
+
+static inline void __kvm_request_set(unsigned req, struct kvm_vcpu *vcpu)
+{
+ set_bit(req, &vcpu->requests);
+}
+
static inline void kvm_request_set(unsigned req, struct kvm_vcpu *vcpu)
{
/*
@@ -1108,13 +1114,23 @@ static inline void kvm_request_set(unsigned req, struct kvm_vcpu *vcpu)
* Paired with the smp_mb__after_atomic in kvm_request_test_and_clear.
*/
smp_wmb();
- set_bit(req, &vcpu->requests);
+ __kvm_request_set(req, vcpu);
+}
+
+static inline bool __kvm_request_test(unsigned req, struct kvm_vcpu *vcpu)
+{
+ return test_bit(req, &vcpu->requests);
+}
+
+static inline void __kvm_request_clear(unsigned req, struct kvm_vcpu *vcpu)
+{
+ test_bit(req, &vcpu->requests);
}

static inline bool kvm_request_test_and_clear(unsigned req, struct kvm_vcpu *vcpu)
{
- if (test_bit(req, &vcpu->requests)) {
- clear_bit(req, &vcpu->requests);
+ if (__kvm_request_test(req, vcpu)) {
+ __kvm_request_clear(req, vcpu);

/*
* Ensure the rest of the request is visible to
--
2.11.1