[PATCH v1] kvm: Make vcpu->requests as 64 bit bitmap

[PATCH v1] kvm: Make vcpu->requests as 64 bit bitmap

[Andrey Smetanin]

Currently on x86 arch we has already 32 requests defined
so the newer request bits can't be placed inside
vcpu->requests(unsigned long) inside x86 32 bit system.
But we are going to add a new request in x86 arch
for Hyper-V tsc page support.

To solve the problem the patch replaces vcpu->requests by
bitmap with 64 bit length and uses bitmap API.

The patch consists of:
* announce kvm_vcpu_has_requests() to check whether vcpu has
requests
* announce kvm_vcpu_requests() to get vcpu requests pointer
* announce kvm_clear_request() to clear particular vcpu request
* replace if (vcpu->requests) by if (kvm_vcpu_has_requests(vcpu))
* replace clear_bit(req, vcpu->requests) by
 kvm_clear_request(req, vcpu)

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: James Hogan <james.hogan@imgtec.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Paul Burton <paul.burton@imgtec.com>
CC: Ralf Baechle <ralf@linux-mips.org>
CC: Alexander Graf <agraf@suse.com>
CC: Christian Borntraeger <borntraeger@de.ibm.com>
CC: Cornelia Huck <cornelia.huck@de.ibm.com>
CC: linux-mips@linux-mips.org
CC: kvm-ppc@vger.kernel.org
CC: linux-s390@vger.kernel.org
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org

---
 arch/mips/kvm/emulate.c           |  4 +---
 arch/powerpc/kvm/book3s_pr.c      |  2 +-
 arch/powerpc/kvm/book3s_pr_papr.c |  2 +-
 arch/powerpc/kvm/booke.c          |  6 +++---
 arch/powerpc/kvm/powerpc.c        |  6 +++---
 arch/powerpc/kvm/trace.h          |  2 +-
 arch/s390/kvm/kvm-s390.c          |  4 ++--
 arch/x86/kvm/vmx.c                |  2 +-
 arch/x86/kvm/x86.c                | 14 +++++++-------
 include/linux/kvm_host.h          | 27 ++++++++++++++++++++++-----
 10 files changed, 42 insertions(+), 27 deletions(-)

diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c
index 41b1b09..14aebe8 100644
--- a/arch/mips/kvm/emulate.c
+++ b/arch/mips/kvm/emulate.c
@@ -774,10 +774,8 @@ enum emulation_result kvm_mips_emul_wait(struct kvm_vcpu *vcpu)
 		 * We we are runnable, then definitely go off to user space to
 		 * check if any I/O interrupts are pending.
 		 */
-		if (kvm_check_request(KVM_REQ_UNHALT, vcpu)) {
-			clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
+		if (kvm_check_request(KVM_REQ_UNHALT, vcpu))
 			vcpu->run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
-		}
 	}
 
 	return EMULATE_DONE;
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index 64891b0..e975279 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_clear_request(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 f2c75a1..60cf393 100644
--- a/arch/powerpc/kvm/book3s_pr_papr.c
+++ b/arch/powerpc/kvm/book3s_pr_papr.c
@@ -309,7 +309,7 @@ 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_clear_request(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 fd58751..6bed382 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -574,7 +574,7 @@ 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_clear_request(KVM_REQ_WATCHDOG, vcpu);
 
 	spin_lock_irqsave(&vcpu->arch.wdt_lock, flags);
 	nr_jiffies = watchdog_next_timeout(vcpu);
@@ -677,7 +677,7 @@ int kvmppc_core_prepare_to_enter(struct kvm_vcpu *vcpu)
 
 	kvmppc_core_check_exceptions(vcpu);
 
-	if (vcpu->requests) {
+	if (kvm_vcpu_has_requests(vcpu)) {
 		/* Exception delivery raised request; start over */
 		return 1;
 	}
@@ -685,7 +685,7 @@ 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_clear_request(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 6fd2405..e2dded7 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -49,7 +49,7 @@ EXPORT_SYMBOL_GPL(kvmppc_pr_ops);
 int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
 {
 	return !!(v->arch.pending_exceptions) ||
-	       v->requests;
+	       kvm_vcpu_has_requests(v);
 }
 
 int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
@@ -98,7 +98,7 @@ int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu)
 		 */
 		smp_mb();
 
-		if (vcpu->requests) {
+		if (kvm_vcpu_has_requests(vcpu)) {
 			/* Make sure we process requests preemptable */
 			local_irq_enable();
 			trace_kvm_check_requests(vcpu);
@@ -225,7 +225,7 @@ 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_clear_request(KVM_REQ_UNHALT, vcpu);
 		break;
 	default:
 		r = EV_UNIMPLEMENTED;
diff --git a/arch/powerpc/kvm/trace.h b/arch/powerpc/kvm/trace.h
index 2e0e67e..4015b88 100644
--- a/arch/powerpc/kvm/trace.h
+++ b/arch/powerpc/kvm/trace.h
@@ -109,7 +109,7 @@ TRACE_EVENT(kvm_check_requests,
 
 	TP_fast_assign(
 		__entry->cpu_nr		= vcpu->vcpu_id;
-		__entry->requests	= vcpu->requests;
+		__entry->requests	= (__u32)kvm_vcpu_requests(vcpu)[0];
 	),
 
 	TP_printk("vcpu=%x requests=%x",
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 8465892..5db1471 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1847,7 +1847,7 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu)
 {
 retry:
 	kvm_s390_vcpu_request_handled(vcpu);
-	if (!vcpu->requests)
+	if (!kvm_vcpu_has_requests(vcpu))
 		return 0;
 	/*
 	 * We use MMU_RELOAD just to re-arm the ipte notifier for the
@@ -1890,7 +1890,7 @@ retry:
 	}
 
 	/* nothing to do, just clear the request */
-	clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
+	kvm_clear_request(KVM_REQ_UNHALT, vcpu);
 
 	return 0;
 }
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 1a8bfaa..599451c 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5957,7 +5957,7 @@ 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 (test_bit(KVM_REQ_EVENT, kvm_vcpu_requests(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 0601c05..aedb1a0 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1702,7 +1702,7 @@ 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_clear_request(KVM_REQ_MCLOCK_INPROGRESS, vcpu);
 
 	spin_unlock(&ka->pvclock_gtod_sync_lock);
 #endif
@@ -2117,7 +2117,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 
 			if (ka->boot_vcpu_runs_old_kvmclock != tmp)
 				set_bit(KVM_REQ_MASTERCLOCK_UPDATE,
-					&vcpu->requests);
+					kvm_vcpu_requests(vcpu));
 
 			ka->boot_vcpu_runs_old_kvmclock = tmp;
 		}
@@ -6410,7 +6410,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 
 	bool req_immediate_exit = false;
 
-	if (vcpu->requests) {
+	if (kvm_vcpu_has_requests(vcpu)) {
 		if (kvm_check_request(KVM_REQ_MMU_RELOAD, vcpu))
 			kvm_mmu_unload(vcpu);
 		if (kvm_check_request(KVM_REQ_MIGRATE_TIMER, vcpu))
@@ -6560,7 +6560,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 
 	local_irq_disable();
 
-	if (vcpu->mode == EXITING_GUEST_MODE || vcpu->requests
+	if (vcpu->mode == EXITING_GUEST_MODE || kvm_vcpu_has_requests(vcpu)
 	    || need_resched() || signal_pending(current)) {
 		vcpu->mode = OUTSIDE_GUEST_MODE;
 		smp_wmb();
@@ -6720,7 +6720,7 @@ static int vcpu_run(struct kvm_vcpu *vcpu)
 		if (r <= 0)
 			break;
 
-		clear_bit(KVM_REQ_PENDING_TIMER, &vcpu->requests);
+		kvm_clear_request(KVM_REQ_PENDING_TIMER, vcpu);
 		if (kvm_cpu_has_pending_timer(vcpu))
 			kvm_inject_pending_timer_irqs(vcpu);
 
@@ -6848,7 +6848,7 @@ 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_clear_request(KVM_REQ_UNHALT, vcpu);
 		r = -EAGAIN;
 		goto out;
 	}
@@ -8048,7 +8048,7 @@ 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 (test_bit(KVM_REQ_SMI, kvm_vcpu_requests(vcpu)))
 		return true;
 
 	if (kvm_arch_interrupt_allowed(vcpu) &&
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index da7a7e4..6877b4d7e 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -146,6 +146,8 @@ static inline bool is_error_page(struct page *page)
 #define KVM_REQ_HV_EXIT           30
 #define KVM_REQ_HV_STIMER         31
 
+#define KVM_REQ_MAX               64
+
 #define KVM_USERSPACE_IRQ_SOURCE_ID		0
 #define KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID	1
 
@@ -233,7 +235,7 @@ struct kvm_vcpu {
 	int vcpu_id;
 	int srcu_idx;
 	int mode;
-	unsigned long requests;
+	DECLARE_BITMAP(requests, KVM_REQ_MAX);
 	unsigned long guest_debug;
 
 	int pre_pcpu;
@@ -286,6 +288,16 @@ struct kvm_vcpu {
 	struct kvm_vcpu_arch arch;
 };
 
+static inline bool kvm_vcpu_has_requests(struct kvm_vcpu *vcpu)
+{
+	return !bitmap_empty(vcpu->requests, KVM_REQ_MAX);
+}
+
+static inline ulong *kvm_vcpu_requests(struct kvm_vcpu *vcpu)
+{
+	return (ulong *)vcpu->requests;
+}
+
 static inline int kvm_vcpu_exiting_guest_mode(struct kvm_vcpu *vcpu)
 {
 	return cmpxchg(&vcpu->mode, IN_GUEST_MODE, EXITING_GUEST_MODE);
@@ -1002,7 +1014,7 @@ static inline bool kvm_is_error_gpa(struct kvm *kvm, gpa_t gpa)
 
 static inline void kvm_migrate_timers(struct kvm_vcpu *vcpu)
 {
-	set_bit(KVM_REQ_MIGRATE_TIMER, &vcpu->requests);
+	set_bit(KVM_REQ_MIGRATE_TIMER, kvm_vcpu_requests(vcpu));
 }
 
 enum kvm_stat_kind {
@@ -1118,19 +1130,24 @@ static inline bool kvm_vcpu_compatible(struct kvm_vcpu *vcpu) { return true; }
 
 static inline void kvm_make_request(int req, struct kvm_vcpu *vcpu)
 {
-	set_bit(req, &vcpu->requests);
+	set_bit(req, kvm_vcpu_requests(vcpu));
 }
 
 static inline bool kvm_check_request(int req, struct kvm_vcpu *vcpu)
 {
-	if (test_bit(req, &vcpu->requests)) {
-		clear_bit(req, &vcpu->requests);
+	if (test_bit(req, kvm_vcpu_requests(vcpu))) {
+		clear_bit(req, kvm_vcpu_requests(vcpu));
 		return true;
 	} else {
 		return false;
 	}
 }
 
+static inline void kvm_clear_request(int req, struct kvm_vcpu *vcpu)
+{
+	clear_bit(req, kvm_vcpu_requests(vcpu));
+}
+
 extern bool kvm_rebooting;
 
 struct kvm_device {
-- 
2.4.3

Re: [PATCH v1] kvm: Make vcpu->requests as 64 bit bitmap

[James Hogan]

[-- Attachment #1: Type: text/plain, Size: 12752 bytes --]

Hi Andrey,

On Thu, Dec 24, 2015 at 12:30:26PM +0300, Andrey Smetanin wrote:
> Currently on x86 arch we has already 32 requests defined
> so the newer request bits can't be placed inside
> vcpu->requests(unsigned long) inside x86 32 bit system.
> But we are going to add a new request in x86 arch
> for Hyper-V tsc page support.
> 
> To solve the problem the patch replaces vcpu->requests by
> bitmap with 64 bit length and uses bitmap API.
> 
> The patch consists of:
> * announce kvm_vcpu_has_requests() to check whether vcpu has
> requests
> * announce kvm_vcpu_requests() to get vcpu requests pointer
> * announce kvm_clear_request() to clear particular vcpu request
> * replace if (vcpu->requests) by if (kvm_vcpu_has_requests(vcpu))
> * replace clear_bit(req, vcpu->requests) by
>  kvm_clear_request(req, vcpu)
> 
> Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
> CC: Paolo Bonzini <pbonzini@redhat.com>
> CC: Gleb Natapov <gleb@kernel.org>
> CC: James Hogan <james.hogan@imgtec.com>
> CC: Paolo Bonzini <pbonzini@redhat.com>
> CC: Paul Burton <paul.burton@imgtec.com>
> CC: Ralf Baechle <ralf@linux-mips.org>
> CC: Alexander Graf <agraf@suse.com>
> CC: Christian Borntraeger <borntraeger@de.ibm.com>
> CC: Cornelia Huck <cornelia.huck@de.ibm.com>
> CC: linux-mips@linux-mips.org
> CC: kvm-ppc@vger.kernel.org
> CC: linux-s390@vger.kernel.org
> CC: Roman Kagan <rkagan@virtuozzo.com>
> CC: Denis V. Lunev <den@openvz.org>
> CC: qemu-devel@nongnu.org

For MIPS KVM bit:
Acked-by: James Hogan <james.hogan@imgtec.com>

Thanks
James

> 
> ---
>  arch/mips/kvm/emulate.c           |  4 +---
>  arch/powerpc/kvm/book3s_pr.c      |  2 +-
>  arch/powerpc/kvm/book3s_pr_papr.c |  2 +-
>  arch/powerpc/kvm/booke.c          |  6 +++---
>  arch/powerpc/kvm/powerpc.c        |  6 +++---
>  arch/powerpc/kvm/trace.h          |  2 +-
>  arch/s390/kvm/kvm-s390.c          |  4 ++--
>  arch/x86/kvm/vmx.c                |  2 +-
>  arch/x86/kvm/x86.c                | 14 +++++++-------
>  include/linux/kvm_host.h          | 27 ++++++++++++++++++++++-----
>  10 files changed, 42 insertions(+), 27 deletions(-)
> 
> diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c
> index 41b1b09..14aebe8 100644
> --- a/arch/mips/kvm/emulate.c
> +++ b/arch/mips/kvm/emulate.c
> @@ -774,10 +774,8 @@ enum emulation_result kvm_mips_emul_wait(struct kvm_vcpu *vcpu)
>  		 * We we are runnable, then definitely go off to user space to
>  		 * check if any I/O interrupts are pending.
>  		 */
> -		if (kvm_check_request(KVM_REQ_UNHALT, vcpu)) {
> -			clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
> +		if (kvm_check_request(KVM_REQ_UNHALT, vcpu))
>  			vcpu->run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
> -		}
>  	}
>  
>  	return EMULATE_DONE;
> diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
> index 64891b0..e975279 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_clear_request(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 f2c75a1..60cf393 100644
> --- a/arch/powerpc/kvm/book3s_pr_papr.c
> +++ b/arch/powerpc/kvm/book3s_pr_papr.c
> @@ -309,7 +309,7 @@ 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_clear_request(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 fd58751..6bed382 100644
> --- a/arch/powerpc/kvm/booke.c
> +++ b/arch/powerpc/kvm/booke.c
> @@ -574,7 +574,7 @@ 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_clear_request(KVM_REQ_WATCHDOG, vcpu);
>  
>  	spin_lock_irqsave(&vcpu->arch.wdt_lock, flags);
>  	nr_jiffies = watchdog_next_timeout(vcpu);
> @@ -677,7 +677,7 @@ int kvmppc_core_prepare_to_enter(struct kvm_vcpu *vcpu)
>  
>  	kvmppc_core_check_exceptions(vcpu);
>  
> -	if (vcpu->requests) {
> +	if (kvm_vcpu_has_requests(vcpu)) {
>  		/* Exception delivery raised request; start over */
>  		return 1;
>  	}
> @@ -685,7 +685,7 @@ 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_clear_request(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 6fd2405..e2dded7 100644
> --- a/arch/powerpc/kvm/powerpc.c
> +++ b/arch/powerpc/kvm/powerpc.c
> @@ -49,7 +49,7 @@ EXPORT_SYMBOL_GPL(kvmppc_pr_ops);
>  int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
>  {
>  	return !!(v->arch.pending_exceptions) ||
> -	       v->requests;
> +	       kvm_vcpu_has_requests(v);
>  }
>  
>  int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
> @@ -98,7 +98,7 @@ int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu)
>  		 */
>  		smp_mb();
>  
> -		if (vcpu->requests) {
> +		if (kvm_vcpu_has_requests(vcpu)) {
>  			/* Make sure we process requests preemptable */
>  			local_irq_enable();
>  			trace_kvm_check_requests(vcpu);
> @@ -225,7 +225,7 @@ 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_clear_request(KVM_REQ_UNHALT, vcpu);
>  		break;
>  	default:
>  		r = EV_UNIMPLEMENTED;
> diff --git a/arch/powerpc/kvm/trace.h b/arch/powerpc/kvm/trace.h
> index 2e0e67e..4015b88 100644
> --- a/arch/powerpc/kvm/trace.h
> +++ b/arch/powerpc/kvm/trace.h
> @@ -109,7 +109,7 @@ TRACE_EVENT(kvm_check_requests,
>  
>  	TP_fast_assign(
>  		__entry->cpu_nr		= vcpu->vcpu_id;
> -		__entry->requests	= vcpu->requests;
> +		__entry->requests	= (__u32)kvm_vcpu_requests(vcpu)[0];
>  	),
>  
>  	TP_printk("vcpu=%x requests=%x",
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 8465892..5db1471 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -1847,7 +1847,7 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu)
>  {
>  retry:
>  	kvm_s390_vcpu_request_handled(vcpu);
> -	if (!vcpu->requests)
> +	if (!kvm_vcpu_has_requests(vcpu))
>  		return 0;
>  	/*
>  	 * We use MMU_RELOAD just to re-arm the ipte notifier for the
> @@ -1890,7 +1890,7 @@ retry:
>  	}
>  
>  	/* nothing to do, just clear the request */
> -	clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
> +	kvm_clear_request(KVM_REQ_UNHALT, vcpu);
>  
>  	return 0;
>  }
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 1a8bfaa..599451c 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -5957,7 +5957,7 @@ 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 (test_bit(KVM_REQ_EVENT, kvm_vcpu_requests(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 0601c05..aedb1a0 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -1702,7 +1702,7 @@ 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_clear_request(KVM_REQ_MCLOCK_INPROGRESS, vcpu);
>  
>  	spin_unlock(&ka->pvclock_gtod_sync_lock);
>  #endif
> @@ -2117,7 +2117,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
>  
>  			if (ka->boot_vcpu_runs_old_kvmclock != tmp)
>  				set_bit(KVM_REQ_MASTERCLOCK_UPDATE,
> -					&vcpu->requests);
> +					kvm_vcpu_requests(vcpu));
>  
>  			ka->boot_vcpu_runs_old_kvmclock = tmp;
>  		}
> @@ -6410,7 +6410,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
>  
>  	bool req_immediate_exit = false;
>  
> -	if (vcpu->requests) {
> +	if (kvm_vcpu_has_requests(vcpu)) {
>  		if (kvm_check_request(KVM_REQ_MMU_RELOAD, vcpu))
>  			kvm_mmu_unload(vcpu);
>  		if (kvm_check_request(KVM_REQ_MIGRATE_TIMER, vcpu))
> @@ -6560,7 +6560,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
>  
>  	local_irq_disable();
>  
> -	if (vcpu->mode == EXITING_GUEST_MODE || vcpu->requests
> +	if (vcpu->mode == EXITING_GUEST_MODE || kvm_vcpu_has_requests(vcpu)
>  	    || need_resched() || signal_pending(current)) {
>  		vcpu->mode = OUTSIDE_GUEST_MODE;
>  		smp_wmb();
> @@ -6720,7 +6720,7 @@ static int vcpu_run(struct kvm_vcpu *vcpu)
>  		if (r <= 0)
>  			break;
>  
> -		clear_bit(KVM_REQ_PENDING_TIMER, &vcpu->requests);
> +		kvm_clear_request(KVM_REQ_PENDING_TIMER, vcpu);
>  		if (kvm_cpu_has_pending_timer(vcpu))
>  			kvm_inject_pending_timer_irqs(vcpu);
>  
> @@ -6848,7 +6848,7 @@ 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_clear_request(KVM_REQ_UNHALT, vcpu);
>  		r = -EAGAIN;
>  		goto out;
>  	}
> @@ -8048,7 +8048,7 @@ 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 (test_bit(KVM_REQ_SMI, kvm_vcpu_requests(vcpu)))
>  		return true;
>  
>  	if (kvm_arch_interrupt_allowed(vcpu) &&
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index da7a7e4..6877b4d7e 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -146,6 +146,8 @@ static inline bool is_error_page(struct page *page)
>  #define KVM_REQ_HV_EXIT           30
>  #define KVM_REQ_HV_STIMER         31
>  
> +#define KVM_REQ_MAX               64
> +
>  #define KVM_USERSPACE_IRQ_SOURCE_ID		0
>  #define KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID	1
>  
> @@ -233,7 +235,7 @@ struct kvm_vcpu {
>  	int vcpu_id;
>  	int srcu_idx;
>  	int mode;
> -	unsigned long requests;
> +	DECLARE_BITMAP(requests, KVM_REQ_MAX);
>  	unsigned long guest_debug;
>  
>  	int pre_pcpu;
> @@ -286,6 +288,16 @@ struct kvm_vcpu {
>  	struct kvm_vcpu_arch arch;
>  };
>  
> +static inline bool kvm_vcpu_has_requests(struct kvm_vcpu *vcpu)
> +{
> +	return !bitmap_empty(vcpu->requests, KVM_REQ_MAX);
> +}
> +
> +static inline ulong *kvm_vcpu_requests(struct kvm_vcpu *vcpu)
> +{
> +	return (ulong *)vcpu->requests;
> +}
> +
>  static inline int kvm_vcpu_exiting_guest_mode(struct kvm_vcpu *vcpu)
>  {
>  	return cmpxchg(&vcpu->mode, IN_GUEST_MODE, EXITING_GUEST_MODE);
> @@ -1002,7 +1014,7 @@ static inline bool kvm_is_error_gpa(struct kvm *kvm, gpa_t gpa)
>  
>  static inline void kvm_migrate_timers(struct kvm_vcpu *vcpu)
>  {
> -	set_bit(KVM_REQ_MIGRATE_TIMER, &vcpu->requests);
> +	set_bit(KVM_REQ_MIGRATE_TIMER, kvm_vcpu_requests(vcpu));
>  }
>  
>  enum kvm_stat_kind {
> @@ -1118,19 +1130,24 @@ static inline bool kvm_vcpu_compatible(struct kvm_vcpu *vcpu) { return true; }
>  
>  static inline void kvm_make_request(int req, struct kvm_vcpu *vcpu)
>  {
> -	set_bit(req, &vcpu->requests);
> +	set_bit(req, kvm_vcpu_requests(vcpu));
>  }
>  
>  static inline bool kvm_check_request(int req, struct kvm_vcpu *vcpu)
>  {
> -	if (test_bit(req, &vcpu->requests)) {
> -		clear_bit(req, &vcpu->requests);
> +	if (test_bit(req, kvm_vcpu_requests(vcpu))) {
> +		clear_bit(req, kvm_vcpu_requests(vcpu));
>  		return true;
>  	} else {
>  		return false;
>  	}
>  }
>  
> +static inline void kvm_clear_request(int req, struct kvm_vcpu *vcpu)
> +{
> +	clear_bit(req, kvm_vcpu_requests(vcpu));
> +}
> +
>  extern bool kvm_rebooting;
>  
>  struct kvm_device {
> -- 
> 2.4.3
> 

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]

Re: [PATCH v1] kvm: Make vcpu->requests as 64 bit bitmap

[James Hogan]

[-- Attachment #1: Type: text/plain, Size: 12752 bytes --]

Hi Andrey,

On Thu, Dec 24, 2015 at 12:30:26PM +0300, Andrey Smetanin wrote:
> Currently on x86 arch we has already 32 requests defined
> so the newer request bits can't be placed inside
> vcpu->requests(unsigned long) inside x86 32 bit system.
> But we are going to add a new request in x86 arch
> for Hyper-V tsc page support.
> 
> To solve the problem the patch replaces vcpu->requests by
> bitmap with 64 bit length and uses bitmap API.
> 
> The patch consists of:
> * announce kvm_vcpu_has_requests() to check whether vcpu has
> requests
> * announce kvm_vcpu_requests() to get vcpu requests pointer
> * announce kvm_clear_request() to clear particular vcpu request
> * replace if (vcpu->requests) by if (kvm_vcpu_has_requests(vcpu))
> * replace clear_bit(req, vcpu->requests) by
>  kvm_clear_request(req, vcpu)
> 
> Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
> CC: Paolo Bonzini <pbonzini@redhat.com>
> CC: Gleb Natapov <gleb@kernel.org>
> CC: James Hogan <james.hogan@imgtec.com>
> CC: Paolo Bonzini <pbonzini@redhat.com>
> CC: Paul Burton <paul.burton@imgtec.com>
> CC: Ralf Baechle <ralf@linux-mips.org>
> CC: Alexander Graf <agraf@suse.com>
> CC: Christian Borntraeger <borntraeger@de.ibm.com>
> CC: Cornelia Huck <cornelia.huck@de.ibm.com>
> CC: linux-mips@linux-mips.org
> CC: kvm-ppc@vger.kernel.org
> CC: linux-s390@vger.kernel.org
> CC: Roman Kagan <rkagan@virtuozzo.com>
> CC: Denis V. Lunev <den@openvz.org>
> CC: qemu-devel@nongnu.org

For MIPS KVM bit:
Acked-by: James Hogan <james.hogan@imgtec.com>

Thanks
James

> 
> ---
>  arch/mips/kvm/emulate.c           |  4 +---
>  arch/powerpc/kvm/book3s_pr.c      |  2 +-
>  arch/powerpc/kvm/book3s_pr_papr.c |  2 +-
>  arch/powerpc/kvm/booke.c          |  6 +++---
>  arch/powerpc/kvm/powerpc.c        |  6 +++---
>  arch/powerpc/kvm/trace.h          |  2 +-
>  arch/s390/kvm/kvm-s390.c          |  4 ++--
>  arch/x86/kvm/vmx.c                |  2 +-
>  arch/x86/kvm/x86.c                | 14 +++++++-------
>  include/linux/kvm_host.h          | 27 ++++++++++++++++++++++-----
>  10 files changed, 42 insertions(+), 27 deletions(-)
> 
> diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c
> index 41b1b09..14aebe8 100644
> --- a/arch/mips/kvm/emulate.c
> +++ b/arch/mips/kvm/emulate.c
> @@ -774,10 +774,8 @@ enum emulation_result kvm_mips_emul_wait(struct kvm_vcpu *vcpu)
>  		 * We we are runnable, then definitely go off to user space to
>  		 * check if any I/O interrupts are pending.
>  		 */
> -		if (kvm_check_request(KVM_REQ_UNHALT, vcpu)) {
> -			clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
> +		if (kvm_check_request(KVM_REQ_UNHALT, vcpu))
>  			vcpu->run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
> -		}
>  	}
>  
>  	return EMULATE_DONE;
> diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
> index 64891b0..e975279 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_clear_request(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 f2c75a1..60cf393 100644
> --- a/arch/powerpc/kvm/book3s_pr_papr.c
> +++ b/arch/powerpc/kvm/book3s_pr_papr.c
> @@ -309,7 +309,7 @@ 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_clear_request(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 fd58751..6bed382 100644
> --- a/arch/powerpc/kvm/booke.c
> +++ b/arch/powerpc/kvm/booke.c
> @@ -574,7 +574,7 @@ 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_clear_request(KVM_REQ_WATCHDOG, vcpu);
>  
>  	spin_lock_irqsave(&vcpu->arch.wdt_lock, flags);
>  	nr_jiffies = watchdog_next_timeout(vcpu);
> @@ -677,7 +677,7 @@ int kvmppc_core_prepare_to_enter(struct kvm_vcpu *vcpu)
>  
>  	kvmppc_core_check_exceptions(vcpu);
>  
> -	if (vcpu->requests) {
> +	if (kvm_vcpu_has_requests(vcpu)) {
>  		/* Exception delivery raised request; start over */
>  		return 1;
>  	}
> @@ -685,7 +685,7 @@ 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_clear_request(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 6fd2405..e2dded7 100644
> --- a/arch/powerpc/kvm/powerpc.c
> +++ b/arch/powerpc/kvm/powerpc.c
> @@ -49,7 +49,7 @@ EXPORT_SYMBOL_GPL(kvmppc_pr_ops);
>  int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
>  {
>  	return !!(v->arch.pending_exceptions) ||
> -	       v->requests;
> +	       kvm_vcpu_has_requests(v);
>  }
>  
>  int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
> @@ -98,7 +98,7 @@ int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu)
>  		 */
>  		smp_mb();
>  
> -		if (vcpu->requests) {
> +		if (kvm_vcpu_has_requests(vcpu)) {
>  			/* Make sure we process requests preemptable */
>  			local_irq_enable();
>  			trace_kvm_check_requests(vcpu);
> @@ -225,7 +225,7 @@ 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_clear_request(KVM_REQ_UNHALT, vcpu);
>  		break;
>  	default:
>  		r = EV_UNIMPLEMENTED;
> diff --git a/arch/powerpc/kvm/trace.h b/arch/powerpc/kvm/trace.h
> index 2e0e67e..4015b88 100644
> --- a/arch/powerpc/kvm/trace.h
> +++ b/arch/powerpc/kvm/trace.h
> @@ -109,7 +109,7 @@ TRACE_EVENT(kvm_check_requests,
>  
>  	TP_fast_assign(
>  		__entry->cpu_nr		= vcpu->vcpu_id;
> -		__entry->requests	= vcpu->requests;
> +		__entry->requests	= (__u32)kvm_vcpu_requests(vcpu)[0];
>  	),
>  
>  	TP_printk("vcpu=%x requests=%x",
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 8465892..5db1471 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -1847,7 +1847,7 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu)
>  {
>  retry:
>  	kvm_s390_vcpu_request_handled(vcpu);
> -	if (!vcpu->requests)
> +	if (!kvm_vcpu_has_requests(vcpu))
>  		return 0;
>  	/*
>  	 * We use MMU_RELOAD just to re-arm the ipte notifier for the
> @@ -1890,7 +1890,7 @@ retry:
>  	}
>  
>  	/* nothing to do, just clear the request */
> -	clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
> +	kvm_clear_request(KVM_REQ_UNHALT, vcpu);
>  
>  	return 0;
>  }
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 1a8bfaa..599451c 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -5957,7 +5957,7 @@ 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 (test_bit(KVM_REQ_EVENT, kvm_vcpu_requests(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 0601c05..aedb1a0 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -1702,7 +1702,7 @@ 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_clear_request(KVM_REQ_MCLOCK_INPROGRESS, vcpu);
>  
>  	spin_unlock(&ka->pvclock_gtod_sync_lock);
>  #endif
> @@ -2117,7 +2117,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
>  
>  			if (ka->boot_vcpu_runs_old_kvmclock != tmp)
>  				set_bit(KVM_REQ_MASTERCLOCK_UPDATE,
> -					&vcpu->requests);
> +					kvm_vcpu_requests(vcpu));
>  
>  			ka->boot_vcpu_runs_old_kvmclock = tmp;
>  		}
> @@ -6410,7 +6410,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
>  
>  	bool req_immediate_exit = false;
>  
> -	if (vcpu->requests) {
> +	if (kvm_vcpu_has_requests(vcpu)) {
>  		if (kvm_check_request(KVM_REQ_MMU_RELOAD, vcpu))
>  			kvm_mmu_unload(vcpu);
>  		if (kvm_check_request(KVM_REQ_MIGRATE_TIMER, vcpu))
> @@ -6560,7 +6560,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
>  
>  	local_irq_disable();
>  
> -	if (vcpu->mode == EXITING_GUEST_MODE || vcpu->requests
> +	if (vcpu->mode == EXITING_GUEST_MODE || kvm_vcpu_has_requests(vcpu)
>  	    || need_resched() || signal_pending(current)) {
>  		vcpu->mode = OUTSIDE_GUEST_MODE;
>  		smp_wmb();
> @@ -6720,7 +6720,7 @@ static int vcpu_run(struct kvm_vcpu *vcpu)
>  		if (r <= 0)
>  			break;
>  
> -		clear_bit(KVM_REQ_PENDING_TIMER, &vcpu->requests);
> +		kvm_clear_request(KVM_REQ_PENDING_TIMER, vcpu);
>  		if (kvm_cpu_has_pending_timer(vcpu))
>  			kvm_inject_pending_timer_irqs(vcpu);
>  
> @@ -6848,7 +6848,7 @@ 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_clear_request(KVM_REQ_UNHALT, vcpu);
>  		r = -EAGAIN;
>  		goto out;
>  	}
> @@ -8048,7 +8048,7 @@ 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 (test_bit(KVM_REQ_SMI, kvm_vcpu_requests(vcpu)))
>  		return true;
>  
>  	if (kvm_arch_interrupt_allowed(vcpu) &&
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index da7a7e4..6877b4d7e 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -146,6 +146,8 @@ static inline bool is_error_page(struct page *page)
>  #define KVM_REQ_HV_EXIT           30
>  #define KVM_REQ_HV_STIMER         31
>  
> +#define KVM_REQ_MAX               64
> +
>  #define KVM_USERSPACE_IRQ_SOURCE_ID		0
>  #define KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID	1
>  
> @@ -233,7 +235,7 @@ struct kvm_vcpu {
>  	int vcpu_id;
>  	int srcu_idx;
>  	int mode;
> -	unsigned long requests;
> +	DECLARE_BITMAP(requests, KVM_REQ_MAX);
>  	unsigned long guest_debug;
>  
>  	int pre_pcpu;
> @@ -286,6 +288,16 @@ struct kvm_vcpu {
>  	struct kvm_vcpu_arch arch;
>  };
>  
> +static inline bool kvm_vcpu_has_requests(struct kvm_vcpu *vcpu)
> +{
> +	return !bitmap_empty(vcpu->requests, KVM_REQ_MAX);
> +}
> +
> +static inline ulong *kvm_vcpu_requests(struct kvm_vcpu *vcpu)
> +{
> +	return (ulong *)vcpu->requests;
> +}
> +
>  static inline int kvm_vcpu_exiting_guest_mode(struct kvm_vcpu *vcpu)
>  {
>  	return cmpxchg(&vcpu->mode, IN_GUEST_MODE, EXITING_GUEST_MODE);
> @@ -1002,7 +1014,7 @@ static inline bool kvm_is_error_gpa(struct kvm *kvm, gpa_t gpa)
>  
>  static inline void kvm_migrate_timers(struct kvm_vcpu *vcpu)
>  {
> -	set_bit(KVM_REQ_MIGRATE_TIMER, &vcpu->requests);
> +	set_bit(KVM_REQ_MIGRATE_TIMER, kvm_vcpu_requests(vcpu));
>  }
>  
>  enum kvm_stat_kind {
> @@ -1118,19 +1130,24 @@ static inline bool kvm_vcpu_compatible(struct kvm_vcpu *vcpu) { return true; }
>  
>  static inline void kvm_make_request(int req, struct kvm_vcpu *vcpu)
>  {
> -	set_bit(req, &vcpu->requests);
> +	set_bit(req, kvm_vcpu_requests(vcpu));
>  }
>  
>  static inline bool kvm_check_request(int req, struct kvm_vcpu *vcpu)
>  {
> -	if (test_bit(req, &vcpu->requests)) {
> -		clear_bit(req, &vcpu->requests);
> +	if (test_bit(req, kvm_vcpu_requests(vcpu))) {
> +		clear_bit(req, kvm_vcpu_requests(vcpu));
>  		return true;
>  	} else {
>  		return false;
>  	}
>  }
>  
> +static inline void kvm_clear_request(int req, struct kvm_vcpu *vcpu)
> +{
> +	clear_bit(req, kvm_vcpu_requests(vcpu));
> +}
> +
>  extern bool kvm_rebooting;
>  
>  struct kvm_device {
> -- 
> 2.4.3
> 

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Re: [PATCH v1] kvm: Make vcpu->requests as 64 bit bitmap

[Roman Kagan]

On Thu, Dec 24, 2015 at 12:30:26PM +0300, Andrey Smetanin wrote:
> Currently on x86 arch we has already 32 requests defined
> so the newer request bits can't be placed inside
> vcpu->requests(unsigned long) inside x86 32 bit system.
> But we are going to add a new request in x86 arch
> for Hyper-V tsc page support.
> 
> To solve the problem the patch replaces vcpu->requests by
> bitmap with 64 bit length and uses bitmap API.
> 
> The patch consists of:
> * announce kvm_vcpu_has_requests() to check whether vcpu has
> requests
> * announce kvm_vcpu_requests() to get vcpu requests pointer

I think that if abstracting out the implementation of the request
container is what you're after, you'd better not define this function;
accesses to the request map should be through your accessor functions.

> * announce kvm_clear_request() to clear particular vcpu request
> * replace if (vcpu->requests) by if (kvm_vcpu_has_requests(vcpu))
> * replace clear_bit(req, vcpu->requests) by
>  kvm_clear_request(req, vcpu)

Apparently one accessor is missing: test the presence of a request
without clearing it from the bitmap (because kvm_check_request() clears
it).

> diff --git a/arch/powerpc/kvm/trace.h b/arch/powerpc/kvm/trace.h
> index 2e0e67e..4015b88 100644
> --- a/arch/powerpc/kvm/trace.h
> +++ b/arch/powerpc/kvm/trace.h
> @@ -109,7 +109,7 @@ TRACE_EVENT(kvm_check_requests,
>  
>  	TP_fast_assign(
>  		__entry->cpu_nr		= vcpu->vcpu_id;
> -		__entry->requests	= vcpu->requests;
> +		__entry->requests	= (__u32)kvm_vcpu_requests(vcpu)[0];
>  	),

This doesn't make sense, to expose only subset of the requests.  BTW I
don't see this event in Linus tree, nor in linux-next, so I'm not quite
sure why it's formed this way; I guess the interesting part is the
request number and the return value (i.e. whether it's set), not the
whole bitmap.

> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -5957,7 +5957,7 @@ 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 (test_bit(KVM_REQ_EVENT, kvm_vcpu_requests(vcpu)))

Here you'd rather want that function to test for the request without
clearing it.

> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -2117,7 +2117,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
>  
>  			if (ka->boot_vcpu_runs_old_kvmclock != tmp)
>  				set_bit(KVM_REQ_MASTERCLOCK_UPDATE,
> -					&vcpu->requests);
> +					kvm_vcpu_requests(vcpu));

This should have been kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);

> @@ -8048,7 +8048,7 @@ 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 (test_bit(KVM_REQ_SMI, kvm_vcpu_requests(vcpu)))

Again the test-only accessor is due here.

> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -146,6 +146,8 @@ static inline bool is_error_page(struct page *page)
>  #define KVM_REQ_HV_EXIT           30
>  #define KVM_REQ_HV_STIMER         31
>  
> +#define KVM_REQ_MAX               64
> +
>  #define KVM_USERSPACE_IRQ_SOURCE_ID		0
>  #define KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID	1
>  
> @@ -233,7 +235,7 @@ struct kvm_vcpu {
>  	int vcpu_id;
>  	int srcu_idx;
>  	int mode;
> -	unsigned long requests;
> +	DECLARE_BITMAP(requests, KVM_REQ_MAX);
>  	unsigned long guest_debug;
>  
>  	int pre_pcpu;
> @@ -286,6 +288,16 @@ struct kvm_vcpu {
>  	struct kvm_vcpu_arch arch;
>  };
>  
> +static inline bool kvm_vcpu_has_requests(struct kvm_vcpu *vcpu)
> +{
> +	return !bitmap_empty(vcpu->requests, KVM_REQ_MAX);
> +}
> +
> +static inline ulong *kvm_vcpu_requests(struct kvm_vcpu *vcpu)
> +{
> +	return (ulong *)vcpu->requests;
> +}

As I wrote above, I believe this function doesn't belong in the API.

> +
>  static inline int kvm_vcpu_exiting_guest_mode(struct kvm_vcpu *vcpu)
>  {
>  	return cmpxchg(&vcpu->mode, IN_GUEST_MODE, EXITING_GUEST_MODE);
> @@ -1002,7 +1014,7 @@ static inline bool kvm_is_error_gpa(struct kvm *kvm, gpa_t gpa)
>  
>  static inline void kvm_migrate_timers(struct kvm_vcpu *vcpu)
>  {
> -	set_bit(KVM_REQ_MIGRATE_TIMER, &vcpu->requests);
> +	set_bit(KVM_REQ_MIGRATE_TIMER, kvm_vcpu_requests(vcpu));

kvm_make_request(KVM_REQ_MIGRATE_TIMER, vcpu);

> @@ -1118,19 +1130,24 @@ static inline bool kvm_vcpu_compatible(struct kvm_vcpu *vcpu) { return true; }
>  
>  static inline void kvm_make_request(int req, struct kvm_vcpu *vcpu)
>  {
> -	set_bit(req, &vcpu->requests);
> +	set_bit(req, kvm_vcpu_requests(vcpu));
>  }
>  
>  static inline bool kvm_check_request(int req, struct kvm_vcpu *vcpu)
>  {
> -	if (test_bit(req, &vcpu->requests)) {
> -		clear_bit(req, &vcpu->requests);
> +	if (test_bit(req, kvm_vcpu_requests(vcpu))) {
> +		clear_bit(req, kvm_vcpu_requests(vcpu));
>  		return true;
>  	} else {
>  		return false;
>  	}

I wonder why this doesn't use test_and_clear_bit instead.

Roman.

Re: [PATCH v1] kvm: Make vcpu->requests as 64 bit bitmap

[Roman Kagan]

On Thu, Dec 24, 2015 at 12:30:26PM +0300, Andrey Smetanin wrote:
> Currently on x86 arch we has already 32 requests defined
> so the newer request bits can't be placed inside
> vcpu->requests(unsigned long) inside x86 32 bit system.
> But we are going to add a new request in x86 arch
> for Hyper-V tsc page support.
> 
> To solve the problem the patch replaces vcpu->requests by
> bitmap with 64 bit length and uses bitmap API.
> 
> The patch consists of:
> * announce kvm_vcpu_has_requests() to check whether vcpu has
> requests
> * announce kvm_vcpu_requests() to get vcpu requests pointer

I think that if abstracting out the implementation of the request
container is what you're after, you'd better not define this function;
accesses to the request map should be through your accessor functions.

> * announce kvm_clear_request() to clear particular vcpu request
> * replace if (vcpu->requests) by if (kvm_vcpu_has_requests(vcpu))
> * replace clear_bit(req, vcpu->requests) by
>  kvm_clear_request(req, vcpu)

Apparently one accessor is missing: test the presence of a request
without clearing it from the bitmap (because kvm_check_request() clears
it).

> diff --git a/arch/powerpc/kvm/trace.h b/arch/powerpc/kvm/trace.h
> index 2e0e67e..4015b88 100644
> --- a/arch/powerpc/kvm/trace.h
> +++ b/arch/powerpc/kvm/trace.h
> @@ -109,7 +109,7 @@ TRACE_EVENT(kvm_check_requests,
>  
>  	TP_fast_assign(
>  		__entry->cpu_nr		= vcpu->vcpu_id;
> -		__entry->requests	= vcpu->requests;
> +		__entry->requests	= (__u32)kvm_vcpu_requests(vcpu)[0];
>  	),

This doesn't make sense, to expose only subset of the requests.  BTW I
don't see this event in Linus tree, nor in linux-next, so I'm not quite
sure why it's formed this way; I guess the interesting part is the
request number and the return value (i.e. whether it's set), not the
whole bitmap.

> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -5957,7 +5957,7 @@ 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 (test_bit(KVM_REQ_EVENT, kvm_vcpu_requests(vcpu)))

Here you'd rather want that function to test for the request without
clearing it.

> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -2117,7 +2117,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
>  
>  			if (ka->boot_vcpu_runs_old_kvmclock != tmp)
>  				set_bit(KVM_REQ_MASTERCLOCK_UPDATE,
> -					&vcpu->requests);
> +					kvm_vcpu_requests(vcpu));

This should have been kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);

> @@ -8048,7 +8048,7 @@ 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 (test_bit(KVM_REQ_SMI, kvm_vcpu_requests(vcpu)))

Again the test-only accessor is due here.

> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -146,6 +146,8 @@ static inline bool is_error_page(struct page *page)
>  #define KVM_REQ_HV_EXIT           30
>  #define KVM_REQ_HV_STIMER         31
>  
> +#define KVM_REQ_MAX               64
> +
>  #define KVM_USERSPACE_IRQ_SOURCE_ID		0
>  #define KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID	1
>  
> @@ -233,7 +235,7 @@ struct kvm_vcpu {
>  	int vcpu_id;
>  	int srcu_idx;
>  	int mode;
> -	unsigned long requests;
> +	DECLARE_BITMAP(requests, KVM_REQ_MAX);
>  	unsigned long guest_debug;
>  
>  	int pre_pcpu;
> @@ -286,6 +288,16 @@ struct kvm_vcpu {
>  	struct kvm_vcpu_arch arch;
>  };
>  
> +static inline bool kvm_vcpu_has_requests(struct kvm_vcpu *vcpu)
> +{
> +	return !bitmap_empty(vcpu->requests, KVM_REQ_MAX);
> +}
> +
> +static inline ulong *kvm_vcpu_requests(struct kvm_vcpu *vcpu)
> +{
> +	return (ulong *)vcpu->requests;
> +}

As I wrote above, I believe this function doesn't belong in the API.

> +
>  static inline int kvm_vcpu_exiting_guest_mode(struct kvm_vcpu *vcpu)
>  {
>  	return cmpxchg(&vcpu->mode, IN_GUEST_MODE, EXITING_GUEST_MODE);
> @@ -1002,7 +1014,7 @@ static inline bool kvm_is_error_gpa(struct kvm *kvm, gpa_t gpa)
>  
>  static inline void kvm_migrate_timers(struct kvm_vcpu *vcpu)
>  {
> -	set_bit(KVM_REQ_MIGRATE_TIMER, &vcpu->requests);
> +	set_bit(KVM_REQ_MIGRATE_TIMER, kvm_vcpu_requests(vcpu));

kvm_make_request(KVM_REQ_MIGRATE_TIMER, vcpu);

> @@ -1118,19 +1130,24 @@ static inline bool kvm_vcpu_compatible(struct kvm_vcpu *vcpu) { return true; }
>  
>  static inline void kvm_make_request(int req, struct kvm_vcpu *vcpu)
>  {
> -	set_bit(req, &vcpu->requests);
> +	set_bit(req, kvm_vcpu_requests(vcpu));
>  }
>  
>  static inline bool kvm_check_request(int req, struct kvm_vcpu *vcpu)
>  {
> -	if (test_bit(req, &vcpu->requests)) {
> -		clear_bit(req, &vcpu->requests);
> +	if (test_bit(req, kvm_vcpu_requests(vcpu))) {
> +		clear_bit(req, kvm_vcpu_requests(vcpu));
>  		return true;
>  	} else {
>  		return false;
>  	}

I wonder why this doesn't use test_and_clear_bit instead.

Roman.

Re: [PATCH v1] kvm: Make vcpu->requests as 64 bit bitmap

[Andrey Smetanin]

On 12/24/2015 02:14 PM, Roman Kagan wrote:
> On Thu, Dec 24, 2015 at 12:30:26PM +0300, Andrey Smetanin wrote:
>> Currently on x86 arch we has already 32 requests defined
>> so the newer request bits can't be placed inside
>> vcpu->requests(unsigned long) inside x86 32 bit system.
>> But we are going to add a new request in x86 arch
>> for Hyper-V tsc page support.
>>
>> To solve the problem the patch replaces vcpu->requests by
>> bitmap with 64 bit length and uses bitmap API.
>>
>> The patch consists of:
>> * announce kvm_vcpu_has_requests() to check whether vcpu has
>> requests
>> * announce kvm_vcpu_requests() to get vcpu requests pointer
>
> I think that if abstracting out the implementation of the request
> container is what you're after, you'd better not define this function;
> accesses to the request map should be through your accessor functions.

Good idea! I'll rework this patch and will send V2.
>
>> * announce kvm_clear_request() to clear particular vcpu request
>> * replace if (vcpu->requests) by if (kvm_vcpu_has_requests(vcpu))
>> * replace clear_bit(req, vcpu->requests) by
>>   kvm_clear_request(req, vcpu)
>
> Apparently one accessor is missing: test the presence of a request
> without clearing it from the bitmap (because kvm_check_request() clears
> it).
agree
>
>> diff --git a/arch/powerpc/kvm/trace.h b/arch/powerpc/kvm/trace.h
>> index 2e0e67e..4015b88 100644
>> --- a/arch/powerpc/kvm/trace.h
>> +++ b/arch/powerpc/kvm/trace.h
>> @@ -109,7 +109,7 @@ TRACE_EVENT(kvm_check_requests,
>>
>>   	TP_fast_assign(
>>   		__entry->cpu_nr		= vcpu->vcpu_id;
>> -		__entry->requests	= vcpu->requests;
>> +		__entry->requests	= (__u32)kvm_vcpu_requests(vcpu)[0];
>>   	),
>
> This doesn't make sense, to expose only subset of the requests.  BTW I
> don't see this event in Linus tree, nor in linux-next,
I found it here:
arch/powerpc/kvm/powerpc.c:104:		trace_kvm_check_requests(vcpu);
 >so I'm not quite
> sure why it's formed this way; I guess the interesting part is the
> request number and the return value (i.e. whether it's set), not the
> whole bitmap.
No, the code actually dumps part of first 32 bit of bitmap:
         TP_printk("vcpu=%x requests=%x",
                 __entry->cpu_nr, __entry->requests)

So, for this corner case we can make __entry->requests as unsigned long 
variable and make the API helper to get first unsigned long from 
vcpu->requests bitmap. Next print part of bitmap this way:
  TP_printk("vcpu=0x%x requests=0x%lx",
__entry->cpu_nr, __entry->requests)
(as unsigned long).

POWERPC guys what do you think about such approach? Or could
we even drop trace_kvm_check_requests() at all. Does 
trace_kvm_check_requests() still useful for you?
>
>> --- a/arch/x86/kvm/vmx.c
>> +++ b/arch/x86/kvm/vmx.c
>> @@ -5957,7 +5957,7 @@ 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 (test_bit(KVM_REQ_EVENT, kvm_vcpu_requests(vcpu)))
>
> Here you'd rather want that function to test for the request without
> clearing it.
agree, i'll provide such function.
>
>> --- a/arch/x86/kvm/x86.c
>> +++ b/arch/x86/kvm/x86.c
>> @@ -2117,7 +2117,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
>>
>>   			if (ka->boot_vcpu_runs_old_kvmclock != tmp)
>>   				set_bit(KVM_REQ_MASTERCLOCK_UPDATE,
>> -					&vcpu->requests);
>> +					kvm_vcpu_requests(vcpu));
>
> This should have been kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
>
agree
>> @@ -8048,7 +8048,7 @@ 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 (test_bit(KVM_REQ_SMI, kvm_vcpu_requests(vcpu)))
>
> Again the test-only accessor is due here.
agree
>
>> --- a/include/linux/kvm_host.h
>> +++ b/include/linux/kvm_host.h
>> @@ -146,6 +146,8 @@ static inline bool is_error_page(struct page *page)
>>   #define KVM_REQ_HV_EXIT           30
>>   #define KVM_REQ_HV_STIMER         31
>>
>> +#define KVM_REQ_MAX               64
>> +
>>   #define KVM_USERSPACE_IRQ_SOURCE_ID		0
>>   #define KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID	1
>>
>> @@ -233,7 +235,7 @@ struct kvm_vcpu {
>>   	int vcpu_id;
>>   	int srcu_idx;
>>   	int mode;
>> -	unsigned long requests;
>> +	DECLARE_BITMAP(requests, KVM_REQ_MAX);
>>   	unsigned long guest_debug;
>>
>>   	int pre_pcpu;
>> @@ -286,6 +288,16 @@ struct kvm_vcpu {
>>   	struct kvm_vcpu_arch arch;
>>   };
>>
>> +static inline bool kvm_vcpu_has_requests(struct kvm_vcpu *vcpu)
>> +{
>> +	return !bitmap_empty(vcpu->requests, KVM_REQ_MAX);
>> +}
>> +
>> +static inline ulong *kvm_vcpu_requests(struct kvm_vcpu *vcpu)
>> +{
>> +	return (ulong *)vcpu->requests;
>> +}
>
> As I wrote above, I believe this function doesn't belong in the API.
agree, i'll drop it.
>
>> +
>>   static inline int kvm_vcpu_exiting_guest_mode(struct kvm_vcpu *vcpu)
>>   {
>>   	return cmpxchg(&vcpu->mode, IN_GUEST_MODE, EXITING_GUEST_MODE);
>> @@ -1002,7 +1014,7 @@ static inline bool kvm_is_error_gpa(struct kvm *kvm, gpa_t gpa)
>>
>>   static inline void kvm_migrate_timers(struct kvm_vcpu *vcpu)
>>   {
>> -	set_bit(KVM_REQ_MIGRATE_TIMER, &vcpu->requests);
>> +	set_bit(KVM_REQ_MIGRATE_TIMER, kvm_vcpu_requests(vcpu));
>
> kvm_make_request(KVM_REQ_MIGRATE_TIMER, vcpu);
agree
>
>> @@ -1118,19 +1130,24 @@ static inline bool kvm_vcpu_compatible(struct kvm_vcpu *vcpu) { return true; }
>>
>>   static inline void kvm_make_request(int req, struct kvm_vcpu *vcpu)
>>   {
>> -	set_bit(req, &vcpu->requests);
>> +	set_bit(req, kvm_vcpu_requests(vcpu));
>>   }
>>
>>   static inline bool kvm_check_request(int req, struct kvm_vcpu *vcpu)
>>   {
>> -	if (test_bit(req, &vcpu->requests)) {
>> -		clear_bit(req, &vcpu->requests);
>> +	if (test_bit(req, kvm_vcpu_requests(vcpu))) {
>> +		clear_bit(req, kvm_vcpu_requests(vcpu));
>>   		return true;
>>   	} else {
>>   		return false;
>>   	}
>
> I wonder why this doesn't use test_and_clear_bit instead.
agree, i'll replace it by test_and_clear_bit
>
> Roman.
>

Re: [PATCH v1] kvm: Make vcpu->requests as 64 bit bitmap

[Andrey Smetanin]

On 12/24/2015 02:14 PM, Roman Kagan wrote:
> On Thu, Dec 24, 2015 at 12:30:26PM +0300, Andrey Smetanin wrote:
>> Currently on x86 arch we has already 32 requests defined
>> so the newer request bits can't be placed inside
>> vcpu->requests(unsigned long) inside x86 32 bit system.
>> But we are going to add a new request in x86 arch
>> for Hyper-V tsc page support.
>>
>> To solve the problem the patch replaces vcpu->requests by
>> bitmap with 64 bit length and uses bitmap API.
>>
>> The patch consists of:
>> * announce kvm_vcpu_has_requests() to check whether vcpu has
>> requests
>> * announce kvm_vcpu_requests() to get vcpu requests pointer
>
> I think that if abstracting out the implementation of the request
> container is what you're after, you'd better not define this function;
> accesses to the request map should be through your accessor functions.

Good idea! I'll rework this patch and will send V2.
>
>> * announce kvm_clear_request() to clear particular vcpu request
>> * replace if (vcpu->requests) by if (kvm_vcpu_has_requests(vcpu))
>> * replace clear_bit(req, vcpu->requests) by
>>   kvm_clear_request(req, vcpu)
>
> Apparently one accessor is missing: test the presence of a request
> without clearing it from the bitmap (because kvm_check_request() clears
> it).
agree
>
>> diff --git a/arch/powerpc/kvm/trace.h b/arch/powerpc/kvm/trace.h
>> index 2e0e67e..4015b88 100644
>> --- a/arch/powerpc/kvm/trace.h
>> +++ b/arch/powerpc/kvm/trace.h
>> @@ -109,7 +109,7 @@ TRACE_EVENT(kvm_check_requests,
>>
>>   	TP_fast_assign(
>>   		__entry->cpu_nr		= vcpu->vcpu_id;
>> -		__entry->requests	= vcpu->requests;
>> +		__entry->requests	= (__u32)kvm_vcpu_requests(vcpu)[0];
>>   	),
>
> This doesn't make sense, to expose only subset of the requests.  BTW I
> don't see this event in Linus tree, nor in linux-next,
I found it here:
arch/powerpc/kvm/powerpc.c:104:		trace_kvm_check_requests(vcpu);
 >so I'm not quite
> sure why it's formed this way; I guess the interesting part is the
> request number and the return value (i.e. whether it's set), not the
> whole bitmap.
No, the code actually dumps part of first 32 bit of bitmap:
         TP_printk("vcpu=%x requests=%x",
                 __entry->cpu_nr, __entry->requests)

So, for this corner case we can make __entry->requests as unsigned long 
variable and make the API helper to get first unsigned long from 
vcpu->requests bitmap. Next print part of bitmap this way:
  TP_printk("vcpu=0x%x requests=0x%lx",
__entry->cpu_nr, __entry->requests)
(as unsigned long).

POWERPC guys what do you think about such approach? Or could
we even drop trace_kvm_check_requests() at all. Does 
trace_kvm_check_requests() still useful for you?
>
>> --- a/arch/x86/kvm/vmx.c
>> +++ b/arch/x86/kvm/vmx.c
>> @@ -5957,7 +5957,7 @@ 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 (test_bit(KVM_REQ_EVENT, kvm_vcpu_requests(vcpu)))
>
> Here you'd rather want that function to test for the request without
> clearing it.
agree, i'll provide such function.
>
>> --- a/arch/x86/kvm/x86.c
>> +++ b/arch/x86/kvm/x86.c
>> @@ -2117,7 +2117,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
>>
>>   			if (ka->boot_vcpu_runs_old_kvmclock != tmp)
>>   				set_bit(KVM_REQ_MASTERCLOCK_UPDATE,
>> -					&vcpu->requests);
>> +					kvm_vcpu_requests(vcpu));
>
> This should have been kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
>
agree
>> @@ -8048,7 +8048,7 @@ 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 (test_bit(KVM_REQ_SMI, kvm_vcpu_requests(vcpu)))
>
> Again the test-only accessor is due here.
agree
>
>> --- a/include/linux/kvm_host.h
>> +++ b/include/linux/kvm_host.h
>> @@ -146,6 +146,8 @@ static inline bool is_error_page(struct page *page)
>>   #define KVM_REQ_HV_EXIT           30
>>   #define KVM_REQ_HV_STIMER         31
>>
>> +#define KVM_REQ_MAX               64
>> +
>>   #define KVM_USERSPACE_IRQ_SOURCE_ID		0
>>   #define KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID	1
>>
>> @@ -233,7 +235,7 @@ struct kvm_vcpu {
>>   	int vcpu_id;
>>   	int srcu_idx;
>>   	int mode;
>> -	unsigned long requests;
>> +	DECLARE_BITMAP(requests, KVM_REQ_MAX);
>>   	unsigned long guest_debug;
>>
>>   	int pre_pcpu;
>> @@ -286,6 +288,16 @@ struct kvm_vcpu {
>>   	struct kvm_vcpu_arch arch;
>>   };
>>
>> +static inline bool kvm_vcpu_has_requests(struct kvm_vcpu *vcpu)
>> +{
>> +	return !bitmap_empty(vcpu->requests, KVM_REQ_MAX);
>> +}
>> +
>> +static inline ulong *kvm_vcpu_requests(struct kvm_vcpu *vcpu)
>> +{
>> +	return (ulong *)vcpu->requests;
>> +}
>
> As I wrote above, I believe this function doesn't belong in the API.
agree, i'll drop it.
>
>> +
>>   static inline int kvm_vcpu_exiting_guest_mode(struct kvm_vcpu *vcpu)
>>   {
>>   	return cmpxchg(&vcpu->mode, IN_GUEST_MODE, EXITING_GUEST_MODE);
>> @@ -1002,7 +1014,7 @@ static inline bool kvm_is_error_gpa(struct kvm *kvm, gpa_t gpa)
>>
>>   static inline void kvm_migrate_timers(struct kvm_vcpu *vcpu)
>>   {
>> -	set_bit(KVM_REQ_MIGRATE_TIMER, &vcpu->requests);
>> +	set_bit(KVM_REQ_MIGRATE_TIMER, kvm_vcpu_requests(vcpu));
>
> kvm_make_request(KVM_REQ_MIGRATE_TIMER, vcpu);
agree
>
>> @@ -1118,19 +1130,24 @@ static inline bool kvm_vcpu_compatible(struct kvm_vcpu *vcpu) { return true; }
>>
>>   static inline void kvm_make_request(int req, struct kvm_vcpu *vcpu)
>>   {
>> -	set_bit(req, &vcpu->requests);
>> +	set_bit(req, kvm_vcpu_requests(vcpu));
>>   }
>>
>>   static inline bool kvm_check_request(int req, struct kvm_vcpu *vcpu)
>>   {
>> -	if (test_bit(req, &vcpu->requests)) {
>> -		clear_bit(req, &vcpu->requests);
>> +	if (test_bit(req, kvm_vcpu_requests(vcpu))) {
>> +		clear_bit(req, kvm_vcpu_requests(vcpu));
>>   		return true;
>>   	} else {
>>   		return false;
>>   	}
>
> I wonder why this doesn't use test_and_clear_bit instead.
agree, i'll replace it by test_and_clear_bit
>
> Roman.
>