[2/2] KVM: Remove KVM_REQ_MCLOCK_INPROGRESS to save a bit in vcpu->requests

Commit Message

Takuya Yoshikawa Jan. 7, 2016, 11:43 a.m. UTC

Now that we are running out of the bits in vcpu->requests, using one
of them just to call kvm_make_all_cpus_request() with a valid request
number should be avoided.

This patch achieves this by making kvm_make_all_cpus_request() handle
an empty request.

Signed-off-by: Takuya Yoshikawa <[e-mail]>
---
 arch/x86/kvm/x86.c       |  2 --
 include/linux/kvm_host.h | 27 +++++++++++++--------------
 virt/kvm/kvm_main.c      |  8 +++++---
 3 files changed, 18 insertions(+), 19 deletions(-)

Patch

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b6102c1..88260d0 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1701,8 +1701,6 @@  static void kvm_gen_update_masterclock(struct kvm *kvm)
 		kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
 
 	/* guest entries allowed */
-	kvm_for_each_vcpu(i, vcpu, kvm)
-		clear_bit(KVM_REQ_MCLOCK_INPROGRESS, &vcpu->requests);
 
 	spin_unlock(&ka->pvclock_gtod_sync_lock);
 #endif
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index ca9b93e..bb9ae4f 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -131,19 +131,18 @@  static inline bool is_error_page(struct page *page)
 #define KVM_REQ_PMI               15
 #define KVM_REQ_WATCHDOG          16
 #define KVM_REQ_MASTERCLOCK_UPDATE 17
-#define KVM_REQ_MCLOCK_INPROGRESS 18
-#define KVM_REQ_EPR_EXIT          19
-#define KVM_REQ_SCAN_IOAPIC       20
-#define KVM_REQ_GLOBAL_CLOCK_UPDATE 21
-#define KVM_REQ_ENABLE_IBS        22
-#define KVM_REQ_DISABLE_IBS       23
-#define KVM_REQ_APIC_PAGE_RELOAD  24
-#define KVM_REQ_SMI               25
-#define KVM_REQ_HV_CRASH          26
-#define KVM_REQ_IOAPIC_EOI_EXIT   27
-#define KVM_REQ_HV_RESET          28
-#define KVM_REQ_HV_EXIT           29
-#define KVM_REQ_HV_STIMER         30
+#define KVM_REQ_EPR_EXIT          18
+#define KVM_REQ_SCAN_IOAPIC       19
+#define KVM_REQ_GLOBAL_CLOCK_UPDATE 20
+#define KVM_REQ_ENABLE_IBS        21
+#define KVM_REQ_DISABLE_IBS       22
+#define KVM_REQ_APIC_PAGE_RELOAD  23
+#define KVM_REQ_SMI               24
+#define KVM_REQ_HV_CRASH          25
+#define KVM_REQ_IOAPIC_EOI_EXIT   26
+#define KVM_REQ_HV_RESET          27
+#define KVM_REQ_HV_EXIT           28
+#define KVM_REQ_HV_STIMER         29
 
 #define KVM_USERSPACE_IRQ_SOURCE_ID		0
 #define KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID	1
@@ -685,7 +684,7 @@  void kvm_flush_remote_tlbs(struct kvm *kvm);
 void kvm_reload_remote_mmus(struct kvm *kvm);
 void kvm_make_mclock_inprogress_request(struct kvm *kvm);
 void kvm_make_scan_ioapic_request(struct kvm *kvm);
-bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req);
+bool kvm_make_all_cpus_request(struct kvm *kvm, int req);
 
 long kvm_arch_dev_ioctl(struct file *filp,
 			unsigned int ioctl, unsigned long arg);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index be3cef1..0100a19 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -156,7 +156,7 @@  static void ack_flush(void *_completed)
 {
 }
 
-bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req)
+bool kvm_make_all_cpus_request(struct kvm *kvm, int req)
 {
 	int i, cpu, me;
 	cpumask_var_t cpus;
@@ -167,7 +167,9 @@  bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req)
 
 	me = get_cpu();
 	kvm_for_each_vcpu(i, vcpu, kvm) {
-		kvm_make_request(req, vcpu);
+		if (req >= 0)
+			kvm_make_request(req, vcpu);
+
 		cpu = vcpu->cpu;
 
 		/* Set ->requests bit before we read ->mode */
@@ -208,7 +210,7 @@  void kvm_reload_remote_mmus(struct kvm *kvm)
 
 void kvm_make_mclock_inprogress_request(struct kvm *kvm)
 {
-	kvm_make_all_cpus_request(kvm, KVM_REQ_MCLOCK_INPROGRESS);
+	kvm_make_all_cpus_request(kvm, -1);
 }
 
 void kvm_make_scan_ioapic_request(struct kvm *kvm)