KVM: rename KVM_REQ_PENDING_TIMER to KVM_REQ_UNBLOCK

KVM_REQ_UNBLOCK will be used to exit a vcpu from
its inner vcpu halt emulation loop.

Rename KVM_REQ_PENDING_TIMER to KVM_REQ_UNBLOCK, switch
PowerPC to arch specific request bit.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

Message-Id: <20210525134321.303768132@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Documentation/virt/kvm/vcpu-requests.rst

@@ -118,10 +118,12 @@ KVM_REQ_MMU_RELOAD
   necessary to inform each VCPU to completely refresh the tables.  This
   request is used for that.
 
-KVM_REQ_PENDING_TIMER
+KVM_REQ_UNBLOCK
 
-  This request may be made from a timer handler run on the host on behalf
-  of a VCPU.  It informs the VCPU thread to inject a timer interrupt.
+  This request informs the vCPU to exit kvm_vcpu_block.  It is used for
+  example from timer handlers that run on the host on behalf of a vCPU,
+  or in order to update the interrupt routing and ensure that assigned
+  devices will wake up the vCPU.
 
 KVM_REQ_UNHALT
 

arch/powerpc/include/asm/kvm_host.h

@@ -51,6 +51,7 @@
 /* PPC-specific vcpu->requests bit members */
 #define KVM_REQ_WATCHDOG	KVM_ARCH_REQ(0)
 #define KVM_REQ_EPR_EXIT	KVM_ARCH_REQ(1)
+#define KVM_REQ_PENDING_TIMER	KVM_ARCH_REQ(2)
 
 #include <linux/mmu_notifier.h>
 

arch/x86/kvm/lapic.c

@@ -1669,7 +1669,7 @@ static void apic_timer_expired(struct kvm_lapic *apic, bool from_timer_fn)
 	}
 
 	atomic_inc(&apic->lapic_timer.pending);
-	kvm_make_request(KVM_REQ_PENDING_TIMER, vcpu);
+	kvm_make_request(KVM_REQ_UNBLOCK, vcpu);
 	if (from_timer_fn)
 		kvm_vcpu_kick(vcpu);
 }

arch/x86/kvm/x86.c

@@ -9501,7 +9501,7 @@ static int vcpu_run(struct kvm_vcpu *vcpu)
 		if (r <= 0)
 			break;
 
-		kvm_clear_request(KVM_REQ_PENDING_TIMER, vcpu);
+		kvm_clear_request(KVM_REQ_UNBLOCK, vcpu);
 		if (kvm_cpu_has_pending_timer(vcpu))
 			kvm_inject_pending_timer_irqs(vcpu);
 

include/linux/kvm_host.h

@@ -147,7 +147,7 @@ static inline bool is_error_page(struct page *page)
  */
 #define KVM_REQ_TLB_FLUSH         (0 | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
 #define KVM_REQ_MMU_RELOAD        (1 | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
-#define KVM_REQ_PENDING_TIMER     2
+#define KVM_REQ_UNBLOCK           2
 #define KVM_REQ_UNHALT            3
 #define KVM_REQUEST_ARCH_BASE     8
 

virt/kvm/kvm_main.c

@@ -2929,6 +2929,8 @@ static int kvm_vcpu_check_block(struct kvm_vcpu *vcpu)
 		goto out;
 	if (signal_pending(current))
 		goto out;
+	if (kvm_check_request(KVM_REQ_UNBLOCK, vcpu))
+		goto out;
 
 	ret = 0;
 out: