[PATCH v3 4/5] KVM: Add new exit reason for dirty ring full conditions

["Cao, Lei" <Lei.Cao@xxxxxxxxxxx>]

Add new exit reason KVM_EXIT_DIRTY_LOG_FULL.

Signed-off-by: Lei Cao <lei.cao@xxxxxxxxxxx>
---
 arch/x86/include/asm/kvm_host.h | 4 ++++
 arch/x86/kvm/mmu.c              | 7 +++++++
 arch/x86/kvm/vmx.c              | 7 +++++++
 arch/x86/kvm/x86.c              | 6 ++++++
 include/uapi/linux/kvm.h        | 1 +
 5 files changed, 25 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 2b385f2..47dcb49 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -74,6 +74,7 @@
 #define KVM_REQ_HV_RESET          28
 #define KVM_REQ_HV_EXIT           29
 #define KVM_REQ_HV_STIMER         30
+#define KVM_REQ_EXIT_DIRTY_LOG_FULL 31
 
 #define CR0_RESERVED_BITS                                               \
 	(~(unsigned long)(X86_CR0_PE | X86_CR0_MP | X86_CR0_EM | X86_CR0_TS \
@@ -1005,6 +1006,7 @@ struct kvm_x86_ops {
 	void (*enable_log_dirty_pt_masked)(struct kvm *kvm,
 					   struct kvm_memory_slot *slot,
 					   gfn_t offset, unsigned long mask);
+	int (*cpu_dirty_log_size)(void);
 	/* pmu operations of sub-arch */
 	const struct kvm_pmu_ops *pmu_ops;
 
@@ -1411,4 +1413,6 @@ static inline int kvm_cpu_get_apicid(int mps_cpu)
 #endif
 }
 
+int kvm_cpu_dirty_log_size(void);
+
 #endif /* _ASM_X86_KVM_HOST_H */
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 7012de4..dd34ac6 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1357,6 +1357,13 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
 		kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask);
 }
 
+int kvm_cpu_dirty_log_size(void)
+{
+	if (kvm_x86_ops->cpu_dirty_log_size)
+		return kvm_x86_ops->cpu_dirty_log_size();
+	return 0;
+}
+
 bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm,
 				    struct kvm_memory_slot *slot, u64 gfn)
 {
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index a236dec..0e11510 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6723,6 +6723,7 @@ static __init int hardware_setup(void)
 		kvm_x86_ops->slot_disable_log_dirty = NULL;
 		kvm_x86_ops->flush_log_dirty = NULL;
 		kvm_x86_ops->enable_log_dirty_pt_masked = NULL;
+		kvm_x86_ops->cpu_dirty_log_size = NULL;
 	}
 
 	if (cpu_has_vmx_preemption_timer() && enable_preemption_timer) {
@@ -11497,6 +11498,11 @@ static void vmx_setup_mce(struct kvm_vcpu *vcpu)
 			~FEATURE_CONTROL_LMCE;
 }
 
+static int vmx_cpu_dirty_log_size(void)
+{
+	return PML_ENTITY_NUM;
+}
+
 static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.cpu_has_kvm_support = cpu_has_kvm_support,
 	.disabled_by_bios = vmx_disabled_by_bios,
@@ -11611,6 +11617,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.slot_disable_log_dirty = vmx_slot_disable_log_dirty,
 	.flush_log_dirty = vmx_flush_log_dirty,
 	.enable_log_dirty_pt_masked = vmx_enable_log_dirty_pt_masked,
+	.cpu_dirty_log_size = vmx_cpu_dirty_log_size,
 
 	.pre_block = vmx_pre_block,
 	.post_block = vmx_post_block,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 378fc98..7ff9f25 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6705,6 +6705,12 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 		 */
 		if (kvm_check_request(KVM_REQ_HV_STIMER, vcpu))
 			kvm_hv_process_stimers(vcpu);
+
+		if (kvm_check_request(KVM_REQ_EXIT_DIRTY_LOG_FULL, vcpu)) {
+			vcpu->run->exit_reason = KVM_EXIT_DIRTY_LOG_FULL;
+			r = -EINTR;
+			goto out;
+		}
 	}
 
 	/*
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 943c5a35..0972721 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -205,6 +205,7 @@ struct kvm_hyperv_exit {
 #define KVM_EXIT_S390_STSI        25
 #define KVM_EXIT_IOAPIC_EOI       26
 #define KVM_EXIT_HYPERV           27
+#define KVM_EXIT_DIRTY_LOG_FULL   28
 
 /* For KVM_EXIT_INTERNAL_ERROR */
 /* Emulate instruction failed. */
-- 
2.5.0