[PATCH v4 11/15] KVM: arm64: Export async PF capability

[Gavin Shan]

This exports the asynchronous page fault capability:

    * Identify capability KVM_CAP_ASYNC_{PF, PF_INT}.

    * Standardize SDEI event for asynchronous page fault.

    * Enable kernel config CONFIG_KVM_ASYNC_{PF, PF_SLOT}.

Signed-off-by: Gavin Shan <gshan@xxxxxxxxxx>
---
 arch/arm64/include/uapi/asm/kvm_sdei.h | 1 +
 arch/arm64/kvm/Kconfig                 | 2 ++
 arch/arm64/kvm/arm.c                   | 4 ++++
 arch/arm64/kvm/sdei.c                  | 5 +++++
 4 files changed, 12 insertions(+)

diff --git a/arch/arm64/include/uapi/asm/kvm_sdei.h b/arch/arm64/include/uapi/asm/kvm_sdei.h
index f7a6b2b22b50..cbe8be3d0a25 100644
--- a/arch/arm64/include/uapi/asm/kvm_sdei.h
+++ b/arch/arm64/include/uapi/asm/kvm_sdei.h
@@ -16,6 +16,7 @@
 #define KVM_SDEI_MAX_VCPUS	512
 #define KVM_SDEI_INVALID_NUM	0
 #define KVM_SDEI_DEFAULT_NUM	0x40400000
+#define KVM_SDEI_ASYNC_PF_NUM	0x40400001
 
 struct kvm_sdei_event_state {
 	__u64	num;
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index a4eba0908bfa..3c6f89b4c9a0 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -29,6 +29,8 @@ menuconfig KVM
 	select SRCU
 	select KVM_VFIO
 	select HAVE_KVM_EVENTFD
+	select KVM_ASYNC_PF
+	select KVM_ASYNC_PF_SLOT
 	select HAVE_KVM_IRQFD
 	select HAVE_KVM_MSI
 	select HAVE_KVM_IRQCHIP
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 74ca5ec51e53..2692bd24df86 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -281,6 +281,10 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_ARM_SDEI:
 		r = 1;
 		break;
+	case KVM_CAP_ASYNC_PF:
+	case KVM_CAP_ASYNC_PF_INT:
+		r = IS_ENABLED(CONFIG_KVM_ASYNC_PF) ? 1 : 0;
+		break;
 	default:
 		r = 0;
 	}
diff --git a/arch/arm64/kvm/sdei.c b/arch/arm64/kvm/sdei.c
index 4f5a582daa97..437303bfafba 100644
--- a/arch/arm64/kvm/sdei.c
+++ b/arch/arm64/kvm/sdei.c
@@ -19,6 +19,11 @@ static struct kvm_sdei_event_state defined_kse[] = {
 	  1,
 	  SDEI_EVENT_PRIORITY_CRITICAL
 	},
+	{ KVM_SDEI_ASYNC_PF_NUM,
+	  SDEI_EVENT_TYPE_PRIVATE,
+	  1,
+	  SDEI_EVENT_PRIORITY_CRITICAL
+	},
 };
 
 static struct kvm_sdei_event *kvm_sdei_find_event(struct kvm *kvm,
-- 
2.23.0