[PATCH v4 08/17] KVM: PPC: Book3S HV: XIVE: add a control to sync the sources

[Cédric Le Goater]

This control will be used by the H_INT_SYNC hcall from QEMU to flush
event notifications on the XIVE IC owning the source.

Signed-off-by: Cédric Le Goater <clg at kaod.org>
Reviewed-by: David Gibson <david at gibson.dropbear.id.au>
---

 Changes since v2 :

 - fixed locking on source block

 arch/powerpc/include/uapi/asm/kvm.h        |  1 +
 arch/powerpc/kvm/book3s_xive_native.c      | 36 ++++++++++++++++++++++
 Documentation/virtual/kvm/devices/xive.txt |  8 +++++
 3 files changed, 45 insertions(+)

diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h
index f045f9dee42e..e4abe30f6fc6 100644
--- a/arch/powerpc/include/uapi/asm/kvm.h
+++ b/arch/powerpc/include/uapi/asm/kvm.h
@@ -683,6 +683,7 @@ struct kvm_ppc_cpu_char {
 #define KVM_DEV_XIVE_GRP_SOURCE		2	/* 64-bit source identifier */
 #define KVM_DEV_XIVE_GRP_SOURCE_CONFIG	3	/* 64-bit source identifier */
 #define KVM_DEV_XIVE_GRP_EQ_CONFIG	4	/* 64-bit EQ identifier */
+#define KVM_DEV_XIVE_GRP_SOURCE_SYNC	5       /* 64-bit source identifier */
 
 /* Layout of 64-bit XIVE source attribute values */
 #define KVM_XIVE_LEVEL_SENSITIVE	(1ULL << 0)
diff --git a/arch/powerpc/kvm/book3s_xive_native.c b/arch/powerpc/kvm/book3s_xive_native.c
index b54d6fa978fe..d45dc2ec0557 100644
--- a/arch/powerpc/kvm/book3s_xive_native.c
+++ b/arch/powerpc/kvm/book3s_xive_native.c
@@ -335,6 +335,38 @@ static int kvmppc_xive_native_set_source_config(struct kvmppc_xive *xive,
 						       priority, masked, eisn);
 }
 
+static int kvmppc_xive_native_sync_source(struct kvmppc_xive *xive,
+					  long irq, u64 addr)
+{
+	struct kvmppc_xive_src_block *sb;
+	struct kvmppc_xive_irq_state *state;
+	struct xive_irq_data *xd;
+	u32 hw_num;
+	u16 src;
+	int rc = 0;
+
+	pr_devel("%s irq=0x%lx", __func__, irq);
+
+	sb = kvmppc_xive_find_source(xive, irq, &src);
+	if (!sb)
+		return -ENOENT;
+
+	state = &sb->irq_state[src];
+
+	rc = -EINVAL;
+
+	arch_spin_lock(&sb->lock);
+
+	if (state->valid) {
+		kvmppc_xive_select_irq(state, &hw_num, &xd);
+		xive_native_sync_source(hw_num);
+		rc = 0;
+	}
+
+	arch_spin_unlock(&sb->lock);
+	return rc;
+}
+
 static int xive_native_validate_queue_size(u32 qshift)
 {
 	/*
@@ -663,6 +695,9 @@ static int kvmppc_xive_native_set_attr(struct kvm_device *dev,
 	case KVM_DEV_XIVE_GRP_EQ_CONFIG:
 		return kvmppc_xive_native_set_queue_config(xive, attr->attr,
 							   attr->addr);
+	case KVM_DEV_XIVE_GRP_SOURCE_SYNC:
+		return kvmppc_xive_native_sync_source(xive, attr->attr,
+						      attr->addr);
 	}
 	return -ENXIO;
 }
@@ -692,6 +727,7 @@ static int kvmppc_xive_native_has_attr(struct kvm_device *dev,
 		break;
 	case KVM_DEV_XIVE_GRP_SOURCE:
 	case KVM_DEV_XIVE_GRP_SOURCE_CONFIG:
+	case KVM_DEV_XIVE_GRP_SOURCE_SYNC:
 		if (attr->attr >= KVMPPC_XIVE_FIRST_IRQ &&
 		    attr->attr < KVMPPC_XIVE_NR_IRQS)
 			return 0;
diff --git a/Documentation/virtual/kvm/devices/xive.txt b/Documentation/virtual/kvm/devices/xive.txt
index acd5cb9d1339..26fc918b02fb 100644
--- a/Documentation/virtual/kvm/devices/xive.txt
+++ b/Documentation/virtual/kvm/devices/xive.txt
@@ -92,3 +92,11 @@ the legacy interrupt mode, referred as XICS (POWER7/8).
     -EINVAL: Invalid queue address
     -EFAULT: Invalid user pointer for attr->addr.
     -EIO:    Configuration of the underlying HW failed
+
+  5. KVM_DEV_XIVE_GRP_SOURCE_SYNC (write only)
+  Synchronize the source to flush event notifications
+  Attributes:
+    Interrupt source number  (64-bit)
+  Errors:
+    -ENOENT: Unknown source number
+    -EINVAL: Not initialized source number
-- 
2.20.1