[PATCH 08/19] KVM: PPC: Book3S HV: add a VC_BASE control to the XIVE native device

[Cédric Le Goater <clg@xxxxxxxx>]

The ESB MMIO region controls the interrupt sources of the guest. QEMU
will query an fd (GET_ESB_FD ioctl) and map this region at a specific
address for the guest to use. The guest will obtain this information
using the H_INT_GET_SOURCE_INFO hcall. To inform KVM of the address
setting used by QEMU, add a VC_BASE control to the KVM XIVE device

Signed-off-by: Cédric Le Goater <clg@xxxxxxxx>
---
 arch/powerpc/include/uapi/asm/kvm.h   |  1 +
 arch/powerpc/kvm/book3s_xive.h        |  3 +++
 arch/powerpc/kvm/book3s_xive_native.c | 39 +++++++++++++++++++++++++++
 3 files changed, 43 insertions(+)

diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h
index 89c140cb9e79..8b78b12aa118 100644
--- a/arch/powerpc/include/uapi/asm/kvm.h
+++ b/arch/powerpc/include/uapi/asm/kvm.h
@@ -679,5 +679,6 @@ struct kvm_ppc_cpu_char {
 #define KVM_DEV_XIVE_GRP_CTRL		1
 #define   KVM_DEV_XIVE_GET_ESB_FD	1
 #define   KVM_DEV_XIVE_GET_TIMA_FD	2
+#define   KVM_DEV_XIVE_VC_BASE		3
 
 #endif /* __LINUX_KVM_POWERPC_H */
diff --git a/arch/powerpc/kvm/book3s_xive.h b/arch/powerpc/kvm/book3s_xive.h
index 5f22415520b4..ae4a670eea63 100644
--- a/arch/powerpc/kvm/book3s_xive.h
+++ b/arch/powerpc/kvm/book3s_xive.h
@@ -125,6 +125,9 @@ struct kvmppc_xive {
 
 	/* Flags */
 	u8	single_escalation;
+
+	/* VC base address for ESBs */
+	u64     vc_base;
 };
 
 #define KVMPPC_XIVE_Q_COUNT	8
diff --git a/arch/powerpc/kvm/book3s_xive_native.c b/arch/powerpc/kvm/book3s_xive_native.c
index ee9d12bf2dae..29a62914de55 100644
--- a/arch/powerpc/kvm/book3s_xive_native.c
+++ b/arch/powerpc/kvm/book3s_xive_native.c
@@ -153,6 +153,25 @@ int kvmppc_xive_native_connect_vcpu(struct kvm_device *dev,
 	return rc;
 }
 
+static int kvmppc_xive_native_set_vc_base(struct kvmppc_xive *xive, u64 addr)
+{
+	u64 __user *ubufp = (u64 __user *) addr;
+
+	if (get_user(xive->vc_base, ubufp))
+		return -EFAULT;
+	return 0;
+}
+
+static int kvmppc_xive_native_get_vc_base(struct kvmppc_xive *xive, u64 addr)
+{
+	u64 __user *ubufp = (u64 __user *) addr;
+
+	if (put_user(xive->vc_base, ubufp))
+		return -EFAULT;
+
+	return 0;
+}
+
 static int xive_native_esb_fault(struct vm_fault *vmf)
 {
 	struct vm_area_struct *vma = vmf->vma;
@@ -289,6 +308,16 @@ static int kvmppc_xive_native_get_tima_fd(struct kvmppc_xive *xive, u64 addr)
 static int kvmppc_xive_native_set_attr(struct kvm_device *dev,
 				       struct kvm_device_attr *attr)
 {
+	struct kvmppc_xive *xive = dev->private;
+
+	switch (attr->group) {
+	case KVM_DEV_XIVE_GRP_CTRL:
+		switch (attr->attr) {
+		case KVM_DEV_XIVE_VC_BASE:
+			return kvmppc_xive_native_set_vc_base(xive, attr->addr);
+		}
+		break;
+	}
 	return -ENXIO;
 }
 
@@ -304,6 +333,8 @@ static int kvmppc_xive_native_get_attr(struct kvm_device *dev,
 			return kvmppc_xive_native_get_esb_fd(xive, attr->addr);
 		case KVM_DEV_XIVE_GET_TIMA_FD:
 			return kvmppc_xive_native_get_tima_fd(xive, attr->addr);
+		case KVM_DEV_XIVE_VC_BASE:
+			return kvmppc_xive_native_get_vc_base(xive, attr->addr);
 		}
 		break;
 	}
@@ -318,6 +349,7 @@ static int kvmppc_xive_native_has_attr(struct kvm_device *dev,
 		switch (attr->attr) {
 		case KVM_DEV_XIVE_GET_ESB_FD:
 		case KVM_DEV_XIVE_GET_TIMA_FD:
+		case KVM_DEV_XIVE_VC_BASE:
 			return 0;
 		}
 		break;
@@ -353,6 +385,11 @@ static void kvmppc_xive_native_free(struct kvm_device *dev)
 	kfree(dev);
 }
 
+/*
+ * ESB MMIO address of chip 0
+ */
+#define XIVE_VC_BASE   0x0006010000000000ull
+
 static int kvmppc_xive_native_create(struct kvm_device *dev, u32 type)
 {
 	struct kvmppc_xive *xive;
@@ -387,6 +424,8 @@ static int kvmppc_xive_native_create(struct kvm_device *dev, u32 type)
 	if (xive->vp_base == XIVE_INVALID_VP)
 		ret = -ENOMEM;
 
+	xive->vc_base = XIVE_VC_BASE;
+
 	xive->single_escalation = xive_native_has_single_escalation();
 
 	if (ret)
-- 
2.20.1