[RFC PATCH 1/5] KVM: redesing kvm_io_bus_ API to pass VCPU structure to the callbacks.

[n.nikolaev@virtualopensystems.com (Nikolay Nikolaev)]

This is needed in e.g. ARM vGIC emulation, where the MMIO handling
depends on the VCPU that does the access.

Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
---
 arch/ia64/kvm/kvm-ia64.c   |    4 ++--
 arch/powerpc/kvm/powerpc.c |    4 ++--
 arch/s390/kvm/diag.c       |    2 +-
 arch/x86/kvm/vmx.c         |    2 +-
 arch/x86/kvm/x86.c         |   11 ++++++-----
 include/linux/kvm_host.h   |   10 +++++-----
 virt/kvm/coalesced_mmio.c  |    5 +++--
 virt/kvm/eventfd.c         |    4 ++--
 virt/kvm/iodev.h           |   23 +++++++++++++++--------
 virt/kvm/kvm_main.c        |   32 ++++++++++++++++----------------
 10 files changed, 53 insertions(+), 44 deletions(-)

diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index ec6b9ac..16f1d26 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -246,10 +246,10 @@ static int handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 	return 0;
 mmio:
 	if (p->dir)
-		r = kvm_io_bus_read(vcpu->kvm, KVM_MMIO_BUS, p->addr,
+		r = kvm_io_bus_read(vcpu, KVM_MMIO_BUS, p->addr,
 				    p->size, &p->data);
 	else
-		r = kvm_io_bus_write(vcpu->kvm, KVM_MMIO_BUS, p->addr,
+		r = kvm_io_bus_write(vcpu, KVM_MMIO_BUS, p->addr,
 				     p->size, &p->data);
 	if (r)
 		printk(KERN_ERR"kvm: No iodevice found! addr:%lx\n", p->addr);
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index c1f8f53..5ac065b 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -814,7 +814,7 @@ int kvmppc_handle_load(struct kvm_run *run, struct kvm_vcpu *vcpu,
 
 	idx = srcu_read_lock(&vcpu->kvm->srcu);
 
-	ret = kvm_io_bus_read(vcpu->kvm, KVM_MMIO_BUS, run->mmio.phys_addr,
+	ret = kvm_io_bus_read(vcpu, KVM_MMIO_BUS, run->mmio.phys_addr,
 			      bytes, &run->mmio.data);
 
 	srcu_read_unlock(&vcpu->kvm->srcu, idx);
@@ -887,7 +887,7 @@ int kvmppc_handle_store(struct kvm_run *run, struct kvm_vcpu *vcpu,
 
 	idx = srcu_read_lock(&vcpu->kvm->srcu);
 
-	ret = kvm_io_bus_write(vcpu->kvm, KVM_MMIO_BUS, run->mmio.phys_addr,
+	ret = kvm_io_bus_write(vcpu, KVM_MMIO_BUS, run->mmio.phys_addr,
 			       bytes, &run->mmio.data);
 
 	srcu_read_unlock(&vcpu->kvm->srcu, idx);
diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c
index 9254aff..329ec75 100644
--- a/arch/s390/kvm/diag.c
+++ b/arch/s390/kvm/diag.c
@@ -213,7 +213,7 @@ static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu)
 	 * - gpr 3 contains the virtqueue index (passed as datamatch)
 	 * - gpr 4 contains the index on the bus (optionally)
 	 */
-	ret = kvm_io_bus_write_cookie(vcpu->kvm, KVM_VIRTIO_CCW_NOTIFY_BUS,
+	ret = kvm_io_bus_write_cookie(vcpu, KVM_VIRTIO_CCW_NOTIFY_BUS,
 				      vcpu->run->s.regs.gprs[2] & 0xffffffff,
 				      8, &vcpu->run->s.regs.gprs[3],
 				      vcpu->run->s.regs.gprs[4]);
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 3e556c6..e6d9f01 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5620,7 +5620,7 @@ static int handle_ept_misconfig(struct kvm_vcpu *vcpu)
 	gpa_t gpa;
 
 	gpa = vmcs_read64(GUEST_PHYSICAL_ADDRESS);
-	if (!kvm_io_bus_write(vcpu->kvm, KVM_FAST_MMIO_BUS, gpa, 0, NULL)) {
+	if (!kvm_io_bus_write(vcpu, KVM_FAST_MMIO_BUS, gpa, 0, NULL)) {
 		skip_emulated_instruction(vcpu);
 		return 1;
 	}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0033df3..bbf9375 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4053,7 +4053,7 @@ static int vcpu_mmio_write(struct kvm_vcpu *vcpu, gpa_t addr, int len,
 		n = min(len, 8);
 		if (!(vcpu->arch.apic &&
 		      !kvm_iodevice_write(&vcpu->arch.apic->dev, addr, n, v))
-		    && kvm_io_bus_write(vcpu->kvm, KVM_MMIO_BUS, addr, n, v))
+		    && kvm_io_bus_write(vcpu, KVM_MMIO_BUS, addr, n, v))
 			break;
 		handled += n;
 		addr += n;
@@ -4072,8 +4072,9 @@ static int vcpu_mmio_read(struct kvm_vcpu *vcpu, gpa_t addr, int len, void *v)
 	do {
 		n = min(len, 8);
 		if (!(vcpu->arch.apic &&
-		      !kvm_iodevice_read(&vcpu->arch.apic->dev, addr, n, v))
-		    && kvm_io_bus_read(vcpu->kvm, KVM_MMIO_BUS, addr, n, v))
+		      !kvm_iodevice_read(vcpu, &vcpu->arch.apic->dev,
+					 addr, n, v))
+		    && kvm_io_bus_read(vcpu, KVM_MMIO_BUS, addr, n, v))
 			break;
 		trace_kvm_mmio(KVM_TRACE_MMIO_READ, n, addr, *(u64 *)v);
 		handled += n;
@@ -4565,10 +4566,10 @@ static int kernel_pio(struct kvm_vcpu *vcpu, void *pd)
 	int r;
 
 	if (vcpu->arch.pio.in)
-		r = kvm_io_bus_read(vcpu->kvm, KVM_PIO_BUS, vcpu->arch.pio.port,
+		r = kvm_io_bus_read(vcpu, KVM_PIO_BUS, vcpu->arch.pio.port,
 				    vcpu->arch.pio.size, pd);
 	else
-		r = kvm_io_bus_write(vcpu->kvm, KVM_PIO_BUS,
+		r = kvm_io_bus_write(vcpu, KVM_PIO_BUS,
 				     vcpu->arch.pio.port, vcpu->arch.pio.size,
 				     pd);
 	return r;
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 4a7798e..1d26571 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -168,12 +168,12 @@ enum kvm_bus {
 	KVM_NR_BUSES
 };
 
-int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
+int kvm_io_bus_write(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
 		     int len, const void *val);
-int kvm_io_bus_write_cookie(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
-			    int len, const void *val, long cookie);
-int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len,
-		    void *val);
+int kvm_io_bus_write_cookie(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx,
+			    gpa_t addr, int len, const void *val, long cookie);
+int kvm_io_bus_read(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
+		    int len, void *val);
 int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
 			    int len, struct kvm_io_device *dev);
 int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c
index 00d8642..c831a40 100644
--- a/virt/kvm/coalesced_mmio.c
+++ b/virt/kvm/coalesced_mmio.c
@@ -60,8 +60,9 @@ static int coalesced_mmio_has_room(struct kvm_coalesced_mmio_dev *dev)
 	return 1;
 }
 
-static int coalesced_mmio_write(struct kvm_io_device *this,
-				gpa_t addr, int len, const void *val)
+static int coalesced_mmio_write(struct kvm_vcpu *vcpu,
+				struct kvm_io_device *this, gpa_t addr,
+				int len, const void *val)
 {
 	struct kvm_coalesced_mmio_dev *dev = to_mmio(this);
 	struct kvm_coalesced_mmio_ring *ring = dev->kvm->coalesced_mmio_ring;
diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index b0fb390..7202039 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -719,8 +719,8 @@ ioeventfd_in_range(struct _ioeventfd *p, gpa_t addr, int len, const void *val)
 
 /* MMIO/PIO writes trigger an event if the addr/val match */
 static int
-ioeventfd_write(struct kvm_io_device *this, gpa_t addr, int len,
-		const void *val)
+ioeventfd_write(struct kvm_vcpu *vcpu, struct kvm_io_device *this, gpa_t addr,
+		int len, const void *val)
 {
 	struct _ioeventfd *p = to_ioeventfd(this);
 
diff --git a/virt/kvm/iodev.h b/virt/kvm/iodev.h
index 12fd3ca..7dd88cb 100644
--- a/virt/kvm/iodev.h
+++ b/virt/kvm/iodev.h
@@ -20,6 +20,7 @@
 #include <asm/errno.h>
 
 struct kvm_io_device;
+struct kvm_vcpu;
 
 /**
  * kvm_io_device_ops are called under kvm slots_lock.
@@ -27,11 +28,13 @@ struct kvm_io_device;
  * or non-zero to have it passed to the next device.
  **/
 struct kvm_io_device_ops {
-	int (*read)(struct kvm_io_device *this,
+	int (*read)(struct kvm_vcpu *vcpu,
+			struct kvm_io_device *this,
 		    gpa_t addr,
 		    int len,
 		    void *val);
-	int (*write)(struct kvm_io_device *this,
+	int (*write)(struct kvm_vcpu *vcpu,
+			 struct kvm_io_device *this,
 		     gpa_t addr,
 		     int len,
 		     const void *val);
@@ -49,16 +52,20 @@ static inline void kvm_iodevice_init(struct kvm_io_device *dev,
 	dev->ops = ops;
 }
 
-static inline int kvm_iodevice_read(struct kvm_io_device *dev,
-				    gpa_t addr, int l, void *v)
+static inline int kvm_iodevice_read(struct kvm_vcpu *vcpu,
+				    struct kvm_io_device *dev, gpa_t addr,
+				    int l, void *v)
 {
-	return dev->ops->read ? dev->ops->read(dev, addr, l, v) : -EOPNOTSUPP;
+	return dev->ops->read ? dev->ops->read(vcpu, dev, addr, l, v)
+				: -EOPNOTSUPP;
 }
 
-static inline int kvm_iodevice_write(struct kvm_io_device *dev,
-				     gpa_t addr, int l, const void *v)
+static inline int kvm_iodevice_write(struct kvm_vcpu *vcpu,
+				     struct kvm_io_device *dev, gpa_t addr,
+				     int l, const void *v)
 {
-	return dev->ops->write ? dev->ops->write(dev, addr, l, v) : -EOPNOTSUPP;
+	return dev->ops->write ? dev->ops->write(vcpu, dev, addr, l, v)
+				 : -EOPNOTSUPP;
 }
 
 static inline void kvm_iodevice_destructor(struct kvm_io_device *dev)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 25ffac9..e93fb53 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2924,7 +2924,7 @@ static int kvm_io_bus_get_first_dev(struct kvm_io_bus *bus,
 	return off;
 }
 
-static int __kvm_io_bus_write(struct kvm_io_bus *bus,
+static int __kvm_io_bus_write(struct kvm_vcpu *vcpu, struct kvm_io_bus *bus,
 			      struct kvm_io_range *range, const void *val)
 {
 	int idx;
@@ -2935,7 +2935,7 @@ static int __kvm_io_bus_write(struct kvm_io_bus *bus,
 
 	while (idx < bus->dev_count &&
 		kvm_io_bus_cmp(range, &bus->range[idx]) == 0) {
-		if (!kvm_iodevice_write(bus->range[idx].dev, range->addr,
+		if (!kvm_iodevice_write(vcpu, bus->range[idx].dev, range->addr,
 					range->len, val))
 			return idx;
 		idx++;
@@ -2945,7 +2945,7 @@ static int __kvm_io_bus_write(struct kvm_io_bus *bus,
 }
 
 /* kvm_io_bus_write - called under kvm->slots_lock */
-int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
+int kvm_io_bus_write(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
 		     int len, const void *val)
 {
 	struct kvm_io_bus *bus;
@@ -2957,14 +2957,14 @@ int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
 		.len = len,
 	};
 
-	bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
-	r = __kvm_io_bus_write(bus, &range, val);
+	bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &kvm->srcu);
+	r = __kvm_io_bus_write(vcpu, bus, &range, val);
 	return r < 0 ? r : 0;
 }
 
 /* kvm_io_bus_write_cookie - called under kvm->slots_lock */
-int kvm_io_bus_write_cookie(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
-			    int len, const void *val, long cookie)
+int kvm_io_bus_write_cookie(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx,
+			    gpa_t addr, int len, const void *val, long cookie)
 {
 	struct kvm_io_bus *bus;
 	struct kvm_io_range range;
@@ -2974,12 +2974,12 @@ int kvm_io_bus_write_cookie(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
 		.len = len,
 	};
 
-	bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
+	bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &kvm->srcu);
 
 	/* First try the device referenced by cookie. */
 	if ((cookie >= 0) && (cookie < bus->dev_count) &&
 	    (kvm_io_bus_cmp(&range, &bus->range[cookie]) == 0))
-		if (!kvm_iodevice_write(bus->range[cookie].dev, addr, len,
+		if (!kvm_iodevice_write(vcpu, bus->range[cookie].dev, addr, len,
 					val))
 			return cookie;
 
@@ -2987,11 +2987,11 @@ int kvm_io_bus_write_cookie(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
 	 * cookie contained garbage; fall back to search and return the
 	 * correct cookie value.
 	 */
-	return __kvm_io_bus_write(bus, &range, val);
+	return __kvm_io_bus_write(vcpu, bus, &range, val);
 }
 
-static int __kvm_io_bus_read(struct kvm_io_bus *bus, struct kvm_io_range *range,
-			     void *val)
+static int __kvm_io_bus_read(struct kvm_vcpu *vcpu, struct kvm_io_bus *bus,
+			     struct kvm_io_range *range, void *val)
 {
 	int idx;
 
@@ -3001,7 +3001,7 @@ static int __kvm_io_bus_read(struct kvm_io_bus *bus, struct kvm_io_range *range,
 
 	while (idx < bus->dev_count &&
 		kvm_io_bus_cmp(range, &bus->range[idx]) == 0) {
-		if (!kvm_iodevice_read(bus->range[idx].dev, range->addr,
+		if (!kvm_iodevice_read(vcpu, bus->range[idx].dev, range->addr,
 				       range->len, val))
 			return idx;
 		idx++;
@@ -3012,7 +3012,7 @@ static int __kvm_io_bus_read(struct kvm_io_bus *bus, struct kvm_io_range *range,
 EXPORT_SYMBOL_GPL(kvm_io_bus_write);
 
 /* kvm_io_bus_read - called under kvm->slots_lock */
-int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
+int kvm_io_bus_read(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
 		    int len, void *val)
 {
 	struct kvm_io_bus *bus;
@@ -3024,8 +3024,8 @@ int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
 		.len = len,
 	};
 
-	bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
-	r = __kvm_io_bus_read(bus, &range, val);
+	bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &kvm->srcu);
+	r = __kvm_io_bus_read(vcpu, bus, &range, val);
 	return r < 0 ? r : 0;
 }