[PATCH 2/4] KVM: Add kvm_io_ext_data to IO handler

[Sheng Yang <sheng@linux.intel.com>]

Add a new parameter to IO writing handler, so that we can transfer information
from IO handler to caller.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
---
 arch/x86/kvm/i8254.c      |    6 ++++--
 arch/x86/kvm/i8259.c      |    3 ++-
 arch/x86/kvm/lapic.c      |    3 ++-
 arch/x86/kvm/x86.c        |   13 ++++++++-----
 include/linux/kvm_host.h  |    9 +++++++--
 virt/kvm/coalesced_mmio.c |    3 ++-
 virt/kvm/eventfd.c        |    2 +-
 virt/kvm/ioapic.c         |    2 +-
 virt/kvm/iodev.h          |    6 ++++--
 virt/kvm/kvm_main.c       |    4 ++--
 10 files changed, 33 insertions(+), 18 deletions(-)

diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index efad723..bd8f0c5 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -439,7 +439,8 @@ static inline int pit_in_range(gpa_t addr)
 }
 
 static int pit_ioport_write(struct kvm_io_device *this,
-			    gpa_t addr, int len, const void *data)
+			    gpa_t addr, int len, const void *data,
+			    struct kvm_io_ext_data *ext_data)
 {
 	struct kvm_pit *pit = dev_to_pit(this);
 	struct kvm_kpit_state *pit_state = &pit->pit_state;
@@ -585,7 +586,8 @@ static int pit_ioport_read(struct kvm_io_device *this,
 }
 
 static int speaker_ioport_write(struct kvm_io_device *this,
-				gpa_t addr, int len, const void *data)
+				gpa_t addr, int len, const void *data,
+				struct kvm_io_ext_data *ext_data)
 {
 	struct kvm_pit *pit = speaker_to_pit(this);
 	struct kvm_kpit_state *pit_state = &pit->pit_state;
diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index 3cece05..96b1070 100644
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -480,7 +480,8 @@ static inline struct kvm_pic *to_pic(struct kvm_io_device *dev)
 }
 
 static int picdev_write(struct kvm_io_device *this,
-			 gpa_t addr, int len, const void *val)
+			 gpa_t addr, int len, const void *val,
+			 struct kvm_io_ext_data *ext_data)
 {
 	struct kvm_pic *s = to_pic(this);
 	unsigned char data = *(unsigned char *)val;
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 93cf9d0..f413e9c 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -836,7 +836,8 @@ static int apic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val)
 }
 
 static int apic_mmio_write(struct kvm_io_device *this,
-			    gpa_t address, int len, const void *data)
+			    gpa_t address, int len, const void *data,
+			    struct kvm_io_ext_data *ext_data)
 {
 	struct kvm_lapic *apic = to_lapic(this);
 	unsigned int offset = address - apic->base_address;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index fa708c9..21b84e2 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3571,13 +3571,14 @@ static void kvm_init_msr_list(void)
 }
 
 static int vcpu_mmio_write(struct kvm_vcpu *vcpu, gpa_t addr, int len,
-			   const void *v)
+			   const void *v, struct kvm_io_ext_data *ext_data)
 {
 	if (vcpu->arch.apic &&
-	    !kvm_iodevice_write(&vcpu->arch.apic->dev, addr, len, v))
+	    !kvm_iodevice_write(&vcpu->arch.apic->dev, addr, len, v, ext_data))
 		return 0;
 
-	return kvm_io_bus_write(vcpu->kvm, KVM_MMIO_BUS, addr, len, v);
+	return kvm_io_bus_write(vcpu->kvm, KVM_MMIO_BUS,
+				addr, len, v, ext_data);
 }
 
 static int vcpu_mmio_read(struct kvm_vcpu *vcpu, gpa_t addr, int len, void *v)
@@ -3807,6 +3808,7 @@ static int emulator_write_emulated_onepage(unsigned long addr,
 					   struct kvm_vcpu *vcpu)
 {
 	gpa_t                 gpa;
+	struct kvm_io_ext_data ext_data;
 
 	gpa = kvm_mmu_gva_to_gpa_write(vcpu, addr, exception);
 
@@ -3825,7 +3827,7 @@ mmio:
 	/*
 	 * Is this MMIO handled locally?
 	 */
-	if (!vcpu_mmio_write(vcpu, gpa, bytes, val))
+	if (!vcpu_mmio_write(vcpu, gpa, bytes, val, &ext_data))
 		return X86EMUL_CONTINUE;
 
 	vcpu->mmio_needed = 1;
@@ -3940,6 +3942,7 @@ static int kernel_pio(struct kvm_vcpu *vcpu, void *pd)
 {
 	/* TODO: String I/O for in kernel device */
 	int r;
+	struct kvm_io_ext_data ext_data;
 
 	if (vcpu->arch.pio.in)
 		r = kvm_io_bus_read(vcpu->kvm, KVM_PIO_BUS, vcpu->arch.pio.port,
@@ -3947,7 +3950,7 @@ static int kernel_pio(struct kvm_vcpu *vcpu, void *pd)
 	else
 		r = kvm_io_bus_write(vcpu->kvm, KVM_PIO_BUS,
 				     vcpu->arch.pio.port, vcpu->arch.pio.size,
-				     pd);
+				     pd, &ext_data);
 	return r;
 }
 
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 7d313e0..a32c53e 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -68,8 +68,12 @@ enum kvm_bus {
 	KVM_NR_BUSES
 };
 
+struct kvm_io_ext_data {
+	int type;   /* Extended data type */
+};
+
 int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
-		     int len, const void *val);
+		     int len, const void *val, struct kvm_io_ext_data *data);
 int kvm_io_bus_read(struct kvm *kvm, 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,
@@ -113,7 +117,8 @@ struct kvm_io_device_ops {
 	int (*write)(struct kvm_io_device *this,
 		     gpa_t addr,
 		     int len,
-		     const void *val);
+		     const void *val,
+		     struct kvm_io_ext_data *data);
 	void (*destructor)(struct kvm_io_device *this);
 };
 
diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c
index fc84875..37b254c 100644
--- a/virt/kvm/coalesced_mmio.c
+++ b/virt/kvm/coalesced_mmio.c
@@ -59,7 +59,8 @@ static int coalesced_mmio_in_range(struct kvm_coalesced_mmio_dev *dev,
 }
 
 static int coalesced_mmio_write(struct kvm_io_device *this,
-				gpa_t addr, int len, const void *val)
+				gpa_t addr, int len, const void *val,
+				struct kvm_io_ext_data *ext_data)
 {
 	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 2ca4535..8edd757 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -483,7 +483,7 @@ 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)
+		const void *val, struct kvm_io_ext_data *ext_data)
 {
 	struct _ioeventfd *p = to_ioeventfd(this);
 
diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
index 0b9df83..6a027ef 100644
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -321,7 +321,7 @@ static int ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
 }
 
 static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
-			     const void *val)
+			     const void *val, struct kvm_io_ext_data *ext_data)
 {
 	struct kvm_ioapic *ioapic = to_ioapic(this);
 	u32 data;
diff --git a/virt/kvm/iodev.h b/virt/kvm/iodev.h
index d1f5651..340ab79 100644
--- a/virt/kvm/iodev.h
+++ b/virt/kvm/iodev.h
@@ -33,9 +33,11 @@ static inline int kvm_iodevice_read(struct kvm_io_device *dev,
 }
 
 static inline int kvm_iodevice_write(struct kvm_io_device *dev,
-				     gpa_t addr, int l, const void *v)
+				     gpa_t addr, int l, const void *v,
+				     struct kvm_io_ext_data *data)
 {
-	return dev->ops->write ? dev->ops->write(dev, addr, l, v) : -EOPNOTSUPP;
+	return dev->ops->write ?
+		dev->ops->write(dev, addr, l, v, data) : -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 b1b6cbb..a61f90e 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2221,14 +2221,14 @@ static void kvm_io_bus_destroy(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 len, const void *val)
+		     int len, const void *val, struct kvm_io_ext_data *ext_data)
 {
 	int i;
 	struct kvm_io_bus *bus;
 
 	bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
 	for (i = 0; i < bus->dev_count; i++)
-		if (!kvm_iodevice_write(bus->devs[i], addr, len, val))
+		if (!kvm_iodevice_write(bus->devs[i], addr, len, val, ext_data))
 			return 0;
 	return -EOPNOTSUPP;
 }
-- 
1.7.0.1