From 52cbfa820ab26fef940ba5c627c3884df72971f3 Mon Sep 17 00:00:00 2001
From: Pekka Enberg <penberg@kernel.org>
Date: Sun, 15 Aug 2010 17:17:43 +0300
Subject: [PATCH] kvm: Fail virtio blk ioports by default

This patch changes virtio block device ioports to fail by default and adds few
specific stubs to keep kernel booting still.

Signed-off-by: Pekka Enberg <penberg@kernel.org>
---
 tools/kvm/blk-virtio.c         | 59 +++++++++++++++++++++++-----------
 tools/kvm/include/kvm/ioport.h | 20 ++++++++++++
 2 files changed, 60 insertions(+), 19 deletions(-)

diff --git a/tools/kvm/blk-virtio.c b/tools/kvm/blk-virtio.c
index 7670f0c572ac..e7eb44e45a57 100644
--- a/tools/kvm/blk-virtio.c
+++ b/tools/kvm/blk-virtio.c
@@ -6,22 +6,13 @@
 
 #define VIRTIO_PCI_IOPORT_SIZE		24
 
-#define PCI_VENDOR_ID_REDHAT_QUMRANET		0x1af4
-#define PCI_DEVICE_ID_VIRTIO_BLK		0x1001
-#define PCI_SUBSYSTEM_VENDOR_ID_REDHAT_QUMRANET	0x1af4
-#define PCI_SUBSYSTEM_ID_VIRTIO_BLK		0x0002
-
-static struct pci_device_header blk_virtio_device = {
-	.vendor_id		= PCI_VENDOR_ID_REDHAT_QUMRANET,
-	.device_id		= PCI_DEVICE_ID_VIRTIO_BLK,
-	.header_type		= PCI_HEADER_TYPE_NORMAL,
-	.revision_id		= 0,
-	.class			= 0x010000,
-	.subsys_vendor_id	= PCI_SUBSYSTEM_VENDOR_ID_REDHAT_QUMRANET,
-	.subsys_id		= PCI_SUBSYSTEM_ID_VIRTIO_BLK,
-	.bar[0]			= IOPORT_VIRTIO | PCI_BASE_ADDRESS_SPACE_IO,
+struct device {
+	uint32_t		guest_features;
+	uint8_t			status;
 };
 
+static struct device device;
+
 static bool blk_virtio_in(struct kvm *self, uint16_t port, void *data, int size, uint32_t count)
 {
 	unsigned long offset;
@@ -30,20 +21,28 @@ static bool blk_virtio_in(struct kvm *self, uint16_t port, void *data, int size,
 
 	switch (offset) {
 	case VIRTIO_PCI_HOST_FEATURES:
+		ioport__write32(data, 0x00);
+		break;
 	case VIRTIO_PCI_GUEST_FEATURES:
 	case VIRTIO_PCI_QUEUE_PFN:
 	case VIRTIO_PCI_QUEUE_NUM:
 	case VIRTIO_PCI_QUEUE_SEL:
 	case VIRTIO_PCI_QUEUE_NOTIFY:
+		return false;
 	case VIRTIO_PCI_STATUS:
+		ioport__write8(data, device.status);
+		break;
 	case VIRTIO_PCI_ISR:
 	case VIRTIO_MSI_CONFIG_VECTOR:
-		return true;
+	default:
+		return false;
 	};
 
-	return false;
+	return true;
 }
 
+#include <stdio.h>
+
 static bool blk_virtio_out(struct kvm *self, uint16_t port, void *data, int size, uint32_t count)
 {
 	unsigned long offset;
@@ -52,16 +51,22 @@ static bool blk_virtio_out(struct kvm *self, uint16_t port, void *data, int size
 
 	switch (offset) {
 	case VIRTIO_PCI_GUEST_FEATURES:
+		device.guest_features	= ioport__read32(data);
+		break;
 	case VIRTIO_PCI_QUEUE_PFN:
 	case VIRTIO_PCI_QUEUE_SEL:
 	case VIRTIO_PCI_QUEUE_NOTIFY:
+		return false;
 	case VIRTIO_PCI_STATUS:
+		device.status		= ioport__read8(data);
+		break;
 	case VIRTIO_MSI_CONFIG_VECTOR:
 	case VIRTIO_MSI_QUEUE_VECTOR:
-		return true;
+	default:
+		return false;
 	};
 
-	return false;
+	return true;
 }
 
 static struct ioport_operations blk_virtio_io_ops = {
@@ -69,9 +74,25 @@ static struct ioport_operations blk_virtio_io_ops = {
 	.io_out		= blk_virtio_out,
 };
 
+#define PCI_VENDOR_ID_REDHAT_QUMRANET		0x1af4
+#define PCI_DEVICE_ID_VIRTIO_BLK		0x1001
+#define PCI_SUBSYSTEM_VENDOR_ID_REDHAT_QUMRANET	0x1af4
+#define PCI_SUBSYSTEM_ID_VIRTIO_BLK		0x0002
+
+static struct pci_device_header blk_virtio_pci_device = {
+	.vendor_id		= PCI_VENDOR_ID_REDHAT_QUMRANET,
+	.device_id		= PCI_DEVICE_ID_VIRTIO_BLK,
+	.header_type		= PCI_HEADER_TYPE_NORMAL,
+	.revision_id		= 0,
+	.class			= 0x010000,
+	.subsys_vendor_id	= PCI_SUBSYSTEM_VENDOR_ID_REDHAT_QUMRANET,
+	.subsys_id		= PCI_SUBSYSTEM_ID_VIRTIO_BLK,
+	.bar[0]			= IOPORT_VIRTIO | PCI_BASE_ADDRESS_SPACE_IO,
+};
+
 void blk_virtio__init(void)
 {
-	pci__register(&blk_virtio_device, 1);
+	pci__register(&blk_virtio_pci_device, 1);
 
 	ioport__register(IOPORT_VIRTIO, &blk_virtio_io_ops, VIRTIO_PCI_IOPORT_SIZE);
 }
diff --git a/tools/kvm/include/kvm/ioport.h b/tools/kvm/include/kvm/ioport.h
index eaedc1e7be82..b4ae9abea61e 100644
--- a/tools/kvm/include/kvm/ioport.h
+++ b/tools/kvm/include/kvm/ioport.h
@@ -17,4 +17,24 @@ struct ioport_operations {
 
 void ioport__register(uint16_t port, struct ioport_operations *ops, int count);
 
+static inline uint8_t ioport__read8(uint8_t *data)
+{
+	return *data;
+}
+
+static inline uint32_t ioport__read32(uint32_t *data)
+{
+	return *data;
+}
+
+static inline void ioport__write8(uint8_t *data, uint8_t value)
+{
+	*data		 = value;
+}
+
+static inline void ioport__write32(uint32_t *data, uint32_t value)
+{
+	*data		 = value;
+}
+
 #endif /* KVM__IOPORT_H */
-- 
2.39.5