Add virtio-transport option and deprecate force-pci and virtio-legacy.

This is a follow-up patch for [0] which proposed the --force-pci option
for riscv. As per the discussion it was concluded to add virtio-tranport
option taking in four options (pci, pci-legacy, mmio, mmio-legacy).

With this change force-pci and virtio-legacy are both deprecated and
arm's default transport changes from MMIO to PCI as agreed in [0].
This is also true for riscv.

Nothing changes for other architectures.

[0]: https://lore.kernel.org/all/20230118172007.408667-1-rkanwal@rivosinc.com/

Signed-off-by: Rajnesh Kanwal <rkanwal@rivosinc.com>
Link: https://lore.kernel.org/r/20230320143344.404307-1-rkanwal@rivosinc.com
Signed-off-by: Will Deacon <will@kernel.org>

16 files changed, 61 insertions, 30 deletions

diff --git a/arm/include/arm-common/kvm-arch.h b/arm/include/arm-common/kvm-arch.h
index b2ae373c..60eec02c 100644
--- a/arm/include/arm-common/kvm-arch.h
+++ b/arm/include/arm-common/kvm-arch.h
@@ -80,11 +80,6 @@
 
 #define KVM_VM_TYPE		0
 
-#define VIRTIO_DEFAULT_TRANS(kvm)					\
-	((kvm)->cfg.arch.virtio_trans_pci ?				\
-	 ((kvm)->cfg.virtio_legacy ? VIRTIO_PCI_LEGACY : VIRTIO_PCI) :	\
-	 ((kvm)->cfg.virtio_legacy ? VIRTIO_MMIO_LEGACY : VIRTIO_MMIO))
-
 #define VIRTIO_RING_ENDIAN	(VIRTIO_ENDIAN_LE | VIRTIO_ENDIAN_BE)
 
 #define ARCH_HAS_PCI_EXP	1
diff --git a/arm/include/arm-common/kvm-config-arch.h b/arm/include/arm-common/kvm-config-arch.h
index 9949bfe4..87f50352 100644
--- a/arm/include/arm-common/kvm-config-arch.h
+++ b/arm/include/arm-common/kvm-config-arch.h
@@ -7,7 +7,6 @@ struct kvm_config_arch {
 	const char	*dump_dtb_filename;
 	const char	*vcpu_affinity;
 	unsigned int	force_cntfrq;
-	bool		virtio_trans_pci;
 	bool		aarch32_guest;
 	bool		has_pmuv3;
 	bool		mte_disabled;
@@ -28,9 +27,10 @@ int irqchip_parser(const struct option *opt, const char *arg, int unset);
 		     "Specify Generic Timer frequency in guest DT to "		\
 		     "work around buggy secure firmware *Firmware should be "	\
 		     "updated to program CNTFRQ correctly*"),			\
-	OPT_BOOLEAN('\0', "force-pci", &(cfg)->virtio_trans_pci,		\
-		    "Force virtio devices to use PCI as their default "		\
-		    "transport"),						\
+	OPT_CALLBACK_NOOPT('\0', "force-pci", NULL, '\0',			\
+			   "Force virtio devices to use PCI as their default "	\
+			   "transport (Deprecated: Use --virtio-transport "	\
+			   "option instead)", virtio_transport_parser, kvm),	\
         OPT_CALLBACK('\0', "irqchip", &(cfg)->irqchip,				\
 		     "[gicv2|gicv2m|gicv3|gicv3-its]",				\
 		     "Type of interrupt controller to emulate in the guest",	\
diff --git a/builtin-run.c b/builtin-run.c
index bb7e6e8d..941ae0e4 100644
--- a/builtin-run.c
+++ b/builtin-run.c
@@ -162,6 +162,12 @@ static int mem_parser(const struct option *opt, const char *arg, int unset)
 	" in megabytes (M)"
 #endif
 
+#if defined(CONFIG_ARM) || defined(CONFIG_ARM64) || defined(CONFIG_RISCV)
+#define VIRTIO_TRANS_OPT_HELP_SHORT    "[pci|pci-legacy|mmio|mmio-legacy]"
+#else
+#define VIRTIO_TRANS_OPT_HELP_SHORT    "[pci|pci-legacy]"
+#endif
+
 #define BUILD_OPTIONS(name, cfg, kvm)					\
 	struct option name[] = {					\
 	OPT_GROUP("Basic options:"),					\
@@ -200,8 +206,15 @@ static int mem_parser(const struct option *opt, const char *arg, int unset)
 			" rootfs"),					\
 	OPT_STRING('\0', "hugetlbfs", &(cfg)->hugetlbfs_path, "path",	\
 			"Hugetlbfs path"),				\
-	OPT_BOOLEAN('\0', "virtio-legacy", &(cfg)->virtio_legacy,	\
-		    "Use legacy virtio transport"),			\
+	OPT_CALLBACK_NOOPT('\0', "virtio-legacy",			\
+			   &(cfg)->virtio_transport, '\0',		\
+			   "Use legacy virtio transport (Deprecated:"	\
+			   " Use --virtio-transport option instead)",	\
+			   virtio_transport_parser, NULL),		\
+	OPT_CALLBACK('\0', "virtio-transport", &(cfg)->virtio_transport,\
+		     VIRTIO_TRANS_OPT_HELP_SHORT,		        \
+		     "Type of virtio transport",			\
+		     virtio_transport_parser, NULL),			\
 									\
 	OPT_GROUP("Kernel options:"),					\
 	OPT_STRING('k', "kernel", &(cfg)->kernel_filename, "kernel",	\
diff --git a/include/kvm/kvm-config.h b/include/kvm/kvm-config.h
index 368e6c7d..592b0357 100644
--- a/include/kvm/kvm-config.h
+++ b/include/kvm/kvm-config.h
@@ -64,7 +64,7 @@ struct kvm_config {
 	bool no_dhcp;
 	bool ioport_debug;
 	bool mmio_debug;
-	bool virtio_legacy;
+	int virtio_transport;
 };
 
 #endif
diff --git a/include/kvm/kvm.h b/include/kvm/kvm.h
index 3872dc65..eb23e2f7 100644
--- a/include/kvm/kvm.h
+++ b/include/kvm/kvm.h
@@ -45,12 +45,6 @@ struct kvm_cpu;
 typedef void (*mmio_handler_fn)(struct kvm_cpu *vcpu, u64 addr, u8 *data,
 				u32 len, u8 is_write, void *ptr);
 
-/* Archs can override this in kvm-arch.h */
-#ifndef VIRTIO_DEFAULT_TRANS
-#define VIRTIO_DEFAULT_TRANS(kvm) \
-	((kvm)->cfg.virtio_legacy ? VIRTIO_PCI_LEGACY : VIRTIO_PCI)
-#endif
-
 enum {
 	KVM_VMSTATE_RUNNING,
 	KVM_VMSTATE_PAUSED,
diff --git a/include/kvm/virtio.h b/include/kvm/virtio.h
index 94bddefe..0e8c7a67 100644
--- a/include/kvm/virtio.h
+++ b/include/kvm/virtio.h
@@ -248,4 +248,6 @@ void virtio_set_guest_features(struct kvm *kvm, struct virtio_device *vdev,
 void virtio_notify_status(struct kvm *kvm, struct virtio_device *vdev,
 			  void *dev, u8 status);
 
+int virtio_transport_parser(const struct option *opt, const char *arg, int unset);
+
 #endif /* KVM__VIRTIO_H */
diff --git a/riscv/include/kvm/kvm-arch.h b/riscv/include/kvm/kvm-arch.h
index d32d2af0..660355b5 100644
--- a/riscv/include/kvm/kvm-arch.h
+++ b/riscv/include/kvm/kvm-arch.h
@@ -52,9 +52,6 @@
 
 #define KVM_VM_TYPE		0
 
-#define VIRTIO_DEFAULT_TRANS(kvm) \
-	((kvm)->cfg.virtio_legacy ? VIRTIO_MMIO_LEGACY : VIRTIO_MMIO)
-
 #define VIRTIO_RING_ENDIAN	VIRTIO_ENDIAN_LE
 
 #define ARCH_HAS_PCI_EXP	1
diff --git a/virtio/9p.c b/virtio/9p.c
index 19b66df8..b809bcd7 100644
--- a/virtio/9p.c
+++ b/virtio/9p.c
@@ -1552,7 +1552,7 @@ int virtio_9p__init(struct kvm *kvm)
 
 	list_for_each_entry(p9dev, &devs, list) {
 		r = virtio_init(kvm, p9dev, &p9dev->vdev, &p9_dev_virtio_ops,
-				VIRTIO_DEFAULT_TRANS(kvm), PCI_DEVICE_ID_VIRTIO_9P,
+				kvm->cfg.virtio_transport, PCI_DEVICE_ID_VIRTIO_9P,
 				VIRTIO_ID_9P, PCI_CLASS_9P);
 		if (r < 0)
 			return r;
diff --git a/virtio/balloon.c b/virtio/balloon.c
index 3a734322..01d19828 100644
--- a/virtio/balloon.c
+++ b/virtio/balloon.c
@@ -279,7 +279,7 @@ int virtio_bln__init(struct kvm *kvm)
 	memset(&bdev.config, 0, sizeof(struct virtio_balloon_config));
 
 	r = virtio_init(kvm, &bdev, &bdev.vdev, &bln_dev_virtio_ops,
-			VIRTIO_DEFAULT_TRANS(kvm), PCI_DEVICE_ID_VIRTIO_BLN,
+			kvm->cfg.virtio_transport, PCI_DEVICE_ID_VIRTIO_BLN,
 			VIRTIO_ID_BALLOON, PCI_CLASS_BLN);
 	if (r < 0)
 		return r;
diff --git a/virtio/blk.c b/virtio/blk.c
index 2d06391f..f3c34f31 100644
--- a/virtio/blk.c
+++ b/virtio/blk.c
@@ -329,7 +329,7 @@ static int virtio_blk__init_one(struct kvm *kvm, struct disk_image *disk)
 	list_add_tail(&bdev->list, &bdevs);
 
 	r = virtio_init(kvm, bdev, &bdev->vdev, &blk_dev_virtio_ops,
-			VIRTIO_DEFAULT_TRANS(kvm), PCI_DEVICE_ID_VIRTIO_BLK,
+			kvm->cfg.virtio_transport, PCI_DEVICE_ID_VIRTIO_BLK,
 			VIRTIO_ID_BLOCK, PCI_CLASS_BLK);
 	if (r < 0)
 		return r;
diff --git a/virtio/console.c b/virtio/console.c
index d29319c8..11a22a98 100644
--- a/virtio/console.c
+++ b/virtio/console.c
@@ -229,7 +229,7 @@ int virtio_console__init(struct kvm *kvm)
 		return 0;
 
 	r = virtio_init(kvm, &cdev, &cdev.vdev, &con_dev_virtio_ops,
-			VIRTIO_DEFAULT_TRANS(kvm), PCI_DEVICE_ID_VIRTIO_CONSOLE,
+			kvm->cfg.virtio_transport, PCI_DEVICE_ID_VIRTIO_CONSOLE,
 			VIRTIO_ID_CONSOLE, PCI_CLASS_CONSOLE);
 	if (r < 0)
 		return r;
diff --git a/virtio/core.c b/virtio/core.c
index ea0e5b65..568243ab 100644
--- a/virtio/core.c
+++ b/virtio/core.c
@@ -21,6 +21,36 @@ const char* virtio_trans_name(enum virtio_trans trans)
 	return "unknown";
 }
 
+int virtio_transport_parser(const struct option *opt, const char *arg, int unset)
+{
+	enum virtio_trans *type = opt->value;
+	struct kvm *kvm;
+
+	if (!strcmp(opt->long_name, "virtio-transport")) {
+		if (!strcmp(arg, "pci")) {
+			*type = VIRTIO_PCI;
+		} else if (!strcmp(arg, "pci-legacy")) {
+			*type = VIRTIO_PCI_LEGACY;
+#if defined(CONFIG_ARM) || defined(CONFIG_ARM64) || defined(CONFIG_RISCV)
+		} else if (!strcmp(arg, "mmio")) {
+			*type = VIRTIO_MMIO;
+		} else if (!strcmp(arg, "mmio-legacy")) {
+			*type = VIRTIO_MMIO_LEGACY;
+#endif
+		} else {
+			pr_err("virtio-transport: unknown type \"%s\"\n", arg);
+			return -1;
+		}
+	} else if (!strcmp(opt->long_name, "virtio-legacy")) {
+		*type = VIRTIO_PCI_LEGACY;
+	} else if (!strcmp(opt->long_name, "force-pci")) {
+		kvm = opt->ptr;
+		kvm->cfg.virtio_transport = VIRTIO_PCI;
+	}
+
+	return 0;
+}
+
 void virt_queue__used_idx_advance(struct virt_queue *queue, u16 jump)
 {
 	u16 idx = virtio_guest_to_host_u16(queue, queue->vring.used->idx);
diff --git a/virtio/net.c b/virtio/net.c
index a5e0cea5..8749ebfe 100644
--- a/virtio/net.c
+++ b/virtio/net.c
@@ -928,10 +928,10 @@ done:
 
 static int virtio_net__init_one(struct virtio_net_params *params)
 {
-	int i, r;
+	enum virtio_trans trans = params->kvm->cfg.virtio_transport;
 	struct net_dev *ndev;
 	struct virtio_ops *ops;
-	enum virtio_trans trans = VIRTIO_DEFAULT_TRANS(params->kvm);
+	int i, r;
 
 	ndev = calloc(1, sizeof(struct net_dev));
 	if (ndev == NULL)
diff --git a/virtio/rng.c b/virtio/rng.c
index 63ab8fce..8f85d5ec 100644
--- a/virtio/rng.c
+++ b/virtio/rng.c
@@ -173,7 +173,7 @@ int virtio_rng__init(struct kvm *kvm)
 	}
 
 	r = virtio_init(kvm, rdev, &rdev->vdev, &rng_dev_virtio_ops,
-			VIRTIO_DEFAULT_TRANS(kvm), PCI_DEVICE_ID_VIRTIO_RNG,
+			kvm->cfg.virtio_transport, PCI_DEVICE_ID_VIRTIO_RNG,
 			VIRTIO_ID_RNG, PCI_CLASS_RNG);
 	if (r < 0)
 		goto cleanup;
diff --git a/virtio/scsi.c b/virtio/scsi.c
index 0286b86f..893dfe60 100644
--- a/virtio/scsi.c
+++ b/virtio/scsi.c
@@ -264,7 +264,7 @@ static int virtio_scsi_init_one(struct kvm *kvm, struct disk_image *disk)
 	list_add_tail(&sdev->list, &sdevs);
 
 	r = virtio_init(kvm, sdev, &sdev->vdev, &scsi_dev_virtio_ops,
-			VIRTIO_DEFAULT_TRANS(kvm), PCI_DEVICE_ID_VIRTIO_SCSI,
+			kvm->cfg.virtio_transport, PCI_DEVICE_ID_VIRTIO_SCSI,
 			VIRTIO_ID_SCSI, PCI_CLASS_BLK);
 	if (r < 0)
 		return r;
diff --git a/virtio/vsock.c b/virtio/vsock.c
index 18b45f3b..a108e637 100644
--- a/virtio/vsock.c
+++ b/virtio/vsock.c
@@ -285,7 +285,7 @@ static int virtio_vsock_init_one(struct kvm *kvm, u64 guest_cid)
 	list_add_tail(&vdev->list, &vdevs);
 
 	r = virtio_init(kvm, vdev, &vdev->vdev, &vsock_dev_virtio_ops,
-		    VIRTIO_DEFAULT_TRANS(kvm), PCI_DEVICE_ID_VIRTIO_VSOCK,
+		    kvm->cfg.virtio_transport, PCI_DEVICE_ID_VIRTIO_VSOCK,
 		    VIRTIO_ID_VSOCK, PCI_CLASS_VSOCK);
 	if (r < 0)
 	    return r;