[PATCH v3 0/2] virtio-spi: Sync Linux headers and add vhost-user-spi device support

[PATCH v3 0/2] virtio-spi: Sync Linux headers and add vhost-user-spi device support

[Haixu Cui]

This patch series introduces vhost-user-spi device support to QEMU
and synchronizes relevant standard headers from upstream Linux.

The series consists of the following changes:
1. Synchronize virtio_spi.h from Linux kernel (v6.18-rc3) using
   scripts/update-linux-headers.sh.
2. Implement vhost-user-spi and vhost-user-spi-pci devices in QEMU,
   enabling virtio-based SPI communication via the vhost-user protocol.

The new device implementation follows the virtio-spi specification and
leverages the upstream Linux virtio-spi driver. This enables QEMU to emulate
SPI devices using the vhost-user protocol, facilitating integration with external
SPI daemons and improving virtualization support for SPI peripherals.

Changes between V3 and V2:
- Removed the patch to update virtio_ids.h since it is already updated
Changes between V2 and V1:
- Added vhost-user-spi entry in docs/system/devices/virtio/vhost-user.rst

[PATCH v3 1/2] standard-headers: Update virtio_spi.h from Linux v6.18-rc3

[Haixu Cui]

Synced virtio_spi.h from upstream Linux kernelusing
scripts/update-linux-headers.sh.

Source:
- Linux commit dcb6fa37fd7bc9c3d2b066329b0d27dedf8becaa (v6.18-rc3)
- Author: Linus Torvalds <torvalds@linux-foundation.org>
- Date:   Sun Oct 26 15:59:49 2025 -0700

This update ensures QEMU's standard headers are consistent with the latest
virtio SPI definitions from Linux v6.18-rc3.

Signed-off-by: Haixu Cui <quic_haixcui@quicinc.com>
Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
---
 include/standard-headers/linux/virtio_spi.h | 181 ++++++++++++++++++++
 1 file changed, 181 insertions(+)
 create mode 100644 include/standard-headers/linux/virtio_spi.h

diff --git a/include/standard-headers/linux/virtio_spi.h b/include/standard-headers/linux/virtio_spi.h
new file mode 100644
index 0000000000..54e570fb4a
--- /dev/null
+++ b/include/standard-headers/linux/virtio_spi.h
@@ -0,0 +1,181 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
+ * Copyright (C) 2023 OpenSynergy GmbH
+ * Copyright (C) 2025 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+#ifndef _LINUX_VIRTIO_VIRTIO_SPI_H
+#define _LINUX_VIRTIO_VIRTIO_SPI_H
+
+#include "standard-headers/linux/types.h"
+#include "standard-headers/linux/virtio_config.h"
+#include "standard-headers/linux/virtio_ids.h"
+#include "standard-headers/linux/virtio_types.h"
+
+/* Sample data on trailing clock edge */
+#define VIRTIO_SPI_CPHA			_BITUL(0)
+/* Clock is high when IDLE */
+#define VIRTIO_SPI_CPOL			_BITUL(1)
+/* Chip Select is active high */
+#define VIRTIO_SPI_CS_HIGH			_BITUL(2)
+/* Transmit LSB first */
+#define VIRTIO_SPI_MODE_LSB_FIRST		_BITUL(3)
+/* Loopback mode */
+#define VIRTIO_SPI_MODE_LOOP			_BITUL(4)
+
+/**
+ * struct virtio_spi_config - All config fields are read-only for the
+ * Virtio SPI driver
+ * @cs_max_number: maximum number of chipselect the host SPI controller
+ *   supports.
+ * @cs_change_supported: indicates if the host SPI controller supports to toggle
+ *   chipselect after each transfer in one message:
+ *   0: unsupported, chipselect will be kept in active state throughout the
+ *      message transaction;
+ *   1: supported.
+ *   Note: Message here contains a sequence of SPI transfers.
+ * @tx_nbits_supported: indicates the supported number of bit for writing:
+ *   bit 0: DUAL (2-bit transfer), 1 for supported
+ *   bit 1: QUAD (4-bit transfer), 1 for supported
+ *   bit 2: OCTAL (8-bit transfer), 1 for supported
+ *   other bits are reserved as 0, 1-bit transfer is always supported.
+ * @rx_nbits_supported: indicates the supported number of bit for reading:
+ *   bit 0: DUAL (2-bit transfer), 1 for supported
+ *   bit 1: QUAD (4-bit transfer), 1 for supported
+ *   bit 2: OCTAL (8-bit transfer), 1 for supported
+ *   other bits are reserved as 0, 1-bit transfer is always supported.
+ * @bits_per_word_mask: mask indicating which values of bits_per_word are
+ *   supported. If not set, no limitation for bits_per_word.
+ * @mode_func_supported: indicates the following features are supported or not:
+ *   bit 0-1: CPHA feature
+ *     0b00: invalid, should support as least one CPHA setting
+ *     0b01: supports CPHA=0 only
+ *     0b10: supports CPHA=1 only
+ *     0b11: supports CPHA=0 and CPHA=1.
+ *   bit 2-3: CPOL feature
+ *     0b00: invalid, should support as least one CPOL setting
+ *     0b01: supports CPOL=0 only
+ *     0b10: supports CPOL=1 only
+ *     0b11: supports CPOL=0 and CPOL=1.
+ *   bit 4: chipselect active high feature, 0 for unsupported and 1 for
+ *     supported, chipselect active low is supported by default.
+ *   bit 5: LSB first feature, 0 for unsupported and 1 for supported,
+ *     MSB first is supported by default.
+ *   bit 6: loopback mode feature, 0 for unsupported and 1 for supported,
+ *     normal mode is supported by default.
+ * @max_freq_hz: the maximum clock rate supported in Hz unit, 0 means no
+ *   limitation for transfer speed.
+ * @max_word_delay_ns: the maximum word delay supported, in nanoseconds.
+ *   A value of 0 indicates that word delay is unsupported.
+ *   Each transfer may consist of a sequence of words.
+ * @max_cs_setup_ns: the maximum delay supported after chipselect is asserted,
+ *   in ns unit, 0 means delay is not supported to introduce after chipselect is
+ *   asserted.
+ * @max_cs_hold_ns: the maximum delay supported before chipselect is deasserted,
+ *   in ns unit, 0 means delay is not supported to introduce before chipselect
+ *   is deasserted.
+ * @max_cs_incative_ns: maximum delay supported after chipselect is deasserted,
+ *   in ns unit, 0 means delay is not supported to introduce after chipselect is
+ *   deasserted.
+ */
+struct virtio_spi_config {
+	uint8_t cs_max_number;
+	uint8_t cs_change_supported;
+#define VIRTIO_SPI_RX_TX_SUPPORT_DUAL		_BITUL(0)
+#define VIRTIO_SPI_RX_TX_SUPPORT_QUAD		_BITUL(1)
+#define VIRTIO_SPI_RX_TX_SUPPORT_OCTAL		_BITUL(2)
+	uint8_t tx_nbits_supported;
+	uint8_t rx_nbits_supported;
+	uint32_t bits_per_word_mask;
+#define VIRTIO_SPI_MF_SUPPORT_CPHA_0		_BITUL(0)
+#define VIRTIO_SPI_MF_SUPPORT_CPHA_1		_BITUL(1)
+#define VIRTIO_SPI_MF_SUPPORT_CPOL_0		_BITUL(2)
+#define VIRTIO_SPI_MF_SUPPORT_CPOL_1		_BITUL(3)
+#define VIRTIO_SPI_MF_SUPPORT_CS_HIGH		_BITUL(4)
+#define VIRTIO_SPI_MF_SUPPORT_LSB_FIRST		_BITUL(5)
+#define VIRTIO_SPI_MF_SUPPORT_LOOPBACK		_BITUL(6)
+	uint32_t mode_func_supported;
+	uint32_t max_freq_hz;
+	uint32_t max_word_delay_ns;
+	uint32_t max_cs_setup_ns;
+	uint32_t max_cs_hold_ns;
+	uint32_t max_cs_inactive_ns;
+};
+
+/**
+ * struct spi_transfer_head - virtio SPI transfer descriptor
+ * @chip_select_id: chipselect index the SPI transfer used.
+ * @bits_per_word: the number of bits in each SPI transfer word.
+ * @cs_change: whether to deselect device after finishing this transfer
+ *     before starting the next transfer, 0 means cs keep asserted and
+ *     1 means cs deasserted then asserted again.
+ * @tx_nbits: bus width for write transfer.
+ *     0,1: bus width is 1, also known as SINGLE
+ *     2  : bus width is 2, also known as DUAL
+ *     4  : bus width is 4, also known as QUAD
+ *     8  : bus width is 8, also known as OCTAL
+ *     other values are invalid.
+ * @rx_nbits: bus width for read transfer.
+ *     0,1: bus width is 1, also known as SINGLE
+ *     2  : bus width is 2, also known as DUAL
+ *     4  : bus width is 4, also known as QUAD
+ *     8  : bus width is 8, also known as OCTAL
+ *     other values are invalid.
+ * @reserved: for future use.
+ * @mode: SPI transfer mode.
+ *     bit 0: CPHA, determines the timing (i.e. phase) of the data
+ *         bits relative to the clock pulses.For CPHA=0, the
+ *         "out" side changes the data on the trailing edge of the
+ *         preceding clock cycle, while the "in" side captures the data
+ *         on (or shortly after) the leading edge of the clock cycle.
+ *         For CPHA=1, the "out" side changes the data on the leading
+ *         edge of the current clock cycle, while the "in" side
+ *         captures the data on (or shortly after) the trailing edge of
+ *         the clock cycle.
+ *     bit 1: CPOL, determines the polarity of the clock. CPOL=0 is a
+ *         clock which idles at 0, and each cycle consists of a pulse
+ *         of 1. CPOL=1 is a clock which idles at 1, and each cycle
+ *         consists of a pulse of 0.
+ *     bit 2: CS_HIGH, if 1, chip select active high, else active low.
+ *     bit 3: LSB_FIRST, determines per-word bits-on-wire, if 0, MSB
+ *         first, else LSB first.
+ *     bit 4: LOOP, loopback mode.
+ * @freq: the transfer speed in Hz.
+ * @word_delay_ns: delay to be inserted between consecutive words of a
+ *     transfer, in ns unit.
+ * @cs_setup_ns: delay to be introduced after CS is asserted, in ns
+ *     unit.
+ * @cs_delay_hold_ns: delay to be introduced before CS is deasserted
+ *     for each transfer, in ns unit.
+ * @cs_change_delay_inactive_ns: delay to be introduced after CS is
+ *     deasserted and before next asserted, in ns unit.
+ */
+struct spi_transfer_head {
+	uint8_t chip_select_id;
+	uint8_t bits_per_word;
+	uint8_t cs_change;
+	uint8_t tx_nbits;
+	uint8_t rx_nbits;
+	uint8_t reserved[3];
+	uint32_t mode;
+	uint32_t freq;
+	uint32_t word_delay_ns;
+	uint32_t cs_setup_ns;
+	uint32_t cs_delay_hold_ns;
+	uint32_t cs_change_delay_inactive_ns;
+};
+
+/**
+ * struct spi_transfer_result - virtio SPI transfer result
+ * @result: Transfer result code.
+ *          VIRTIO_SPI_TRANS_OK: Transfer successful.
+ *          VIRTIO_SPI_PARAM_ERR: Parameter error.
+ *          VIRTIO_SPI_TRANS_ERR: Transfer error.
+ */
+struct spi_transfer_result {
+#define VIRTIO_SPI_TRANS_OK	0
+#define VIRTIO_SPI_PARAM_ERR	1
+#define VIRTIO_SPI_TRANS_ERR	2
+	uint8_t result;
+};
+
+#endif /* #ifndef _LINUX_VIRTIO_VIRTIO_SPI_H */
-- 
2.34.1

[PATCH v3 2/2] virtio-spi: Add vhost-user-spi device support

[Haixu Cui]

This patch introduces support for vhost-user-spi and vhost-user-spi-pci
devices in QEMU, enabling virtio-based SPI communication via the vhost-user
protocol.

The implementation follows the virtio-spi specification and leverages
the upstream virtio-spi driver in Linux. Relevant references:

- Virtio SPI specification:
  https://github.com/oasis-tcs/virtio-spec/tree/master/device-types/spi
- Linux virtio-spi driver:
  https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/spi/spi-virtio.c?h=v6.18-rc3
- vhost-user-spi daemon:
  https://github.com/rust-vmm/vhost-device/tree/main/vhost-device-spi

Example usage with rust-vmm vhost-user-spi daemon:

Start the vhost-user-spi daemon:
    vhost-device-spi --socket-path=vspi.sock --socket-count=1 \
        --device "/dev/spidev0.0"

Launch QEMU with:
    qemu-system-aarch64 -m 1G \
        -chardev socket,path=/home/root/vspi.sock0,id=vspi \
        -device vhost-user-spi-device,chardev=vspi,id=spi \
        -object memory-backend-file,id=mem,size=1G,mem-path=/dev/shm,share=on \
        -numa node,memdev=mem

Signed-off-by: Haixu Cui <quic_haixcui@quicinc.com>
Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
---
 MAINTAINERS                               |  6 ++
 docs/system/devices/virtio/vhost-user.rst |  3 +
 hw/virtio/Kconfig                         |  5 ++
 hw/virtio/meson.build                     |  3 +
 hw/virtio/vhost-user-spi-pci.c            | 69 +++++++++++++++++++++++
 hw/virtio/vhost-user-spi.c                | 65 +++++++++++++++++++++
 hw/virtio/virtio.c                        |  4 +-
 include/hw/virtio/vhost-user-spi.h        | 25 ++++++++
 8 files changed, 179 insertions(+), 1 deletion(-)
 create mode 100644 hw/virtio/vhost-user-spi-pci.c
 create mode 100644 hw/virtio/vhost-user-spi.c
 create mode 100644 include/hw/virtio/vhost-user-spi.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 63e9ba521b..790607b557 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2525,6 +2525,12 @@ F: hw/virtio/vhost-user-scmi*
 F: include/hw/virtio/vhost-user-scmi.h
 F: tests/qtest/libqos/virtio-scmi.*
 
+vhost-user-spi
+M: Haixu Cui <quic_haixcui@quicinc.com>
+S: Maintained
+F: include/hw/virtio/vhost-user-spi.h
+F: hw/virtio/vhost-user-spi*
+
 virtio-crypto
 M: Gonglei <arei.gonglei@huawei.com>
 S: Supported
diff --git a/docs/system/devices/virtio/vhost-user.rst b/docs/system/devices/virtio/vhost-user.rst
index f556a840e9..2806d81ca2 100644
--- a/docs/system/devices/virtio/vhost-user.rst
+++ b/docs/system/devices/virtio/vhost-user.rst
@@ -58,6 +58,9 @@ platform details for what sort of virtio bus to use.
   * - vhost-user-vsock
     - Socket based communication
     - `vhost-device-vsock <https://github.com/rust-vmm/vhost-device/tree/main/vhost-device-vsock>`_
+  * - vhost-user-spi
+    - Proxy spi devices to host
+    - `vhost-device-spi <https://github.com/rust-vmm/vhost-device/tree/main/vhost-device-spi>`_
 
 The referenced *daemons* are not exhaustive, any conforming backend
 implementing the device and using the vhost-user protocol should work.
diff --git a/hw/virtio/Kconfig b/hw/virtio/Kconfig
index 10f5c53ac0..8895682c61 100644
--- a/hw/virtio/Kconfig
+++ b/hw/virtio/Kconfig
@@ -127,6 +127,11 @@ config VHOST_USER_SCMI
     default y
     depends on VIRTIO && VHOST_USER && ARM
 
+config VHOST_USER_SPI
+    bool
+    default y
+    depends on VIRTIO && VHOST_USER
+
 config VHOST_USER_TEST
     bool
     default y
diff --git a/hw/virtio/meson.build b/hw/virtio/meson.build
index affd66887d..6675b63ce6 100644
--- a/hw/virtio/meson.build
+++ b/hw/virtio/meson.build
@@ -28,6 +28,7 @@ if have_vhost
     system_virtio_ss.add(when: 'CONFIG_VHOST_USER_RNG', if_true: files('vhost-user-rng.c'))
     system_virtio_ss.add(when: 'CONFIG_VHOST_USER_SND', if_true: files('vhost-user-snd.c'))
     system_virtio_ss.add(when: 'CONFIG_VHOST_USER_INPUT', if_true: files('vhost-user-input.c'))
+    system_virtio_ss.add(when: 'CONFIG_VHOST_USER_SPI', if_true: files('vhost-user-spi.c'))
 
     # PCI Stubs
     system_virtio_ss.add(when: ['CONFIG_VIRTIO_PCI', 'CONFIG_VHOST_USER_TEST'],
@@ -42,6 +43,8 @@ if have_vhost
                          if_true: files('vhost-user-snd-pci.c'))
     system_virtio_ss.add(when: ['CONFIG_VIRTIO_PCI', 'CONFIG_VHOST_USER_INPUT'],
                          if_true: files('vhost-user-input-pci.c'))
+    system_virtio_ss.add(when: ['CONFIG_VIRTIO_PCI', 'CONFIG_VHOST_USER_SPI'],
+                         if_true: files('vhost-user-spi-pci.c'))
   endif
   if have_vhost_vdpa
     system_virtio_ss.add(files('vhost-vdpa.c'))
diff --git a/hw/virtio/vhost-user-spi-pci.c b/hw/virtio/vhost-user-spi-pci.c
new file mode 100644
index 0000000000..095aba5760
--- /dev/null
+++ b/hw/virtio/vhost-user-spi-pci.c
@@ -0,0 +1,69 @@
+/*
+ * Vhost-user spi virtio device PCI glue
+ *
+ * Copyright (C) 2025 Qualcomm Innovation Center, Inc. All Rights Reserved.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "hw/qdev-properties.h"
+#include "hw/virtio/vhost-user-spi.h"
+#include "hw/virtio/virtio-pci.h"
+
+struct VHostUserSPIPCI {
+    VirtIOPCIProxy parent_obj;
+    VHostUserSPI vdev;
+};
+
+typedef struct VHostUserSPIPCI VHostUserSPIPCI;
+
+#define TYPE_VHOST_USER_SPI_PCI "vhost-user-spi-pci-base"
+
+DECLARE_INSTANCE_CHECKER(VHostUserSPIPCI, VHOST_USER_SPI_PCI,
+                         TYPE_VHOST_USER_SPI_PCI)
+
+static void vhost_user_spi_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
+{
+    VHostUserSPIPCI *dev = VHOST_USER_SPI_PCI(vpci_dev);
+    DeviceState *vdev = DEVICE(&dev->vdev);
+
+    vpci_dev->nvectors = 1;
+    qdev_realize(vdev, BUS(&vpci_dev->bus), errp);
+}
+
+static void vhost_user_spi_pci_class_init(ObjectClass *klass, const void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtioPCIClass *k = VIRTIO_PCI_CLASS(klass);
+    PCIDeviceClass *pcidev_k = PCI_DEVICE_CLASS(klass);
+    k->realize = vhost_user_spi_pci_realize;
+    set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
+    pcidev_k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
+    pcidev_k->device_id = 0; /* Set by virtio-pci based on virtio id */
+    pcidev_k->revision = 0x00;
+    pcidev_k->class_id = PCI_CLASS_COMMUNICATION_OTHER;
+}
+
+static void vhost_user_spi_pci_instance_init(Object *obj)
+{
+    VHostUserSPIPCI *dev = VHOST_USER_SPI_PCI(obj);
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VHOST_USER_SPI);
+}
+
+static const VirtioPCIDeviceTypeInfo vhost_user_spi_pci_info = {
+    .base_name = TYPE_VHOST_USER_SPI_PCI,
+    .non_transitional_name = "vhost-user-spi-pci",
+    .instance_size = sizeof(VHostUserSPIPCI),
+    .instance_init = vhost_user_spi_pci_instance_init,
+    .class_init = vhost_user_spi_pci_class_init,
+};
+
+static void vhost_user_spi_pci_register(void)
+{
+    virtio_pci_types_register(&vhost_user_spi_pci_info);
+}
+
+type_init(vhost_user_spi_pci_register);
diff --git a/hw/virtio/vhost-user-spi.c b/hw/virtio/vhost-user-spi.c
new file mode 100644
index 0000000000..0d44dec46a
--- /dev/null
+++ b/hw/virtio/vhost-user-spi.c
@@ -0,0 +1,65 @@
+/*
+ * Vhost-user spi virtio device
+ *
+ * Copyright (C) 2025 Qualcomm Innovation Center, Inc. All Rights Reserved.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "hw/qdev-properties.h"
+#include "hw/virtio/virtio-bus.h"
+#include "hw/virtio/vhost-user-spi.h"
+#include "qemu/error-report.h"
+#include "standard-headers/linux/virtio_ids.h"
+#include "standard-headers/linux/virtio_spi.h"
+
+static const Property vspi_properties[] = {
+    DEFINE_PROP_CHR("chardev", VHostUserBase, chardev),
+};
+
+static void vspi_realize(DeviceState *dev, Error **errp)
+{
+    VHostUserBase *vub = VHOST_USER_BASE(dev);
+    VHostUserBaseClass *vubc = VHOST_USER_BASE_GET_CLASS(dev);
+
+    /* Fixed for SPI */
+    vub->virtio_id = VIRTIO_ID_SPI;
+    vub->num_vqs = 1;
+    vub->vq_size = 4;
+    vub->config_size = sizeof(struct virtio_spi_config);
+
+    vubc->parent_realize(dev, errp);
+}
+
+static const VMStateDescription vu_spi_vmstate = {
+    .name = "vhost-user-spi",
+    .unmigratable = 1,
+};
+
+static void vu_spi_class_init(ObjectClass *klass, const void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VHostUserBaseClass *vubc = VHOST_USER_BASE_CLASS(klass);
+
+    dc->vmsd = &vu_spi_vmstate;
+    device_class_set_props(dc, vspi_properties);
+    device_class_set_parent_realize(dc, vspi_realize,
+                                    &vubc->parent_realize);
+    set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
+}
+
+static const TypeInfo vu_spi_info = {
+    .name = TYPE_VHOST_USER_SPI,
+    .parent = TYPE_VHOST_USER_BASE,
+    .instance_size = sizeof(VHostUserSPI),
+    .class_init = vu_spi_class_init,
+};
+
+static void vu_spi_register_types(void)
+{
+    type_register_static(&vu_spi_info);
+}
+
+type_init(vu_spi_register_types)
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 257cda506a..d2ff634b14 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -48,6 +48,7 @@
 #include "standard-headers/linux/virtio_iommu.h"
 #include "standard-headers/linux/virtio_mem.h"
 #include "standard-headers/linux/virtio_vsock.h"
+#include "standard-headers/linux/virtio_spi.h"
 
 /*
  * Maximum size of virtio device config space
@@ -196,7 +197,8 @@ const char *virtio_device_names[] = {
     [VIRTIO_ID_PARAM_SERV] = "virtio-param-serv",
     [VIRTIO_ID_AUDIO_POLICY] = "virtio-audio-pol",
     [VIRTIO_ID_BT] = "virtio-bluetooth",
-    [VIRTIO_ID_GPIO] = "virtio-gpio"
+    [VIRTIO_ID_GPIO] = "virtio-gpio",
+    [VIRTIO_ID_SPI] = "virtio-spi"
 };
 
 static const char *virtio_id_to_name(uint16_t device_id)
diff --git a/include/hw/virtio/vhost-user-spi.h b/include/hw/virtio/vhost-user-spi.h
new file mode 100644
index 0000000000..a1a65820cd
--- /dev/null
+++ b/include/hw/virtio/vhost-user-spi.h
@@ -0,0 +1,25 @@
+/*
+ * Vhost-user spi virtio device
+ *
+ * Copyright (C) 2025 Qualcomm Innovation Center, Inc. All Rights Reserved.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef QEMU_VHOST_USER_SPI_H
+#define QEMU_VHOST_USER_SPI_H
+
+#include "hw/virtio/virtio.h"
+#include "hw/virtio/vhost.h"
+#include "hw/virtio/vhost-user.h"
+#include "hw/virtio/vhost-user-base.h"
+
+#define TYPE_VHOST_USER_SPI "vhost-user-spi-device"
+
+OBJECT_DECLARE_SIMPLE_TYPE(VHostUserSPI, VHOST_USER_SPI)
+
+struct VHostUserSPI {
+    VHostUserBase parent_obj;
+};
+
+#endif /* QEMU_VHOST_USER_SPI_H */
-- 
2.34.1

Re: [PATCH v3 0/2] virtio-spi: Sync Linux headers and add vhost-user-spi device support

[Haixu Cui]

Hi QEMU developers,

I’m following up on my patch posted on 12/16/2025, and haven’t received 
any review yet.

Could you please take a look when you get a chance? I’m happy to update 
it based on feedback.

Thanks,
Haixu

On 12/16/2025 11:21 AM, Haixu Cui wrote:
> This patch series introduces vhost-user-spi device support to QEMU
> and synchronizes relevant standard headers from upstream Linux.
> 
> The series consists of the following changes:
> 1. Synchronize virtio_spi.h from Linux kernel (v6.18-rc3) using
>     scripts/update-linux-headers.sh.
> 2. Implement vhost-user-spi and vhost-user-spi-pci devices in QEMU,
>     enabling virtio-based SPI communication via the vhost-user protocol.
> 
> The new device implementation follows the virtio-spi specification and
> leverages the upstream Linux virtio-spi driver. This enables QEMU to emulate
> SPI devices using the vhost-user protocol, facilitating integration with external
> SPI daemons and improving virtualization support for SPI peripherals.
> 
> Changes between V3 and V2:
> - Removed the patch to update virtio_ids.h since it is already updated
> Changes between V2 and V1:
> - Added vhost-user-spi entry in docs/system/devices/virtio/vhost-user.rst
> 
> 
> 
> 

Re: [PATCH v3 0/2] virtio-spi: Sync Linux headers and add vhost-user-spi device support

[Michael S. Tsirkin]

On Tue, Jan 13, 2026 at 03:20:57PM +0800, Haixu Cui wrote:
> Hi QEMU developers,
> 
> I’m following up on my patch posted on 12/16/2025, and haven’t received any
> review yet.
> 
> Could you please take a look when you get a chance? I’m happy to update it
> based on feedback.
> 
> Thanks,
> Haixu

I already tagged this, will follow up shortly.