// SPDX-License-Identifier: GPL-2.0-only /* * Mediated virtual PCI serial host device driver * * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved. * Author: Neo Jia * Kirti Wankhede * * Sample driver that creates mdev device that simulates serial port over PCI * card. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * #defines */ #define VERSION_STRING "0.1" #define DRIVER_AUTHOR "NVIDIA Corporation" #define MTTY_CLASS_NAME "mtty" #define MTTY_NAME "mtty" #define MTTY_STRING_LEN 16 #define MTTY_CONFIG_SPACE_SIZE 0xff #define MTTY_IO_BAR_SIZE 0x8 #define MTTY_MMIO_BAR_SIZE 0x100000 #define STORE_LE16(addr, val) (*(u16 *)addr = val) #define STORE_LE32(addr, val) (*(u32 *)addr = val) #define MAX_FIFO_SIZE 16 #define CIRCULAR_BUF_INC_IDX(idx) (idx = (idx + 1) & (MAX_FIFO_SIZE - 1)) #define MTTY_VFIO_PCI_OFFSET_SHIFT 40 #define MTTY_VFIO_PCI_OFFSET_TO_INDEX(off) (off >> MTTY_VFIO_PCI_OFFSET_SHIFT) #define MTTY_VFIO_PCI_INDEX_TO_OFFSET(index) \ ((u64)(index) << MTTY_VFIO_PCI_OFFSET_SHIFT) #define MTTY_VFIO_PCI_OFFSET_MASK \ (((u64)(1) << MTTY_VFIO_PCI_OFFSET_SHIFT) - 1) #define MAX_MTTYS 24 /* * Global Structures */ static struct mtty_dev { dev_t vd_devt; struct class *vd_class; struct cdev vd_cdev; struct idr vd_idr; struct device dev; struct mdev_parent parent; } mtty_dev; struct mdev_region_info { u64 start; u64 phys_start; u32 size; u64 vfio_offset; }; #if defined(DEBUG_REGS) static const char *wr_reg[] = { "TX", "IER", "FCR", "LCR", "MCR", "LSR", "MSR", "SCR" }; static const char *rd_reg[] = { "RX", "IER", "IIR", "LCR", "MCR", "LSR", "MSR", "SCR" }; #endif /* loop back buffer */ struct rxtx { u8 fifo[MAX_FIFO_SIZE]; u8 head, tail; u8 count; }; struct serial_port { u8 uart_reg[8]; /* 8 registers */ struct rxtx rxtx; /* loop back buffer */ bool dlab; bool overrun; u16 divisor; u8 fcr; /* FIFO control register */ u8 max_fifo_size; u8 intr_trigger_level; /* interrupt trigger level */ }; struct mtty_data { u64 magic; #define MTTY_MAGIC 0x7e9d09898c3e2c4e /* Nothing clever, just random */ u32 major_ver; #define MTTY_MAJOR_VER 1 u32 minor_ver; #define MTTY_MINOR_VER 0 u32 nr_ports; u32 flags; struct serial_port ports[2]; }; struct mdev_state; struct mtty_migration_file { struct file *filp; struct mutex lock; struct mdev_state *mdev_state; struct mtty_data data; ssize_t filled_size; u8 disabled:1; }; /* State of each mdev device */ struct mdev_state { struct vfio_device vdev; struct eventfd_ctx *intx_evtfd; struct eventfd_ctx *msi_evtfd; int irq_index; u8 *vconfig; struct mutex ops_lock; struct mdev_device *mdev; struct mdev_region_info region_info[VFIO_PCI_NUM_REGIONS]; u32 bar_mask[VFIO_PCI_NUM_REGIONS]; struct list_head next; struct serial_port s[2]; struct mutex rxtx_lock; struct vfio_device_info dev_info; int nr_ports; enum vfio_device_mig_state state; struct mutex state_mutex; struct mutex reset_mutex; struct mtty_migration_file *saving_migf; struct mtty_migration_file *resuming_migf; u8 deferred_reset:1; u8 intx_mask:1; }; static struct mtty_type { struct mdev_type type; int nr_ports; } mtty_types[2] = { { .nr_ports = 1, .type.sysfs_name = "1", .type.pretty_name = "Single port serial" }, { .nr_ports = 2, .type.sysfs_name = "2", .type.pretty_name = "Dual port serial" }, }; static struct mdev_type *mtty_mdev_types[] = { &mtty_types[0].type, &mtty_types[1].type, }; static atomic_t mdev_avail_ports = ATOMIC_INIT(MAX_MTTYS); static const struct file_operations vd_fops = { .owner = THIS_MODULE, }; static const struct vfio_device_ops mtty_dev_ops; /* Helper functions */ static void dump_buffer(u8 *buf, uint32_t count) { #if defined(DEBUG) int i; pr_info("Buffer:\n"); for (i = 0; i < count; i++) { pr_info("%2x ", *(buf + i)); if ((i + 1) % 16 == 0) pr_info("\n"); } #endif } static bool is_intx(struct mdev_state *mdev_state) { return mdev_state->irq_index == VFIO_PCI_INTX_IRQ_INDEX; } static bool is_msi(struct mdev_state *mdev_state) { return mdev_state->irq_index == VFIO_PCI_MSI_IRQ_INDEX; } static bool is_noirq(struct mdev_state *mdev_state) { return !is_intx(mdev_state) && !is_msi(mdev_state); } static void mtty_trigger_interrupt(struct mdev_state *mdev_state) { lockdep_assert_held(&mdev_state->ops_lock); if (is_msi(mdev_state)) { if (mdev_state->msi_evtfd) eventfd_signal(mdev_state->msi_evtfd, 1); } else if (is_intx(mdev_state)) { if (mdev_state->intx_evtfd && !mdev_state->intx_mask) { eventfd_signal(mdev_state->intx_evtfd, 1); mdev_state->intx_mask = true; } } } static void mtty_create_config_space(struct mdev_state *mdev_state) { /* PCI dev ID */ STORE_LE32((u32 *) &mdev_state->vconfig[0x0], 0x32534348); /* Control: I/O+, Mem-, BusMaster- */ STORE_LE16((u16 *) &mdev_state->vconfig[0x4], 0x0001); /* Status: capabilities list absent */ STORE_LE16((u16 *) &mdev_state->vconfig[0x6], 0x0200); /* Rev ID */ mdev_state->vconfig[0x8] = 0x10; /* programming interface class : 16550-compatible serial controller */ mdev_state->vconfig[0x9] = 0x02; /* Sub class : 00 */ mdev_state->vconfig[0xa] = 0x00; /* Base class : Simple Communication controllers */ mdev_state->vconfig[0xb] = 0x07; /* base address registers */ /* BAR0: IO space */ STORE_LE32((u32 *) &mdev_state->vconfig[0x10], 0x000001); mdev_state->bar_mask[0] = ~(MTTY_IO_BAR_SIZE) + 1; if (mdev_state->nr_ports == 2) { /* BAR1: IO space */ STORE_LE32((u32 *) &mdev_state->vconfig[0x14], 0x000001); mdev_state->bar_mask[1] = ~(MTTY_IO_BAR_SIZE) + 1; } /* Subsystem ID */ STORE_LE32((u32 *) &mdev_state->vconfig[0x2c], 0x32534348); mdev_state->vconfig[0x34] = 0x00; /* Cap Ptr */ mdev_state->vconfig[0x3d] = 0x01; /* interrupt pin (INTA#) */ /* Vendor specific data */ mdev_state->vconfig[0x40] = 0x23; mdev_state->vconfig[0x43] = 0x80; mdev_state->vconfig[0x44] = 0x23; mdev_state->vconfig[0x48] = 0x23; mdev_state->vconfig[0x4c] = 0x23; mdev_state->vconfig[0x60] = 0x50; mdev_state->vconfig[0x61] = 0x43; mdev_state->vconfig[0x62] = 0x49; mdev_state->vconfig[0x63] = 0x20; mdev_state->vconfig[0x64] = 0x53; mdev_state->vconfig[0x65] = 0x65; mdev_state->vconfig[0x66] = 0x72; mdev_state->vconfig[0x67] = 0x69; mdev_state->vconfig[0x68] = 0x61; mdev_state->vconfig[0x69] = 0x6c; mdev_state->vconfig[0x6a] = 0x2f; mdev_state->vconfig[0x6b] = 0x55; mdev_state->vconfig[0x6c] = 0x41; mdev_state->vconfig[0x6d] = 0x52; mdev_state->vconfig[0x6e] = 0x54; } static void handle_pci_cfg_write(struct mdev_state *mdev_state, u16 offset, u8 *buf, u32 count) { u32 cfg_addr, bar_mask, bar_index = 0; switch (offset) { case 0x04: /* device control */ case 0x06: /* device status */ /* do nothing */ break; case 0x3c: /* interrupt line */ mdev_state->vconfig[0x3c] = buf[0]; break; case 0x3d: /* * Interrupt Pin is hardwired to INTA. * This field is write protected by hardware */ break; case 0x10: /* BAR0 */ case 0x14: /* BAR1 */ if (offset == 0x10) bar_index = 0; else if (offset == 0x14) bar_index = 1; if ((mdev_state->nr_ports == 1) && (bar_index == 1)) { STORE_LE32(&mdev_state->vconfig[offset], 0); break; } cfg_addr = *(u32 *)buf; pr_info("BAR%d addr 0x%x\n", bar_index, cfg_addr); if (cfg_addr == 0xffffffff) { bar_mask = mdev_state->bar_mask[bar_index]; cfg_addr = (cfg_addr & bar_mask); } cfg_addr |= (mdev_state->vconfig[offset] & 0x3ul); STORE_LE32(&mdev_state->vconfig[offset], cfg_addr); break; case 0x18: /* BAR2 */ case 0x1c: /* BAR3 */ case 0x20: /* BAR4 */ STORE_LE32(&mdev_state->vconfig[offset], 0); break; default: pr_info("PCI config write @0x%x of %d bytes not handled\n", offset, count); break; } } static void handle_bar_write(unsigned int index, struct mdev_state *mdev_state, u16 offset, u8 *buf, u32 count) { u8 data = *buf; /* Handle data written by guest */ switch (offset) { case UART_TX: /* if DLAB set, data is LSB of divisor */ if (mdev_state->s[index].dlab) { mdev_state->s[index].divisor |= data; break; } mutex_lock(&mdev_state->rxtx_lock); /* save in TX buffer */ if (mdev_state->s[index].rxtx.count < mdev_state->s[index].max_fifo_size) { mdev_state->s[index].rxtx.fifo[ mdev_state->s[index].rxtx.head] = data; mdev_state->s[index].rxtx.count++; CIRCULAR_BUF_INC_IDX(mdev_state->s[index].rxtx.head); mdev_state->s[index].overrun = false; /* * Trigger interrupt if receive data interrupt is * enabled and fifo reached trigger level */ if ((mdev_state->s[index].uart_reg[UART_IER] & UART_IER_RDI) && (mdev_state->s[index].rxtx.count == mdev_state->s[index].intr_trigger_level)) { /* trigger interrupt */ #if defined(DEBUG_INTR) pr_err("Serial port %d: Fifo level trigger\n", index); #endif mtty_trigger_interrupt(mdev_state); } } else { #if defined(DEBUG_INTR) pr_err("Serial port %d: Buffer Overflow\n", index); #endif mdev_state->s[index].overrun = true; /* * Trigger interrupt if receiver line status interrupt * is enabled */ if (mdev_state->s[index].uart_reg[UART_IER] & UART_IER_RLSI) mtty_trigger_interrupt(mdev_state); } mutex_unlock(&mdev_state->rxtx_lock); break; case UART_IER: /* if DLAB set, data is MSB of divisor */ if (mdev_state->s[index].dlab) mdev_state->s[index].divisor |= (u16)data << 8; else { mdev_state->s[index].uart_reg[offset] = data; mutex_lock(&mdev_state->rxtx_lock); if ((data & UART_IER_THRI) && (mdev_state->s[index].rxtx.head == mdev_state->s[index].rxtx.tail)) { #if defined(DEBUG_INTR) pr_err("Serial port %d: IER_THRI write\n", index); #endif mtty_trigger_interrupt(mdev_state); } mutex_unlock(&mdev_state->rxtx_lock); } break; case UART_FCR: mdev_state->s[index].fcr = data; mutex_lock(&mdev_state->rxtx_lock); if (data & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT)) { /* clear loop back FIFO */ mdev_state->s[index].rxtx.count = 0; mdev_state->s[index].rxtx.head = 0; mdev_state->s[index].rxtx.tail = 0; } mutex_unlock(&mdev_state->rxtx_lock); switch (data & UART_FCR_TRIGGER_MASK) { case UART_FCR_TRIGGER_1: mdev_state->s[index].intr_trigger_level = 1; break; case UART_FCR_TRIGGER_4: mdev_state->s[index].intr_trigger_level = 4; break; case UART_FCR_TRIGGER_8: mdev_state->s[index].intr_trigger_level = 8; break; case UART_FCR_TRIGGER_14: mdev_state->s[index].intr_trigger_level = 14; break; } /* * Set trigger level to 1 otherwise or implement timer with * timeout of 4 characters and on expiring that timer set * Recevice data timeout in IIR register */ mdev_state->s[index].intr_trigger_level = 1; if (data & UART_FCR_ENABLE_FIFO) mdev_state->s[index].max_fifo_size = MAX_FIFO_SIZE; else { mdev_state->s[index].max_fifo_size = 1; mdev_state->s[index].intr_trigger_level = 1; } break; case UART_LCR: if (data & UART_LCR_DLAB) { mdev_state->s[index].dlab = true; mdev_state->s[index].divisor = 0; } else mdev_state->s[index].dlab = false; mdev_state->s[index].uart_reg[offset] = data; break; case UART_MCR: mdev_state->s[index].uart_reg[offset] = data; if ((mdev_state->s[index].uart_reg[UART_IER] & UART_IER_MSI) && (data & UART_MCR_OUT2)) { #if defined(DEBUG_INTR) pr_err("Serial port %d: MCR_OUT2 write\n", index); #endif mtty_trigger_interrupt(mdev_state); } if ((mdev_state->s[index].uart_reg[UART_IER] & UART_IER_MSI) && (data & (UART_MCR_RTS | UART_MCR_DTR))) { #if defined(DEBUG_INTR) pr_err("Serial port %d: MCR RTS/DTR write\n", index); #endif mtty_trigger_interrupt(mdev_state); } break; case UART_LSR: case UART_MSR: /* do nothing */ break; case UART_SCR: mdev_state->s[index].uart_reg[offset] = data; break; default: break; } } static void handle_bar_read(unsigned int index, struct mdev_state *mdev_state, u16 offset, u8 *buf, u32 count) { /* Handle read requests by guest */ switch (offset) { case UART_RX: /* if DLAB set, data is LSB of divisor */ if (mdev_state->s[index].dlab) { *buf = (u8)mdev_state->s[index].divisor; break; } mutex_lock(&mdev_state->rxtx_lock); /* return data in tx buffer */ if (mdev_state->s[index].rxtx.head != mdev_state->s[index].rxtx.tail) { *buf = mdev_state->s[index].rxtx.fifo[ mdev_state->s[index].rxtx.tail]; mdev_state->s[index].rxtx.count--; CIRCULAR_BUF_INC_IDX(mdev_state->s[index].rxtx.tail); } if (mdev_state->s[index].rxtx.head == mdev_state->s[index].rxtx.tail) { /* * Trigger interrupt if tx buffer empty interrupt is * enabled and fifo is empty */ #if defined(DEBUG_INTR) pr_err("Serial port %d: Buffer Empty\n", index); #endif if (mdev_state->s[index].uart_reg[UART_IER] & UART_IER_THRI) mtty_trigger_interrupt(mdev_state); } mutex_unlock(&mdev_state->rxtx_lock); break; case UART_IER: if (mdev_state->s[index].dlab) { *buf = (u8)(mdev_state->s[index].divisor >> 8); break; } *buf = mdev_state->s[index].uart_reg[offset] & 0x0f; break; case UART_IIR: { u8 ier = mdev_state->s[index].uart_reg[UART_IER]; *buf = 0; mutex_lock(&mdev_state->rxtx_lock); /* Interrupt priority 1: Parity, overrun, framing or break */ if ((ier & UART_IER_RLSI) && mdev_state->s[index].overrun) *buf |= UART_IIR_RLSI; /* Interrupt priority 2: Fifo trigger level reached */ if ((ier & UART_IER_RDI) && (mdev_state->s[index].rxtx.count >= mdev_state->s[index].intr_trigger_level)) *buf |= UART_IIR_RDI; /* Interrupt priotiry 3: transmitter holding register empty */ if ((ier & UART_IER_THRI) && (mdev_state->s[index].rxtx.head == mdev_state->s[index].rxtx.tail)) *buf |= UART_IIR_THRI; /* Interrupt priotiry 4: Modem status: CTS, DSR, RI or DCD */ if ((ier & UART_IER_MSI) && (mdev_state->s[index].uart_reg[UART_MCR] & (UART_MCR_RTS | UART_MCR_DTR))) *buf |= UART_IIR_MSI; /* bit0: 0=> interrupt pending, 1=> no interrupt is pending */ if (*buf == 0) *buf = UART_IIR_NO_INT; /* set bit 6 & 7 to be 16550 compatible */ *buf |= 0xC0; mutex_unlock(&mdev_state->rxtx_lock); } break; case UART_LCR: case UART_MCR: *buf = mdev_state->s[index].uart_reg[offset]; break; case UART_LSR: { u8 lsr = 0; mutex_lock(&mdev_state->rxtx_lock); /* atleast one char in FIFO */ if (mdev_state->s[index].rxtx.head != mdev_state->s[index].rxtx.tail) lsr |= UART_LSR_DR; /* if FIFO overrun */ if (mdev_state->s[index].overrun) lsr |= UART_LSR_OE; /* transmit FIFO empty and tramsitter empty */ if (mdev_state->s[index].rxtx.head == mdev_state->s[index].rxtx.tail) lsr |= UART_LSR_TEMT | UART_LSR_THRE; mutex_unlock(&mdev_state->rxtx_lock); *buf = lsr; break; } case UART_MSR: *buf = UART_MSR_DSR | UART_MSR_DDSR | UART_MSR_DCD; mutex_lock(&mdev_state->rxtx_lock); /* if AFE is 1 and FIFO have space, set CTS bit */ if (mdev_state->s[index].uart_reg[UART_MCR] & UART_MCR_AFE) { if (mdev_state->s[index].rxtx.count < mdev_state->s[index].max_fifo_size) *buf |= UART_MSR_CTS | UART_MSR_DCTS; } else *buf |= UART_MSR_CTS | UART_MSR_DCTS; mutex_unlock(&mdev_state->rxtx_lock); break; case UART_SCR: *buf = mdev_state->s[index].uart_reg[offset]; break; default: break; } } static void mdev_read_base(struct mdev_state *mdev_state) { int index, pos; u32 start_lo, start_hi; u32 mem_type; pos = PCI_BASE_ADDRESS_0; for (index = 0; index <= VFIO_PCI_BAR5_REGION_INDEX; index++) { if (!mdev_state->region_info[index].size) continue; start_lo = (*(u32 *)(mdev_state->vconfig + pos)) & PCI_BASE_ADDRESS_MEM_MASK; mem_type = (*(u32 *)(mdev_state->vconfig + pos)) & PCI_BASE_ADDRESS_MEM_TYPE_MASK; switch (mem_type) { case PCI_BASE_ADDRESS_MEM_TYPE_64: start_hi = (*(u32 *)(mdev_state->vconfig + pos + 4)); pos += 4; break; case PCI_BASE_ADDRESS_MEM_TYPE_32: case PCI_BASE_ADDRESS_MEM_TYPE_1M: /* 1M mem BAR treated as 32-bit BAR */ default: /* mem unknown type treated as 32-bit BAR */ start_hi = 0; break; } pos += 4; mdev_state->region_info[index].start = ((u64)start_hi << 32) | start_lo; } } static ssize_t mdev_access(struct mdev_state *mdev_state, u8 *buf, size_t count, loff_t pos, bool is_write) { unsigned int index; loff_t offset; int ret = 0; if (!buf) return -EINVAL; mutex_lock(&mdev_state->ops_lock); index = MTTY_VFIO_PCI_OFFSET_TO_INDEX(pos); offset = pos & MTTY_VFIO_PCI_OFFSET_MASK; switch (index) { case VFIO_PCI_CONFIG_REGION_INDEX: #if defined(DEBUG) pr_info("%s: PCI config space %s at offset 0x%llx\n", __func__, is_write ? "write" : "read", offset); #endif if (is_write) { dump_buffer(buf, count); handle_pci_cfg_write(mdev_state, offset, buf, count); } else { memcpy(buf, (mdev_state->vconfig + offset), count); dump_buffer(buf, count); } break; case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX: if (!mdev_state->region_info[index].start) mdev_read_base(mdev_state); if (is_write) { dump_buffer(buf, count); #if defined(DEBUG_REGS) pr_info("%s: BAR%d WR @0x%llx %s val:0x%02x dlab:%d\n", __func__, index, offset, wr_reg[offset], *buf, mdev_state->s[index].dlab); #endif handle_bar_write(index, mdev_state, offset, buf, count); } else { handle_bar_read(index, mdev_state, offset, buf, count); dump_buffer(buf, count); #if defined(DEBUG_REGS) pr_info("%s: BAR%d RD @0x%llx %s val:0x%02x dlab:%d\n", __func__, index, offset, rd_reg[offset], *buf, mdev_state->s[index].dlab); #endif } break; default: ret = -1; goto accessfailed; } ret = count; accessfailed: mutex_unlock(&mdev_state->ops_lock); return ret; } static size_t mtty_data_size(struct mdev_state *mdev_state) { return offsetof(struct mtty_data, ports) + (mdev_state->nr_ports * sizeof(struct serial_port)); } static void mtty_disable_file(struct mtty_migration_file *migf) { mutex_lock(&migf->lock); migf->disabled = true; migf->filled_size = 0; migf->filp->f_pos = 0; mutex_unlock(&migf->lock); } static void mtty_disable_files(struct mdev_state *mdev_state) { if (mdev_state->saving_migf) { mtty_disable_file(mdev_state->saving_migf); fput(mdev_state->saving_migf->filp); mdev_state->saving_migf = NULL; } if (mdev_state->resuming_migf) { mtty_disable_file(mdev_state->resuming_migf); fput(mdev_state->resuming_migf->filp); mdev_state->resuming_migf = NULL; } } static void mtty_state_mutex_unlock(struct mdev_state *mdev_state) { again: mutex_lock(&mdev_state->reset_mutex); if (mdev_state->deferred_reset) { mdev_state->deferred_reset = false; mutex_unlock(&mdev_state->reset_mutex); mdev_state->state = VFIO_DEVICE_STATE_RUNNING; mtty_disable_files(mdev_state); goto again; } mutex_unlock(&mdev_state->state_mutex); mutex_unlock(&mdev_state->reset_mutex); } static int mtty_release_migf(struct inode *inode, struct file *filp) { struct mtty_migration_file *migf = filp->private_data; mtty_disable_file(migf); mutex_destroy(&migf->lock); kfree(migf); return 0; } static long mtty_precopy_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { struct mtty_migration_file *migf = filp->private_data; struct mdev_state *mdev_state = migf->mdev_state; loff_t *pos = &filp->f_pos; struct vfio_precopy_info info = {}; unsigned long minsz; int ret; if (cmd != VFIO_MIG_GET_PRECOPY_INFO) return -ENOTTY; minsz = offsetofend(struct vfio_precopy_info, dirty_bytes); if (copy_from_user(&info, (void __user *)arg, minsz)) return -EFAULT; if (info.argsz < minsz) return -EINVAL; mutex_lock(&mdev_state->state_mutex); if (mdev_state->state != VFIO_DEVICE_STATE_PRE_COPY && mdev_state->state != VFIO_DEVICE_STATE_PRE_COPY_P2P) { ret = -EINVAL; goto unlock; } mutex_lock(&migf->lock); if (migf->disabled) { mutex_unlock(&migf->lock); ret = -ENODEV; goto unlock; } if (*pos > migf->filled_size) { mutex_unlock(&migf->lock); ret = -EINVAL; goto unlock; } info.dirty_bytes = 0; info.initial_bytes = migf->filled_size - *pos; mutex_unlock(&migf->lock); ret = copy_to_user((void __user *)arg, &info, minsz) ? -EFAULT : 0; unlock: mtty_state_mutex_unlock(mdev_state); return ret; } static ssize_t mtty_save_read(struct file *filp, char __user *buf, size_t len, loff_t *pos) { struct mtty_migration_file *migf = filp->private_data; ssize_t ret = 0; if (pos) return -ESPIPE; pos = &filp->f_pos; mutex_lock(&migf->lock); dev_dbg(migf->mdev_state->vdev.dev, "%s ask %zu\n", __func__, len); if (migf->disabled) { ret = -ENODEV; goto out_unlock; } if (*pos > migf->filled_size) { ret = -EINVAL; goto out_unlock; } len = min_t(size_t, migf->filled_size - *pos, len); if (len) { if (copy_to_user(buf, (void *)&migf->data + *pos, len)) { ret = -EFAULT; goto out_unlock; } *pos += len; ret = len; } out_unlock: dev_dbg(migf->mdev_state->vdev.dev, "%s read %zu\n", __func__, ret); mutex_unlock(&migf->lock); return ret; } static const struct file_operations mtty_save_fops = { .owner = THIS_MODULE, .read = mtty_save_read, .unlocked_ioctl = mtty_precopy_ioctl, .compat_ioctl = compat_ptr_ioctl, .release = mtty_release_migf, .llseek = no_llseek, }; static void mtty_save_state(struct mdev_state *mdev_state) { struct mtty_migration_file *migf = mdev_state->saving_migf; int i; mutex_lock(&migf->lock); for (i = 0; i < mdev_state->nr_ports; i++) { memcpy(&migf->data.ports[i], &mdev_state->s[i], sizeof(struct serial_port)); migf->filled_size += sizeof(struct serial_port); } dev_dbg(mdev_state->vdev.dev, "%s filled to %zu\n", __func__, migf->filled_size); mutex_unlock(&migf->lock); } static int mtty_load_state(struct mdev_state *mdev_state) { struct mtty_migration_file *migf = mdev_state->resuming_migf; int i; mutex_lock(&migf->lock); /* magic and version already tested by resume write fn */ if (migf->filled_size < mtty_data_size(mdev_state)) { dev_dbg(mdev_state->vdev.dev, "%s expected %zu, got %zu\n", __func__, mtty_data_size(mdev_state), migf->filled_size); mutex_unlock(&migf->lock); return -EINVAL; } for (i = 0; i < mdev_state->nr_ports; i++) memcpy(&mdev_state->s[i], &migf->data.ports[i], sizeof(struct serial_port)); mutex_unlock(&migf->lock); return 0; } static struct mtty_migration_file * mtty_save_device_data(struct mdev_state *mdev_state, enum vfio_device_mig_state state) { struct mtty_migration_file *migf = mdev_state->saving_migf; struct mtty_migration_file *ret = NULL; if (migf) { if (state == VFIO_DEVICE_STATE_STOP_COPY) goto fill_data; return ret; } migf = kzalloc(sizeof(*migf), GFP_KERNEL_ACCOUNT); if (!migf) return ERR_PTR(-ENOMEM); migf->filp = anon_inode_getfile("mtty_mig", &mtty_save_fops, migf, O_RDONLY); if (IS_ERR(migf->filp)) { int rc = PTR_ERR(migf->filp); kfree(migf); return ERR_PTR(rc); } stream_open(migf->filp->f_inode, migf->filp); mutex_init(&migf->lock); migf->mdev_state = mdev_state; migf->data.magic = MTTY_MAGIC; migf->data.major_ver = MTTY_MAJOR_VER; migf->data.minor_ver = MTTY_MINOR_VER; migf->data.nr_ports = mdev_state->nr_ports; migf->filled_size = offsetof(struct mtty_data, ports); dev_dbg(mdev_state->vdev.dev, "%s filled header to %zu\n", __func__, migf->filled_size); ret = mdev_state->saving_migf = migf; fill_data: if (state == VFIO_DEVICE_STATE_STOP_COPY) mtty_save_state(mdev_state); return ret; } static ssize_t mtty_resume_write(struct file *filp, const char __user *buf, size_t len, loff_t *pos) { struct mtty_migration_file *migf = filp->private_data; struct mdev_state *mdev_state = migf->mdev_state; loff_t requested_length; ssize_t ret = 0; if (pos) return -ESPIPE; pos = &filp->f_pos; if (*pos < 0 || check_add_overflow((loff_t)len, *pos, &requested_length)) return -EINVAL; if (requested_length > mtty_data_size(mdev_state)) return -ENOMEM; mutex_lock(&migf->lock); if (migf->disabled) { ret = -ENODEV; goto out_unlock; } if (copy_from_user((void *)&migf->data + *pos, buf, len)) { ret = -EFAULT; goto out_unlock; } *pos += len; ret = len; dev_dbg(migf->mdev_state->vdev.dev, "%s received %zu, total %zu\n", __func__, len, migf->filled_size + len); if (migf->filled_size < offsetof(struct mtty_data, ports) && migf->filled_size + len >= offsetof(struct mtty_data, ports)) { if (migf->data.magic != MTTY_MAGIC || migf->data.flags || migf->data.major_ver != MTTY_MAJOR_VER || migf->data.minor_ver != MTTY_MINOR_VER || migf->data.nr_ports != mdev_state->nr_ports) { dev_dbg(migf->mdev_state->vdev.dev, "%s failed validation\n", __func__); ret = -EFAULT; } else { dev_dbg(migf->mdev_state->vdev.dev, "%s header validated\n", __func__); } } migf->filled_size += len; out_unlock: mutex_unlock(&migf->lock); return ret; } static const struct file_operations mtty_resume_fops = { .owner = THIS_MODULE, .write = mtty_resume_write, .release = mtty_release_migf, .llseek = no_llseek, }; static struct mtty_migration_file * mtty_resume_device_data(struct mdev_state *mdev_state) { struct mtty_migration_file *migf; int ret; migf = kzalloc(sizeof(*migf), GFP_KERNEL_ACCOUNT); if (!migf) return ERR_PTR(-ENOMEM); migf->filp = anon_inode_getfile("mtty_mig", &mtty_resume_fops, migf, O_WRONLY); if (IS_ERR(migf->filp)) { ret = PTR_ERR(migf->filp); kfree(migf); return ERR_PTR(ret); } stream_open(migf->filp->f_inode, migf->filp); mutex_init(&migf->lock); migf->mdev_state = mdev_state; mdev_state->resuming_migf = migf; return migf; } static struct file *mtty_step_state(struct mdev_state *mdev_state, enum vfio_device_mig_state new) { enum vfio_device_mig_state cur = mdev_state->state; dev_dbg(mdev_state->vdev.dev, "%s: %d -> %d\n", __func__, cur, new); /* * The following state transitions are no-op considering * mtty does not do DMA nor require any explicit start/stop. * * RUNNING -> RUNNING_P2P * RUNNING_P2P -> RUNNING * RUNNING_P2P -> STOP * PRE_COPY -> PRE_COPY_P2P * PRE_COPY_P2P -> PRE_COPY * STOP -> RUNNING_P2P */ if ((cur == VFIO_DEVICE_STATE_RUNNING && new == VFIO_DEVICE_STATE_RUNNING_P2P) || (cur == VFIO_DEVICE_STATE_RUNNING_P2P && (new == VFIO_DEVICE_STATE_RUNNING || new == VFIO_DEVICE_STATE_STOP)) || (cur == VFIO_DEVICE_STATE_PRE_COPY && new == VFIO_DEVICE_STATE_PRE_COPY_P2P) || (cur == VFIO_DEVICE_STATE_PRE_COPY_P2P && new == VFIO_DEVICE_STATE_PRE_COPY) || (cur == VFIO_DEVICE_STATE_STOP && new == VFIO_DEVICE_STATE_RUNNING_P2P)) return NULL; /* * The following state transitions simply close migration files, * with the exception of RESUMING -> STOP, which needs to load * the state first. * * RESUMING -> STOP * PRE_COPY -> RUNNING * PRE_COPY_P2P -> RUNNING_P2P * STOP_COPY -> STOP */ if (cur == VFIO_DEVICE_STATE_RESUMING && new == VFIO_DEVICE_STATE_STOP) { int ret; ret = mtty_load_state(mdev_state); if (ret) return ERR_PTR(ret); mtty_disable_files(mdev_state); return NULL; } if ((cur == VFIO_DEVICE_STATE_PRE_COPY && new == VFIO_DEVICE_STATE_RUNNING) || (cur == VFIO_DEVICE_STATE_PRE_COPY_P2P && new == VFIO_DEVICE_STATE_RUNNING_P2P) || (cur == VFIO_DEVICE_STATE_STOP_COPY && new == VFIO_DEVICE_STATE_STOP)) { mtty_disable_files(mdev_state); return NULL; } /* * The following state transitions return migration files. * * RUNNING -> PRE_COPY * RUNNING_P2P -> PRE_COPY_P2P * STOP -> STOP_COPY * STOP -> RESUMING * PRE_COPY_P2P -> STOP_COPY */ if ((cur == VFIO_DEVICE_STATE_RUNNING && new == VFIO_DEVICE_STATE_PRE_COPY) || (cur == VFIO_DEVICE_STATE_RUNNING_P2P && new == VFIO_DEVICE_STATE_PRE_COPY_P2P) || (cur == VFIO_DEVICE_STATE_STOP && new == VFIO_DEVICE_STATE_STOP_COPY) || (cur == VFIO_DEVICE_STATE_PRE_COPY_P2P && new == VFIO_DEVICE_STATE_STOP_COPY)) { struct mtty_migration_file *migf; migf = mtty_save_device_data(mdev_state, new); if (IS_ERR(migf)) return ERR_CAST(migf); if (migf) { get_file(migf->filp); return migf->filp; } return NULL; } if (cur == VFIO_DEVICE_STATE_STOP && new == VFIO_DEVICE_STATE_RESUMING) { struct mtty_migration_file *migf; migf = mtty_resume_device_data(mdev_state); if (IS_ERR(migf)) return ERR_CAST(migf); get_file(migf->filp); return migf->filp; } /* vfio_mig_get_next_state() does not use arcs other than the above */ WARN_ON(true); return ERR_PTR(-EINVAL); } static struct file *mtty_set_state(struct vfio_device *vdev, enum vfio_device_mig_state new_state) { struct mdev_state *mdev_state = container_of(vdev, struct mdev_state, vdev); struct file *ret = NULL; dev_dbg(vdev->dev, "%s -> %d\n", __func__, new_state); mutex_lock(&mdev_state->state_mutex); while (mdev_state->state != new_state) { enum vfio_device_mig_state next_state; int rc = vfio_mig_get_next_state(vdev, mdev_state->state, new_state, &next_state); if (rc) { ret = ERR_PTR(rc); break; } ret = mtty_step_state(mdev_state, next_state); if (IS_ERR(ret)) break; mdev_state->state = next_state; if (WARN_ON(ret && new_state != next_state)) { fput(ret); ret = ERR_PTR(-EINVAL); break; } } mtty_state_mutex_unlock(mdev_state); return ret; } static int mtty_get_state(struct vfio_device *vdev, enum vfio_device_mig_state *current_state) { struct mdev_state *mdev_state = container_of(vdev, struct mdev_state, vdev); mutex_lock(&mdev_state->state_mutex); *current_state = mdev_state->state; mtty_state_mutex_unlock(mdev_state); return 0; } static int mtty_get_data_size(struct vfio_device *vdev, unsigned long *stop_copy_length) { struct mdev_state *mdev_state = container_of(vdev, struct mdev_state, vdev); *stop_copy_length = mtty_data_size(mdev_state); return 0; } static const struct vfio_migration_ops mtty_migration_ops = { .migration_set_state = mtty_set_state, .migration_get_state = mtty_get_state, .migration_get_data_size = mtty_get_data_size, }; static int mtty_log_start(struct vfio_device *vdev, struct rb_root_cached *ranges, u32 nnodes, u64 *page_size) { return 0; } static int mtty_log_stop(struct vfio_device *vdev) { return 0; } static int mtty_log_read_and_clear(struct vfio_device *vdev, unsigned long iova, unsigned long length, struct iova_bitmap *dirty) { return 0; } static const struct vfio_log_ops mtty_log_ops = { .log_start = mtty_log_start, .log_stop = mtty_log_stop, .log_read_and_clear = mtty_log_read_and_clear, }; static int mtty_init_dev(struct vfio_device *vdev) { struct mdev_state *mdev_state = container_of(vdev, struct mdev_state, vdev); struct mdev_device *mdev = to_mdev_device(vdev->dev); struct mtty_type *type = container_of(mdev->type, struct mtty_type, type); int avail_ports = atomic_read(&mdev_avail_ports); int ret; do { if (avail_ports < type->nr_ports) return -ENOSPC; } while (!atomic_try_cmpxchg(&mdev_avail_ports, &avail_ports, avail_ports - type->nr_ports)); mdev_state->nr_ports = type->nr_ports; mdev_state->irq_index = -1; mdev_state->s[0].max_fifo_size = MAX_FIFO_SIZE; mdev_state->s[1].max_fifo_size = MAX_FIFO_SIZE; mutex_init(&mdev_state->rxtx_lock); mdev_state->vconfig = kzalloc(MTTY_CONFIG_SPACE_SIZE, GFP_KERNEL); if (!mdev_state->vconfig) { ret = -ENOMEM; goto err_nr_ports; } mutex_init(&mdev_state->ops_lock); mdev_state->mdev = mdev; mtty_create_config_space(mdev_state); mutex_init(&mdev_state->state_mutex); mutex_init(&mdev_state->reset_mutex); vdev->migration_flags = VFIO_MIGRATION_STOP_COPY | VFIO_MIGRATION_P2P | VFIO_MIGRATION_PRE_COPY; vdev->mig_ops = &mtty_migration_ops; vdev->log_ops = &mtty_log_ops; mdev_state->state = VFIO_DEVICE_STATE_RUNNING; return 0; err_nr_ports: atomic_add(type->nr_ports, &mdev_avail_ports); return ret; } static int mtty_probe(struct mdev_device *mdev) { struct mdev_state *mdev_state; int ret; mdev_state = vfio_alloc_device(mdev_state, vdev, &mdev->dev, &mtty_dev_ops); if (IS_ERR(mdev_state)) return PTR_ERR(mdev_state); ret = vfio_register_emulated_iommu_dev(&mdev_state->vdev); if (ret) goto err_put_vdev; dev_set_drvdata(&mdev->dev, mdev_state); return 0; err_put_vdev: vfio_put_device(&mdev_state->vdev); return ret; } static void mtty_release_dev(struct vfio_device *vdev) { struct mdev_state *mdev_state = container_of(vdev, struct mdev_state, vdev); mutex_destroy(&mdev_state->reset_mutex); mutex_destroy(&mdev_state->state_mutex); atomic_add(mdev_state->nr_ports, &mdev_avail_ports); kfree(mdev_state->vconfig); } static void mtty_remove(struct mdev_device *mdev) { struct mdev_state *mdev_state = dev_get_drvdata(&mdev->dev); vfio_unregister_group_dev(&mdev_state->vdev); vfio_put_device(&mdev_state->vdev); } static int mtty_reset(struct mdev_state *mdev_state) { pr_info("%s: called\n", __func__); mutex_lock(&mdev_state->reset_mutex); mdev_state->deferred_reset = true; if (!mutex_trylock(&mdev_state->state_mutex)) { mutex_unlock(&mdev_state->reset_mutex); return 0; } mutex_unlock(&mdev_state->reset_mutex); mtty_state_mutex_unlock(mdev_state); return 0; } static ssize_t mtty_read(struct vfio_device *vdev, char __user *buf, size_t count, loff_t *ppos) { struct mdev_state *mdev_state = container_of(vdev, struct mdev_state, vdev); unsigned int done = 0; int ret; while (count) { size_t filled; if (count >= 4 && !(*ppos % 4)) { u32 val; ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val), *ppos, false); if (ret <= 0) goto read_err; if (copy_to_user(buf, &val, sizeof(val))) goto read_err; filled = 4; } else if (count >= 2 && !(*ppos % 2)) { u16 val; ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val), *ppos, false); if (ret <= 0) goto read_err; if (copy_to_user(buf, &val, sizeof(val))) goto read_err; filled = 2; } else { u8 val; ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val), *ppos, false); if (ret <= 0) goto read_err; if (copy_to_user(buf, &val, sizeof(val))) goto read_err; filled = 1; } count -= filled; done += filled; *ppos += filled; buf += filled; } return done; read_err: return -EFAULT; } static ssize_t mtty_write(struct vfio_device *vdev, const char __user *buf, size_t count, loff_t *ppos) { struct mdev_state *mdev_state = container_of(vdev, struct mdev_state, vdev); unsigned int done = 0; int ret; while (count) { size_t filled; if (count >= 4 && !(*ppos % 4)) { u32 val; if (copy_from_user(&val, buf, sizeof(val))) goto write_err; ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val), *ppos, true); if (ret <= 0) goto write_err; filled = 4; } else if (count >= 2 && !(*ppos % 2)) { u16 val; if (copy_from_user(&val, buf, sizeof(val))) goto write_err; ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val), *ppos, true); if (ret <= 0) goto write_err; filled = 2; } else { u8 val; if (copy_from_user(&val, buf, sizeof(val))) goto write_err; ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val), *ppos, true); if (ret <= 0) goto write_err; filled = 1; } count -= filled; done += filled; *ppos += filled; buf += filled; } return done; write_err: return -EFAULT; } static void mtty_disable_intx(struct mdev_state *mdev_state) { if (mdev_state->intx_evtfd) { eventfd_ctx_put(mdev_state->intx_evtfd); mdev_state->intx_evtfd = NULL; mdev_state->intx_mask = false; mdev_state->irq_index = -1; } } static void mtty_disable_msi(struct mdev_state *mdev_state) { if (mdev_state->msi_evtfd) { eventfd_ctx_put(mdev_state->msi_evtfd); mdev_state->msi_evtfd = NULL; mdev_state->irq_index = -1; } } static int mtty_set_irqs(struct mdev_state *mdev_state, uint32_t flags, unsigned int index, unsigned int start, unsigned int count, void *data) { int ret = 0; mutex_lock(&mdev_state->ops_lock); switch (index) { case VFIO_PCI_INTX_IRQ_INDEX: switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) { case VFIO_IRQ_SET_ACTION_MASK: if (!is_intx(mdev_state) || start != 0 || count != 1) { ret = -EINVAL; break; } if (flags & VFIO_IRQ_SET_DATA_NONE) { mdev_state->intx_mask = true; } else if (flags & VFIO_IRQ_SET_DATA_BOOL) { uint8_t mask = *(uint8_t *)data; if (mask) mdev_state->intx_mask = true; } else if (flags & VFIO_IRQ_SET_DATA_EVENTFD) { ret = -ENOTTY; /* No support for mask fd */ } break; case VFIO_IRQ_SET_ACTION_UNMASK: if (!is_intx(mdev_state) || start != 0 || count != 1) { ret = -EINVAL; break; } if (flags & VFIO_IRQ_SET_DATA_NONE) { mdev_state->intx_mask = false; } else if (flags & VFIO_IRQ_SET_DATA_BOOL) { uint8_t mask = *(uint8_t *)data; if (mask) mdev_state->intx_mask = false; } else if (flags & VFIO_IRQ_SET_DATA_EVENTFD) { ret = -ENOTTY; /* No support for unmask fd */ } break; case VFIO_IRQ_SET_ACTION_TRIGGER: if (is_intx(mdev_state) && !count && (flags & VFIO_IRQ_SET_DATA_NONE)) { mtty_disable_intx(mdev_state); break; } if (!(is_intx(mdev_state) || is_noirq(mdev_state)) || start != 0 || count != 1) { ret = -EINVAL; break; } if (flags & VFIO_IRQ_SET_DATA_EVENTFD) { int fd = *(int *)data; struct eventfd_ctx *evt; mtty_disable_intx(mdev_state); if (fd < 0) break; evt = eventfd_ctx_fdget(fd); if (IS_ERR(evt)) { ret = PTR_ERR(evt); break; } mdev_state->intx_evtfd = evt; mdev_state->irq_index = index; break; } if (!is_intx(mdev_state)) { ret = -EINVAL; break; } if (flags & VFIO_IRQ_SET_DATA_NONE) { mtty_trigger_interrupt(mdev_state); } else if (flags & VFIO_IRQ_SET_DATA_BOOL) { uint8_t trigger = *(uint8_t *)data; if (trigger) mtty_trigger_interrupt(mdev_state); } break; } break; case VFIO_PCI_MSI_IRQ_INDEX: switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) { case VFIO_IRQ_SET_ACTION_MASK: case VFIO_IRQ_SET_ACTION_UNMASK: ret = -ENOTTY; break; case VFIO_IRQ_SET_ACTION_TRIGGER: if (is_msi(mdev_state) && !count && (flags & VFIO_IRQ_SET_DATA_NONE)) { mtty_disable_msi(mdev_state); break; } if (!(is_msi(mdev_state) || is_noirq(mdev_state)) || start != 0 || count != 1) { ret = -EINVAL; break; } if (flags & VFIO_IRQ_SET_DATA_EVENTFD) { int fd = *(int *)data; struct eventfd_ctx *evt; mtty_disable_msi(mdev_state); if (fd < 0) break; evt = eventfd_ctx_fdget(fd); if (IS_ERR(evt)) { ret = PTR_ERR(evt); break; } mdev_state->msi_evtfd = evt; mdev_state->irq_index = index; break; } if (!is_msi(mdev_state)) { ret = -EINVAL; break; } if (flags & VFIO_IRQ_SET_DATA_NONE) { mtty_trigger_interrupt(mdev_state); } else if (flags & VFIO_IRQ_SET_DATA_BOOL) { uint8_t trigger = *(uint8_t *)data; if (trigger) mtty_trigger_interrupt(mdev_state); } break; } break; case VFIO_PCI_MSIX_IRQ_INDEX: dev_dbg(mdev_state->vdev.dev, "%s: MSIX_IRQ\n", __func__); ret = -ENOTTY; break; case VFIO_PCI_ERR_IRQ_INDEX: dev_dbg(mdev_state->vdev.dev, "%s: ERR_IRQ\n", __func__); ret = -ENOTTY; break; case VFIO_PCI_REQ_IRQ_INDEX: dev_dbg(mdev_state->vdev.dev, "%s: REQ_IRQ\n", __func__); ret = -ENOTTY; break; } mutex_unlock(&mdev_state->ops_lock); return ret; } static int mtty_get_region_info(struct mdev_state *mdev_state, struct vfio_region_info *region_info, u16 *cap_type_id, void **cap_type) { unsigned int size = 0; u32 bar_index; bar_index = region_info->index; if (bar_index >= VFIO_PCI_NUM_REGIONS) return -EINVAL; mutex_lock(&mdev_state->ops_lock); switch (bar_index) { case VFIO_PCI_CONFIG_REGION_INDEX: size = MTTY_CONFIG_SPACE_SIZE; break; case VFIO_PCI_BAR0_REGION_INDEX: size = MTTY_IO_BAR_SIZE; break; case VFIO_PCI_BAR1_REGION_INDEX: if (mdev_state->nr_ports == 2) size = MTTY_IO_BAR_SIZE; break; default: size = 0; break; } mdev_state->region_info[bar_index].size = size; mdev_state->region_info[bar_index].vfio_offset = MTTY_VFIO_PCI_INDEX_TO_OFFSET(bar_index); region_info->size = size; region_info->offset = MTTY_VFIO_PCI_INDEX_TO_OFFSET(bar_index); region_info->flags = VFIO_REGION_INFO_FLAG_READ | VFIO_REGION_INFO_FLAG_WRITE; mutex_unlock(&mdev_state->ops_lock); return 0; } static int mtty_get_irq_info(struct vfio_irq_info *irq_info) { if (irq_info->index != VFIO_PCI_INTX_IRQ_INDEX && irq_info->index != VFIO_PCI_MSI_IRQ_INDEX) return -EINVAL; irq_info->flags = VFIO_IRQ_INFO_EVENTFD; irq_info->count = 1; if (irq_info->index == VFIO_PCI_INTX_IRQ_INDEX) irq_info->flags |= VFIO_IRQ_INFO_MASKABLE | VFIO_IRQ_INFO_AUTOMASKED; else irq_info->flags |= VFIO_IRQ_INFO_NORESIZE; return 0; } static int mtty_get_device_info(struct vfio_device_info *dev_info) { dev_info->flags = VFIO_DEVICE_FLAGS_PCI; dev_info->num_regions = VFIO_PCI_NUM_REGIONS; dev_info->num_irqs = VFIO_PCI_NUM_IRQS; return 0; } static long mtty_ioctl(struct vfio_device *vdev, unsigned int cmd, unsigned long arg) { struct mdev_state *mdev_state = container_of(vdev, struct mdev_state, vdev); int ret = 0; unsigned long minsz; switch (cmd) { case VFIO_DEVICE_GET_INFO: { struct vfio_device_info info; minsz = offsetofend(struct vfio_device_info, num_irqs); if (copy_from_user(&info, (void __user *)arg, minsz)) return -EFAULT; if (info.argsz < minsz) return -EINVAL; ret = mtty_get_device_info(&info); if (ret) return ret; memcpy(&mdev_state->dev_info, &info, sizeof(info)); if (copy_to_user((void __user *)arg, &info, minsz)) return -EFAULT; return 0; } case VFIO_DEVICE_GET_REGION_INFO: { struct vfio_region_info info; u16 cap_type_id = 0; void *cap_type = NULL; minsz = offsetofend(struct vfio_region_info, offset); if (copy_from_user(&info, (void __user *)arg, minsz)) return -EFAULT; if (info.argsz < minsz) return -EINVAL; ret = mtty_get_region_info(mdev_state, &info, &cap_type_id, &cap_type); if (ret) return ret; if (copy_to_user((void __user *)arg, &info, minsz)) return -EFAULT; return 0; } case VFIO_DEVICE_GET_IRQ_INFO: { struct vfio_irq_info info; minsz = offsetofend(struct vfio_irq_info, count); if (copy_from_user(&info, (void __user *)arg, minsz)) return -EFAULT; if ((info.argsz < minsz) || (info.index >= mdev_state->dev_info.num_irqs)) return -EINVAL; ret = mtty_get_irq_info(&info); if (ret) return ret; if (copy_to_user((void __user *)arg, &info, minsz)) return -EFAULT; return 0; } case VFIO_DEVICE_SET_IRQS: { struct vfio_irq_set hdr; u8 *data = NULL, *ptr = NULL; size_t data_size = 0; minsz = offsetofend(struct vfio_irq_set, count); if (copy_from_user(&hdr, (void __user *)arg, minsz)) return -EFAULT; ret = vfio_set_irqs_validate_and_prepare(&hdr, mdev_state->dev_info.num_irqs, VFIO_PCI_NUM_IRQS, &data_size); if (ret) return ret; if (data_size) { ptr = data = memdup_user((void __user *)(arg + minsz), data_size); if (IS_ERR(data)) return PTR_ERR(data); } ret = mtty_set_irqs(mdev_state, hdr.flags, hdr.index, hdr.start, hdr.count, data); kfree(ptr); return ret; } case VFIO_DEVICE_RESET: return mtty_reset(mdev_state); } return -ENOTTY; } static ssize_t sample_mdev_dev_show(struct device *dev, struct device_attribute *attr, char *buf) { return sprintf(buf, "This is MDEV %s\n", dev_name(dev)); } static DEVICE_ATTR_RO(sample_mdev_dev); static struct attribute *mdev_dev_attrs[] = { &dev_attr_sample_mdev_dev.attr, NULL, }; static const struct attribute_group mdev_dev_group = { .name = "vendor", .attrs = mdev_dev_attrs, }; static const struct attribute_group *mdev_dev_groups[] = { &mdev_dev_group, NULL, }; static unsigned int mtty_get_available(struct mdev_type *mtype) { struct mtty_type *type = container_of(mtype, struct mtty_type, type); return atomic_read(&mdev_avail_ports) / type->nr_ports; } static void mtty_close(struct vfio_device *vdev) { struct mdev_state *mdev_state = container_of(vdev, struct mdev_state, vdev); mtty_disable_files(mdev_state); mtty_disable_intx(mdev_state); mtty_disable_msi(mdev_state); } static const struct vfio_device_ops mtty_dev_ops = { .name = "vfio-mtty", .init = mtty_init_dev, .release = mtty_release_dev, .read = mtty_read, .write = mtty_write, .ioctl = mtty_ioctl, .bind_iommufd = vfio_iommufd_emulated_bind, .unbind_iommufd = vfio_iommufd_emulated_unbind, .attach_ioas = vfio_iommufd_emulated_attach_ioas, .detach_ioas = vfio_iommufd_emulated_detach_ioas, .close_device = mtty_close, }; static struct mdev_driver mtty_driver = { .device_api = VFIO_DEVICE_API_PCI_STRING, .driver = { .name = "mtty", .owner = THIS_MODULE, .mod_name = KBUILD_MODNAME, .dev_groups = mdev_dev_groups, }, .probe = mtty_probe, .remove = mtty_remove, .get_available = mtty_get_available, }; static void mtty_device_release(struct device *dev) { dev_dbg(dev, "mtty: released\n"); } static int __init mtty_dev_init(void) { int ret = 0; pr_info("mtty_dev: %s\n", __func__); memset(&mtty_dev, 0, sizeof(mtty_dev)); idr_init(&mtty_dev.vd_idr); ret = alloc_chrdev_region(&mtty_dev.vd_devt, 0, MINORMASK + 1, MTTY_NAME); if (ret < 0) { pr_err("Error: failed to register mtty_dev, err:%d\n", ret); return ret; } cdev_init(&mtty_dev.vd_cdev, &vd_fops); cdev_add(&mtty_dev.vd_cdev, mtty_dev.vd_devt, MINORMASK + 1); pr_info("major_number:%d\n", MAJOR(mtty_dev.vd_devt)); ret = mdev_register_driver(&mtty_driver); if (ret) goto err_cdev; mtty_dev.vd_class = class_create(MTTY_CLASS_NAME); if (IS_ERR(mtty_dev.vd_class)) { pr_err("Error: failed to register mtty_dev class\n"); ret = PTR_ERR(mtty_dev.vd_class); goto err_driver; } mtty_dev.dev.class = mtty_dev.vd_class; mtty_dev.dev.release = mtty_device_release; dev_set_name(&mtty_dev.dev, "%s", MTTY_NAME); ret = device_register(&mtty_dev.dev); if (ret) goto err_put; ret = mdev_register_parent(&mtty_dev.parent, &mtty_dev.dev, &mtty_driver, mtty_mdev_types, ARRAY_SIZE(mtty_mdev_types)); if (ret) goto err_device; return 0; err_device: device_del(&mtty_dev.dev); err_put: put_device(&mtty_dev.dev); class_destroy(mtty_dev.vd_class); err_driver: mdev_unregister_driver(&mtty_driver); err_cdev: cdev_del(&mtty_dev.vd_cdev); unregister_chrdev_region(mtty_dev.vd_devt, MINORMASK + 1); return ret; } static void __exit mtty_dev_exit(void) { mtty_dev.dev.bus = NULL; mdev_unregister_parent(&mtty_dev.parent); device_unregister(&mtty_dev.dev); idr_destroy(&mtty_dev.vd_idr); mdev_unregister_driver(&mtty_driver); cdev_del(&mtty_dev.vd_cdev); unregister_chrdev_region(mtty_dev.vd_devt, MINORMASK + 1); class_destroy(mtty_dev.vd_class); mtty_dev.vd_class = NULL; pr_info("mtty_dev: Unloaded!\n"); } module_init(mtty_dev_init) module_exit(mtty_dev_exit) MODULE_LICENSE("GPL v2"); MODULE_INFO(supported, "Test driver that simulate serial port over PCI"); MODULE_VERSION(VERSION_STRING); MODULE_AUTHOR(DRIVER_AUTHOR);