diff options
Diffstat (limited to 'drivers/vfio/pci/vfio_pci_config.c')
| -rw-r--r-- | drivers/vfio/pci/vfio_pci_config.c | 1540 |
1 files changed, 1540 insertions, 0 deletions
diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c new file mode 100644 index 000000000000..8b8f7d11e102 --- /dev/null +++ b/drivers/vfio/pci/vfio_pci_config.c @@ -0,0 +1,1540 @@ +/* + * VFIO PCI config space virtualization + * + * Copyright (C) 2012 Red Hat, Inc. All rights reserved. + * Author: Alex Williamson <alex.williamson@redhat.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Derived from original vfio: + * Copyright 2010 Cisco Systems, Inc. All rights reserved. + * Author: Tom Lyon, pugs@cisco.com + */ + +/* + * This code handles reading and writing of PCI configuration registers. + * This is hairy because we want to allow a lot of flexibility to the + * user driver, but cannot trust it with all of the config fields. + * Tables determine which fields can be read and written, as well as + * which fields are 'virtualized' - special actions and translations to + * make it appear to the user that he has control, when in fact things + * must be negotiated with the underlying OS. + */ + +#include <linux/fs.h> +#include <linux/pci.h> +#include <linux/uaccess.h> +#include <linux/vfio.h> + +#include "vfio_pci_private.h" + +#define PCI_CFG_SPACE_SIZE 256 + +/* Useful "pseudo" capabilities */ +#define PCI_CAP_ID_BASIC 0 +#define PCI_CAP_ID_INVALID 0xFF + +#define is_bar(offset) \ + ((offset >= PCI_BASE_ADDRESS_0 && offset < PCI_BASE_ADDRESS_5 + 4) || \ + (offset >= PCI_ROM_ADDRESS && offset < PCI_ROM_ADDRESS + 4)) + +/* + * Lengths of PCI Config Capabilities + * 0: Removed from the user visible capability list + * FF: Variable length + */ +static u8 pci_cap_length[] = { + [PCI_CAP_ID_BASIC] = PCI_STD_HEADER_SIZEOF, /* pci config header */ + [PCI_CAP_ID_PM] = PCI_PM_SIZEOF, + [PCI_CAP_ID_AGP] = PCI_AGP_SIZEOF, + [PCI_CAP_ID_VPD] = PCI_CAP_VPD_SIZEOF, + [PCI_CAP_ID_SLOTID] = 0, /* bridge - don't care */ + [PCI_CAP_ID_MSI] = 0xFF, /* 10, 14, 20, or 24 */ + [PCI_CAP_ID_CHSWP] = 0, /* cpci - not yet */ + [PCI_CAP_ID_PCIX] = 0xFF, /* 8 or 24 */ + [PCI_CAP_ID_HT] = 0xFF, /* hypertransport */ + [PCI_CAP_ID_VNDR] = 0xFF, /* variable */ + [PCI_CAP_ID_DBG] = 0, /* debug - don't care */ + [PCI_CAP_ID_CCRC] = 0, /* cpci - not yet */ + [PCI_CAP_ID_SHPC] = 0, /* hotswap - not yet */ + [PCI_CAP_ID_SSVID] = 0, /* bridge - don't care */ + [PCI_CAP_ID_AGP3] = 0, /* AGP8x - not yet */ + [PCI_CAP_ID_SECDEV] = 0, /* secure device not yet */ + [PCI_CAP_ID_EXP] = 0xFF, /* 20 or 44 */ + [PCI_CAP_ID_MSIX] = PCI_CAP_MSIX_SIZEOF, + [PCI_CAP_ID_SATA] = 0xFF, + [PCI_CAP_ID_AF] = PCI_CAP_AF_SIZEOF, +}; + +/* + * Lengths of PCIe/PCI-X Extended Config Capabilities + * 0: Removed or masked from the user visible capabilty list + * FF: Variable length + */ +static u16 pci_ext_cap_length[] = { + [PCI_EXT_CAP_ID_ERR] = PCI_ERR_ROOT_COMMAND, + [PCI_EXT_CAP_ID_VC] = 0xFF, + [PCI_EXT_CAP_ID_DSN] = PCI_EXT_CAP_DSN_SIZEOF, + [PCI_EXT_CAP_ID_PWR] = PCI_EXT_CAP_PWR_SIZEOF, + [PCI_EXT_CAP_ID_RCLD] = 0, /* root only - don't care */ + [PCI_EXT_CAP_ID_RCILC] = 0, /* root only - don't care */ + [PCI_EXT_CAP_ID_RCEC] = 0, /* root only - don't care */ + [PCI_EXT_CAP_ID_MFVC] = 0xFF, + [PCI_EXT_CAP_ID_VC9] = 0xFF, /* same as CAP_ID_VC */ + [PCI_EXT_CAP_ID_RCRB] = 0, /* root only - don't care */ + [PCI_EXT_CAP_ID_VNDR] = 0xFF, + [PCI_EXT_CAP_ID_CAC] = 0, /* obsolete */ + [PCI_EXT_CAP_ID_ACS] = 0xFF, + [PCI_EXT_CAP_ID_ARI] = PCI_EXT_CAP_ARI_SIZEOF, + [PCI_EXT_CAP_ID_ATS] = PCI_EXT_CAP_ATS_SIZEOF, + [PCI_EXT_CAP_ID_SRIOV] = PCI_EXT_CAP_SRIOV_SIZEOF, + [PCI_EXT_CAP_ID_MRIOV] = 0, /* not yet */ + [PCI_EXT_CAP_ID_MCAST] = PCI_EXT_CAP_MCAST_ENDPOINT_SIZEOF, + [PCI_EXT_CAP_ID_PRI] = PCI_EXT_CAP_PRI_SIZEOF, + [PCI_EXT_CAP_ID_AMD_XXX] = 0, /* not yet */ + [PCI_EXT_CAP_ID_REBAR] = 0xFF, + [PCI_EXT_CAP_ID_DPA] = 0xFF, + [PCI_EXT_CAP_ID_TPH] = 0xFF, + [PCI_EXT_CAP_ID_LTR] = PCI_EXT_CAP_LTR_SIZEOF, + [PCI_EXT_CAP_ID_SECPCI] = 0, /* not yet */ + [PCI_EXT_CAP_ID_PMUX] = 0, /* not yet */ + [PCI_EXT_CAP_ID_PASID] = 0, /* not yet */ +}; + +/* + * Read/Write Permission Bits - one bit for each bit in capability + * Any field can be read if it exists, but what is read depends on + * whether the field is 'virtualized', or just pass thru to the + * hardware. Any virtualized field is also virtualized for writes. + * Writes are only permitted if they have a 1 bit here. + */ +struct perm_bits { + u8 *virt; /* read/write virtual data, not hw */ + u8 *write; /* writeable bits */ + int (*readfn)(struct vfio_pci_device *vdev, int pos, int count, + struct perm_bits *perm, int offset, __le32 *val); + int (*writefn)(struct vfio_pci_device *vdev, int pos, int count, + struct perm_bits *perm, int offset, __le32 val); +}; + +#define NO_VIRT 0 +#define ALL_VIRT 0xFFFFFFFFU +#define NO_WRITE 0 +#define ALL_WRITE 0xFFFFFFFFU + +static int vfio_user_config_read(struct pci_dev *pdev, int offset, + __le32 *val, int count) +{ + int ret = -EINVAL; + u32 tmp_val = 0; + + switch (count) { + case 1: + { + u8 tmp; + ret = pci_user_read_config_byte(pdev, offset, &tmp); + tmp_val = tmp; + break; + } + case 2: + { + u16 tmp; + ret = pci_user_read_config_word(pdev, offset, &tmp); + tmp_val = tmp; + break; + } + case 4: + ret = pci_user_read_config_dword(pdev, offset, &tmp_val); + break; + } + + *val = cpu_to_le32(tmp_val); + + return pcibios_err_to_errno(ret); +} + +static int vfio_user_config_write(struct pci_dev *pdev, int offset, + __le32 val, int count) +{ + int ret = -EINVAL; + u32 tmp_val = le32_to_cpu(val); + + switch (count) { + case 1: + ret = pci_user_write_config_byte(pdev, offset, tmp_val); + break; + case 2: + ret = pci_user_write_config_word(pdev, offset, tmp_val); + break; + case 4: + ret = pci_user_write_config_dword(pdev, offset, tmp_val); + break; + } + + return pcibios_err_to_errno(ret); +} + +static int vfio_default_config_read(struct vfio_pci_device *vdev, int pos, + int count, struct perm_bits *perm, + int offset, __le32 *val) +{ + __le32 virt = 0; + + memcpy(val, vdev->vconfig + pos, count); + + memcpy(&virt, perm->virt + offset, count); + + /* Any non-virtualized bits? */ + if (cpu_to_le32(~0U >> (32 - (count * 8))) != virt) { + struct pci_dev *pdev = vdev->pdev; + __le32 phys_val = 0; + int ret; + + ret = vfio_user_config_read(pdev, pos, &phys_val, count); + if (ret) + return ret; + + *val = (phys_val & ~virt) | (*val & virt); + } + + return count; +} + +static int vfio_default_config_write(struct vfio_pci_device *vdev, int pos, + int count, struct perm_bits *perm, + int offset, __le32 val) +{ + __le32 virt = 0, write = 0; + + memcpy(&write, perm->write + offset, count); + + if (!write) + return count; /* drop, no writable bits */ + + memcpy(&virt, perm->virt + offset, count); + + /* Virtualized and writable bits go to vconfig */ + if (write & virt) { + __le32 virt_val = 0; + + memcpy(&virt_val, vdev->vconfig + pos, count); + + virt_val &= ~(write & virt); + virt_val |= (val & (write & virt)); + + memcpy(vdev->vconfig + pos, &virt_val, count); + } + + /* Non-virtualzed and writable bits go to hardware */ + if (write & ~virt) { + struct pci_dev *pdev = vdev->pdev; + __le32 phys_val = 0; + int ret; + + ret = vfio_user_config_read(pdev, pos, &phys_val, count); + if (ret) + return ret; + + phys_val &= ~(write & ~virt); + phys_val |= (val & (write & ~virt)); + + ret = vfio_user_config_write(pdev, pos, phys_val, count); + if (ret) + return ret; + } + + return count; +} + +/* Allow direct read from hardware, except for capability next pointer */ +static int vfio_direct_config_read(struct vfio_pci_device *vdev, int pos, + int count, struct perm_bits *perm, + int offset, __le32 *val) +{ + int ret; + + ret = vfio_user_config_read(vdev->pdev, pos, val, count); + if (ret) + return pcibios_err_to_errno(ret); + + if (pos >= PCI_CFG_SPACE_SIZE) { /* Extended cap header mangling */ + if (offset < 4) + memcpy(val, vdev->vconfig + pos, count); + } else if (pos >= PCI_STD_HEADER_SIZEOF) { /* Std cap mangling */ + if (offset == PCI_CAP_LIST_ID && count > 1) + memcpy(val, vdev->vconfig + pos, + min(PCI_CAP_FLAGS, count)); + else if (offset == PCI_CAP_LIST_NEXT) + memcpy(val, vdev->vconfig + pos, 1); + } + + return count; +} + +static int vfio_direct_config_write(struct vfio_pci_device *vdev, int pos, + int count, struct perm_bits *perm, + int offset, __le32 val) +{ + int ret; + + ret = vfio_user_config_write(vdev->pdev, pos, val, count); + if (ret) + return ret; + + return count; +} + +/* Default all regions to read-only, no-virtualization */ +static struct perm_bits cap_perms[PCI_CAP_ID_MAX + 1] = { + [0 ... PCI_CAP_ID_MAX] = { .readfn = vfio_direct_config_read } +}; +static struct perm_bits ecap_perms[PCI_EXT_CAP_ID_MAX + 1] = { + [0 ... PCI_EXT_CAP_ID_MAX] = { .readfn = vfio_direct_config_read } +}; + +static void free_perm_bits(struct perm_bits *perm) +{ + kfree(perm->virt); + kfree(perm->write); + perm->virt = NULL; + perm->write = NULL; +} + +static int alloc_perm_bits(struct perm_bits *perm, int size) +{ + /* + * Round up all permission bits to the next dword, this lets us + * ignore whether a read/write exceeds the defined capability + * structure. We can do this because: + * - Standard config space is already dword aligned + * - Capabilities are all dword alinged (bits 0:1 of next reserved) + * - Express capabilities defined as dword aligned + */ + size = round_up(size, 4); + + /* + * Zero state is + * - All Readable, None Writeable, None Virtualized + */ + perm->virt = kzalloc(size, GFP_KERNEL); + perm->write = kzalloc(size, GFP_KERNEL); + if (!perm->virt || !perm->write) { + free_perm_bits(perm); + return -ENOMEM; + } + + perm->readfn = vfio_default_config_read; + perm->writefn = vfio_default_config_write; + + return 0; +} + +/* + * Helper functions for filling in permission tables + */ +static inline void p_setb(struct perm_bits *p, int off, u8 virt, u8 write) +{ + p->virt[off] = virt; + p->write[off] = write; +} + +/* Handle endian-ness - pci and tables are little-endian */ +static inline void p_setw(struct perm_bits *p, int off, u16 virt, u16 write) +{ + *(__le16 *)(&p->virt[off]) = cpu_to_le16(virt); + *(__le16 *)(&p->write[off]) = cpu_to_le16(write); +} + +/* Handle endian-ness - pci and tables are little-endian */ +static inline void p_setd(struct perm_bits *p, int off, u32 virt, u32 write) +{ + *(__le32 *)(&p->virt[off]) = cpu_to_le32(virt); + *(__le32 *)(&p->write[off]) = cpu_to_le32(write); +} + +/* + * Restore the *real* BARs after we detect a FLR or backdoor reset. + * (backdoor = some device specific technique that we didn't catch) + */ +static void vfio_bar_restore(struct vfio_pci_device *vdev) +{ + struct pci_dev *pdev = vdev->pdev; + u32 *rbar = vdev->rbar; + int i; + + if (pdev->is_virtfn) + return; + + pr_info("%s: %s reset recovery - restoring bars\n", + __func__, dev_name(&pdev->dev)); + + for (i = PCI_BASE_ADDRESS_0; i <= PCI_BASE_ADDRESS_5; i += 4, rbar++) + pci_user_write_config_dword(pdev, i, *rbar); + + pci_user_write_config_dword(pdev, PCI_ROM_ADDRESS, *rbar); +} + +static __le32 vfio_generate_bar_flags(struct pci_dev *pdev, int bar) +{ + unsigned long flags = pci_resource_flags(pdev, bar); + u32 val; + + if (flags & IORESOURCE_IO) + return cpu_to_le32(PCI_BASE_ADDRESS_SPACE_IO); + + val = PCI_BASE_ADDRESS_SPACE_MEMORY; + + if (flags & IORESOURCE_PREFETCH) + val |= PCI_BASE_ADDRESS_MEM_PREFETCH; + + if (flags & IORESOURCE_MEM_64) + val |= PCI_BASE_ADDRESS_MEM_TYPE_64; + + return cpu_to_le32(val); +} + +/* + * Pretend we're hardware and tweak the values of the *virtual* PCI BARs + * to reflect the hardware capabilities. This implements BAR sizing. + */ +static void vfio_bar_fixup(struct vfio_pci_device *vdev) +{ + struct pci_dev *pdev = vdev->pdev; + int i; + __le32 *bar; + u64 mask; + + bar = (__le32 *)&vdev->vconfig[PCI_BASE_ADDRESS_0]; + + for (i = PCI_STD_RESOURCES; i <= PCI_STD_RESOURCE_END; i++, bar++) { + if (!pci_resource_start(pdev, i)) { + *bar = 0; /* Unmapped by host = unimplemented to user */ + continue; + } + + mask = ~(pci_resource_len(pdev, i) - 1); + + *bar &= cpu_to_le32((u32)mask); + *bar |= vfio_generate_bar_flags(pdev, i); + + if (*bar & cpu_to_le32(PCI_BASE_ADDRESS_MEM_TYPE_64)) { + bar++; + *bar &= cpu_to_le32((u32)(mask >> 32)); + i++; + } + } + + bar = (__le32 *)&vdev->vconfig[PCI_ROM_ADDRESS]; + + /* + * NB. we expose the actual BAR size here, regardless of whether + * we can read it. When we report the REGION_INFO for the ROM + * we report what PCI tells us is the actual ROM size. + */ + if (pci_resource_start(pdev, PCI_ROM_RESOURCE)) { + mask = ~(pci_resource_len(pdev, PCI_ROM_RESOURCE) - 1); + mask |= PCI_ROM_ADDRESS_ENABLE; + *bar &= cpu_to_le32((u32)mask); + } else + *bar = 0; + + vdev->bardirty = false; +} + +static int vfio_basic_config_read(struct vfio_pci_device *vdev, int pos, + int count, struct perm_bits *perm, + int offset, __le32 *val) +{ + if (is_bar(offset)) /* pos == offset for basic config */ + vfio_bar_fixup(vdev); + + count = vfio_default_config_read(vdev, pos, count, perm, offset, val); + + /* Mask in virtual memory enable for SR-IOV devices */ + if (offset == PCI_COMMAND && vdev->pdev->is_virtfn) { + u16 cmd = le16_to_cpu(*(__le16 *)&vdev->vconfig[PCI_COMMAND]); + u32 tmp_val = le32_to_cpu(*val); + + tmp_val |= cmd & PCI_COMMAND_MEMORY; + *val = cpu_to_le32(tmp_val); + } + + return count; +} + +static int vfio_basic_config_write(struct vfio_pci_device *vdev, int pos, + int count, struct perm_bits *perm, + int offset, __le32 val) +{ + struct pci_dev *pdev = vdev->pdev; + __le16 *virt_cmd; + u16 new_cmd = 0; + int ret; + + virt_cmd = (__le16 *)&vdev->vconfig[PCI_COMMAND]; + + if (offset == PCI_COMMAND) { + bool phys_mem, virt_mem, new_mem, phys_io, virt_io, new_io; + u16 phys_cmd; + + ret = pci_user_read_config_word(pdev, PCI_COMMAND, &phys_cmd); + if (ret) + return ret; + + new_cmd = le32_to_cpu(val); + + phys_mem = !!(phys_cmd & PCI_COMMAND_MEMORY); + virt_mem = !!(le16_to_cpu(*virt_cmd) & PCI_COMMAND_MEMORY); + new_mem = !!(new_cmd & PCI_COMMAND_MEMORY); + + phys_io = !!(phys_cmd & PCI_COMMAND_IO); + virt_io = !!(le16_to_cpu(*virt_cmd) & PCI_COMMAND_IO); + new_io = !!(new_cmd & PCI_COMMAND_IO); + + /* + * If the user is writing mem/io enable (new_mem/io) and we + * think it's already enabled (virt_mem/io), but the hardware + * shows it disabled (phys_mem/io, then the device has + * undergone some kind of backdoor reset and needs to be + * restored before we allow it to enable the bars. + * SR-IOV devices will trigger this, but we catch them later + */ + if ((new_mem && virt_mem && !phys_mem) || + (new_io && virt_io && !phys_io)) + vfio_bar_restore(vdev); + } + + count = vfio_default_config_write(vdev, pos, count, perm, offset, val); + if (count < 0) + return count; + + /* + * Save current memory/io enable bits in vconfig to allow for + * the test above next time. + */ + if (offset == PCI_COMMAND) { + u16 mask = PCI_COMMAND_MEMORY | PCI_COMMAND_IO; + + *virt_cmd &= cpu_to_le16(~mask); + *virt_cmd |= cpu_to_le16(new_cmd & mask); + } + + /* Emulate INTx disable */ + if (offset >= PCI_COMMAND && offset <= PCI_COMMAND + 1) { + bool virt_intx_disable; + + virt_intx_disable = !!(le16_to_cpu(*virt_cmd) & + PCI_COMMAND_INTX_DISABLE); + + if (virt_intx_disable && !vdev->virq_disabled) { + vdev->virq_disabled = true; + vfio_pci_intx_mask(vdev); + } else if (!virt_intx_disable && vdev->virq_disabled) { + vdev->virq_disabled = false; + vfio_pci_intx_unmask(vdev); + } + } + + if (is_bar(offset)) + vdev->bardirty = true; + + return count; +} + +/* Permissions for the Basic PCI Header */ +static int __init init_pci_cap_basic_perm(struct perm_bits *perm) +{ + if (alloc_perm_bits(perm, PCI_STD_HEADER_SIZEOF)) + return -ENOMEM; + + perm->readfn = vfio_basic_config_read; + perm->writefn = vfio_basic_config_write; + + /* Virtualized for SR-IOV functions, which just have FFFF */ + p_setw(perm, PCI_VENDOR_ID, (u16)ALL_VIRT, NO_WRITE); + p_setw(perm, PCI_DEVICE_ID, (u16)ALL_VIRT, NO_WRITE); + + /* + * Virtualize INTx disable, we use it internally for interrupt + * control and can emulate it for non-PCI 2.3 devices. + */ + p_setw(perm, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE, (u16)ALL_WRITE); + + /* Virtualize capability list, we might want to skip/disable */ + p_setw(perm, PCI_STATUS, PCI_STATUS_CAP_LIST, NO_WRITE); + + /* No harm to write */ + p_setb(perm, PCI_CACHE_LINE_SIZE, NO_VIRT, (u8)ALL_WRITE); + p_setb(perm, PCI_LATENCY_TIMER, NO_VIRT, (u8)ALL_WRITE); + p_setb(perm, PCI_BIST, NO_VIRT, (u8)ALL_WRITE); + + /* Virtualize all bars, can't touch the real ones */ + p_setd(perm, PCI_BASE_ADDRESS_0, ALL_VIRT, ALL_WRITE); + p_setd(perm, PCI_BASE_ADDRESS_1, ALL_VIRT, ALL_WRITE); + p_setd(perm, PCI_BASE_ADDRESS_2, ALL_VIRT, ALL_WRITE); + p_setd(perm, PCI_BASE_ADDRESS_3, ALL_VIRT, ALL_WRITE); + p_setd(perm, PCI_BASE_ADDRESS_4, ALL_VIRT, ALL_WRITE); + p_setd(perm, PCI_BASE_ADDRESS_5, ALL_VIRT, ALL_WRITE); + p_setd(perm, PCI_ROM_ADDRESS, ALL_VIRT, ALL_WRITE); + + /* Allow us to adjust capability chain */ + p_setb(perm, PCI_CAPABILITY_LIST, (u8)ALL_VIRT, NO_WRITE); + + /* Sometimes used by sw, just virtualize */ + p_setb(perm, PCI_INTERRUPT_LINE, (u8)ALL_VIRT, (u8)ALL_WRITE); + return 0; +} + +/* Permissions for the Power Management capability */ +static int __init init_pci_cap_pm_perm(struct perm_bits *perm) +{ + if (alloc_perm_bits(perm, pci_cap_length[PCI_CAP_ID_PM])) + return -ENOMEM; + + /* + * We always virtualize the next field so we can remove + * capabilities from the chain if we want to. + */ + p_setb(perm, PCI_CAP_LIST_NEXT, (u8)ALL_VIRT, NO_WRITE); + + /* + * Power management is defined *per function*, + * so we let the user write this + */ + p_setd(perm, PCI_PM_CTRL, NO_VIRT, ALL_WRITE); + return 0; +} + +/* Permissions for PCI-X capability */ +static int __init init_pci_cap_pcix_perm(struct perm_bits *perm) +{ + /* Alloc 24, but only 8 are used in v0 */ + if (alloc_perm_bits(perm, PCI_CAP_PCIX_SIZEOF_V2)) + return -ENOMEM; + + p_setb(perm, PCI_CAP_LIST_NEXT, (u8)ALL_VIRT, NO_WRITE); + + p_setw(perm, PCI_X_CMD, NO_VIRT, (u16)ALL_WRITE); + p_setd(perm, PCI_X_ECC_CSR, NO_VIRT, ALL_WRITE); + return 0; +} + +/* Permissions for PCI Express capability */ +static int __init init_pci_cap_exp_perm(struct perm_bits *perm) +{ + /* Alloc larger of two possible sizes */ + if (alloc_perm_bits(perm, PCI_CAP_EXP_ENDPOINT_SIZEOF_V2)) + return -ENOMEM; + + p_setb(perm, PCI_CAP_LIST_NEXT, (u8)ALL_VIRT, NO_WRITE); + + /* + * Allow writes to device control fields (includes FLR!) + * but not to devctl_phantom which could confuse IOMMU + * or to the ARI bit in devctl2 which is set at probe time + */ + p_setw(perm, PCI_EXP_DEVCTL, NO_VIRT, ~PCI_EXP_DEVCTL_PHANTOM); + p_setw(perm, PCI_EXP_DEVCTL2, NO_VIRT, ~PCI_EXP_DEVCTL2_ARI); + return 0; +} + +/* Permissions for Advanced Function capability */ +static int __init init_pci_cap_af_perm(struct perm_bits *perm) +{ + if (alloc_perm_bits(perm, pci_cap_length[PCI_CAP_ID_AF])) + return -ENOMEM; + + p_setb(perm, PCI_CAP_LIST_NEXT, (u8)ALL_VIRT, NO_WRITE); + p_setb(perm, PCI_AF_CTRL, NO_VIRT, PCI_AF_CTRL_FLR); + return 0; +} + +/* Permissions for Advanced Error Reporting extended capability */ +static int __init init_pci_ext_cap_err_perm(struct perm_bits *perm) +{ + u32 mask; + + if (alloc_perm_bits(perm, pci_ext_cap_length[PCI_EXT_CAP_ID_ERR])) + return -ENOMEM; + + /* + * Virtualize the first dword of all express capabilities + * because it includes the next pointer. This lets us later + * remove capabilities from the chain if we need to. + */ + p_setd(perm, 0, ALL_VIRT, NO_WRITE); + + /* Writable bits mask */ + mask = PCI_ERR_UNC_TRAIN | /* Training */ + PCI_ERR_UNC_DLP | /* Data Link Protocol */ + PCI_ERR_UNC_SURPDN | /* Surprise Down */ + PCI_ERR_UNC_POISON_TLP | /* Poisoned TLP */ + PCI_ERR_UNC_FCP | /* Flow Control Protocol */ + PCI_ERR_UNC_COMP_TIME | /* Completion Timeout */ + PCI_ERR_UNC_COMP_ABORT | /* Completer Abort */ + PCI_ERR_UNC_UNX_COMP | /* Unexpected Completion */ + PCI_ERR_UNC_RX_OVER | /* Receiver Overflow */ + PCI_ERR_UNC_MALF_TLP | /* Malformed TLP */ + PCI_ERR_UNC_ECRC | /* ECRC Error Status */ + PCI_ERR_UNC_UNSUP | /* Unsupported Request */ + PCI_ERR_UNC_ACSV | /* ACS Violation */ + PCI_ERR_UNC_INTN | /* internal error */ + PCI_ERR_UNC_MCBTLP | /* MC blocked TLP */ + PCI_ERR_UNC_ATOMEG | /* Atomic egress blocked */ + PCI_ERR_UNC_TLPPRE; /* TLP prefix blocked */ + p_setd(perm, PCI_ERR_UNCOR_STATUS, NO_VIRT, mask); + p_setd(perm, PCI_ERR_UNCOR_MASK, NO_VIRT, mask); + p_setd(perm, PCI_ERR_UNCOR_SEVER, NO_VIRT, mask); + + mask = PCI_ERR_COR_RCVR | /* Receiver Error Status */ + PCI_ERR_COR_BAD_TLP | /* Bad TLP Status */ + PCI_ERR_COR_BAD_DLLP | /* Bad DLLP Status */ + PCI_ERR_COR_REP_ROLL | /* REPLAY_NUM Rollover */ + PCI_ERR_COR_REP_TIMER | /* Replay Timer Timeout */ + PCI_ERR_COR_ADV_NFAT | /* Advisory Non-Fatal */ + PCI_ERR_COR_INTERNAL | /* Corrected Internal */ + PCI_ERR_COR_LOG_OVER; /* Header Log Overflow */ + p_setd(perm, PCI_ERR_COR_STATUS, NO_VIRT, mask); + p_setd(perm, PCI_ERR_COR_MASK, NO_VIRT, mask); + + mask = PCI_ERR_CAP_ECRC_GENE | /* ECRC Generation Enable */ + PCI_ERR_CAP_ECRC_CHKE; /* ECRC Check Enable */ + p_setd(perm, PCI_ERR_CAP, NO_VIRT, mask); + return 0; +} + +/* Permissions for Power Budgeting extended capability */ +static int __init init_pci_ext_cap_pwr_perm(struct perm_bits *perm) +{ + if (alloc_perm_bits(perm, pci_ext_cap_length[PCI_EXT_CAP_ID_PWR])) + return -ENOMEM; + + p_setd(perm, 0, ALL_VIRT, NO_WRITE); + + /* Writing the data selector is OK, the info is still read-only */ + p_setb(perm, PCI_PWR_DATA, NO_VIRT, (u8)ALL_WRITE); + return 0; +} + +/* + * Initialize the shared permission tables + */ +void vfio_pci_uninit_perm_bits(void) +{ + free_perm_bits(&cap_perms[PCI_CAP_ID_BASIC]); + + free_perm_bits(&cap_perms[PCI_CAP_ID_PM]); + free_perm_bits(&cap_perms[PCI_CAP_ID_PCIX]); + free_perm_bits(&cap_perms[PCI_CAP_ID_EXP]); + free_perm_bits(&cap_perms[PCI_CAP_ID_AF]); + + free_perm_bits(&ecap_perms[PCI_EXT_CAP_ID_ERR]); + free_perm_bits(&ecap_perms[PCI_EXT_CAP_ID_PWR]); +} + +int __init vfio_pci_init_perm_bits(void) +{ + int ret; + + /* Basic config space */ + ret = init_pci_cap_basic_perm(&cap_perms[PCI_CAP_ID_BASIC]); + + /* Capabilities */ + ret |= init_pci_cap_pm_perm(&cap_perms[PCI_CAP_ID_PM]); + cap_perms[PCI_CAP_ID_VPD].writefn = vfio_direct_config_write; + ret |= init_pci_cap_pcix_perm(&cap_perms[PCI_CAP_ID_PCIX]); + cap_perms[PCI_CAP_ID_VNDR].writefn = vfio_direct_config_write; + ret |= init_pci_cap_exp_perm(&cap_perms[PCI_CAP_ID_EXP]); + ret |= init_pci_cap_af_perm(&cap_perms[PCI_CAP_ID_AF]); + + /* Extended capabilities */ + ret |= init_pci_ext_cap_err_perm(&ecap_perms[PCI_EXT_CAP_ID_ERR]); + ret |= init_pci_ext_cap_pwr_perm(&ecap_perms[PCI_EXT_CAP_ID_PWR]); + ecap_perms[PCI_EXT_CAP_ID_VNDR].writefn = vfio_direct_config_write; + + if (ret) + vfio_pci_uninit_perm_bits(); + + return ret; +} + +static int vfio_find_cap_start(struct vfio_pci_device *vdev, int pos) +{ + u8 cap; + int base = (pos >= PCI_CFG_SPACE_SIZE) ? PCI_CFG_SPACE_SIZE : + PCI_STD_HEADER_SIZEOF; + base /= 4; + pos /= 4; + + cap = vdev->pci_config_map[pos]; + + if (cap == PCI_CAP_ID_BASIC) + return 0; + + /* XXX Can we have to abutting capabilities of the same type? */ + while (pos - 1 >= base && vdev->pci_config_map[pos - 1] == cap) + pos--; + + return pos * 4; +} + +static int vfio_msi_config_read(struct vfio_pci_device *vdev, int pos, + int count, struct perm_bits *perm, + int offset, __le32 *val) +{ + /* Update max available queue size from msi_qmax */ + if (offset <= PCI_MSI_FLAGS && offset + count >= PCI_MSI_FLAGS) { + __le16 *flags; + int start; + + start = vfio_find_cap_start(vdev, pos); + + flags = (__le16 *)&vdev->vconfig[start]; + + *flags &= cpu_to_le16(~PCI_MSI_FLAGS_QMASK); + *flags |= cpu_to_le16(vdev->msi_qmax << 1); + } + + return vfio_default_config_read(vdev, pos, count, perm, offset, val); +} + +static int vfio_msi_config_write(struct vfio_pci_device *vdev, int pos, + int count, struct perm_bits *perm, + int offset, __le32 val) +{ + count = vfio_default_config_write(vdev, pos, count, perm, offset, val); + if (count < 0) + return count; + + /* Fixup and write configured queue size and enable to hardware */ + if (offset <= PCI_MSI_FLAGS && offset + count >= PCI_MSI_FLAGS) { + __le16 *pflags; + u16 flags; + int start, ret; + + start = vfio_find_cap_start(vdev, pos); + + pflags = (__le16 *)&vdev->vconfig[start + PCI_MSI_FLAGS]; + + flags = le16_to_cpu(*pflags); + + /* MSI is enabled via ioctl */ + if (!is_msi(vdev)) + flags &= ~PCI_MSI_FLAGS_ENABLE; + + /* Check queue size */ + if ((flags & PCI_MSI_FLAGS_QSIZE) >> 4 > vdev->msi_qmax) { + flags &= ~PCI_MSI_FLAGS_QSIZE; + flags |= vdev->msi_qmax << 4; + } + + /* Write back to virt and to hardware */ + *pflags = cpu_to_le16(flags); + ret = pci_user_write_config_word(vdev->pdev, + start + PCI_MSI_FLAGS, + flags); + if (ret) + return pcibios_err_to_errno(ret); + } + + return count; +} + +/* + * MSI determination is per-device, so this routine gets used beyond + * initialization time. Don't add __init + */ +static int init_pci_cap_msi_perm(struct perm_bits *perm, int len, u16 flags) +{ + if (alloc_perm_bits(perm, len)) + return -ENOMEM; + + perm->readfn = vfio_msi_config_read; + perm->writefn = vfio_msi_config_write; + + p_setb(perm, PCI_CAP_LIST_NEXT, (u8)ALL_VIRT, NO_WRITE); + + /* + * The upper byte of the control register is reserved, + * just setup the lower byte. + */ + p_setb(perm, PCI_MSI_FLAGS, (u8)ALL_VIRT, (u8)ALL_WRITE); + p_setd(perm, PCI_MSI_ADDRESS_LO, ALL_VIRT, ALL_WRITE); + if (flags & PCI_MSI_FLAGS_64BIT) { + p_setd(perm, PCI_MSI_ADDRESS_HI, ALL_VIRT, ALL_WRITE); + p_setw(perm, PCI_MSI_DATA_64, (u16)ALL_VIRT, (u16)ALL_WRITE); + if (flags & PCI_MSI_FLAGS_MASKBIT) { + p_setd(perm, PCI_MSI_MASK_64, NO_VIRT, ALL_WRITE); + p_setd(perm, PCI_MSI_PENDING_64, NO_VIRT, ALL_WRITE); + } + } else { + p_setw(perm, PCI_MSI_DATA_32, (u16)ALL_VIRT, (u16)ALL_WRITE); + if (flags & PCI_MSI_FLAGS_MASKBIT) { + p_setd(perm, PCI_MSI_MASK_32, NO_VIRT, ALL_WRITE); + p_setd(perm, PCI_MSI_PENDING_32, NO_VIRT, ALL_WRITE); + } + } + return 0; +} + +/* Determine MSI CAP field length; initialize msi_perms on 1st call per vdev */ +static int vfio_msi_cap_len(struct vfio_pci_device *vdev, u8 pos) +{ + struct pci_dev *pdev = vdev->pdev; + int len, ret; + u16 flags; + + ret = pci_read_config_word(pdev, pos + PCI_MSI_FLAGS, &flags); + if (ret) + return pcibios_err_to_errno(ret); + + len = 10; /* Minimum size */ + if (flags & PCI_MSI_FLAGS_64BIT) + len += 4; + if (flags & PCI_MSI_FLAGS_MASKBIT) + len += 10; + + if (vdev->msi_perm) + return len; + + vdev->msi_perm = kmalloc(sizeof(struct perm_bits), GFP_KERNEL); + if (!vdev->msi_perm) + return -ENOMEM; + + ret = init_pci_cap_msi_perm(vdev->msi_perm, len, flags); + if (ret) + return ret; + + return len; +} + +/* Determine extended capability length for VC (2 & 9) and MFVC */ +static int vfio_vc_cap_len(struct vfio_pci_device *vdev, u16 pos) +{ + struct pci_dev *pdev = vdev->pdev; + u32 tmp; + int ret, evcc, phases, vc_arb; + int len = PCI_CAP_VC_BASE_SIZEOF; + + ret = pci_read_config_dword(pdev, pos + PCI_VC_PORT_REG1, &tmp); + if (ret) + return pcibios_err_to_errno(ret); + + evcc = tmp & PCI_VC_REG1_EVCC; /* extended vc count */ + ret = pci_read_config_dword(pdev, pos + PCI_VC_PORT_REG2, &tmp); + if (ret) + return pcibios_err_to_errno(ret); + + if (tmp & PCI_VC_REG2_128_PHASE) + phases = 128; + else if (tmp & PCI_VC_REG2_64_PHASE) + phases = 64; + else if (tmp & PCI_VC_REG2_32_PHASE) + phases = 32; + else + phases = 0; + + vc_arb = phases * 4; + + /* + * Port arbitration tables are root & switch only; + * function arbitration tables are function 0 only. + * In either case, we'll never let user write them so + * we don't care how big they are + */ + len += (1 + evcc) * PCI_CAP_VC_PER_VC_SIZEOF; + if (vc_arb) { + len = round_up(len, 16); + len += vc_arb / 8; + } + return len; +} + +static int vfio_cap_len(struct vfio_pci_device *vdev, u8 cap, u8 pos) +{ + struct pci_dev *pdev = vdev->pdev; + u16 word; + u8 byte; + int ret; + + switch (cap) { + case PCI_CAP_ID_MSI: + return vfio_msi_cap_len(vdev, pos); + case PCI_CAP_ID_PCIX: + ret = pci_read_config_word(pdev, pos + PCI_X_CMD, &word); + if (ret) + return pcibios_err_to_errno(ret); + + if (PCI_X_CMD_VERSION(word)) { + vdev->extended_caps = true; + return PCI_CAP_PCIX_SIZEOF_V2; + } else + return PCI_CAP_PCIX_SIZEOF_V0; + case PCI_CAP_ID_VNDR: + /* length follows next field */ + ret = pci_read_config_byte(pdev, pos + PCI_CAP_FLAGS, &byte); + if (ret) + return pcibios_err_to_errno(ret); + + return byte; + case PCI_CAP_ID_EXP: + /* length based on version */ + ret = pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, &word); + if (ret) + return pcibios_err_to_errno(ret); + + if ((word & PCI_EXP_FLAGS_VERS) == 1) + return PCI_CAP_EXP_ENDPOINT_SIZEOF_V1; + else { + vdev->extended_caps = true; + return PCI_CAP_EXP_ENDPOINT_SIZEOF_V2; + } + case PCI_CAP_ID_HT: + ret = pci_read_config_byte(pdev, pos + 3, &byte); + if (ret) + return pcibios_err_to_errno(ret); + + return (byte & HT_3BIT_CAP_MASK) ? + HT_CAP_SIZEOF_SHORT : HT_CAP_SIZEOF_LONG; + case PCI_CAP_ID_SATA: + ret = pci_read_config_byte(pdev, pos + PCI_SATA_REGS, &byte); + if (ret) + return pcibios_err_to_errno(ret); + + byte &= PCI_SATA_REGS_MASK; + if (byte == PCI_SATA_REGS_INLINE) + return PCI_SATA_SIZEOF_LONG; + else + return PCI_SATA_SIZEOF_SHORT; + default: + pr_warn("%s: %s unknown length for pci cap 0x%x@0x%x\n", + dev_name(&pdev->dev), __func__, cap, pos); + } + + return 0; +} + +static int vfio_ext_cap_len(struct vfio_pci_device *vdev, u16 ecap, u16 epos) +{ + struct pci_dev *pdev = vdev->pdev; + u8 byte; + u32 dword; + int ret; + + switch (ecap) { + case PCI_EXT_CAP_ID_VNDR: + ret = pci_read_config_dword(pdev, epos + PCI_VSEC_HDR, &dword); + if (ret) + return pcibios_err_to_errno(ret); + + return dword >> PCI_VSEC_HDR_LEN_SHIFT; + case PCI_EXT_CAP_ID_VC: + case PCI_EXT_CAP_ID_VC9: + case PCI_EXT_CAP_ID_MFVC: + return vfio_vc_cap_len(vdev, epos); + case PCI_EXT_CAP_ID_ACS: + ret = pci_read_config_byte(pdev, epos + PCI_ACS_CAP, &byte); + if (ret) + return pcibios_err_to_errno(ret); + + if (byte & PCI_ACS_EC) { + int bits; + + ret = pci_read_config_byte(pdev, + epos + PCI_ACS_EGRESS_BITS, + &byte); + if (ret) + return pcibios_err_to_errno(ret); + + bits = byte ? round_up(byte, 32) : 256; + return 8 + (bits / 8); + } + return 8; + + case PCI_EXT_CAP_ID_REBAR: + ret = pci_read_config_byte(pdev, epos + PCI_REBAR_CTRL, &byte); + if (ret) + return pcibios_err_to_errno(ret); + + byte &= PCI_REBAR_CTRL_NBAR_MASK; + byte >>= PCI_REBAR_CTRL_NBAR_SHIFT; + + return 4 + (byte * 8); + case PCI_EXT_CAP_ID_DPA: + ret = pci_read_config_byte(pdev, epos + PCI_DPA_CAP, &byte); + if (ret) + return pcibios_err_to_errno(ret); + + byte &= PCI_DPA_CAP_SUBSTATE_MASK; + byte = round_up(byte + 1, 4); + return PCI_DPA_BASE_SIZEOF + byte; + case PCI_EXT_CAP_ID_TPH: + ret = pci_read_config_dword(pdev, epos + PCI_TPH_CAP, &dword); + if (ret) + return pcibios_err_to_errno(ret); + + if ((dword & PCI_TPH_CAP_LOC_MASK) == PCI_TPH_LOC_CAP) { + int sts; + + sts = byte & PCI_TPH_CAP_ST_MASK; + sts >>= PCI_TPH_CAP_ST_SHIFT; + return PCI_TPH_BASE_SIZEOF + round_up(sts * 2, 4); + } + return PCI_TPH_BASE_SIZEOF; + default: + pr_warn("%s: %s unknown length for pci ecap 0x%x@0x%x\n", + dev_name(&pdev->dev), __func__, ecap, epos); + } + + return 0; +} + +static int vfio_fill_vconfig_bytes(struct vfio_pci_device *vdev, + int offset, int size) +{ + struct pci_dev *pdev = vdev->pdev; + int ret = 0; + + /* + * We try to read physical config space in the largest chunks + * we can, assuming that all of the fields support dword access. + * pci_save_state() makes this same assumption and seems to do ok. + */ + while (size) { + int filled; + + if (size >= 4 && !(offset % 4)) { + __le32 *dwordp = (__le32 *)&vdev->vconfig[offset]; + u32 dword; + + ret = pci_read_config_dword(pdev, offset, &dword); + if (ret) + return ret; + *dwordp = cpu_to_le32(dword); + filled = 4; + } else if (size >= 2 && !(offset % 2)) { + __le16 *wordp = (__le16 *)&vdev->vconfig[offset]; + u16 word; + + ret = pci_read_config_word(pdev, offset, &word); + if (ret) + return ret; + *wordp = cpu_to_le16(word); + filled = 2; + } else { + u8 *byte = &vdev->vconfig[offset]; + ret = pci_read_config_byte(pdev, offset, byte); + if (ret) + return ret; + filled = 1; + } + + offset += filled; + size -= filled; + } + + return ret; +} + +static int vfio_cap_init(struct vfio_pci_device *vdev) +{ + struct pci_dev *pdev = vdev->pdev; + u8 *map = vdev->pci_config_map; + u16 status; + u8 pos, *prev, cap; + int loops, ret, caps = 0; + + /* Any capabilities? */ + ret = pci_read_config_word(pdev, PCI_STATUS, &status); + if (ret) + return ret; + + if (!(status & PCI_STATUS_CAP_LIST)) + return 0; /* Done */ + + ret = pci_read_config_byte(pdev, PCI_CAPABILITY_LIST, &pos); + if (ret) + return ret; + + /* Mark the previous position in case we want to skip a capability */ + prev = &vdev->vconfig[PCI_CAPABILITY_LIST]; + + /* We can bound our loop, capabilities are dword aligned */ + loops = (PCI_CFG_SPACE_SIZE - PCI_STD_HEADER_SIZEOF) / PCI_CAP_SIZEOF; + while (pos && loops--) { + u8 next; + int i, len = 0; + + ret = pci_read_config_byte(pdev, pos, &cap); + if (ret) + return ret; + + ret = pci_read_config_byte(pdev, + pos + PCI_CAP_LIST_NEXT, &next); + if (ret) + return ret; + + if (cap <= PCI_CAP_ID_MAX) { + len = pci_cap_length[cap]; + if (len == 0xFF) { /* Variable length */ + len = vfio_cap_len(vdev, cap, pos); + if (len < 0) + return len; + } + } + + if (!len) { + pr_info("%s: %s hiding cap 0x%x\n", + __func__, dev_name(&pdev->dev), cap); + *prev = next; + pos = next; + continue; + } + + /* Sanity check, do we overlap other capabilities? */ + for (i = 0; i < len; i += 4) { + if (likely(map[(pos + i) / 4] == PCI_CAP_ID_INVALID)) + continue; + + pr_warn("%s: %s pci config conflict @0x%x, was cap 0x%x now cap 0x%x\n", + __func__, dev_name(&pdev->dev), + pos + i, map[pos + i], cap); + } + + memset(map + (pos / 4), cap, len / 4); + ret = vfio_fill_vconfig_bytes(vdev, pos, len); + if (ret) + return ret; + + prev = &vdev->vconfig[pos + PCI_CAP_LIST_NEXT]; + pos = next; + caps++; + } + + /* If we didn't fill any capabilities, clear the status flag */ + if (!caps) { + __le16 *vstatus = (__le16 *)&vdev->vconfig[PCI_STATUS]; + *vstatus &= ~cpu_to_le16(PCI_STATUS_CAP_LIST); + } + + return 0; +} + +static int vfio_ecap_init(struct vfio_pci_device *vdev) +{ + struct pci_dev *pdev = vdev->pdev; + u8 *map = vdev->pci_config_map; + u16 epos; + __le32 *prev = NULL; + int loops, ret, ecaps = 0; + + if (!vdev->extended_caps) + return 0; + + epos = PCI_CFG_SPACE_SIZE; + + loops = (pdev->cfg_size - PCI_CFG_SPACE_SIZE) / PCI_CAP_SIZEOF; + + while (loops-- && epos >= PCI_CFG_SPACE_SIZE) { + u32 header; + u16 ecap; + int i, len = 0; + bool hidden = false; + + ret = pci_read_config_dword(pdev, epos, &header); + if (ret) + return ret; + + ecap = PCI_EXT_CAP_ID(header); + + if (ecap <= PCI_EXT_CAP_ID_MAX) { + len = pci_ext_cap_length[ecap]; + if (len == 0xFF) { + len = vfio_ext_cap_len(vdev, ecap, epos); + if (len < 0) + return ret; + } + } + + if (!len) { + pr_info("%s: %s hiding ecap 0x%x@0x%x\n", + __func__, dev_name(&pdev->dev), ecap, epos); + + /* If not the first in the chain, we can skip over it */ + if (prev) { + u32 val = epos = PCI_EXT_CAP_NEXT(header); + *prev &= cpu_to_le32(~(0xffcU << 20)); + *prev |= cpu_to_le32(val << 20); + continue; + } + + /* + * Otherwise, fill in a placeholder, the direct + * readfn will virtualize this automatically + */ + len = PCI_CAP_SIZEOF; + hidden = true; + } + + for (i = 0; i < len; i += 4) { + if (likely(map[(epos + i) / 4] == PCI_CAP_ID_INVALID)) + continue; + + pr_warn("%s: %s pci config conflict @0x%x, was ecap 0x%x now ecap 0x%x\n", + __func__, dev_name(&pdev->dev), + epos + i, map[epos + i], ecap); + } + + /* + * Even though ecap is 2 bytes, we're currently a long way + * from exceeding 1 byte capabilities. If we ever make it + * up to 0xFF we'll need to up this to a two-byte, byte map. + */ + BUILD_BUG_ON(PCI_EXT_CAP_ID_MAX >= PCI_CAP_ID_INVALID); + + memset(map + (epos / 4), ecap, len / 4); + ret = vfio_fill_vconfig_bytes(vdev, epos, len); + if (ret) + return ret; + + /* + * If we're just using this capability to anchor the list, + * hide the real ID. Only count real ecaps. XXX PCI spec + * indicates to use cap id = 0, version = 0, next = 0 if + * ecaps are absent, hope users check all the way to next. + */ + if (hidden) + *(__le32 *)&vdev->vconfig[epos] &= + cpu_to_le32((0xffcU << 20)); + else + ecaps++; + + prev = (__le32 *)&vdev->vconfig[epos]; + epos = PCI_EXT_CAP_NEXT(header); + } + + if (!ecaps) + *(u32 *)&vdev->vconfig[PCI_CFG_SPACE_SIZE] = 0; + + return 0; +} + +/* + * For each device we allocate a pci_config_map that indicates the + * capability occupying each dword and thus the struct perm_bits we + * use for read and write. We also allocate a virtualized config + * space which tracks reads and writes to bits that we emulate for + * the user. Initial values filled from device. + * + * Using shared stuct perm_bits between all vfio-pci devices saves + * us from allocating cfg_size buffers for virt and write for every + * device. We could remove vconfig and allocate individual buffers + * for each area requring emulated bits, but the array of pointers + * would be comparable in size (at least for standard config space). + */ +int vfio_config_init(struct vfio_pci_device *vdev) +{ + struct pci_dev *pdev = vdev->pdev; + u8 *map, *vconfig; + int ret; + + /* + * Config space, caps and ecaps are all dword aligned, so we can + * use one byte per dword to record the type. + */ + map = kmalloc(pdev->cfg_size / 4, GFP_KERNEL); + if (!map) + return -ENOMEM; + + vconfig = kmalloc(pdev->cfg_size, GFP_KERNEL); + if (!vconfig) { + kfree(map); + return -ENOMEM; + } + + vdev->pci_config_map = map; + vdev->vconfig = vconfig; + + memset(map, PCI_CAP_ID_BASIC, PCI_STD_HEADER_SIZEOF / 4); + memset(map + (PCI_STD_HEADER_SIZEOF / 4), PCI_CAP_ID_INVALID, + (pdev->cfg_size - PCI_STD_HEADER_SIZEOF) / 4); + + ret = vfio_fill_vconfig_bytes(vdev, 0, PCI_STD_HEADER_SIZEOF); + if (ret) + goto out; + + vdev->bardirty = true; + + /* + * XXX can we just pci_load_saved_state/pci_restore_state? + * may need to rebuild vconfig after that + */ + + /* For restore after reset */ + vdev->rbar[0] = le32_to_cpu(*(__le32 *)&vconfig[PCI_BASE_ADDRESS_0]); + vdev->rbar[1] = le32_to_cpu(*(__le32 *)&vconfig[PCI_BASE_ADDRESS_1]); + vdev->rbar[2] = le32_to_cpu(*(__le32 *)&vconfig[PCI_BASE_ADDRESS_2]); + vdev->rbar[3] = le32_to_cpu(*(__le32 *)&vconfig[PCI_BASE_ADDRESS_3]); + vdev->rbar[4] = le32_to_cpu(*(__le32 *)&vconfig[PCI_BASE_ADDRESS_4]); + vdev->rbar[5] = le32_to_cpu(*(__le32 *)&vconfig[PCI_BASE_ADDRESS_5]); + vdev->rbar[6] = le32_to_cpu(*(__le32 *)&vconfig[PCI_ROM_ADDRESS]); + + if (pdev->is_virtfn) { + *(__le16 *)&vconfig[PCI_VENDOR_ID] = cpu_to_le16(pdev->vendor); + *(__le16 *)&vconfig[PCI_DEVICE_ID] = cpu_to_le16(pdev->device); + } + + ret = vfio_cap_init(vdev); + if (ret) + goto out; + + ret = vfio_ecap_init(vdev); + if (ret) + goto out; + + return 0; + +out: + kfree(map); + vdev->pci_config_map = NULL; + kfree(vconfig); + vdev->vconfig = NULL; + return pcibios_err_to_errno(ret); +} + +void vfio_config_free(struct vfio_pci_device *vdev) +{ + kfree(vdev->vconfig); + vdev->vconfig = NULL; + kfree(vdev->pci_config_map); + vdev->pci_config_map = NULL; + kfree(vdev->msi_perm); + vdev->msi_perm = NULL; +} + +static ssize_t vfio_config_do_rw(struct vfio_pci_device *vdev, char __user *buf, + size_t count, loff_t *ppos, bool iswrite) +{ + struct pci_dev *pdev = vdev->pdev; + struct perm_bits *perm; + __le32 val = 0; + int cap_start = 0, offset; + u8 cap_id; + ssize_t ret = count; + + if (*ppos < 0 || *ppos + count > pdev->cfg_size) + return -EFAULT; + + /* + * gcc can't seem to figure out we're a static function, only called + * with count of 1/2/4 and hits copy_from_user_overflow without this. + */ + if (count > sizeof(val)) + return -EINVAL; + + cap_id = vdev->pci_config_map[*ppos / 4]; + + if (cap_id == PCI_CAP_ID_INVALID) { + if (iswrite) + return ret; /* drop */ + + /* + * Per PCI spec 3.0, section 6.1, reads from reserved and + * unimplemented registers return 0 + */ + if (copy_to_user(buf, &val, count)) + return -EFAULT; + + return ret; + } + + /* + * All capabilities are minimum 4 bytes and aligned on dword + * boundaries. Since we don't support unaligned accesses, we're + * only ever accessing a single capability. + */ + if (*ppos >= PCI_CFG_SPACE_SIZE) { + WARN_ON(cap_id > PCI_EXT_CAP_ID_MAX); + + perm = &ecap_perms[cap_id]; + cap_start = vfio_find_cap_start(vdev, *ppos); + + } else { + WARN_ON(cap_id > PCI_CAP_ID_MAX); + + perm = &cap_perms[cap_id]; + + if (cap_id == PCI_CAP_ID_MSI) + perm = vdev->msi_perm; + + if (cap_id > PCI_CAP_ID_BASIC) + cap_start = vfio_find_cap_start(vdev, *ppos); + } + + WARN_ON(!cap_start && cap_id != PCI_CAP_ID_BASIC); + WARN_ON(cap_start > *ppos); + + offset = *ppos - cap_start; + + if (iswrite) { + if (!perm->writefn) + return ret; + + if (copy_from_user(&val, buf, count)) + return -EFAULT; + + ret = perm->writefn(vdev, *ppos, count, perm, offset, val); + } else { + if (perm->readfn) { + ret = perm->readfn(vdev, *ppos, count, + perm, offset, &val); + if (ret < 0) + return ret; + } + + if (copy_to_user(buf, &val, count)) + return -EFAULT; + } + + return ret; +} + +ssize_t vfio_pci_config_readwrite(struct vfio_pci_device *vdev, + char __user *buf, size_t count, + loff_t *ppos, bool iswrite) +{ + size_t done = 0; + int ret = 0; + loff_t pos = *ppos; + + pos &= VFIO_PCI_OFFSET_MASK; + + /* + * We want to both keep the access size the caller users as well as + * support reading large chunks of config space in a single call. + * PCI doesn't support unaligned accesses, so we can safely break + * those apart. + */ + while (count) { + if (count >= 4 && !(pos % 4)) + ret = vfio_config_do_rw(vdev, buf, 4, &pos, iswrite); + else if (count >= 2 && !(pos % 2)) + ret = vfio_config_do_rw(vdev, buf, 2, &pos, iswrite); + else + ret = vfio_config_do_rw(vdev, buf, 1, &pos, iswrite); + + if (ret < 0) + return ret; + + count -= ret; + done += ret; + buf += ret; + pos += ret; + } + + *ppos += done; + + return done; +} |