/* * VFIO PCI config space virtualization * * Copyright (C) 2012 Red Hat, Inc. All rights reserved. * Author: Alex Williamson * * 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 #include #include #include #include #include "vfio_pci_private.h" #define PCI_CFG_SPACE_SIZE 256 /* Fake capability ID for standard config space */ #define PCI_CAP_ID_BASIC 0 #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 const u8 pci_cap_length[PCI_CAP_ID_MAX + 1] = { [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 capability list * FF: Variable length */ static const u16 pci_ext_cap_length[PCI_EXT_CAP_ID_MAX + 1] = { [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; } /* Raw access skips any kind of virtualization */ static int vfio_raw_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; } static int vfio_raw_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); return count; } /* Virt access uses only virtualization */ static int vfio_virt_config_write(struct vfio_pci_device *vdev, int pos, int count, struct perm_bits *perm, int offset, __le32 val) { memcpy(vdev->vconfig + pos, &val, count); return count; } static int vfio_virt_config_read(struct vfio_pci_device *vdev, int pos, int count, struct perm_bits *perm, int offset, __le32 *val) { memcpy(val, vdev->vconfig + pos, count); return count; } /* Default capability 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 } }; /* * Default unassigned regions to raw read-write access. Some devices * require this to function as they hide registers between the gaps in * config space (be2net). Like MMIO and I/O port registers, we have * to trust the hardware isolation. */ static struct perm_bits unassigned_perms = { .readfn = vfio_raw_config_read, .writefn = vfio_raw_config_write }; static struct perm_bits virt_perms = { .readfn = vfio_virt_config_read, .writefn = vfio_virt_config_write }; 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 aligned (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); } /* Caller should hold memory_lock semaphore */ bool __vfio_pci_memory_enabled(struct vfio_pci_device *vdev) { struct pci_dev *pdev = vdev->pdev; u16 cmd = le16_to_cpu(*(__le16 *)&vdev->vconfig[PCI_COMMAND]); /* * SR-IOV VF memory enable is handled by the MSE bit in the * PF SR-IOV capability, there's therefore no need to trigger * faults based on the virtual value. */ return pdev->is_virtfn || (cmd & PCI_COMMAND_MEMORY); } /* * 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; u16 cmd; 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); if (vdev->nointx) { pci_user_read_config_word(pdev, PCI_COMMAND, &cmd); cmd |= PCI_COMMAND_INTX_DISABLE; pci_user_write_config_word(pdev, PCI_COMMAND, cmd); } } 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. REGION_INFO will have reported zero size if we weren't able * to read the ROM, but we still return the actual BAR size here if * it exists (or the shadow ROM space). */ 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 if (pdev->resource[PCI_ROM_RESOURCE].flags & IORESOURCE_ROM_SHADOW) { mask = ~(0x20000 - 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; } /* Test whether BARs match the value we think they should contain */ static bool vfio_need_bar_restore(struct vfio_pci_device *vdev) { int i = 0, pos = PCI_BASE_ADDRESS_0, ret; u32 bar; for (; pos <= PCI_BASE_ADDRESS_5; i++, pos += 4) { if (vdev->rbar[i]) { ret = pci_user_read_config_dword(vdev->pdev, pos, &bar); if (ret || vdev->rbar[i] != bar) return true; } } return false; } 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_io = !!(phys_cmd & PCI_COMMAND_IO); virt_io = !!(le16_to_cpu(*virt_cmd) & PCI_COMMAND_IO); new_io = !!(new_cmd & PCI_COMMAND_IO); phys_mem = !!(phys_cmd & PCI_COMMAND_MEMORY); virt_mem = !!(le16_to_cpu(*virt_cmd) & PCI_COMMAND_MEMORY); new_mem = !!(new_cmd & PCI_COMMAND_MEMORY); if (!new_mem) vfio_pci_zap_and_down_write_memory_lock(vdev); else down_write(&vdev->memory_lock); /* * 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_need_bar_restore(vdev)) vfio_bar_restore(vdev); } count = vfio_default_config_write(vdev, pos, count, perm, offset, val); if (count < 0) { if (offset == PCI_COMMAND) up_write(&vdev->memory_lock); 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); up_write(&vdev->memory_lock); } /* 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); /* Virtualize interrupt pin to allow hiding INTx */ p_setb(perm, PCI_INTERRUPT_PIN, (u8)ALL_VIRT, (u8)NO_WRITE); return 0; } static int vfio_pm_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; if (offset == PCI_PM_CTRL) { pci_power_t state; switch (le32_to_cpu(val) & PCI_PM_CTRL_STATE_MASK) { case 0: state = PCI_D0; break; case 1: state = PCI_D1; break; case 2: state = PCI_D2; break; case 3: state = PCI_D3hot; break; } pci_set_power_state(vdev->pdev, state); } return count; } /* 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; perm->writefn = vfio_pm_config_write; /* * 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 can let * the user change power state, but we trap and initiate the * change ourselves, so the state bits are read-only. */ p_setd(perm, PCI_PM_CTRL, NO_VIRT, ~PCI_PM_CTRL_STATE_MASK); return 0; } static int vfio_vpd_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 *paddr = (__le16 *)(vdev->vconfig + pos - offset + PCI_VPD_ADDR); __le32 *pdata = (__le32 *)(vdev->vconfig + pos - offset + PCI_VPD_DATA); u16 addr; u32 data; /* * Write through to emulation. If the write includes the upper byte * of PCI_VPD_ADDR, then the PCI_VPD_ADDR_F bit is written and we * have work to do. */ count = vfio_default_config_write(vdev, pos, count, perm, offset, val); if (count < 0 || offset > PCI_VPD_ADDR + 1 || offset + count <= PCI_VPD_ADDR + 1) return count; addr = le16_to_cpu(*paddr); if (addr & PCI_VPD_ADDR_F) { data = le32_to_cpu(*pdata); if (pci_write_vpd(pdev, addr & ~PCI_VPD_ADDR_F, 4, &data) != 4) return count; } else { data = 0; if (pci_read_vpd(pdev, addr, 4, &data) < 0) return count; *pdata = cpu_to_le32(data); } /* * Toggle PCI_VPD_ADDR_F in the emulated PCI_VPD_ADDR register to * signal completion. If an error occurs above, we assume that not * toggling this bit will induce a driver timeout. */ addr ^= PCI_VPD_ADDR_F; *paddr = cpu_to_le16(addr); return count; } /* Permissions for Vital Product Data capability */ static int __init init_pci_cap_vpd_perm(struct perm_bits *perm) { if (alloc_perm_bits(perm, pci_cap_length[PCI_CAP_ID_VPD])) return -ENOMEM; perm->writefn = vfio_vpd_config_write; /* * 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); /* * Both the address and data registers are virtualized to * enable access through the pci_vpd_read/write functions */ p_setw(perm, PCI_VPD_ADDR, (u16)ALL_VIRT, (u16)ALL_WRITE); p_setd(perm, PCI_VPD_DATA, ALL_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; } static int vfio_exp_config_write(struct vfio_pci_device *vdev, int pos, int count, struct perm_bits *perm, int offset, __le32 val) { __le16 *ctrl = (__le16 *)(vdev->vconfig + pos - offset + PCI_EXP_DEVCTL); int readrq = le16_to_cpu(*ctrl) & PCI_EXP_DEVCTL_READRQ; count = vfio_default_config_write(vdev, pos, count, perm, offset, val); if (count < 0) return count; /* * The FLR bit is virtualized, if set and the device supports PCIe * FLR, issue a reset_function. Regardless, clear the bit, the spec * requires it to be always read as zero. NB, reset_function might * not use a PCIe FLR, we don't have that level of granularity. */ if (*ctrl & cpu_to_le16(PCI_EXP_DEVCTL_BCR_FLR)) { u32 cap; int ret; *ctrl &= ~cpu_to_le16(PCI_EXP_DEVCTL_BCR_FLR); ret = pci_user_read_config_dword(vdev->pdev, pos - offset + PCI_EXP_DEVCAP, &cap); if (!ret && (cap & PCI_EXP_DEVCAP_FLR)) { vfio_pci_zap_and_down_write_memory_lock(vdev); pci_try_reset_function(vdev->pdev); up_write(&vdev->memory_lock); } } /* * MPS is virtualized to the user, writes do not change the physical * register since determining a proper MPS value requires a system wide * device view. The MRRS is largely independent of MPS, but since the * user does not have that system-wide view, they might set a safe, but * inefficiently low value. Here we allow writes through to hardware, * but we set the floor to the physical device MPS setting, so that * we can at least use full TLPs, as defined by the MPS value. * * NB, if any devices actually depend on an artificially low MRRS * setting, this will need to be revisited, perhaps with a quirk * though pcie_set_readrq(). */ if (readrq != (le16_to_cpu(*ctrl) & PCI_EXP_DEVCTL_READRQ)) { readrq = 128 << ((le16_to_cpu(*ctrl) & PCI_EXP_DEVCTL_READRQ) >> 12); readrq = max(readrq, pcie_get_mps(vdev->pdev)); pcie_set_readrq(vdev->pdev, readrq); } return count; } /* 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; perm->writefn = vfio_exp_config_write; p_setb(perm, PCI_CAP_LIST_NEXT, (u8)ALL_VIRT, NO_WRITE); /* * Allow writes to device control fields, except devctl_phantom, * which could confuse IOMMU, MPS, which can break communication * with other physical devices, and the ARI bit in devctl2, which * is set at probe time. FLR and MRRS get virtualized via our * writefn. */ p_setw(perm, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR | PCI_EXP_DEVCTL_PAYLOAD | PCI_EXP_DEVCTL_READRQ, ~PCI_EXP_DEVCTL_PHANTOM); p_setw(perm, PCI_EXP_DEVCTL2, NO_VIRT, ~PCI_EXP_DEVCTL2_ARI); return 0; } static int vfio_af_config_write(struct vfio_pci_device *vdev, int pos, int count, struct perm_bits *perm, int offset, __le32 val) { u8 *ctrl = vdev->vconfig + pos - offset + PCI_AF_CTRL; count = vfio_default_config_write(vdev, pos, count, perm, offset, val); if (count < 0) return count; /* * The FLR bit is virtualized, if set and the device supports AF * FLR, issue a reset_function. Regardless, clear the bit, the spec * requires it to be always read as zero. NB, reset_function might * not use an AF FLR, we don't have that level of granularity. */ if (*ctrl & PCI_AF_CTRL_FLR) { u8 cap; int ret; *ctrl &= ~PCI_AF_CTRL_FLR; ret = pci_user_read_config_byte(vdev->pdev, pos - offset + PCI_AF_CAP, &cap); if (!ret && (cap & PCI_AF_CAP_FLR) && (cap & PCI_AF_CAP_TP)) { vfio_pci_zap_and_down_write_memory_lock(vdev); pci_try_reset_function(vdev->pdev); up_write(&vdev->memory_lock); } } return count; } /* 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; perm->writefn = vfio_af_config_write; p_setb(perm, PCI_CAP_LIST_NEXT, (u8)ALL_VIRT, NO_WRITE); p_setb(perm, PCI_AF_CTRL, PCI_AF_CTRL_FLR, 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_UND | /* Undefined */ 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_VPD]); 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]); ret |= init_pci_cap_vpd_perm(&cap_perms[PCI_CAP_ID_VPD]); ret |= init_pci_cap_pcix_perm(&cap_perms[PCI_CAP_ID_PCIX]); cap_perms[PCI_CAP_ID_VNDR].writefn = vfio_raw_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_raw_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; 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; } 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) { kfree(vdev->msi_perm); 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_CAP1, &tmp); if (ret) return pcibios_err_to_errno(ret); evcc = tmp & PCI_VC_CAP1_EVCC; /* extended vc count */ ret = pci_read_config_dword(pdev, pos + PCI_VC_PORT_CAP2, &tmp); if (ret) return pcibios_err_to_errno(ret); if (tmp & PCI_VC_CAP2_128_PHASE) phases = 128; else if (tmp & PCI_VC_CAP2_64_PHASE) phases = 64; else if (tmp & PCI_VC_CAP2_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; u32 dword; 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)) { if (pdev->cfg_size > PCI_CFG_SPACE_SIZE) { /* Test for extended capabilities */ pci_read_config_dword(pdev, PCI_CFG_SPACE_SIZE, &dword); vdev->extended_caps = (dword != 0); } 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: if (pdev->cfg_size > PCI_CFG_SPACE_SIZE) { /* Test for extended capabilities */ pci_read_config_dword(pdev, PCI_CFG_SPACE_SIZE, &dword); vdev->extended_caps = (dword != 0); } /* length based on version */ if ((pcie_caps_reg(pdev) & PCI_EXP_FLAGS_VERS) == 1) return PCI_CAP_EXP_ENDPOINT_SIZEOF_V1; else 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; return PCI_DPA_BASE_SIZEOF + byte + 1; 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 = dword & PCI_TPH_CAP_ST_MASK; sts >>= PCI_TPH_CAP_ST_SHIFT; return PCI_TPH_BASE_SIZEOF + (sts * 2) + 2; } 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; /* * ID 0 is a NULL capability, conflicting with our fake * PCI_CAP_ID_BASIC. As it has no content, consider it * hidden for now. */ if (cap && 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++) { if (likely(map[pos + i] == 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); } BUILD_BUG_ON(PCI_CAP_ID_MAX >= PCI_CAP_ID_INVALID_VIRT); memset(map + pos, cap, len); 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 len; } } 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++) { if (likely(map[epos + i] == 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 0xFE we'll need to up this to a two-byte, byte map. */ BUILD_BUG_ON(PCI_EXT_CAP_ID_MAX >= PCI_CAP_ID_INVALID_VIRT); memset(map + epos, ecap, len); 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; } /* * Nag about hardware bugs, hopefully to have vendors fix them, but at least * to collect a list of dependencies for the VF INTx pin quirk below. */ static const struct pci_device_id known_bogus_vf_intx_pin[] = { { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x270c) }, {} }; /* * 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 struct 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 requiring 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 could * use one byte per dword to record the type. However, there are * no requiremenst on the length of a capability, so the gap between * capabilities needs byte granularity. */ map = kmalloc(pdev->cfg_size, 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); memset(map + PCI_STD_HEADER_SIZEOF, PCI_CAP_ID_INVALID, pdev->cfg_size - PCI_STD_HEADER_SIZEOF); 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); /* * Per SR-IOV spec rev 1.1, 3.4.1.18 the interrupt pin register * does not apply to VFs and VFs must implement this register * as read-only with value zero. Userspace is not readily able * to identify whether a device is a VF and thus that the pin * definition on the device is bogus should it violate this * requirement. We already virtualize the pin register for * other purposes, so we simply need to replace the bogus value * and consider VFs when we determine INTx IRQ count. */ if (vconfig[PCI_INTERRUPT_PIN] && !pci_match_id(known_bogus_vf_intx_pin, pdev)) pci_warn(pdev, "Hardware bug: VF reports bogus INTx pin %d\n", vconfig[PCI_INTERRUPT_PIN]); vconfig[PCI_INTERRUPT_PIN] = 0; /* Gratuitous for good VFs */ /* * VFs do no implement the memory enable bit of the COMMAND * register therefore we'll not have it set in our initial * copy of config space after pci_enable_device(). For * consistency with PFs, set the virtual enable bit here. */ *(__le16 *)&vconfig[PCI_COMMAND] |= cpu_to_le16(PCI_COMMAND_MEMORY); } if (!IS_ENABLED(CONFIG_VFIO_PCI_INTX) || vdev->nointx) vconfig[PCI_INTERRUPT_PIN] = 0; 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; if (vdev->msi_perm) { free_perm_bits(vdev->msi_perm); kfree(vdev->msi_perm); vdev->msi_perm = NULL; } } /* * Find the remaining number of bytes in a dword that match the given * position. Stop at either the end of the capability or the dword boundary. */ static size_t vfio_pci_cap_remaining_dword(struct vfio_pci_device *vdev, loff_t pos) { u8 cap = vdev->pci_config_map[pos]; size_t i; for (i = 1; (pos + i) % 4 && vdev->pci_config_map[pos + i] == cap; i++) /* nop */; return i; } 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; if (*ppos < 0 || *ppos >= pdev->cfg_size || *ppos + count > pdev->cfg_size) return -EFAULT; /* * Chop accesses into aligned chunks containing no more than a * single capability. Caller increments to the next chunk. */ count = min(count, vfio_pci_cap_remaining_dword(vdev, *ppos)); if (count >= 4 && !(*ppos % 4)) count = 4; else if (count >= 2 && !(*ppos % 2)) count = 2; else count = 1; ret = count; cap_id = vdev->pci_config_map[*ppos]; if (cap_id == PCI_CAP_ID_INVALID) { perm = &unassigned_perms; cap_start = *ppos; } else if (cap_id == PCI_CAP_ID_INVALID_VIRT) { perm = &virt_perms; cap_start = *ppos; } else { 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_rw(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; while (count) { ret = vfio_config_do_rw(vdev, buf, count, &pos, iswrite); if (ret < 0) return ret; count -= ret; done += ret; buf += ret; pos += ret; } *ppos += done; return done; }