/*
* 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 <linux/slab.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;
}
/* 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;
}
/* 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 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;
}
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;
}
/* 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_raw_config_write;
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)
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 */
vdev->extended_caps = true;
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;
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++) {
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);
}
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 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++) {
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 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, 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;
}
/*
* 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 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);
}
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;
}
/*
* 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 (*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;
}