Sync code to the same with tk4 pub/lts/0017-kabi, except deleted rue
and wujing. Partners can submit pull requests to this branch, and we
can pick the commits to tk4 pub/lts/0017-kabi easly.
Signed-off-by: Jianping Liu <frankjpliu@tencent.com>
Gitee limit the repo's size to 3GB, to reduce the size of the code,
sync codes to ock 5.4.119-20.0009.21 in one commit.
Signed-off-by: Jianping Liu <frankjpliu@tencent.com>
Based on 2 normalized pattern(s):
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
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 #
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 4122 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use dev_printk() when possible to make messages consistent with other
device-related messages.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
PCI core handles save and restore of device state around reset, but
when using pci_set_power_state() we can unintentionally trigger a soft
reset of the device, where PCI core only restores the BAR state. If
we're using vfio-pci's idle D3 support to try to put devices into low
power when unused, this might trigger a reset when the device is woken
for use. Also power state management by the user, or within a guest,
can put the device into D3 power state with potentially limited
ability to restore the device if it should undergo a reset. The PCI
spec does not define the extent of a soft reset and many devices
reporting soft reset on D3->D0 transition do not undergo a PCI config
space reset. It's therefore assumed safe to unconditionally restore
the remainder of the state if the device indicates soft reset
support, even on a user initiated wakeup.
Implement a wrapper in vfio-pci to tag devices reporting PM reset
support, save their state on transitions into D3 and restore on
transitions back to D0.
Reported-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The SR-IOV spec requires that VFs must report zero for the INTx pin
register as VFs are precluded from INTx support. It's much easier for
the host kernel to understand whether a device is a VF and therefore
whether a non-zero pin register value is bogus than it is to do the
same in userspace. Override the INTx count for such devices and
virtualize the pin register to provide a consistent view of the device
to the user.
As this is clearly a spec violation, warn about it to support hardware
validation, but also provide a known whitelist as it doesn't do much
good to continue complaining if the hardware vendor doesn't plan to
fix it.
Known devices with this issue: 8086:270c
Tested-by: Gage Eads <gage.eads@intel.com>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Free allocated vdev->msi_perm in error path.
Signed-off-by: Li Qiang <liq3ea@gmail.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
MRRS defines the maximum read request size a device is allowed to
make. Drivers will often increase this to allow more data transfer
with a single request. Completions to this request are bound by the
MPS setting for the bus. Aside from device quirks (none known), it
doesn't seem to make sense to set an MRRS value less than MPS, yet
this is a likely scenario given that user drivers do not have a
system-wide view of the PCI topology. Virtualize MRRS such that the
user can set MRRS >= MPS, but use MPS as the floor value that we'll
write to hardware.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
With virtual PCI-Express chipsets, we now see userspace/guest drivers
trying to match the physical MPS setting to a virtual downstream port.
Of course a lone physical device surrounded by virtual interconnects
cannot make a correct decision for a proper MPS setting. Instead,
let's virtualize the MPS control register so that writes through to
hardware are disallowed. Userspace drivers like QEMU assume they can
write anything to the device and we'll filter out anything dangerous.
Since mismatched MPS can lead to AER and other faults, let's add it
to the kernel side rather than relying on userspace virtualization to
handle it.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Root complex integrated endpoints do not have a link and therefore may
use a smaller PCIe capability in config space than we expect when
building our config map. Add a case for these to avoid reporting an
erroneous overlap.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=ut0k
-----END PGP SIGNATURE-----
Merge tag 'pci-v4.10-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
Pull PCI updates from Bjorn Helgaas:
"PCI changes:
- add support for PCI on ARM64 boxes with ACPI. We already had this
for theoretical spec-compliant hardware; now we're adding quirks
for the actual hardware (Cavium, HiSilicon, Qualcomm, X-Gene)
- add runtime PM support for hotplug ports
- enable runtime suspend for Intel UHCI that uses platform-specific
wakeup signaling
- add yet another host bridge registration interface. We hope this is
extensible enough to subsume the others
- expose device revision in sysfs for DRM
- to avoid device conflicts, make sure any VF BAR updates are done
before enabling the VF
- avoid unnecessary link retrains for ASPM
- allow INTx masking on Mellanox devices that support it
- allow access to non-standard VPD for Chelsio devices
- update Broadcom iProc support for PAXB v2, PAXC v2, inbound DMA,
etc
- update Rockchip support for max-link-speed
- add NVIDIA Tegra210 support
- add Layerscape LS1046a support
- update R-Car compatibility strings
- add Qualcomm MSM8996 support
- remove some uninformative bootup messages"
* tag 'pci-v4.10-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (115 commits)
PCI: Enable access to non-standard VPD for Chelsio devices (cxgb3)
PCI: Expand "VPD access disabled" quirk message
PCI: pciehp: Remove loading message
PCI: hotplug: Remove hotplug core message
PCI: Remove service driver load/unload messages
PCI/AER: Log AER IRQ when claiming Root Port
PCI/AER: Log errors with PCI device, not PCIe service device
PCI/AER: Remove unused version macros
PCI/PME: Log PME IRQ when claiming Root Port
PCI/PME: Drop unused support for PMEs from Root Complex Event Collectors
PCI: Move config space size macros to pci_regs.h
x86/platform/intel-mid: Constify mid_pci_platform_pm
PCI/ASPM: Don't retrain link if ASPM not possible
PCI: iproc: Skip check for legacy IRQ on PAXC buses
PCI: pciehp: Leave power indicator on when enabling already-enabled slot
PCI: pciehp: Prioritize data-link event over presence detect
PCI: rcar: Add gen3 fallback compatibility string for pcie-rcar
PCI: rcar: Use gen2 fallback compatibility last
PCI: rcar-gen2: Use gen2 fallback compatibility last
PCI: rockchip: Move the deassert of pm/aclk/pclk after phy_init()
..
Move PCI configuration space size macros (PCI_CFG_SPACE_SIZE and
PCI_CFG_SPACE_EXP_SIZE) from drivers/pci/pci.h to
include/uapi/linux/pci_regs.h so they can be used by more drivers and
eliminate duplicate definitions.
[bhelgaas: Expand comment to include PCI-X details]
Signed-off-by: Wang Sheng-Hui <shhuiw@foxmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
As of commit d97ffe2368 ("PCI: Fix return value from
pci_user_{read,write}_config_*()") it's unnecessary to call
pcibios_err_to_errno() to fixup the return value from these functions.
pcibios_err_to_errno() already does simple passthrough of -errno values,
therefore no functional change is expected.
[aw: changelog]
Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
We use a BAR restore trick to try to detect when a user has performed
a device reset, possibly through FLR or other backdoors, to put things
back into a working state. This is important for backdoor resets, but
we can actually just virtualize the "front door" resets provided via
PCIe and AF FLR. Set these bits as virtualized + writable, allowing
the default write to set them in vconfig, then we can simply check the
bit, perform an FLR of our own, and clear the bit. We don't actually
have the granularity in PCI to specify the type of reset we want to
do, but generally devices don't implement both PCIe and AF FLR and
we'll favor these over other types of reset, so we should generally
lineup. We do test whether the device provides the requested FLR type
to stay consistent with hardware capabilities though.
This seems to fix several instance of devices getting into bad states
with userspace drivers, like dpdk, running inside a VM.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Greg Rose <grose@lightfleet.com>
The size of the VPD area is not necessarily 4-byte aligned, so a
pci_vpd_read() might return less than 4 bytes. Zero our buffer and
accept anything other than an error. Intel X710 NICs exercise this.
Fixes: 4e1a635552 ("vfio/pci: Use kernel VPD access functions")
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
PCI-Express spec says that reading 4 bytes at offset 100h should return
zero if there is no extended capability so VFIO reads this dword to
know if there are extended capabilities.
However it is not always possible to access the extended space so
generic PCI code in pci_cfg_space_size_ext() checks if
pci_read_config_dword() can read beyond 100h and if the check fails,
it sets the config space size to 100h.
VFIO does its own extended capabilities check by reading at offset 100h
which may produce 0xffffffff which VFIO treats as the extended config
space presense and calls vfio_ecap_init() which fails to parse
capabilities (which is expected) but right before the exit, it writes
zero at offset 100h which is beyond the buffer allocated for
vdev->vconfig (which is 256 bytes) which leads to random memory
corruption.
This makes VFIO only check for the extended capabilities if
the discovered config size is more than 256 bytes.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
If a device is reset without the memory or i/o bits enabled in the
command register we may not detect it, potentially leaving the device
without valid BAR programming. Add an additional test to check the
BARs on each write to the command register.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
INTx masking has two components, the first is that we need the ability
to prevent the device from continuing to assert INTx. This is
provided via the DisINTx bit in the command register and is the only
thing we can really probe for when testing if INTx masking is
supported. The second component is that the device needs to indicate
if INTx is asserted via the interrupt status bit in the device status
register. With these two features we can generically determine if one
of the devices we own is asserting INTx, signal the user, and mask the
interrupt while the user services the device.
Generally if one or both of these components is broken we resort to
APIC level interrupt masking, which requires an exclusive interrupt
since we have no way to determine the source of the interrupt in a
shared configuration. This often makes it difficult or impossible to
configure the system for userspace use of the device, for an interrupt
mode that the user may not need.
One possible configuration of broken INTx masking is that the DisINTx
support is fully functional, but the interrupt status bit never
signals interrupt assertion. In this case we do have the ability to
prevent the device from asserting INTx, but lack the ability to
identify the interrupt source. For this case we can simply pretend
that the device lacks INTx support entirely, keeping DisINTx set on
the physical device, virtualizing this bit for the user, and
virtualizing the interrupt pin register to indicate no INTx support.
We already support virtualization of the DisINTx bit and already
virtualize the interrupt pin for platforms without INTx support. By
tying these components together, setting DisINTx on open and reset,
and identifying devices broken in this particular way, we can provide
support for them w/o the handicap of APIC level INTx masking.
Intel i40e (XL710/X710) 10/20/40GbE NICs have been identified as being
broken in this specific way. We leave the vfio-pci.nointxmask option
as a mechanism to bypass this support, enabling INTx on the device
with all the requirements of APIC level masking.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Cc: John Ronciak <john.ronciak@intel.com>
Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
Integrated graphics may have their ROM shadowed at 0xc0000 rather than
implement a PCI option ROM. Make this ROM appear to the user using
the ROM BAR.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Typically config space for a device is mapped out into capability
specific handlers and unassigned space. The latter allows direct
read/write access to config space. Sometimes we know about registers
living in this void space and would like an easy way to virtualize
them, similar to how BAR registers are managed. To do this, create
one more pseudo (fake) PCI capability to be handled as purely virtual
space. Reads and writes are serviced entirely from virtual config
space.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Smatch complains about a possible out of bounds error:
drivers/vfio/pci/vfio_pci_config.c:1241 vfio_cap_init()
error: buffer overflow 'pci_cap_length' 20 <= 20
The problem is that pci_cap_length[] was defined as large enough to
hold "PCI_CAP_ID_AF + 1" elements. The code in vfio_cap_init() assumes
it has PCI_CAP_ID_MAX + 1 elements. Originally, PCI_CAP_ID_AF and
PCI_CAP_ID_MAX were the same but then we introduced PCI_CAP_ID_EA in
commit f80b0ba959 ("PCI: Add Enhanced Allocation register entries")
so now the array is too small.
Let's fix this by making the array size PCI_CAP_ID_MAX + 1. And let's
make a similar change to pci_ext_cap_length[] for consistency. Also
both these arrays can be made const.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The PCI VPD capability operates on a set of window registers in PCI
config space. Writing to the address register triggers either a read
or write, depending on the setting of the PCI_VPD_ADDR_F bit within
the address register. The data register provides either the source
for writes or the target for reads.
This model is susceptible to being broken by concurrent access, for
which the kernel has adopted a set of access functions to serialize
these registers. Additionally, commits like 932c435cab ("PCI: Add
dev_flags bit to access VPD through function 0") and 7aa6ca4d39
("PCI: Add VPD function 0 quirk for Intel Ethernet devices") indicate
that VPD registers can be shared between functions on multifunction
devices creating dependencies between otherwise independent devices.
Fortunately it's quite easy to emulate the VPD registers, simply
storing copies of the address and data registers in memory and
triggering a VPD read or write on writes to the address register.
This allows vfio users to avoid seeing spurious register changes from
accesses on other devices and enables the use of shared quirks in the
host kernel. We can theoretically still race with access through
sysfs, but the window of opportunity is much smaller.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Mark Rustad <mark.d.rustad@intel.com>
add Kconfig switch to hide INTx
add Kconfig switch to let vfio announce PCI BARs are not mapable
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
In PCIe r1.0, sec 5.10.2, bit 0 of the Uncorrectable Error Status, Mask,
and Severity Registers was for "Training Error." In PCIe r1.1, sec 7.10.2,
bit 0 was redefined to be "Undefined."
Rename PCI_ERR_UNC_TRAIN to PCI_ERR_UNC_UND to reflect this change.
No functional change.
[bhelgaas: changelog]
Signed-off-by: Chen, Gong <gong.chen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
When sizing the TPH capability we store the register containing the
table size into the 'dword' variable, but then use the uninitialized
'byte' variable to analyze the size. The table size is also actually
reported as an N-1 value, so correct sizing to account for this.
The round_up() for both TPH and DPA is unnecessary, remove it.
Detected by Coverity: CID 714665 & 715156
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
These are set of two capability registers, it's pretty much given that
they're registers, so reflect their purpose in the name.
Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Having PCIe/PCI-X capability isn't enough to assume that there are
extended capabilities. Both specs define that the first capability
header is all zero if there are no extended capabilities. Testing
for this avoids an erroneous message about hiding capability 0x0 at
offset 0x100.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Changes include extension to support PCI AER notification to userspace, byte granularity of PCI config space and access to unarchitected PCI config space, better protection around IOMMU driver accesses, default file mode fix, and a few misc cleanups.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.13 (GNU/Linux)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=F0Cc
-----END PGP SIGNATURE-----
Merge tag 'vfio-for-v3.10' of git://github.com/awilliam/linux-vfio
Pull vfio updates from Alex Williamson:
"Changes include extension to support PCI AER notification to
userspace, byte granularity of PCI config space and access to
unarchitected PCI config space, better protection around IOMMU driver
accesses, default file mode fix, and a few misc cleanups."
* tag 'vfio-for-v3.10' of git://github.com/awilliam/linux-vfio:
vfio: Set container device mode
vfio: Use down_reads to protect iommu disconnects
vfio: Convert container->group_lock to rwsem
PCI/VFIO: use pcie_flags_reg instead of access PCI-E Capabilities Register
vfio-pci: Enable raw access to unassigned config space
vfio-pci: Use byte granularity in config map
vfio: make local function vfio_pci_intx_unmask_handler() static
VFIO-AER: Vfio-pci driver changes for supporting AER
VFIO: Wrapper for getting reference to vfio_device
Currently, we use pcie_flags_reg to cache PCI-E Capabilities Register,
because PCI-E Capabilities Register bits are almost read-only. This patch
use pcie_caps_reg() instead of another access PCI-E Capabilities Register.
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Devices like be2net hide registers between the gaps in capabilities
and architected regions of PCI config space. Our choices to support
such devices is to either build an ever growing and unmanageable white
list or rely on hardware isolation to protect us. These registers are
really no different than MMIO or I/O port space registers, which we
don't attempt to regulate, so treat PCI config space in the same way.
Reported-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Gavin Shan <shangw@linux.vnet.ibm.com>
The config map previously used a byte per dword to map regions of
config space to capabilities. Modulo a bug where we round the length
of capabilities down instead of up, this theoretically works well and
saves space so long as devices don't try to hide registers in the gaps
between capabilities. Unfortunately they do exactly that so we need
byte granularity on our config space map. Increase the allocation of
the config map and split accesses at capability region boundaries.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Gavin Shan <shangw@linux.vnet.ibm.com>
The vfio drivers call kmalloc or kzalloc, but do not
include <linux/slab.h>, which causes build errors on
ARM.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Cc: kvm@vger.kernel.org
We give the user access to change the power state of the device but
certain transitions result in an uninitialized state which the user
cannot resolve. To fix this we need to mark the PowerState field of
the PMCSR register read-only and effect the requested change on behalf
of the user. This has the added benefit that pdev->current_state
remains accurate while controlled by the user.
The primary example of this bug is a QEMU guest doing a reboot where
the device it put into D3 on shutdown and becomes unusable on the next
boot because the device did a soft reset on D3->D0 (NoSoftRst-).
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
We can actually handle MMIO and I/O port from the same access function
since PCI already does abstraction of this. The ROM BAR only requires
a minor difference, so it gets included too. vfio_pci_config_readwrite
gets renamed for consistency.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Add PCI device support for VFIO. PCI devices expose regions
for accessing config space, I/O port space, and MMIO areas
of the device. PCI config access is virtualized in the kernel,
allowing us to ensure the integrity of the system, by preventing
various accesses while reducing duplicate support across various
userspace drivers. I/O port supports read/write access while
MMIO also supports mmap of sufficiently sized regions. Support
for INTx, MSI, and MSI-X interrupts are provided using eventfds to
userspace.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>