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Just like normal RAM, there is a limited amount of enclave memory available
and overcommitting it is a very valuable tool to reduce resource use.
Introduce a simple reclaim mechanism for enclave pages.
In contrast to normal page reclaim, the kernel cannot directly access
enclave memory. To get around this, the SGX architecture provides a set of
functions to help. Among other things, these functions copy enclave memory
to and from normal memory, encrypting it and protecting its integrity in
the process.
Implement a page reclaimer by using these functions. Picks victim pages in
LRU fashion from all the enclaves running in the system. A new kernel
thread (ksgxswapd) reclaims pages in the background based on watermarks,
similar to normal kswapd.
All enclave pages can be reclaimed, architecturally. But, there are some
limits to this, such as the special SECS metadata page which must be
reclaimed last. The page version array (used to mitigate replaying old
reclaimed pages) is also architecturally reclaimable, but not yet
implemented. The end result is that the vast majority of enclave pages are
currently reclaimable.
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-22-jarkko@kernel.org
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The whole point of SGX is to create a hardware protected place to do
“stuff”. But, before someone is willing to hand over the keys to
the castle , an enclave must often prove that it is running on an
SGX-protected processor. Provisioning enclaves play a key role in
providing proof.
There are actually three different enclaves in play in order to make this
happen:
1. The application enclave. The familiar one we know and love that runs
the actual code that’s doing real work. There can be many of these on
a single system, or even in a single application.
2. The quoting enclave (QE). The QE is mentioned in lots of silly
whitepapers, but, for the purposes of kernel enabling, just pretend they
do not exist.
3. The provisioning enclave. There is typically only one of these
enclaves per system. Provisioning enclaves have access to a special
hardware key.
They can use this key to help to generate certificates which serve as
proof that enclaves are running on trusted SGX hardware. These
certificates can be passed around without revealing the special key.
Any user who can create a provisioning enclave can access the
processor-unique Provisioning Certificate Key which has privacy and
fingerprinting implications. Even if a user is permitted to create
normal application enclaves (via /dev/sgx_enclave), they should not be
able to create provisioning enclaves. That means a separate permissions
scheme is needed to control provisioning enclave privileges.
Implement a separate device file (/dev/sgx_provision) which allows
creating provisioning enclaves. This device will typically have more
strict permissions than the plain enclave device.
The actual device “driver” is an empty stub. Open file descriptors for
this device will represent a token which allows provisioning enclave duty.
This file descriptor can be passed around and ultimately given as an
argument to the /dev/sgx_enclave driver ioctl().
[ bp: Touchups. ]
Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: linux-security-module@vger.kernel.org
Link: https://lkml.kernel.org/r/20201112220135.165028-16-jarkko@kernel.org
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Enclaves have two basic states. They are either being built and are
malleable and can be modified by doing things like adding pages. Or,
they are locked down and not accepting changes. They can only be run
after they have been locked down. The ENCLS[EINIT] function induces the
transition from being malleable to locked-down.
Add an ioctl() that performs ENCLS[EINIT]. After this, new pages can
no longer be added with ENCLS[EADD]. This is also the time where the
enclave can be measured to verify its integrity.
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-15-jarkko@kernel.org
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SGX enclave pages are inaccessible to normal software. They must be
populated with data by copying from normal memory with the help of the
EADD and EEXTEND functions of the ENCLS instruction.
Add an ioctl() which performs EADD that adds new data to an enclave, and
optionally EEXTEND functions that hash the page contents and use the
hash as part of enclave “measurement” to ensure enclave integrity.
The enclave author gets to decide which pages will be included in the
enclave measurement with EEXTEND. Measurement is very slow and has
sometimes has very little value. For instance, an enclave _could_
measure every page of data and code, but would be slow to initialize.
Or, it might just measure its code and then trust that code to
initialize the bulk of its data after it starts running.
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-14-jarkko@kernel.org
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Add an ioctl() that performs the ECREATE function of the ENCLS
instruction, which creates an SGX Enclave Control Structure (SECS).
Although the SECS is an in-memory data structure, it is present in
enclave memory and is not directly accessible by software.
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-13-jarkko@kernel.org
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Intel(R) SGX is a new hardware functionality that can be used by
applications to set aside private regions of code and data called
enclaves. New hardware protects enclave code and data from outside
access and modification.
Add a driver that presents a device file and ioctl API to build and
manage enclaves.
[ bp: Small touchups, remove unused encl variable in sgx_encl_find() as
Reported-by: kernel test robot <lkp@intel.com> ]
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-12-jarkko@kernel.org
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Add functions for runtime allocation and free.
This allocator and its algorithms are as simple as it gets. They do a
linear search across all EPC sections and find the first free page. They
are not NUMA-aware and only hand out individual pages. The SGX hardware
does not support large pages, so something more complicated like a buddy
allocator is unwarranted.
The free function (sgx_free_epc_page()) implicitly calls ENCLS[EREMOVE],
which returns the page to the uninitialized state. This ensures that the
page is ready for use at the next allocation.
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-10-jarkko@kernel.org
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Add a kernel parameter to disable SGX kernel support and document it.
[ bp: Massage. ]
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Acked-by: Jethro Beekman <jethro@fortanix.com>
Tested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-9-jarkko@kernel.org
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Kernel support for SGX is ultimately decided by the state of the launch
control bits in the feature control MSR (MSR_IA32_FEAT_CTL). If the
hardware supports SGX, but neglects to support flexible launch control, the
kernel will not enable SGX.
Enable SGX at feature control MSR initialization and update the associated
X86_FEATURE flags accordingly. Disable X86_FEATURE_SGX (and all
derivatives) if the kernel is not able to establish itself as the authority
over SGX Launch Control.
All checks are performed for each logical CPU (not just boot CPU) in order
to verify that MSR_IA32_FEATURE_CONTROL is correctly configured on all
CPUs. All SGX code in this series expects the same configuration from all
CPUs.
This differs from VMX where X86_FEATURE_VMX is intentionally cleared only
for the current CPU so that KVM can provide additional information if KVM
fails to load like which CPU doesn't support VMX. There’s not much the
kernel or an administrator can do to fix the situation, so SGX neglects to
convey additional details about these kinds of failures if they occur.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Co-developed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-8-jarkko@kernel.org
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Although carved out of normal DRAM, enclave memory is marked in the
system memory map as reserved and is not managed by the core mm. There
may be several regions spread across the system. Each contiguous region
is called an Enclave Page Cache (EPC) section. EPC sections are
enumerated via CPUID
Enclave pages can only be accessed when they are mapped as part of an
enclave, by a hardware thread running inside the enclave.
Parse CPUID data, create metadata for EPC pages and populate a simple
EPC page allocator. Although much smaller, ‘struct sgx_epc_page’
metadata is the SGX analog of the core mm ‘struct page’.
Similar to how the core mm’s page->flags encode zone and NUMA
information, embed the EPC section index to the first eight bits of
sgx_epc_page->desc. This allows a quick reverse lookup from EPC page to
EPC section. Existing client hardware supports only a single section,
while upcoming server hardware will support at most eight sections.
Thus, eight bits should be enough for long term needs.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Co-developed-by: Serge Ayoun <serge.ayoun@intel.com>
Signed-off-by: Serge Ayoun <serge.ayoun@intel.com>
Co-developed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-6-jarkko@kernel.org
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ENCLS is the userspace instruction which wraps virtually all
unprivileged SGX functionality for managing enclaves. It is essentially
the ioctl() of instructions with each function implementing different
SGX-related functionality.
Add macros to wrap the ENCLS functionality. There are two main groups,
one for functions which do not return error codes and a “ret_” set for
those that do.
ENCLS functions are documented in Intel SDM section 36.6.
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-3-jarkko@kernel.org
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Define the SGX architectural data structures used by various SGX
functions. This is not an exhaustive representation of all SGX data
structures but only those needed by the kernel.
The goal is to sequester hardware structures in "sgx/arch.h" and keep
them separate from kernel-internal or uapi structures.
The data structures are described in Intel SDM section 37.6.
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-2-jarkko@kernel.org
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loading
Currently, scan_microcode() leverages microcode_matches() to check
if the microcode matches the CPU by comparing the family and model.
However, the processor stepping and flags of the microcode signature
should also be considered when saving a microcode patch for early
update.
Use find_matching_signature() in scan_microcode() and get rid of the
now-unused microcode_matches() which is a good cleanup in itself.
Complete the verification of the patch being saved for early loading in
save_microcode_patch() directly. This needs to be done there too because
save_mc_for_early() will call save_microcode_patch() too.
The second reason why this needs to be done is because the loader still
tries to support, at least hypothetically, mixed-steppings systems and
thus adds all patches to the cache that belong to the same CPU model
albeit with different steppings.
For example:
microcode: CPU: sig=0x906ec, pf=0x2, rev=0xd6
microcode: mc_saved[0]: sig=0x906e9, pf=0x2a, rev=0xd6, total size=0x19400, date = 2020-04-23
microcode: mc_saved[1]: sig=0x906ea, pf=0x22, rev=0xd6, total size=0x19000, date = 2020-04-27
microcode: mc_saved[2]: sig=0x906eb, pf=0x2, rev=0xd6, total size=0x19400, date = 2020-04-23
microcode: mc_saved[3]: sig=0x906ec, pf=0x22, rev=0xd6, total size=0x19000, date = 2020-04-27
microcode: mc_saved[4]: sig=0x906ed, pf=0x22, rev=0xd6, total size=0x19400, date = 2020-04-23
The patch which is being saved for early loading, however, can only be
the one which fits the CPU this runs on so do the signature verification
before saving.
[ bp: Do signature verification in save_microcode_patch()
and rewrite commit message. ]
Fixes: ec400ddeff20 ("x86/microcode_intel_early.c: Early update ucode on Intel's CPU")
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=208535
Link: https://lkml.kernel.org/r/20201113015923.13960-1-yu.c.chen@intel.com
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Booting as a guest under KVM results in error messages about
unchecked MSR access:
unchecked MSR access error: RDMSR from 0x17f at rIP: 0xffffffff84483f16 (mce_intel_feature_init+0x156/0x270)
because KVM doesn't provide emulation for random model specific
registers.
Switch to using rdmsrl_safe()/wrmsrl_safe() to avoid the message.
Fixes: 68299a42f842 ("x86/mce: Enable additional error logging on certain Intel CPUs")
Reported-by: Qian Cai <cai@redhat.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201111003954.GA11878@agluck-desk2.amr.corp.intel.com
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Currently, accessing /proc/cpuinfo sends IPIs to idle CPUs in order to
learn their clock frequency. Which is a bit strange, given that waking
them from idle likely significantly changes their clock frequency.
This commit therefore avoids sending /proc/cpuinfo-induced IPIs to
idle CPUs.
[ paulmck: Also check for idle in arch_freq_prepare_all(). ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <x86@kernel.org>
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The aperfmperf_snapshot_cpu() function is invoked upon access to
/proc/cpuinfo, and it does do an early exit if the specified CPU has
recently done a snapshot. Unfortunately, the indication that a snapshot
has been completed is set in an IPI handler, and the execution of this
handler can be delayed by any number of unfortunate events. This means
that a system that starts a number of applications, each of which
parses /proc/cpuinfo, can suffer from an smp_call_function_single()
storm, especially given that each access to /proc/cpuinfo invokes
smp_call_function_single() for all CPUs. Please note that this is not
theoretical speculation. Note also that one CPU's pending IPI serves
all requests, so there is no point in ever having more than one IPI
pending to a given CPU.
This commit therefore suppresses duplicate IPIs to a given CPU via a
new ->scfpending field in the aperfmperf_sample structure. This field
is set to the value one if an IPI is pending to the corresponding CPU
and to zero otherwise.
The aperfmperf_snapshot_cpu() function uses atomic_xchg() to set this
field to the value one and sample the old value. If this function's
"wait" parameter is zero, smp_call_function_single() is called only if
the old value of the ->scfpending field was zero. The IPI handler uses
atomic_set_release() to set this new field to zero just before returning,
so that the prior stores into the aperfmperf_sample structure are seen
by future requests that get to the atomic_xchg(). Future requests that
pass the elapsed-time check are ordered by the fact that on x86 loads act
as acquire loads, just as was the case prior to this change. The return
value is based off of the age of the prior snapshot, just as before.
Reported-by: Dave Jones <davej@codemonkey.org.uk>
[ paulmck: Allow /proc/cpuinfo to take advantage of arch_freq_get_on_cpu(). ]
[ paulmck: Add comment on memory barrier. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <x86@kernel.org>
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Commit
c9c6d216ed28 ("x86/mce: Rename "first" function as "early"")
changed the enumeration of MCE notifier priorities. Correct the check
for notifier priorities to cover the new range.
[ bp: Rewrite commit message, remove superfluous brackets in
conditional. ]
Fixes: c9c6d216ed28 ("x86/mce: Rename "first" function as "early"")
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201106141216.2062-2-thunder.leizhen@huawei.com
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Fix the following coccinelle warnings:
./arch/x86/kernel/cpu/mce/core.c:1765:3-20: WARNING: Assignment of 0/1 to bool variable
./arch/x86/kernel/cpu/mce/core.c:1584:2-9: WARNING: Assignment of 0/1 to bool variable
[ bp: Massage commit message. ]
Reported-by: Tosk Robot <tencent_os_robot@tencent.com>
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/1604654363-1463-1-git-send-email-kaixuxia@tencent.com
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always-on STIBP
On AMD CPUs which have the feature X86_FEATURE_AMD_STIBP_ALWAYS_ON,
STIBP is set to on and
spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED
At the same time, IBPB can be set to conditional.
However, this leads to the case where it's impossible to turn on IBPB
for a process because in the PR_SPEC_DISABLE case in ib_prctl_set() the
spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED
condition leads to a return before the task flag is set. Similarly,
ib_prctl_get() will return PR_SPEC_DISABLE even though IBPB is set to
conditional.
More generally, the following cases are possible:
1. STIBP = conditional && IBPB = on for spectre_v2_user=seccomp,ibpb
2. STIBP = on && IBPB = conditional for AMD CPUs with
X86_FEATURE_AMD_STIBP_ALWAYS_ON
The first case functions correctly today, but only because
spectre_v2_user_ibpb isn't updated to reflect the IBPB mode.
At a high level, this change does one thing. If either STIBP or IBPB
is set to conditional, allow the prctl to change the task flag.
Also, reflect that capability when querying the state. This isn't
perfect since it doesn't take into account if only STIBP or IBPB is
unconditionally on. But it allows the conditional feature to work as
expected, without affecting the unconditional one.
[ bp: Massage commit message and comment; space out statements for
better readability. ]
Fixes: 21998a351512 ("x86/speculation: Avoid force-disabling IBPB based on STIBP and enhanced IBRS.")
Signed-off-by: Anand K Mistry <amistry@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lkml.kernel.org/r/20201105163246.v2.1.Ifd7243cd3e2c2206a893ad0a5b9a4f19549e22c6@changeid
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Lockdep state handling on NMI enter and exit is nothing specific to X86. It's
not any different on other architectures. Also the extra state type is not
necessary, irqentry_state_t can carry the necessary information as well.
Move it to common code and extend irqentry_state_t to carry lockdep state.
[ Ira: Make exit_rcu and lockdep a union as they are mutually exclusive
between the IRQ and NMI exceptions, and add kernel documentation for
struct irqentry_state_t ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201102205320.1458656-7-ira.weiny@intel.com
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When a Linux VM runs on Hyper-V, if the VM has CPUs with >255 APIC IDs,
the CPUs can't be the destination of IOAPIC interrupts, because the
IOAPIC RTE's Dest Field has only 8 bits. Currently the hackery driver
drivers/iommu/hyperv-iommu.c is used to ensure IOAPIC interrupts are
only routed to CPUs that don't have >255 APIC IDs. However, there is
an issue with kdump, because the kdump kernel can run on any CPU, and
hence IOAPIC interrupts can't work if the kdump kernel run on a CPU
with a >255 APIC ID.
The kdump issue can be fixed by the Extended Dest ID, which is introduced
recently by David Woodhouse (for IOAPIC, see the field virt_destid_8_14 in
struct IO_APIC_route_entry). Of course, the Extended Dest ID needs the
support of the underlying hypervisor. The latest Hyper-V has added the
support recently: with this commit, on such a Hyper-V host, Linux VM
does not use hyperv-iommu.c because hyperv_prepare_irq_remapping()
returns -ENODEV; instead, Linux kernel's generic support of Extended Dest
ID from David is used, meaning that Linux VM is able to support up to
32K CPUs, and IOAPIC interrupts can be routed to all the CPUs.
On an old Hyper-V host that doesn't support the Extended Dest ID, nothing
changes with this commit: Linux VM is still able to bring up the CPUs with
> 255 APIC IDs with the help of hyperv-iommu.c, but IOAPIC interrupts still
can not go to such CPUs, and the kdump kernel still can not work properly
on such CPUs.
[ tglx: Updated comment as suggested by David ]
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lore.kernel.org/r/20201103011136.59108-1-decui@microsoft.com
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Kernel-doc markup should use this format:
identifier - description
Fix it.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/2217cd4ae9e561da2825485eb97de77c65741489.1603469755.git.mchehab+huawei@kernel.org
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The Xeon versions of Sandy Bridge, Ivy Bridge and Haswell support an
optional additional error logging mode which is enabled by an MSR.
Previously, this mode was enabled from the mcelog(8) tool via /dev/cpu,
but userspace should not be poking at MSRs. So move the enabling into
the kernel.
[ bp: Correct the explanation why this is done. ]
Suggested-by: Boris Petkov <bp@alien8.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201030190807.GA13884@agluck-desk2.amr.corp.intel.com
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Intel Memory Bandwidth Monitoring (MBM) counters may report system
memory bandwidth incorrectly on some Intel processors. The errata SKX99
for Skylake server, BDF102 for Broadwell server, and the correction
factor table are documented in Documentation/x86/resctrl.rst.
Intel MBM counters track metrics according to the assigned Resource
Monitor ID (RMID) for that logical core. The IA32_QM_CTR register
(MSR 0xC8E) used to report these metrics, may report incorrect system
bandwidth for certain RMID values.
Due to the errata, system memory bandwidth may not match what is
reported.
To work around the errata, correct MBM total and local readings using a
correction factor table. If rmid > rmid threshold, MBM total and local
values should be multiplied by the correction factor.
[ bp: Mark mbm_cf_table[] __initdata. ]
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20201014004927.1839452-3-fenghua.yu@intel.com
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A break is not needed if it is preceded by a return.
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201019200803.17619-1-trix@redhat.com
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A break is not needed if it is preceded by a return.
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201019200629.17247-1-trix@redhat.com
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Use a more generic form for __section that requires quotes to avoid
complications with clang and gcc differences.
Remove the quote operator # from compiler_attributes.h __section macro.
Convert all unquoted __section(foo) uses to quoted __section("foo").
Also convert __attribute__((section("foo"))) uses to __section("foo")
even if the __attribute__ has multiple list entry forms.
Conversion done using the script at:
https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl
Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@gooogle.com>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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A previous commit changed the notification mode from true/false to an
int, allowing notify-no, notify-yes, or signal-notify. This was
backwards compatible in the sense that any existing true/false user
would translate to either 0 (on notification sent) or 1, the latter
which mapped to TWA_RESUME. TWA_SIGNAL was assigned a value of 2.
Clean this up properly, and define a proper enum for the notification
mode. Now we have:
- TWA_NONE. This is 0, same as before the original change, meaning no
notification requested.
- TWA_RESUME. This is 1, same as before the original change, meaning
that we use TIF_NOTIFY_RESUME.
- TWA_SIGNAL. This uses TIF_SIGPENDING/JOBCTL_TASK_WORK for the
notification.
Clean up all the callers, switching their 0/1/false/true to using the
appropriate TWA_* mode for notifications.
Fixes: e91b48162332 ("task_work: teach task_work_add() to do signal_wake_up()")
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull another Hyper-V update from Wei Liu:
"One patch from Michael to get VMbus interrupt from ACPI DSDT"
* tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
Drivers: hv: vmbus: Add parsing of VMbus interrupt in ACPI DSDT
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On ARM64, Hyper-V now specifies the interrupt to be used by VMbus
in the ACPI DSDT. This information is not used on x86 because the
interrupt vector must be hardcoded. But update the generic
VMbus driver to do the parsing and pass the information to the
architecture specific code that sets up the Linux IRQ. Update
consumers of the interrupt to get it from an architecture specific
function.
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1597434304-40631-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 SEV-ES support from Borislav Petkov:
"SEV-ES enhances the current guest memory encryption support called SEV
by also encrypting the guest register state, making the registers
inaccessible to the hypervisor by en-/decrypting them on world
switches. Thus, it adds additional protection to Linux guests against
exfiltration, control flow and rollback attacks.
With SEV-ES, the guest is in full control of what registers the
hypervisor can access. This is provided by a guest-host exchange
mechanism based on a new exception vector called VMM Communication
Exception (#VC), a new instruction called VMGEXIT and a shared
Guest-Host Communication Block which is a decrypted page shared
between the guest and the hypervisor.
Intercepts to the hypervisor become #VC exceptions in an SEV-ES guest
so in order for that exception mechanism to work, the early x86 init
code needed to be made able to handle exceptions, which, in itself,
brings a bunch of very nice cleanups and improvements to the early
boot code like an early page fault handler, allowing for on-demand
building of the identity mapping. With that, !KASLR configurations do
not use the EFI page table anymore but switch to a kernel-controlled
one.
The main part of this series adds the support for that new exchange
mechanism. The goal has been to keep this as much as possibly separate
from the core x86 code by concentrating the machinery in two
SEV-ES-specific files:
arch/x86/kernel/sev-es-shared.c
arch/x86/kernel/sev-es.c
Other interaction with core x86 code has been kept at minimum and
behind static keys to minimize the performance impact on !SEV-ES
setups.
Work by Joerg Roedel and Thomas Lendacky and others"
* tag 'x86_seves_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (73 commits)
x86/sev-es: Use GHCB accessor for setting the MMIO scratch buffer
x86/sev-es: Check required CPU features for SEV-ES
x86/efi: Add GHCB mappings when SEV-ES is active
x86/sev-es: Handle NMI State
x86/sev-es: Support CPU offline/online
x86/head/64: Don't call verify_cpu() on starting APs
x86/smpboot: Load TSS and getcpu GDT entry before loading IDT
x86/realmode: Setup AP jump table
x86/realmode: Add SEV-ES specific trampoline entry point
x86/vmware: Add VMware-specific handling for VMMCALL under SEV-ES
x86/kvm: Add KVM-specific VMMCALL handling under SEV-ES
x86/paravirt: Allow hypervisor-specific VMMCALL handling under SEV-ES
x86/sev-es: Handle #DB Events
x86/sev-es: Handle #AC Events
x86/sev-es: Handle VMMCALL Events
x86/sev-es: Handle MWAIT/MWAITX Events
x86/sev-es: Handle MONITOR/MONITORX Events
x86/sev-es: Handle INVD Events
x86/sev-es: Handle RDPMC Events
x86/sev-es: Handle RDTSC(P) Events
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asm updates from Borislav Petkov:
"Two asm wrapper fixes:
- Use XORL instead of XORQ to avoid a REX prefix and save some bytes
in the .fixup section, by Uros Bizjak.
- Replace __force_order dummy variable with a memory clobber to fix
LLVM requiring a definition for former and to prevent memory
accesses from still being cached/reordered, by Arvind Sankar"
* tag 'x86_asm_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/asm: Replace __force_order with a memory clobber
x86/uaccess: Use XORL %0,%0 in __get_user_asm()
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 Hyper-V update from Ingo Molnar:
"A single commit harmonizing the x86 and ARM64 Hyper-V constants
namespace"
* tag 'x86-hyperv-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/hyperv: Remove aliases with X64 in their name
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 paravirt cleanup from Ingo Molnar:
"Clean up the paravirt code after the removal of 32-bit Xen PV support"
* tag 'x86-paravirt-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/paravirt: Avoid needless paravirt step clearing page table entries
x86/paravirt: Remove set_pte_at() pv-op
x86/entry/32: Simplify CONFIG_XEN_PV build dependency
x86/paravirt: Use CONFIG_PARAVIRT_XXL instead of CONFIG_PARAVIRT
x86/paravirt: Clean up paravirt macros
x86/paravirt: Remove 32-bit support from CONFIG_PARAVIRT_XXL
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cache resource control updates from Borislav Petkov:
- Misc cleanups to the resctrl code in preparation for the ARM side
(James Morse)
- Add support for controlling per-thread memory bandwidth throttling
delay values on hw which supports it (Fenghua Yu)
* tag 'x86_cache_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/resctrl: Enable user to view thread or core throttling mode
x86/resctrl: Enumerate per-thread MBA controls
cacheinfo: Move resctrl's get_cache_id() to the cacheinfo header file
x86/resctrl: Add struct rdt_cache::arch_has_{sparse, empty}_bitmaps
x86/resctrl: Merge AMD/Intel parse_bw() calls
x86/resctrl: Add struct rdt_membw::arch_needs_linear to explain AMD/Intel MBA difference
x86/resctrl: Use is_closid_match() in more places
x86/resctrl: Include pid.h
x86/resctrl: Use container_of() in delayed_work handlers
x86/resctrl: Fix stale comment
x86/resctrl: Remove struct rdt_membw::max_delay
x86/resctrl: Remove unused struct mbm_state::chunks_bw
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cleanups from Borislav Petkov:
"Misc minor cleanups"
* tag 'x86_cleanups_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/entry: Fix typo in comments for syscall_enter_from_user_mode()
x86/resctrl: Fix spelling in user-visible warning messages
x86/entry/64: Do not include inst.h in calling.h
x86/mpparse: Remove duplicate io_apic.h include
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fpu updates from Borislav Petkov:
- Allow clearcpuid= to accept multiple bits (Arvind Sankar)
- Move clearcpuid= parameter handling earlier in the boot, away from
the FPU init code and to a generic location (Mike Hommey)
* tag 'x86_fpu_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/fpu: Handle FPU-related and clearcpuid command line arguments earlier
x86/fpu: Allow multiple bits in clearcpuid= parameter
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 PASID updates from Borislav Petkov:
"Initial support for sharing virtual addresses between the CPU and
devices which doesn't need pinning of pages for DMA anymore.
Add support for the command submission to devices using new x86
instructions like ENQCMD{,S} and MOVDIR64B. In addition, add support
for process address space identifiers (PASIDs) which are referenced by
those command submission instructions along with the handling of the
PASID state on context switch as another extended state.
Work by Fenghua Yu, Ashok Raj, Yu-cheng Yu and Dave Jiang"
* tag 'x86_pasid_for_5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/asm: Add an enqcmds() wrapper for the ENQCMDS instruction
x86/asm: Carve out a generic movdir64b() helper for general usage
x86/mmu: Allocate/free a PASID
x86/cpufeatures: Mark ENQCMD as disabled when configured out
mm: Add a pasid member to struct mm_struct
x86/msr-index: Define an IA32_PASID MSR
x86/fpu/xstate: Add supervisor PASID state for ENQCMD
x86/cpufeatures: Enumerate ENQCMD and ENQCMDS instructions
Documentation/x86: Add documentation for SVA (Shared Virtual Addressing)
iommu/vt-d: Change flags type to unsigned int in binding mm
drm, iommu: Change type of pasid to u32
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cpu updates from Borislav Petkov:
- Add support for hardware-enforced cache coherency on AMD which
obviates the need to flush cachelines before changing the PTE
encryption bit (Krish Sadhukhan)
- Add Centaur initialization support for families >= 7 (Tony W Wang-oc)
- Add a feature flag for, and expose TSX suspend load tracking feature
to KVM (Cathy Zhang)
- Emulate SLDT and STR so that windows programs don't crash on UMIP
machines (Brendan Shanks and Ricardo Neri)
- Use the new SERIALIZE insn on Intel hardware which supports it
(Ricardo Neri)
- Misc cleanups and fixes
* tag 'x86_cpu_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
KVM: SVM: Don't flush cache if hardware enforces cache coherency across encryption domains
x86/mm/pat: Don't flush cache if hardware enforces cache coherency across encryption domnains
x86/cpu: Add hardware-enforced cache coherency as a CPUID feature
x86/cpu/centaur: Add Centaur family >=7 CPUs initialization support
x86/cpu/centaur: Replace two-condition switch-case with an if statement
x86/kvm: Expose TSX Suspend Load Tracking feature
x86/cpufeatures: Enumerate TSX suspend load address tracking instructions
x86/umip: Add emulation/spoofing for SLDT and STR instructions
x86/cpu: Fix typos and improve the comments in sync_core()
x86/cpu: Use XGETBV and XSETBV mnemonics in fpu/internal.h
x86/cpu: Use SERIALIZE in sync_core() when available
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RAS updates from Borislav Petkov:
- Extend the recovery from MCE in kernel space also to processes which
encounter an MCE in kernel space but while copying from user memory
by sending them a SIGBUS on return to user space and umapping the
faulty memory, by Tony Luck and Youquan Song.
- memcpy_mcsafe() rework by splitting the functionality into
copy_mc_to_user() and copy_mc_to_kernel(). This, as a result, enables
support for new hardware which can recover from a machine check
encountered during a fast string copy and makes that the default and
lets the older hardware which does not support that advance recovery,
opt in to use the old, fragile, slow variant, by Dan Williams.
- New AMD hw enablement, by Yazen Ghannam and Akshay Gupta.
- Do not use MSR-tracing accessors in #MC context and flag any fault
while accessing MCA architectural MSRs as an architectural violation
with the hope that such hw/fw misdesigns are caught early during the
hw eval phase and they don't make it into production.
- Misc fixes, improvements and cleanups, as always.
* tag 'ras_updates_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mce: Allow for copy_mc_fragile symbol checksum to be generated
x86/mce: Decode a kernel instruction to determine if it is copying from user
x86/mce: Recover from poison found while copying from user space
x86/mce: Avoid tail copy when machine check terminated a copy from user
x86/mce: Add _ASM_EXTABLE_CPY for copy user access
x86/mce: Provide method to find out the type of an exception handler
x86/mce: Pass pointer to saved pt_regs to severity calculation routines
x86/copy_mc: Introduce copy_mc_enhanced_fast_string()
x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}()
x86/mce: Drop AMD-specific "DEFERRED" case from Intel severity rule list
x86/mce: Add Skylake quirk for patrol scrub reported errors
RAS/CEC: Convert to DEFINE_SHOW_ATTRIBUTE()
x86/mce: Annotate mce_rd/wrmsrl() with noinstr
x86/mce/dev-mcelog: Do not update kflags on AMD systems
x86/mce: Stop mce_reign() from re-computing severity for every CPU
x86/mce: Make mce_rdmsrl() panic on an inaccessible MSR
x86/mce: Increase maximum number of banks to 64
x86/mce: Delay clearing IA32_MCG_STATUS to the end of do_machine_check()
x86/MCE/AMD, EDAC/mce_amd: Remove struct smca_hwid.xec_bitmap
RAS/CEC: Fix cec_init() prototype
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All instructions copying data between kernel and user memory
are tagged with either _ASM_EXTABLE_UA or _ASM_EXTABLE_CPY
entries in the exception table. ex_fault_handler_type() returns
EX_HANDLER_UACCESS for both of these.
Recovery is only possible when the machine check was triggered
on a read from user memory. In this case the same strategy for
recovery applies as if the user had made the access in ring3. If
the fault was in kernel memory while copying to user there is no
current recovery plan.
For MOV and MOVZ instructions a full decode of the instruction
is done to find the source address. For MOVS instructions
the source address is in the %rsi register. The function
fault_in_kernel_space() determines whether the source address is
kernel or user, upgrade it from "static" so it can be used here.
Co-developed-by: Youquan Song <youquan.song@intel.com>
Signed-off-by: Youquan Song <youquan.song@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201006210910.21062-7-tony.luck@intel.com
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Existing kernel code can only recover from a machine check on code that
is tagged in the exception table with a fault handling recovery path.
Add two new fields in the task structure to pass information from
machine check handler to the "task_work" that is queued to run before
the task returns to user mode:
+ mce_vaddr: will be initialized to the user virtual address of the fault
in the case where the fault occurred in the kernel copying data from
a user address. This is so that kill_me_maybe() can provide that
information to the user SIGBUS handler.
+ mce_kflags: copy of the struct mce.kflags needed by kill_me_maybe()
to determine if mce_vaddr is applicable to this error.
Add code to recover from a machine check while copying data from user
space to the kernel. Action for this case is the same as if the user
touched the poison directly; unmap the page and send a SIGBUS to the task.
Use a new helper function to share common code between the "fault
in user mode" case and the "fault while copying from user" case.
New code paths will be activated by the next patch which sets
MCE_IN_KERNEL_COPYIN.
Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201006210910.21062-6-tony.luck@intel.com
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Avoid a proliferation of ex_has_*_handler() functions by having just
one function that returns the type of the handler (if any).
Drop the __visible attribute for this function. It is not called
from assembler so the attribute is not necessary.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201006210910.21062-3-tony.luck@intel.com
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New recovery features require additional information about processor
state when a machine check occurred. Pass pt_regs down to the routines
that need it.
No functional change.
Signed-off-by: Youquan Song <youquan.song@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201006210910.21062-2-tony.luck@intel.com
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In reaction to a proposal to introduce a memcpy_mcsafe_fast()
implementation Linus points out that memcpy_mcsafe() is poorly named
relative to communicating the scope of the interface. Specifically what
addresses are valid to pass as source, destination, and what faults /
exceptions are handled.
Of particular concern is that even though x86 might be able to handle
the semantics of copy_mc_to_user() with its common copy_user_generic()
implementation other archs likely need / want an explicit path for this
case:
On Fri, May 1, 2020 at 11:28 AM Linus Torvalds <torvalds@linux-foundation.org> wrote:
>
> On Thu, Apr 30, 2020 at 6:21 PM Dan Williams <dan.j.williams@intel.com> wrote:
> >
> > However now I see that copy_user_generic() works for the wrong reason.
> > It works because the exception on the source address due to poison
> > looks no different than a write fault on the user address to the
> > caller, it's still just a short copy. So it makes copy_to_user() work
> > for the wrong reason relative to the name.
>
> Right.
>
> And it won't work that way on other architectures. On x86, we have a
> generic function that can take faults on either side, and we use it
> for both cases (and for the "in_user" case too), but that's an
> artifact of the architecture oddity.
>
> In fact, it's probably wrong even on x86 - because it can hide bugs -
> but writing those things is painful enough that everybody prefers
> having just one function.
Replace a single top-level memcpy_mcsafe() with either
copy_mc_to_user(), or copy_mc_to_kernel().
Introduce an x86 copy_mc_fragile() name as the rename for the
low-level x86 implementation formerly named memcpy_mcsafe(). It is used
as the slow / careful backend that is supplanted by a fast
copy_mc_generic() in a follow-on patch.
One side-effect of this reorganization is that separating copy_mc_64.S
to its own file means that perf no longer needs to track dependencies
for its memcpy_64.S benchmarks.
[ bp: Massage a bit. ]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: <stable@vger.kernel.org>
Link: http://lore.kernel.org/r/CAHk-=wjSqtXAqfUJxFtWNwmguFASTgB0dz1dT3V-78Quiezqbg@mail.gmail.com
Link: https://lkml.kernel.org/r/160195561680.2163339.11574962055305783722.stgit@dwillia2-desk3.amr.corp.intel.com
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The CRn accessor functions use __force_order as a dummy operand to
prevent the compiler from reordering CRn reads/writes with respect to
each other.
The fact that the asm is volatile should be enough to prevent this:
volatile asm statements should be executed in program order. However GCC
4.9.x and 5.x have a bug that might result in reordering. This was fixed
in 8.1, 7.3 and 6.5. Versions prior to these, including 5.x and 4.9.x,
may reorder volatile asm statements with respect to each other.
There are some issues with __force_order as implemented:
- It is used only as an input operand for the write functions, and hence
doesn't do anything additional to prevent reordering writes.
- It allows memory accesses to be cached/reordered across write
functions, but CRn writes affect the semantics of memory accesses, so
this could be dangerous.
- __force_order is not actually defined in the kernel proper, but the
LLVM toolchain can in some cases require a definition: LLVM (as well
as GCC 4.9) requires it for PIE code, which is why the compressed
kernel has a definition, but also the clang integrated assembler may
consider the address of __force_order to be significant, resulting in
a reference that requires a definition.
Fix this by:
- Using a memory clobber for the write functions to additionally prevent
caching/reordering memory accesses across CRn writes.
- Using a dummy input operand with an arbitrary constant address for the
read functions, instead of a global variable. This will prevent reads
from being reordered across writes, while allowing memory loads to be
cached/reordered across CRn reads, which should be safe.
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82602
Link: https://lore.kernel.org/lkml/20200527135329.1172644-1-arnd@arndb.de/
Link: https://lkml.kernel.org/r/20200902232152.3709896-1-nivedita@alum.mit.edu
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The recent fix for NMI vs. IRQ state tracking missed to apply the cure
to the MCE handler.
Fixes: ba1f2b2eaa2a ("x86/entry: Fix NMI vs IRQ state tracking")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/87mu17ism2.fsf@nanos.tec.linutronix.de
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Way back in v3.19 Intel and AMD shared the same machine check severity
grading code. So it made sense to add a case for AMD DEFERRED errors in
commit
e3480271f592 ("x86, mce, severity: Extend the the mce_severity mechanism to handle UCNA/DEFERRED error")
But later in v4.2 AMD switched to a separate grading function in
commit
bf80bbd7dcf5 ("x86/mce: Add an AMD severities-grading function")
Belatedly drop the DEFERRED case from the Intel rule list.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200930021313.31810-3-tony.luck@intel.com
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The patrol scrubber in Skylake and Cascade Lake systems can be configured
to report uncorrected errors using a special signature in the machine
check bank and to signal using CMCI instead of machine check.
Update the severity calculation mechanism to allow specifying the model,
minimum stepping and range of machine check bank numbers.
Add a new rule to detect the special signature (on model 0x55, stepping
>=4 in any of the memory controller banks).
[ bp: Rewrite it.
aegl: Productize it. ]
Suggested-by: Youquan Song <youquan.song@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Co-developed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200930021313.31810-2-tony.luck@intel.com
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In the architecture independent version of hyperv-tlfs.h, commit c55a844f46f958b
removed the "X64" in the symbol names so they would make sense for both x86 and
ARM64. That commit added aliases with the "X64" in the x86 version of hyperv-tlfs.h
so that existing x86 code would continue to compile.
As a cleanup, update the x86 code to use the symbols without the "X64", then remove
the aliases. There's no functional change.
Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com>
Link: https://lore.kernel.org/r/1601130386-11111-1-git-send-email-jsalisbury@linux.microsoft.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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