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Wangxun NICs support the connection with SFP to RJ45 module. In this case,
PCS need to be configured in SGMII mode.
According to chapter 6.11.1 "SGMII Auto-Negitiation" of DesignWare Cores
Ethernet PCS (version 3.20a) and custom design manual, do the following
configuration when the interface mode is SGMII.
1. program VR_MII_AN_CTRL bit(3) [TX_CONFIG] = 1b (PHY side SGMII)
2. program VR_MII_AN_CTRL bit(8) [MII_CTRL] = 1b (8-bit MII)
3. program VR_MII_DIG_CTRL1 bit(0) [PHY_MODE_CTRL] = 1b
Also CL37 AN in backplane configurations need to be enabled because of the
special hardware design. Another thing to note is that PMA needs to be
reconfigured before each CL37 AN configuration for SGMII, otherwise AN will
fail, although we don't know why.
On this device, CL37_ANSGM_STS (bit[4:1] of VR_MII_AN_INTR_STS) indicates
the status received from remote link during the auto-negotiation, and
self-clear after the auto-negotiation is complete.
Meanwhile, CL37_ANCMPLT_INTR will be set to 1, to indicate CL37 AN is
complete. So add another way to get the state for CL37 SGMII.
Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Enable CL37 AN complete interrupt for DW XPCS. It requires to clear the
bit(0) [CL37_ANCMPLT_INTR] of VR_MII_AN_INTR_STS after AN completed.
And there is a quirk for Wangxun devices to enable CL37 AN in backplane
configurations because of the special hardware design.
Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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According to chapter 6 of DesignWare Cores Ethernet PCS (version 3.20a)
and custom design manual, add a configuration flow for switching interface
mode.
If the interface changes, the following setting is required:
1. wait VR_XS_PCS_DIG_STS bit(4, 2) [PSEQ_STATE] = 100b (Power-Good)
2. write SR_XS_PCS_CTRL2 to select various PCS type
3. write SR_PMA_CTRL1 and/or SR_XS_PCS_CTRL1 for link speed
4. program PMA registers
5. write VR_XS_PCS_DIG_CTRL1 bit(15) [VR_RST] = 1b (Vendor-Specific
Soft Reset)
6. wait for VR_XS_PCS_DIG_CTRL1 bit(15) [VR_RST] to get cleared
Only 10GBASE-R/SGMII/1000BASE-X modes are planned for the current Wangxun
devices. And there is a quirk for Wangxun devices to switch mode although
the interface in phylink state has not changed, since PCS will change to
default 10GBASE-R when the ethernet driver(txgbe) do LAN reset.
Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Since Wangxun 10Gb NICs require some special configuration on the IP of
Synopsys Designware XPCS, introduce dev_flag for different vendors. Read
OUI from device identifier registers, to detect Wangxun devices.
And xpcs_soft_reset() is skipped to avoid the reset of device identifier
registers.
Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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The ChannelSequence field in the SMB3 header is supposed to be
increased after reconnect to allow the server to distinguish
requests from before and after the reconnect. We had always
been setting it to zero. There are cases where incrementing
ChannelSequence on requests after network reconnects can reduce
the chance of data corruptions.
See MS-SMB2 3.2.4.1 and 3.2.7.1
Signed-off-by: Steve French <stfrench@microsoft.com>
Cc: stable@vger.kernel.org # 5.16+
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git://anongit.freedesktop.org/drm/drm-intel into drm-next
- Fix TLB invalidation (Alan)
- Fix Display HPD polling (Imre)
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/ZOdOP31OE/Cf1ojo@intel.com
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git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix ring buffer being permanently disabled due to missed
record_disabled()
Changing the trace cpu mask will disable the ring buffers for the
CPUs no longer in the mask. But it fails to update the snapshot
buffer. If a snapshot takes place, the accounting for the ring buffer
being disabled is corrupted and this can lead to the ring buffer
being permanently disabled.
- Add test case for snapshot and cpu mask working together
- Fix memleak by the function graph tracer not getting closed properly.
The iterator is used to read the ring buffer. When it opens, it calls
the open function of a tracer, and when it is closed, it calls the
close iteration. While a trace is being read, it is still possible to
change the tracer.
If this happens between the function graph tracer and the wakeup
tracer (which uses function graph tracing), the tracers are not
closed properly during when the iterator sees the switch, and the
wakeup function did not initialize its private pointer to NULL, which
is used to know if the function graph tracer was the last tracer. It
could be fooled in thinking it is, but then on exit it does not call
the close function of the function graph tracer to clean up its data.
- Fix synthetic events on big endian machines, by introducing a union
that does the conversions properly.
- Fix synthetic events from printing out the number of elements in the
stacktrace when it shouldn't.
- Fix synthetic events stacktrace to not print a bogus value at the
end.
- Introduce a pipe_cpumask that prevents the trace_pipe files from
being opened by more than one task (file descriptor).
There was a race found where if splice is called, the iter->ent could
become stale and events could be missed. There's no point reading a
producer/consumer file by more than one task as they will corrupt
each other anyway. Add a cpumask that keeps track of the per_cpu
trace_pipe files as well as the global trace_pipe file that prevents
more than one open of a trace_pipe file that represents the same ring
buffer. This prevents the race from happening.
- Fix ftrace samples for arm64 to work with older compilers.
* tag 'trace-v6.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
samples: ftrace: Replace bti assembly with hint for older compiler
tracing: Introduce pipe_cpumask to avoid race on trace_pipes
tracing: Fix memleak due to race between current_tracer and trace
tracing/synthetic: Allocate one additional element for size
tracing/synthetic: Skip first entry for stack traces
tracing/synthetic: Use union instead of casts
selftests/ftrace: Add a basic testcase for snapshot
tracing: Fix cpu buffers unavailable due to 'record_disabled' missed
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Commit 41320b18a0e0 ("scsi: snic: Fix possible memory leak if device_add()
fails") fixed the memory leak caused by dev_set_name() when device_add()
failed. However, it did not consider that 'tgt' has already been released
when put_device(&tgt->dev) is called. Remove kfree(tgt) in the error path
to avoid double free of 'tgt' and move put_device(&tgt->dev) after the
removed kfree(tgt) to avoid a use-after-free.
Fixes: 41320b18a0e0 ("scsi: snic: Fix possible memory leak if device_add() fails")
Signed-off-by: Zhu Wang <wangzhu9@huawei.com>
Link: https://lore.kernel.org/r/20230819083941.164365-1-wangzhu9@huawei.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media fix from Mauro Carvalho Chehab:
"Fix a potential array out-of-bounds in the mediatek vcodec driver"
* tag 'media/v6.5-4' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
media: vcodec: Fix potential array out-of-bounds in encoder queue_setup
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Jakub Kicinski says:
====================
tools: ynl: handful of forward looking updates
Small YNL improvements, mostly for work-in-progress families.
====================
Link: https://lore.kernel.org/r/20230824003056.1436637-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Fix up the indentation. This has no functional effect, AFAICT.
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20230824003056.1436637-6-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Differentiate between empty list and None for member lists.
New families may want to create request responses with no attribute.
If we treat those the same as None we end up rendering
a full parsing policy in user space, instead of an empty one.
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20230824003056.1436637-5-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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We look for attributes inside do.request, but there's another
layer of nesting in the spec, look inside do.request.attributes.
This bug had no effect as all global policies we generate (fou)
seem to be full, anyway, and we treat full and empty the same.
Next patch will change the treatment of empty policies.
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20230824003056.1436637-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Remember to set the length field in the request setters.
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20230824003056.1436637-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Recent changes made us assume that input for binary data is in hex.
When using YNL as a Python library it's possible to pass in raw bytes.
Bring the ability to do that back.
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20230824003056.1436637-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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used as core library"
Recent merge had a conflict in:
drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec_fs.c
between commit:
aeb660171b06 ("net/mlx5e: fix double free in macsec_fs_tx_create_crypto_table_groups")
from Linus' tree and commit:
cb5ebe4896f9 ("net/mlx5e: Move MACsec flow steering operations to be used as core library")
from the mlx5-next tree. This was missed and the former commit
got lost, bring it back.
Fixes: 3c5066c6b0a5 ("Merge branch 'mlx5-next' of https://git.kernel.org/pub/scm/linux/kernel/git/mellanox/linux")
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Link: https://lore.kernel.org/r/20230815123725.4ef5b7b9@canb.auug.org.au
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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The raid_component_add() function was added to the kernel tree via patch
"[SCSI] embryonic RAID class" (2005). Remove this function since it never
has had any callers in the Linux kernel. And also raid_component_release()
is only used in raid_component_add(), so it is also removed.
Signed-off-by: Zhu Wang <wangzhu9@huawei.com>
Link: https://lore.kernel.org/r/20230822015254.184270-1-wangzhu9@huawei.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Fixes: 04b5b5cb0136 ("scsi: core: Fix possible memory leak if device_add() fails")
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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John Garry <john.g.garry@oracle.com> says:
This series tidies-up libsas a bit, including:
- delete structure(s) with only one member
- delete structure members which are only ever set
- delete structure members which are never set and code which relies on
that member being set
This conflicts with the following series:
https://lore.kernel.org/linux-scsi/20230809132249.37948-1-yuehaibing@huawei.com/
Any conflict should be trivial to resolve.
Based on mkp-scsi staging at a18e81d17a7e ("scsi: ufs: ufs-pci: Add support for QEMU")
Link: https://lore.kernel.org/r/20230815115156.343535-1-john.g.garry@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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Igor Pylypiv <ipylypiv@google.com> says:
This patch series plumbs libata's request for a result taskfile
(ATA_QCFLAG_RESULT_TF) through libsas to pm80xx LLDD. Other libsas LLDDs
can start using the newly added return_fis_on_success as well, if needed.
For Command Duration Limits policy 0xD (command completes without an
error) libata needs FIS in order to detect the ATA_SENSE bit and read
the Sense Data for Successful NCQ Commands log (0Fh). pm80xx HBAs do
not return FIS on success by default, hence, the driver is updated to
set the RETFIS bit (Return FIS on good completion) when requested by
libsas.
Link: https://lore.kernel.org/r/20230819213040.1101044-1-ipylypiv@google.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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Use a dynamic calculation to determine the shift value for the internal
timer cyclecounter that will lead to the highest precision frequency
adjustments. Previously used a constant for the shift value assuming all
devices supported by the driver had a nominal frequency of 1GHz. However,
there are devices that operate at different frequencies. The previous shift
value constant would break the PHC functionality for those devices.
Reported-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Closes: https://lore.kernel.org/netdev/20230815151507.3028503-1-vadfed@meta.com/
Fixes: 6a4010927562 ("net/mlx5: Update cyclecounter shift value to improve ptp free running mode precision")
Signed-off-by: Rahul Rameshbabu <rrameshbabu@nvidia.com>
Tested-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Acked-by: Saeed Mahameed <saeedm@nvidia.com>
Link: https://lore.kernel.org/r/20230821230554.236210-1-rrameshbabu@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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./arch/x86/hyperv/ivm.c: asm/sev.h is included more than once.
./arch/x86/hyperv/ivm.c: asm/coco.h is included more than once.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=6212
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20230824080352.98945-1-jiapeng.chong@linux.alibaba.com
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Group the code this way so that we can avoid too many ifdef's:
Data only used in an SNP VM with the paravisor;
Functions only used in an SNP VM with the paravisor;
Data only used in an SNP VM without the paravisor;
Functions only used in an SNP VM without the paravisor;
Functions only used in a TDX VM, with and without the paravisor;
Functions used in an SNP or TDX VM, when the paravisor is present;
Functions always used, even in a regular non-CoCo VM.
No functional change.
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20230824080712.30327-11-decui@microsoft.com
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In ms_hyperv_init_platform(), do not distinguish between a SNP VM with
the paravisor and a SNP VM without the paravisor.
Replace hv_isolation_type_en_snp() with
!ms_hyperv.paravisor_present && hv_isolation_type_snp().
The hv_isolation_type_en_snp() in drivers/hv/hv.c and
drivers/hv/hv_common.c can be changed to hv_isolation_type_snp() since
we know !ms_hyperv.paravisor_present is true there.
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20230824080712.30327-10-decui@microsoft.com
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When the paravisor is present, a SNP VM must use GHCB to access some
special MSRs, including HV_X64_MSR_GUEST_OS_ID and some SynIC MSRs.
Similarly, when the paravisor is present, a TDX VM must use TDX GHCI
to access the same MSRs.
Implement hv_tdx_msr_write() and hv_tdx_msr_read(), and use the helper
functions hv_ivm_msr_read() and hv_ivm_msr_write() to access the MSRs
in a unified way for SNP/TDX VMs with the paravisor.
Do not export hv_tdx_msr_write() and hv_tdx_msr_read(), because we never
really used hv_ghcb_msr_write() and hv_ghcb_msr_read() in any module.
Update arch/x86/include/asm/mshyperv.h so that the kernel can still build
if CONFIG_AMD_MEM_ENCRYPT or CONFIG_INTEL_TDX_GUEST is not set, or
neither is set.
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20230824080712.30327-9-decui@microsoft.com
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The post_msg_page was removed in
commit 9a6b1a170ca8 ("Drivers: hv: vmbus: Remove the per-CPU post_msg_page")
However, it turns out that we need to bring it back, but only for a TDX VM
with the paravisor: in such a VM, the hyperv_pcpu_input_arg is not decrypted,
but the HVCALL_POST_MESSAGE in such a VM needs a decrypted page as the
hypercall input page: see the comments in hyperv_init() for a detailed
explanation.
Except for HVCALL_POST_MESSAGE and HVCALL_SIGNAL_EVENT, the other hypercalls
in a TDX VM with the paravisor still use hv_hypercall_pg and must use the
hyperv_pcpu_input_arg (which is encrypted in such a VM), when a hypercall
input page is used.
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20230824080712.30327-8-decui@microsoft.com
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The new variable hyperv_paravisor_present is set only when the VM
is a SNP/TDX VM with the paravisor running: see ms_hyperv_init_platform().
We introduce hyperv_paravisor_present because we can not use
ms_hyperv.paravisor_present in arch/x86/include/asm/mshyperv.h:
struct ms_hyperv_info is defined in include/asm-generic/mshyperv.h, which
is included at the end of arch/x86/include/asm/mshyperv.h, but at the
beginning of arch/x86/include/asm/mshyperv.h, we would already need to use
struct ms_hyperv_info in hv_do_hypercall().
We use hyperv_paravisor_present only in include/asm-generic/mshyperv.h,
and use ms_hyperv.paravisor_present elsewhere. In the future, we'll
introduce a hypercall function structure for different VM types, and
at boot time, the right function pointers would be written into the
structure so that runtime testing of TDX vs. SNP vs. normal will be
avoided and hyperv_paravisor_present will no longer be needed.
Call hv_vtom_init() when it's a VBS VM or when ms_hyperv.paravisor_present
is true, i.e. the VM is a SNP VM or TDX VM with the paravisor.
Enhance hv_vtom_init() for a TDX VM with the paravisor.
In hv_common_cpu_init(), don't decrypt the hyperv_pcpu_input_arg
for a TDX VM with the paravisor, just like we don't decrypt the page
for a SNP VM with the paravisor.
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20230824080712.30327-7-decui@microsoft.com
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Don't set *this_cpu_ptr(hyperv_pcpu_input_arg) before the function
set_memory_decrypted() returns, otherwise we run into this ticky issue:
For a fully enlightened TDX/SNP VM, in hv_common_cpu_init(),
*this_cpu_ptr(hyperv_pcpu_input_arg) is an encrypted page before
the set_memory_decrypted() returns.
When such a VM has more than 64 VPs, if the hyperv_pcpu_input_arg is not
NULL, hv_common_cpu_init() -> set_memory_decrypted() -> ... ->
cpa_flush() -> on_each_cpu() -> ... -> hv_send_ipi_mask() -> ... ->
__send_ipi_mask_ex() tries to call hv_do_rep_hypercall() with the
hyperv_pcpu_input_arg as the hypercall input page, which must be a
decrypted page in such a VM, but the page is still encrypted at this
point, and a fatal fault is triggered.
Fix the issue by setting *this_cpu_ptr(hyperv_pcpu_input_arg) after
set_memory_decrypted(): if the hyperv_pcpu_input_arg is NULL,
__send_ipi_mask_ex() returns HV_STATUS_INVALID_PARAMETER immediately,
and hv_send_ipi_mask() falls back to orig_apic.send_IPI_mask(),
which can use x2apic_send_IPI_all(), which may be slightly slower than
the hypercall but still works correctly in such a VM.
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20230824080712.30327-6-decui@microsoft.com
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When a fully enlightened TDX guest runs on Hyper-V, the UEFI firmware sets
the HW_REDUCED flag and consequently ttyS0 interrupts can't work. Fix the
issue by overriding x86_init.acpi.reduced_hw_early_init().
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20230824080712.30327-5-decui@microsoft.com
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Add Hyper-V specific code so that a fully enlightened TDX guest (i.e.
without the paravisor) can run on Hyper-V:
Don't use hv_vp_assist_page. Use GHCI instead.
Don't try to use the unsupported HV_REGISTER_CRASH_CTL.
Don't trust (use) Hyper-V's TLB-flushing hypercalls.
Don't use lazy EOI.
Share the SynIC Event/Message pages with the hypervisor.
Don't use the Hyper-V TSC page for now, because non-trivial work is
required to share the page with the hypervisor.
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20230824080712.30327-4-decui@microsoft.com
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A fully enlightened TDX guest on Hyper-V (i.e. without the paravisor) only
uses the GHCI call rather than hv_hypercall_pg. Do not initialize
hypercall_pg for such a guest.
In hv_common_cpu_init(), the hyperv_pcpu_input_arg page needs to be
decrypted in such a guest.
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20230824080712.30327-3-decui@microsoft.com
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No logic change to SNP/VBS guests.
hv_isolation_type_tdx() will be used to instruct a TDX guest on Hyper-V to
do some TDX-specific operations, e.g. for a fully enlightened TDX guest
(i.e. without the paravisor), hv_do_hypercall() should use
__tdx_hypercall() and such a guest on Hyper-V should handle the Hyper-V
Event/Message/Monitor pages specially.
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20230824080712.30327-2-decui@microsoft.com
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Add the comment to explain that while_each_thread(g,t) is not rcu-safe
unless g is stable (e.g. current). Even if g is a group leader and thus
can't exit before t, t or another sub-thread can exec and remove g from
the thread_group list.
The only lockless user of while_each_thread() is first_tid() and it is
fine in that it can't loop forever, yet for_each_thread() looks better and
I am going to change while_each_thread/next_thread.
Link: https://lkml.kernel.org/r/20230823170806.GA11724@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Merge padding, shrinking "struct memdev" from 32 bytes to 24 bytes
on 64-bit.
Link: https://lkml.kernel.org/r/fe4d62ab-2427-4635-b9f4-467853fb63e3@p183
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
crash_prepare_elf64_headers() writes into the elfcorehdr an ELF PT_NOTE
for all possible CPUs. As such, subsequent changes to CPUs (ie. hot
un/plug, online/offline) do not need to rewrite the elfcorehdr.
The kimage->file_mode term covers kdump images loaded via the
kexec_file_load() syscall. Since crash_prepare_elf64_headers() wrote the
initial elfcorehdr, no update to the elfcorehdr is needed for CPU changes.
The kimage->elfcorehdr_updated term covers kdump images loaded via the
kexec_load() syscall. At least one memory or CPU change must occur to
cause crash_prepare_elf64_headers() to rewrite the elfcorehdr.
Afterwards, no update to the elfcorehdr is needed for CPU changes.
This code is intentionally *NOT* hoisted into crash_handle_hotplug_event()
as it would prevent the arch-specific handler from running for CPU
changes. This would break PPC, for example, which needs to update other
information besides the elfcorehdr, on CPU changes.
Link: https://lkml.kernel.org/r/20230814214446.6659-9-eric.devolder@oracle.com
Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Akhil Raj <lf32.dev@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Weißschuh <linux@weissschuh.net>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The function crash_prepare_elf64_headers() generates the elfcorehdr which
describes the CPUs and memory in the system for the crash kernel. In
particular, it writes out ELF PT_NOTEs for memory regions and the CPUs in
the system.
With respect to the CPUs, the current implementation utilizes
for_each_present_cpu() which means that as CPUs are added and removed, the
elfcorehdr must again be updated to reflect the new set of CPUs.
The reasoning behind the move to use for_each_possible_cpu(), is:
- At kernel boot time, all percpu crash_notes are allocated for all
possible CPUs; that is, crash_notes are not allocated dynamically
when CPUs are plugged/unplugged. Thus the crash_notes for each
possible CPU are always available.
- The crash_prepare_elf64_headers() creates an ELF PT_NOTE per CPU.
Changing to for_each_possible_cpu() is valid as the crash_notes
pointed to by each CPU PT_NOTE are present and always valid.
Furthermore, examining a common crash processing path of:
kernel panic -> crash kernel -> makedumpfile -> 'crash' analyzer
elfcorehdr /proc/vmcore vmcore
reveals how the ELF CPU PT_NOTEs are utilized:
- Upon panic, each CPU is sent an IPI and shuts itself down, recording
its state in its crash_notes. When all CPUs are shutdown, the
crash kernel is launched with a pointer to the elfcorehdr.
- The crash kernel via linux/fs/proc/vmcore.c does not examine or
use the contents of the PT_NOTEs, it exposes them via /proc/vmcore.
- The makedumpfile utility uses /proc/vmcore and reads the CPU
PT_NOTEs to craft a nr_cpus variable, which is reported in a
header but otherwise generally unused. Makedumpfile creates the
vmcore.
- The 'crash' dump analyzer does not appear to reference the CPU
PT_NOTEs. Instead it looks-up the cpu_[possible|present|onlin]_mask
symbols and directly examines those structure contents from vmcore
memory. From that information it is able to determine which CPUs
are present and online, and locate the corresponding crash_notes.
Said differently, it appears that 'crash' analyzer does not rely
on the ELF PT_NOTEs for CPUs; rather it obtains the information
directly via kernel symbols and the memory within the vmcore.
(There maybe other vmcore generating and analysis tools that do use these
PT_NOTEs, but 'makedumpfile' and 'crash' seems to be the most common
solution.)
This results in the benefit of having all CPUs described in the
elfcorehdr, and therefore reducing the need to re-generate the elfcorehdr
on CPU changes, at the small expense of an additional 56 bytes per PT_NOTE
for not-present-but-possible CPUs.
On systems where kexec_file_load() syscall is utilized, all the above is
valid. On systems where kexec_load() syscall is utilized, there may be
the need for the elfcorehdr to be regenerated once. The reason being that
some archs only populate the 'present' CPUs from the
/sys/devices/system/cpus entries, which the userspace 'kexec' utility uses
to generate the userspace-supplied elfcorehdr. In this situation, one
memory or CPU change will rewrite the elfcorehdr via the
crash_prepare_elf64_headers() function and now all possible CPUs will be
described, just as with kexec_file_load() syscall.
Link: https://lkml.kernel.org/r/20230814214446.6659-8-eric.devolder@oracle.com
Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
Suggested-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Akhil Raj <lf32.dev@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Weißschuh <linux@weissschuh.net>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The hotplug support for kexec_load() requires changes to the userspace
kexec-tools and a little extra help from the kernel.
Given a kdump capture kernel loaded via kexec_load(), and a subsequent
hotplug event, the crash hotplug handler finds the elfcorehdr and rewrites
it to reflect the hotplug change. That is the desired outcome, however,
at kernel panic time, the purgatory integrity check fails (because the
elfcorehdr changed), and the capture kernel does not boot and no vmcore is
generated.
Therefore, the userspace kexec-tools/kexec must indicate to the kernel
that the elfcorehdr can be modified (because the kexec excluded the
elfcorehdr from the digest, and sized the elfcorehdr memory buffer
appropriately).
To facilitate hotplug support with kexec_load():
- a new kexec flag KEXEC_UPATE_ELFCOREHDR indicates that it is
safe for the kernel to modify the kexec_load()'d elfcorehdr
- the /sys/kernel/crash_elfcorehdr_size node communicates the
preferred size of the elfcorehdr memory buffer
- The sysfs crash_hotplug nodes (ie.
/sys/devices/system/[cpu|memory]/crash_hotplug) dynamically
take into account kexec_file_load() vs kexec_load() and
KEXEC_UPDATE_ELFCOREHDR.
This is critical so that the udev rule processing of crash_hotplug
is all that is needed to determine if the userspace unload-then-load
of the kdump image is to be skipped, or not. The proposed udev
rule change looks like:
# The kernel updates the crash elfcorehdr for CPU and memory changes
SUBSYSTEM=="cpu", ATTRS{crash_hotplug}=="1", GOTO="kdump_reload_end"
SUBSYSTEM=="memory", ATTRS{crash_hotplug}=="1", GOTO="kdump_reload_end"
The table below indicates the behavior of kexec_load()'d kdump image
updates (with the new udev crash_hotplug rule in place):
Kernel |Kexec
-------+-----+----
Old |Old |New
| a | a
-------+-----+----
New | a | b
-------+-----+----
where kexec 'old' and 'new' delineate kexec-tools has the needed
modifications for the crash hotplug feature, and kernel 'old' and 'new'
delineate the kernel supports this crash hotplug feature.
Behavior 'a' indicates the unload-then-reload of the entire kdump image.
For the kexec 'old' column, the unload-then-reload occurs due to the
missing flag KEXEC_UPDATE_ELFCOREHDR. An 'old' kernel (with 'new' kexec)
does not present the crash_hotplug sysfs node, which leads to the
unload-then-reload of the kdump image.
Behavior 'b' indicates the desired optimized behavior of the kernel
directly modifying the elfcorehdr and avoiding the unload-then-reload of
the kdump image.
If the udev rule is not updated with crash_hotplug node check, then no
matter any combination of kernel or kexec is new or old, the kdump image
continues to be unload-then-reload on hotplug changes.
To fully support crash hotplug feature, there needs to be a rollout of
kernel, kexec-tools and udev rule changes. However, the order of the
rollout of these pieces does not matter; kexec_load()'d kdump images still
function for hotplug as-is.
Link: https://lkml.kernel.org/r/20230814214446.6659-7-eric.devolder@oracle.com
Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
Suggested-by: Hari Bathini <hbathini@linux.ibm.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Akhil Raj <lf32.dev@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Sourabh Jain <sourabhjain@linux.ibm.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Weißschuh <linux@weissschuh.net>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
When CPU or memory is hot un/plugged, or off/onlined, the crash
elfcorehdr, which describes the CPUs and memory in the system, must also
be updated.
A new elfcorehdr is generated from the available CPUs and memory and
replaces the existing elfcorehdr. The segment containing the elfcorehdr
is identified at run-time in crash_core:crash_handle_hotplug_event().
No modifications to purgatory (see 'kexec: exclude elfcorehdr from the
segment digest') or boot_params (as the elfcorehdr= capture kernel command
line parameter pointer remains unchanged and correct) are needed, just
elfcorehdr.
For kexec_file_load(), the elfcorehdr segment size is based on NR_CPUS and
CRASH_MAX_MEMORY_RANGES in order to accommodate a growing number of CPU
and memory resources.
For kexec_load(), the userspace kexec utility needs to size the elfcorehdr
segment in the same/similar manner.
To accommodate kexec_load() syscall in the absence of kexec_file_load()
syscall support, prepare_elf_headers() and dependents are moved outside of
CONFIG_KEXEC_FILE.
[eric.devolder@oracle.com: correct unused function build error]
Link: https://lkml.kernel.org/r/20230821182644.2143-1-eric.devolder@oracle.com
Link: https://lkml.kernel.org/r/20230814214446.6659-6-eric.devolder@oracle.com
Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Akhil Raj <lf32.dev@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Weißschuh <linux@weissschuh.net>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Introduce the crash_hotplug attribute for memory and CPUs for use by
userspace. These attributes directly facilitate the udev rule for
managing userspace re-loading of the crash kernel upon hot un/plug
changes.
For memory, expose the crash_hotplug attribute to the
/sys/devices/system/memory directory. For example:
# udevadm info --attribute-walk /sys/devices/system/memory/memory81
looking at device '/devices/system/memory/memory81':
KERNEL=="memory81"
SUBSYSTEM=="memory"
DRIVER==""
ATTR{online}=="1"
ATTR{phys_device}=="0"
ATTR{phys_index}=="00000051"
ATTR{removable}=="1"
ATTR{state}=="online"
ATTR{valid_zones}=="Movable"
looking at parent device '/devices/system/memory':
KERNELS=="memory"
SUBSYSTEMS==""
DRIVERS==""
ATTRS{auto_online_blocks}=="offline"
ATTRS{block_size_bytes}=="8000000"
ATTRS{crash_hotplug}=="1"
For CPUs, expose the crash_hotplug attribute to the
/sys/devices/system/cpu directory. For example:
# udevadm info --attribute-walk /sys/devices/system/cpu/cpu0
looking at device '/devices/system/cpu/cpu0':
KERNEL=="cpu0"
SUBSYSTEM=="cpu"
DRIVER=="processor"
ATTR{crash_notes}=="277c38600"
ATTR{crash_notes_size}=="368"
ATTR{online}=="1"
looking at parent device '/devices/system/cpu':
KERNELS=="cpu"
SUBSYSTEMS==""
DRIVERS==""
ATTRS{crash_hotplug}=="1"
ATTRS{isolated}==""
ATTRS{kernel_max}=="8191"
ATTRS{nohz_full}==" (null)"
ATTRS{offline}=="4-7"
ATTRS{online}=="0-3"
ATTRS{possible}=="0-7"
ATTRS{present}=="0-3"
With these sysfs attributes in place, it is possible to efficiently
instruct the udev rule to skip crash kernel reloading for kernels
configured with crash hotplug support.
For example, the following is the proposed udev rule change for RHEL
system 98-kexec.rules (as the first lines of the rule file):
# The kernel updates the crash elfcorehdr for CPU and memory changes
SUBSYSTEM=="cpu", ATTRS{crash_hotplug}=="1", GOTO="kdump_reload_end"
SUBSYSTEM=="memory", ATTRS{crash_hotplug}=="1", GOTO="kdump_reload_end"
When examined in the context of 98-kexec.rules, the above rules test if
crash_hotplug is set, and if so, the userspace initiated
unload-then-reload of the crash kernel is skipped.
CPU and memory checks are separated in accordance with CONFIG_HOTPLUG_CPU
and CONFIG_MEMORY_HOTPLUG kernel config options. If an architecture
supports, for example, memory hotplug but not CPU hotplug, then the
/sys/devices/system/memory/crash_hotplug attribute file is present, but
the /sys/devices/system/cpu/crash_hotplug attribute file will NOT be
present. Thus the udev rule skips userspace processing of memory hot
un/plug events, but the udev rule will evaluate false for CPU events, thus
allowing userspace to process CPU hot un/plug events (ie the
unload-then-reload of the kdump capture kernel).
Link: https://lkml.kernel.org/r/20230814214446.6659-5-eric.devolder@oracle.com
Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Akhil Raj <lf32.dev@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Weißschuh <linux@weissschuh.net>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
When a crash kernel is loaded via the kexec_file_load() syscall, the
kernel places the various segments (ie crash kernel, crash initrd,
boot_params, elfcorehdr, purgatory, etc) in memory. For those
architectures that utilize purgatory, a hash digest of the segments is
calculated for integrity checking. The digest is embedded into the
purgatory image prior to placing in memory.
Updates to the elfcorehdr in response to CPU and memory changes would
cause the purgatory integrity checking to fail (at crash time, and no
vmcore created). Therefore, the elfcorehdr segment is explicitly excluded
from the purgatory digest, enabling updates to the elfcorehdr while also
avoiding the need to recompute the hash digest and reload purgatory.
Link: https://lkml.kernel.org/r/20230814214446.6659-4-eric.devolder@oracle.com
Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
Suggested-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Akhil Raj <lf32.dev@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Weißschuh <linux@weissschuh.net>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
To support crash hotplug, a mechanism is needed to update the crash
elfcorehdr upon CPU or memory changes (eg. hot un/plug or off/ onlining).
The crash elfcorehdr describes the CPUs and memory to be written into the
vmcore.
To track CPU changes, callbacks are registered with the cpuhp mechanism
via cpuhp_setup_state_nocalls(CPUHP_BP_PREPARE_DYN). The crash hotplug
elfcorehdr update has no explicit ordering requirement (relative to other
cpuhp states), so meets the criteria for utilizing CPUHP_BP_PREPARE_DYN.
CPUHP_BP_PREPARE_DYN is a dynamic state and avoids the need to introduce a
new state for crash hotplug. Also, CPUHP_BP_PREPARE_DYN is the last state
in the PREPARE group, just prior to the STARTING group, which is very
close to the CPU starting up in a plug/online situation, or stopping in a
unplug/ offline situation. This minimizes the window of time during an
actual plug/online or unplug/offline situation in which the elfcorehdr
would be inaccurate. Note that for a CPU being unplugged or offlined, the
CPU will still be present in the list of CPUs generated by
crash_prepare_elf64_headers(). However, there is no need to explicitly
omit the CPU, see justification in 'crash: change
crash_prepare_elf64_headers() to for_each_possible_cpu()'.
To track memory changes, a notifier is registered to capture the memblock
MEM_ONLINE and MEM_OFFLINE events via register_memory_notifier().
The CPU callbacks and memory notifiers invoke crash_handle_hotplug_event()
which performs needed tasks and then dispatches the event to the
architecture specific arch_crash_handle_hotplug_event() to update the
elfcorehdr with the current state of CPUs and memory. During the process,
the kexec_lock is held.
Link: https://lkml.kernel.org/r/20230814214446.6659-3-eric.devolder@oracle.com
Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Akhil Raj <lf32.dev@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Weißschuh <linux@weissschuh.net>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "crash: Kernel handling of CPU and memory hot un/plug", v28.
Once the kdump service is loaded, if changes to CPUs or memory occur,
either by hot un/plug or off/onlining, the crash elfcorehdr must also be
updated.
The elfcorehdr describes to kdump the CPUs and memory in the system, and
any inaccuracies can result in a vmcore with missing CPU context or memory
regions.
The current solution utilizes udev to initiate an unload-then-reload of
the kdump image (eg. kernel, initrd, boot_params, purgatory and
elfcorehdr) by the userspace kexec utility. In the original post I
outlined the significant performance problems related to offloading this
activity to userspace.
This patchset introduces a generic crash handler that registers with the
CPU and memory notifiers. Upon CPU or memory changes, from either hot
un/plug or off/onlining, this generic handler is invoked and performs
important housekeeping, for example obtaining the appropriate lock, and
then invokes an architecture specific handler to do the appropriate
elfcorehdr update.
Note the description in patch 'crash: change crash_prepare_elf64_headers()
to for_each_possible_cpu()' and 'x86/crash: optimize CPU changes' that
enables further optimizations related to CPU plug/unplug/online/offline
performance of elfcorehdr updates.
In the case of x86_64, the arch specific handler generates a new
elfcorehdr, and overwrites the old one in memory; thus no involvement with
userspace needed.
To realize the benefits/test this patchset, one must make a couple
of minor changes to userspace:
- Prevent udev from updating kdump crash kernel on hot un/plug changes.
Add the following as the first lines to the RHEL udev rule file
/usr/lib/udev/rules.d/98-kexec.rules:
# The kernel updates the crash elfcorehdr for CPU and memory changes
SUBSYSTEM=="cpu", ATTRS{crash_hotplug}=="1", GOTO="kdump_reload_end"
SUBSYSTEM=="memory", ATTRS{crash_hotplug}=="1", GOTO="kdump_reload_end"
With this changeset applied, the two rules evaluate to false for
CPU and memory change events and thus skip the userspace
unload-then-reload of kdump.
- Change to the kexec_file_load for loading the kdump kernel:
Eg. on RHEL: in /usr/bin/kdumpctl, change to:
standard_kexec_args="-p -d -s"
which adds the -s to select kexec_file_load() syscall.
This kernel patchset also supports kexec_load() with a modified kexec
userspace utility. A working changeset to the kexec userspace utility is
posted to the kexec-tools mailing list here:
http://lists.infradead.org/pipermail/kexec/2023-May/027049.html
To use the kexec-tools patch, apply, build and install kexec-tools, then
change the kdumpctl's standard_kexec_args to replace the -s with
--hotplug. The removal of -s reverts to the kexec_load syscall and the
addition of --hotplug invokes the changes put forth in the kexec-tools
patch.
This patch (of 8):
The crash hotplug support leans on the work for the kexec_file_load()
syscall. To also support the kexec_load() syscall, a few bits of code
need to be move outside of CONFIG_KEXEC_FILE. As such, these bits are
moved out of kexec_file.c and into a common location crash_core.c.
In addition, struct crash_mem and crash_notes were moved to new locales so
that PROC_KCORE, which sets CRASH_CORE alone, builds correctly.
No functionality change intended.
Link: https://lkml.kernel.org/r/20230814214446.6659-1-eric.devolder@oracle.com
Link: https://lkml.kernel.org/r/20230814214446.6659-2-eric.devolder@oracle.com
Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Akhil Raj <lf32.dev@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Weißschuh <linux@weissschuh.net>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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Pack the members of struct maple_tree to avoid holes on 64-bit. The size
shrinks from 24 to 16 bytes which will save eight bytes in every structure
which embeds it.
[willy@infradead.org: changelog alterations]
Link: https://lkml.kernel.org/r/20230821225145.2169848-1-mjguzik@gmail.com
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Avoid setting the variables until necessary, and actually use the
variables where applicable. Introducing a variable for the slots array
avoids spanning multiple lines.
Add the missing argument to the documentation.
Use the node type when setting the metadata instead of blindly assuming
the type.
Finally, add a trace point to the function for successful store.
Link: https://lkml.kernel.org/r/20230819004356.1454718-3-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The only caller already has a folio, so use it to save calling
compound_head() in PageLRU() and remove a use of page->mapping.
Link: https://lkml.kernel.org/r/20230822202335.179081-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Since at least kernel 6.1, flush_dcache_page() is called with IRQs
disabled, e.g. from aio_complete().
But the current implementation for flush_dcache_page() on NIOS2
unintentionally re-enables IRQs, which may lead to deadlocks.
Fix it by using xa_lock_irqsave() and xa_unlock_irqrestore() for the
flush_dcache_mmap_*lock() macros instead.
Link: https://lkml.kernel.org/r/ZOTF5WWURQNH9+iw@p100
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
This is an exported symbol, so it should have kernel-doc. Update it to
mention folios, and point out that they might be larger than the supported
page size for this VMA.
Link: https://lkml.kernel.org/r/20230822172459.4190699-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
There are many files in mm/ that contain kernel-doc which is not
currently published on kernel.org. Some of it is easily categorisable,
but most of it is going into the miscellaneous documentation section to
be organised later.
Some files aren't ready to be included; they contain documentation with
build errors. Or they're nommu.c which duplicates documentation from
"real" MMU systems. Those files are noted with a # mark (although really
anything which isn't a recognised directive would do to prevent inclusion)
Link: https://lkml.kernel.org/r/20230818200630.2719595-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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Turn the a), b) into an unordered ReST list and remove the unnecessary
'Note:' prefix.
Link: https://lkml.kernel.org/r/20230818200630.2719595-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Convert the return values to an ReST list and tidy up the wording while
I'm touching it.
[akpm@linux-foundation.org: changes suggested by Randy]
[willy@infradead.org: another change suggested by Randy]
Link: https://lkml.kernel.org/r/ZOUZtZizeQG7PcsM@casper.infradead.org
Link: https://lkml.kernel.org/r/20230818200630.2719595-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "Improve mm documentation".
If you build with W=1, kernel-doc complains about tlb_flush_rmaps(). Then
I ran scripts/find-unused-docs.sh against mm/ and found a large number of
files which weren't included in the ReST documentation. I fixed up a
couple of them, and added all those without erros to the rst files.
There's a lot more work to do to organise all of this, but at least now if
we have documentation that refers to these functions, we'll get a nice
link to them.
This patch (of 4):
The vma parameter wasn't described.
Link: https://lkml.kernel.org/r/20230818200630.2719595-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20230818200630.2719595-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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