License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 17:07:57 +03:00
|
|
|
/* SPDX-License-Identifier: GPL-2.0 */
|
2015-06-19 14:54:23 +03:00
|
|
|
#ifndef __KVM_X86_PMU_H
|
|
|
|
|
#define __KVM_X86_PMU_H
|
|
|
|
|
|
2019-12-11 23:47:48 +03:00
|
|
|
#include <linux/nospec.h>
|
|
|
|
|
|
2015-06-19 14:54:23 +03:00
|
|
|
#define vcpu_to_pmu(vcpu) (&(vcpu)->arch.pmu)
|
|
|
|
|
#define pmu_to_vcpu(pmu) (container_of((pmu), struct kvm_vcpu, arch.pmu))
|
|
|
|
|
#define pmc_to_pmu(pmc) (&(pmc)->vcpu->arch.pmu)
|
|
|
|
|
|
2022-06-01 06:19:25 +03:00
|
|
|
#define MSR_IA32_MISC_ENABLE_PMU_RO_MASK (MSR_IA32_MISC_ENABLE_PEBS_UNAVAIL | \
|
|
|
|
|
MSR_IA32_MISC_ENABLE_BTS_UNAVAIL)
|
|
|
|
|
|
2015-06-19 16:45:05 +03:00
|
|
|
/* retrieve the 4 bits for EN and PMI out of IA32_FIXED_CTR_CTRL */
|
|
|
|
|
#define fixed_ctrl_field(ctrl_reg, idx) (((ctrl_reg) >> ((idx)*4)) & 0xf)
|
|
|
|
|
|
2018-03-12 14:12:53 +03:00
|
|
|
#define VMWARE_BACKDOOR_PMC_HOST_TSC 0x10000
|
|
|
|
|
#define VMWARE_BACKDOOR_PMC_REAL_TIME 0x10001
|
|
|
|
|
#define VMWARE_BACKDOOR_PMC_APPARENT_TIME 0x10002
|
|
|
|
|
|
2015-06-19 16:45:05 +03:00
|
|
|
struct kvm_pmu_ops {
|
2022-05-18 16:25:12 +03:00
|
|
|
bool (*hw_event_available)(struct kvm_pmc *pmc);
|
2015-06-19 16:45:05 +03:00
|
|
|
bool (*pmc_is_enabled)(struct kvm_pmc *pmc);
|
|
|
|
|
struct kvm_pmc *(*pmc_idx_to_pmc)(struct kvm_pmu *pmu, int pmc_idx);
|
2019-10-27 13:52:40 +03:00
|
|
|
struct kvm_pmc *(*rdpmc_ecx_to_pmc)(struct kvm_vcpu *vcpu,
|
|
|
|
|
unsigned int idx, u64 *mask);
|
2019-10-27 13:52:41 +03:00
|
|
|
struct kvm_pmc *(*msr_idx_to_pmc)(struct kvm_vcpu *vcpu, u32 msr);
|
2021-11-05 23:20:58 +03:00
|
|
|
bool (*is_valid_rdpmc_ecx)(struct kvm_vcpu *vcpu, unsigned int idx);
|
2022-06-11 03:57:52 +03:00
|
|
|
bool (*is_valid_msr)(struct kvm_vcpu *vcpu, u32 msr);
|
2020-05-29 10:43:44 +03:00
|
|
|
int (*get_msr)(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
|
2015-06-19 16:45:05 +03:00
|
|
|
int (*set_msr)(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
|
|
|
|
|
void (*refresh)(struct kvm_vcpu *vcpu);
|
|
|
|
|
void (*init)(struct kvm_vcpu *vcpu);
|
|
|
|
|
void (*reset)(struct kvm_vcpu *vcpu);
|
2021-02-01 08:10:36 +03:00
|
|
|
void (*deliver_pmi)(struct kvm_vcpu *vcpu);
|
2021-02-01 08:10:37 +03:00
|
|
|
void (*cleanup)(struct kvm_vcpu *vcpu);
|
2022-12-20 19:12:30 +03:00
|
|
|
|
|
|
|
|
const u64 EVENTSEL_EVENT;
|
2023-01-25 02:49:00 +03:00
|
|
|
const int MAX_NR_GP_COUNTERS;
|
2015-06-19 16:45:05 +03:00
|
|
|
};
|
|
|
|
|
|
2022-03-30 02:50:52 +03:00
|
|
|
void kvm_pmu_ops_update(const struct kvm_pmu_ops *pmu_ops);
|
|
|
|
|
|
2015-06-19 16:45:05 +03:00
|
|
|
static inline u64 pmc_bitmask(struct kvm_pmc *pmc)
|
|
|
|
|
{
|
|
|
|
|
struct kvm_pmu *pmu = pmc_to_pmu(pmc);
|
|
|
|
|
|
|
|
|
|
return pmu->counter_bitmask[pmc->type];
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline u64 pmc_read_counter(struct kvm_pmc *pmc)
|
|
|
|
|
{
|
|
|
|
|
u64 counter, enabled, running;
|
|
|
|
|
|
|
|
|
|
counter = pmc->counter;
|
KVM: x86/pmu: Introduce pmc->is_paused to reduce the call time of perf interfaces
Based on our observations, after any vm-exit associated with vPMU, there
are at least two or more perf interfaces to be called for guest counter
emulation, such as perf_event_{pause, read_value, period}(), and each one
will {lock, unlock} the same perf_event_ctx. The frequency of calls becomes
more severe when guest use counters in a multiplexed manner.
Holding a lock once and completing the KVM request operations in the perf
context would introduce a set of impractical new interfaces. So we can
further optimize the vPMU implementation by avoiding repeated calls to
these interfaces in the KVM context for at least one pattern:
After we call perf_event_pause() once, the event will be disabled and its
internal count will be reset to 0. So there is no need to pause it again
or read its value. Once the event is paused, event period will not be
updated until the next time it's resumed or reprogrammed. And there is
also no need to call perf_event_period twice for a non-running counter,
considering the perf_event for a running counter is never paused.
Based on this implementation, for the following common usage of
sampling 4 events using perf on a 4u8g guest:
echo 0 > /proc/sys/kernel/watchdog
echo 25 > /proc/sys/kernel/perf_cpu_time_max_percent
echo 10000 > /proc/sys/kernel/perf_event_max_sample_rate
echo 0 > /proc/sys/kernel/perf_cpu_time_max_percent
for i in `seq 1 1 10`
do
taskset -c 0 perf record \
-e cpu-cycles -e instructions -e branch-instructions -e cache-misses \
/root/br_instr a
done
the average latency of the guest NMI handler is reduced from
37646.7 ns to 32929.3 ns (~1.14x speed up) on the Intel ICX server.
Also, in addition to collecting more samples, no loss of sampling
accuracy was observed compared to before the optimization.
Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20210728120705.6855-1-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
2021-07-28 15:07:05 +03:00
|
|
|
if (pmc->perf_event && !pmc->is_paused)
|
2015-06-19 16:45:05 +03:00
|
|
|
counter += perf_event_read_value(pmc->perf_event,
|
|
|
|
|
&enabled, &running);
|
|
|
|
|
/* FIXME: Scaling needed? */
|
|
|
|
|
return counter & pmc_bitmask(pmc);
|
|
|
|
|
}
|
|
|
|
|
|
KVM: x86/vPMU: Reuse perf_event to avoid unnecessary pmc_reprogram_counter
The perf_event_create_kernel_counter() in the pmc_reprogram_counter() is
a heavyweight and high-frequency operation, especially when host disables
the watchdog (maximum 21000000 ns) which leads to an unacceptable latency
of the guest NMI handler. It limits the use of vPMUs in the guest.
When a vPMC is fully enabled, the legacy reprogram_*_counter() would stop
and release its existing perf_event (if any) every time EVEN in most cases
almost the same requested perf_event will be created and configured again.
For each vPMC, if the reuqested config ('u64 eventsel' for gp and 'u8 ctrl'
for fixed) is the same as its current config AND a new sample period based
on pmc->counter is accepted by host perf interface, the current event could
be reused safely as a new created one does. Otherwise, do release the
undesirable perf_event and reprogram a new one as usual.
It's light-weight to call pmc_pause_counter (disable, read and reset event)
and pmc_resume_counter (recalibrate period and re-enable event) as guest
expects instead of release-and-create again on any condition. Compared to
use the filterable event->attr or hw.config, a new 'u64 current_config'
field is added to save the last original programed config for each vPMC.
Based on this implementation, the number of calls to pmc_reprogram_counter
is reduced by ~82.5% for a gp sampling event and ~99.9% for a fixed event.
In the usage of multiplexing perf sampling mode, the average latency of the
guest NMI handler is reduced from 104923 ns to 48393 ns (~2.16x speed up).
If host disables watchdog, the minimum latecy of guest NMI handler could be
speed up at ~3413x (from 20407603 to 5979 ns) and at ~786x in the average.
Suggested-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Like Xu <like.xu@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-27 13:52:42 +03:00
|
|
|
static inline void pmc_release_perf_event(struct kvm_pmc *pmc)
|
2015-06-19 16:45:05 +03:00
|
|
|
{
|
|
|
|
|
if (pmc->perf_event) {
|
|
|
|
|
perf_event_release_kernel(pmc->perf_event);
|
|
|
|
|
pmc->perf_event = NULL;
|
KVM: x86/vPMU: Reuse perf_event to avoid unnecessary pmc_reprogram_counter
The perf_event_create_kernel_counter() in the pmc_reprogram_counter() is
a heavyweight and high-frequency operation, especially when host disables
the watchdog (maximum 21000000 ns) which leads to an unacceptable latency
of the guest NMI handler. It limits the use of vPMUs in the guest.
When a vPMC is fully enabled, the legacy reprogram_*_counter() would stop
and release its existing perf_event (if any) every time EVEN in most cases
almost the same requested perf_event will be created and configured again.
For each vPMC, if the reuqested config ('u64 eventsel' for gp and 'u8 ctrl'
for fixed) is the same as its current config AND a new sample period based
on pmc->counter is accepted by host perf interface, the current event could
be reused safely as a new created one does. Otherwise, do release the
undesirable perf_event and reprogram a new one as usual.
It's light-weight to call pmc_pause_counter (disable, read and reset event)
and pmc_resume_counter (recalibrate period and re-enable event) as guest
expects instead of release-and-create again on any condition. Compared to
use the filterable event->attr or hw.config, a new 'u64 current_config'
field is added to save the last original programed config for each vPMC.
Based on this implementation, the number of calls to pmc_reprogram_counter
is reduced by ~82.5% for a gp sampling event and ~99.9% for a fixed event.
In the usage of multiplexing perf sampling mode, the average latency of the
guest NMI handler is reduced from 104923 ns to 48393 ns (~2.16x speed up).
If host disables watchdog, the minimum latecy of guest NMI handler could be
speed up at ~3413x (from 20407603 to 5979 ns) and at ~786x in the average.
Suggested-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Like Xu <like.xu@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-27 13:52:42 +03:00
|
|
|
pmc->current_config = 0;
|
2019-10-27 13:52:43 +03:00
|
|
|
pmc_to_pmu(pmc)->event_count--;
|
KVM: x86/vPMU: Reuse perf_event to avoid unnecessary pmc_reprogram_counter
The perf_event_create_kernel_counter() in the pmc_reprogram_counter() is
a heavyweight and high-frequency operation, especially when host disables
the watchdog (maximum 21000000 ns) which leads to an unacceptable latency
of the guest NMI handler. It limits the use of vPMUs in the guest.
When a vPMC is fully enabled, the legacy reprogram_*_counter() would stop
and release its existing perf_event (if any) every time EVEN in most cases
almost the same requested perf_event will be created and configured again.
For each vPMC, if the reuqested config ('u64 eventsel' for gp and 'u8 ctrl'
for fixed) is the same as its current config AND a new sample period based
on pmc->counter is accepted by host perf interface, the current event could
be reused safely as a new created one does. Otherwise, do release the
undesirable perf_event and reprogram a new one as usual.
It's light-weight to call pmc_pause_counter (disable, read and reset event)
and pmc_resume_counter (recalibrate period and re-enable event) as guest
expects instead of release-and-create again on any condition. Compared to
use the filterable event->attr or hw.config, a new 'u64 current_config'
field is added to save the last original programed config for each vPMC.
Based on this implementation, the number of calls to pmc_reprogram_counter
is reduced by ~82.5% for a gp sampling event and ~99.9% for a fixed event.
In the usage of multiplexing perf sampling mode, the average latency of the
guest NMI handler is reduced from 104923 ns to 48393 ns (~2.16x speed up).
If host disables watchdog, the minimum latecy of guest NMI handler could be
speed up at ~3413x (from 20407603 to 5979 ns) and at ~786x in the average.
Suggested-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Like Xu <like.xu@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-27 13:52:42 +03:00
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline void pmc_stop_counter(struct kvm_pmc *pmc)
|
|
|
|
|
{
|
|
|
|
|
if (pmc->perf_event) {
|
|
|
|
|
pmc->counter = pmc_read_counter(pmc);
|
|
|
|
|
pmc_release_perf_event(pmc);
|
2015-06-19 16:45:05 +03:00
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline bool pmc_is_gp(struct kvm_pmc *pmc)
|
|
|
|
|
{
|
|
|
|
|
return pmc->type == KVM_PMC_GP;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline bool pmc_is_fixed(struct kvm_pmc *pmc)
|
|
|
|
|
{
|
|
|
|
|
return pmc->type == KVM_PMC_FIXED;
|
|
|
|
|
}
|
|
|
|
|
|
2019-11-14 03:17:15 +03:00
|
|
|
static inline bool kvm_valid_perf_global_ctrl(struct kvm_pmu *pmu,
|
|
|
|
|
u64 data)
|
|
|
|
|
{
|
|
|
|
|
return !(pmu->global_ctrl_mask & data);
|
|
|
|
|
}
|
|
|
|
|
|
2015-06-19 16:45:05 +03:00
|
|
|
/* returns general purpose PMC with the specified MSR. Note that it can be
|
|
|
|
|
* used for both PERFCTRn and EVNTSELn; that is why it accepts base as a
|
2021-03-18 17:28:01 +03:00
|
|
|
* parameter to tell them apart.
|
2015-06-19 16:45:05 +03:00
|
|
|
*/
|
|
|
|
|
static inline struct kvm_pmc *get_gp_pmc(struct kvm_pmu *pmu, u32 msr,
|
|
|
|
|
u32 base)
|
|
|
|
|
{
|
2019-12-11 23:47:48 +03:00
|
|
|
if (msr >= base && msr < base + pmu->nr_arch_gp_counters) {
|
|
|
|
|
u32 index = array_index_nospec(msr - base,
|
|
|
|
|
pmu->nr_arch_gp_counters);
|
|
|
|
|
|
|
|
|
|
return &pmu->gp_counters[index];
|
|
|
|
|
}
|
2015-06-19 16:45:05 +03:00
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* returns fixed PMC with the specified MSR */
|
|
|
|
|
static inline struct kvm_pmc *get_fixed_pmc(struct kvm_pmu *pmu, u32 msr)
|
|
|
|
|
{
|
|
|
|
|
int base = MSR_CORE_PERF_FIXED_CTR0;
|
|
|
|
|
|
2019-12-11 23:47:48 +03:00
|
|
|
if (msr >= base && msr < base + pmu->nr_arch_fixed_counters) {
|
|
|
|
|
u32 index = array_index_nospec(msr - base,
|
|
|
|
|
pmu->nr_arch_fixed_counters);
|
|
|
|
|
|
|
|
|
|
return &pmu->fixed_counters[index];
|
|
|
|
|
}
|
2015-06-19 16:45:05 +03:00
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
2020-02-22 05:34:13 +03:00
|
|
|
static inline u64 get_sample_period(struct kvm_pmc *pmc, u64 counter_value)
|
|
|
|
|
{
|
|
|
|
|
u64 sample_period = (-counter_value) & pmc_bitmask(pmc);
|
|
|
|
|
|
|
|
|
|
if (!sample_period)
|
|
|
|
|
sample_period = pmc_bitmask(pmc) + 1;
|
|
|
|
|
return sample_period;
|
|
|
|
|
}
|
|
|
|
|
|
2022-04-09 04:52:26 +03:00
|
|
|
static inline void pmc_update_sample_period(struct kvm_pmc *pmc)
|
|
|
|
|
{
|
2022-12-07 10:15:05 +03:00
|
|
|
if (!pmc->perf_event || pmc->is_paused ||
|
|
|
|
|
!is_sampling_event(pmc->perf_event))
|
2022-04-09 04:52:26 +03:00
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
perf_event_period(pmc->perf_event,
|
|
|
|
|
get_sample_period(pmc, pmc->counter));
|
|
|
|
|
}
|
|
|
|
|
|
2022-04-11 13:19:42 +03:00
|
|
|
static inline bool pmc_speculative_in_use(struct kvm_pmc *pmc)
|
|
|
|
|
{
|
|
|
|
|
struct kvm_pmu *pmu = pmc_to_pmu(pmc);
|
|
|
|
|
|
|
|
|
|
if (pmc_is_fixed(pmc))
|
|
|
|
|
return fixed_ctrl_field(pmu->fixed_ctr_ctrl,
|
|
|
|
|
pmc->idx - INTEL_PMC_IDX_FIXED) & 0x3;
|
|
|
|
|
|
|
|
|
|
return pmc->eventsel & ARCH_PERFMON_EVENTSEL_ENABLE;
|
|
|
|
|
}
|
|
|
|
|
|
2022-04-11 13:19:44 +03:00
|
|
|
extern struct x86_pmu_capability kvm_pmu_cap;
|
|
|
|
|
|
2023-01-25 02:49:00 +03:00
|
|
|
static inline void kvm_init_pmu_capability(const struct kvm_pmu_ops *pmu_ops)
|
2022-04-11 13:19:44 +03:00
|
|
|
{
|
2022-05-18 20:01:18 +03:00
|
|
|
bool is_intel = boot_cpu_data.x86_vendor == X86_VENDOR_INTEL;
|
|
|
|
|
|
KVM: x86/pmu: Disable vPMU support on hybrid CPUs (host PMUs)
Disable KVM support for virtualizing PMUs on hosts with hybrid PMUs until
KVM gains a sane way to enumeration the hybrid vPMU to userspace and/or
gains a mechanism to let userspace opt-in to the dangers of exposing a
hybrid vPMU to KVM guests. Virtualizing a hybrid PMU, or at least part of
a hybrid PMU, is possible, but it requires careful, deliberate
configuration from userspace.
E.g. to expose full functionality, vCPUs need to be pinned to pCPUs to
prevent migrating a vCPU between a big core and a little core, userspace
must enumerate a reasonable topology to the guest, and guest CPUID must be
curated per vCPU to enumerate accurate vPMU capabilities.
The last point is especially problematic, as KVM doesn't control which
pCPU it runs on when enumerating KVM's vPMU capabilities to userspace,
i.e. userspace can't rely on KVM_GET_SUPPORTED_CPUID in it's current form.
Alternatively, userspace could enable vPMU support by enumerating the
set of features that are common and coherent across all cores, e.g. by
filtering PMU events and restricting guest capabilities. But again, that
requires userspace to take action far beyond reflecting KVM's supported
feature set into the guest.
For now, simply disable vPMU support on hybrid CPUs to avoid inducing
seemingly random #GPs in guests, and punt support for hybrid CPUs to a
future enabling effort.
Reported-by: Jianfeng Gao <jianfeng.gao@intel.com>
Cc: stable@vger.kernel.org
Cc: Andrew Cooper <Andrew.Cooper3@citrix.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Link: https://lore.kernel.org/all/20220818181530.2355034-1-kan.liang@linux.intel.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230208204230.1360502-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-02-08 23:42:29 +03:00
|
|
|
/*
|
|
|
|
|
* Hybrid PMUs don't play nice with virtualization without careful
|
|
|
|
|
* configuration by userspace, and KVM's APIs for reporting supported
|
|
|
|
|
* vPMU features do not account for hybrid PMUs. Disable vPMU support
|
|
|
|
|
* for hybrid PMUs until KVM gains a way to let userspace opt-in.
|
|
|
|
|
*/
|
|
|
|
|
if (cpu_feature_enabled(X86_FEATURE_HYBRID_CPU))
|
2022-05-18 20:01:18 +03:00
|
|
|
enable_pmu = false;
|
2022-06-01 06:19:24 +03:00
|
|
|
|
KVM: x86/pmu: Disable vPMU support on hybrid CPUs (host PMUs)
Disable KVM support for virtualizing PMUs on hosts with hybrid PMUs until
KVM gains a sane way to enumeration the hybrid vPMU to userspace and/or
gains a mechanism to let userspace opt-in to the dangers of exposing a
hybrid vPMU to KVM guests. Virtualizing a hybrid PMU, or at least part of
a hybrid PMU, is possible, but it requires careful, deliberate
configuration from userspace.
E.g. to expose full functionality, vCPUs need to be pinned to pCPUs to
prevent migrating a vCPU between a big core and a little core, userspace
must enumerate a reasonable topology to the guest, and guest CPUID must be
curated per vCPU to enumerate accurate vPMU capabilities.
The last point is especially problematic, as KVM doesn't control which
pCPU it runs on when enumerating KVM's vPMU capabilities to userspace,
i.e. userspace can't rely on KVM_GET_SUPPORTED_CPUID in it's current form.
Alternatively, userspace could enable vPMU support by enumerating the
set of features that are common and coherent across all cores, e.g. by
filtering PMU events and restricting guest capabilities. But again, that
requires userspace to take action far beyond reflecting KVM's supported
feature set into the guest.
For now, simply disable vPMU support on hybrid CPUs to avoid inducing
seemingly random #GPs in guests, and punt support for hybrid CPUs to a
future enabling effort.
Reported-by: Jianfeng Gao <jianfeng.gao@intel.com>
Cc: stable@vger.kernel.org
Cc: Andrew Cooper <Andrew.Cooper3@citrix.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Link: https://lore.kernel.org/all/20220818181530.2355034-1-kan.liang@linux.intel.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230208204230.1360502-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-02-08 23:42:29 +03:00
|
|
|
if (enable_pmu) {
|
|
|
|
|
perf_get_x86_pmu_capability(&kvm_pmu_cap);
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* For Intel, only support guest architectural pmu
|
|
|
|
|
* on a host with architectural pmu.
|
|
|
|
|
*/
|
|
|
|
|
if ((is_intel && !kvm_pmu_cap.version) ||
|
|
|
|
|
!kvm_pmu_cap.num_counters_gp)
|
|
|
|
|
enable_pmu = false;
|
|
|
|
|
}
|
|
|
|
|
|
2022-06-01 06:19:24 +03:00
|
|
|
if (!enable_pmu) {
|
|
|
|
|
memset(&kvm_pmu_cap, 0, sizeof(kvm_pmu_cap));
|
2022-05-18 20:01:18 +03:00
|
|
|
return;
|
|
|
|
|
}
|
2022-04-11 13:19:44 +03:00
|
|
|
|
|
|
|
|
kvm_pmu_cap.version = min(kvm_pmu_cap.version, 2);
|
2023-01-25 02:49:00 +03:00
|
|
|
kvm_pmu_cap.num_counters_gp = min(kvm_pmu_cap.num_counters_gp,
|
|
|
|
|
pmu_ops->MAX_NR_GP_COUNTERS);
|
2022-04-11 13:19:44 +03:00
|
|
|
kvm_pmu_cap.num_counters_fixed = min(kvm_pmu_cap.num_counters_fixed,
|
|
|
|
|
KVM_PMC_MAX_FIXED);
|
|
|
|
|
}
|
|
|
|
|
|
2023-03-10 14:33:49 +03:00
|
|
|
static inline void kvm_pmu_request_counter_reprogram(struct kvm_pmc *pmc)
|
2022-09-23 03:13:54 +03:00
|
|
|
{
|
|
|
|
|
set_bit(pmc->idx, pmc_to_pmu(pmc)->reprogram_pmi);
|
|
|
|
|
kvm_make_request(KVM_REQ_PMU, pmc->vcpu);
|
|
|
|
|
}
|
2015-06-19 16:45:05 +03:00
|
|
|
|
2015-06-19 14:54:23 +03:00
|
|
|
void kvm_pmu_deliver_pmi(struct kvm_vcpu *vcpu);
|
|
|
|
|
void kvm_pmu_handle_event(struct kvm_vcpu *vcpu);
|
|
|
|
|
int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned pmc, u64 *data);
|
2021-11-05 23:20:58 +03:00
|
|
|
bool kvm_pmu_is_valid_rdpmc_ecx(struct kvm_vcpu *vcpu, unsigned int idx);
|
2022-06-11 03:57:52 +03:00
|
|
|
bool kvm_pmu_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr);
|
2020-05-29 10:43:44 +03:00
|
|
|
int kvm_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
|
2015-06-19 14:54:23 +03:00
|
|
|
int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
|
|
|
|
|
void kvm_pmu_refresh(struct kvm_vcpu *vcpu);
|
|
|
|
|
void kvm_pmu_reset(struct kvm_vcpu *vcpu);
|
|
|
|
|
void kvm_pmu_init(struct kvm_vcpu *vcpu);
|
2019-10-27 13:52:43 +03:00
|
|
|
void kvm_pmu_cleanup(struct kvm_vcpu *vcpu);
|
2015-06-19 14:54:23 +03:00
|
|
|
void kvm_pmu_destroy(struct kvm_vcpu *vcpu);
|
2019-07-11 04:25:15 +03:00
|
|
|
int kvm_vm_ioctl_set_pmu_event_filter(struct kvm *kvm, void __user *argp);
|
2021-11-30 10:42:20 +03:00
|
|
|
void kvm_pmu_trigger_event(struct kvm_vcpu *vcpu, u64 perf_hw_id);
|
2015-06-19 14:54:23 +03:00
|
|
|
|
2018-03-12 14:12:53 +03:00
|
|
|
bool is_vmware_backdoor_pmc(u32 pmc_idx);
|
|
|
|
|
|
2015-06-19 16:45:05 +03:00
|
|
|
extern struct kvm_pmu_ops intel_pmu_ops;
|
|
|
|
|
extern struct kvm_pmu_ops amd_pmu_ops;
|
2015-06-19 14:54:23 +03:00
|
|
|
#endif /* __KVM_X86_PMU_H */
|
