Commit Graph

142 Commits

Author SHA1 Message Date
Paolo Bonzini
21adec30f6 kvm: fix memory leak on failure to read stats descriptors
Reported by Coverity as CID 1490142.  Since the size is constant and the
lifetime is the same as the StatsDescriptors struct, embed the struct
directly instead of using a separate allocation.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-09-18 09:17:40 +02:00
Paolo Bonzini
52281c6d11 KVM: use store-release to mark dirty pages as harvested
The following scenario can happen if QEMU sets more RESET flags while
the KVM_RESET_DIRTY_RINGS ioctl is ongoing on another host CPU:

    CPU0                     CPU1               CPU2
    ------------------------ ------------------ ------------------------
                                                fill gfn0
                                                store-rel flags for gfn0
                                                fill gfn1
                                                store-rel flags for gfn1
    load-acq flags for gfn0
    set RESET for gfn0
    load-acq flags for gfn1
    set RESET for gfn1
    do ioctl! ----------->
                             ioctl(RESET_RINGS)
                                                fill gfn2
                                                store-rel flags for gfn2
    load-acq flags for gfn2
    set RESET for gfn2
                             process gfn0
                             process gfn1
                             process gfn2
    do ioctl!
    etc.

The three load-acquire in CPU0 synchronize with the three store-release
in CPU2, but CPU0 and CPU1 are only synchronized up to gfn1 and CPU1
may miss gfn2's fields other than flags.

The kernel must be able to cope with invalid values of the fields, and
userspace *will* invoke the ioctl once more.  However, once the RESET flag
is cleared on gfn2, it is lost forever, therefore in the above scenario
CPU1 must read the correct value of gfn2's fields.

Therefore RESET must be set with a store-release, that will synchronize
with KVM's load-acquire in CPU1.

Cc: Gavin Shan <gshan@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-09-18 09:17:40 +02:00
Paolo Bonzini
4802bf910e KVM: dirty ring: add missing memory barrier
The KVM_DIRTY_GFN_F_DIRTY flag ensures that the entry is valid.  If
the read of the fields are not ordered after the read of the flag,
QEMU might see stale values.

Cc: Gavin Shan <gshan@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-09-01 08:37:04 +02:00
Paolo Bonzini
a9197ad210 kvm: fix segfault with query-stats-schemas and -M none
-M none creates a guest without a vCPU, causing the following error:

$ ./qemu-system-x86_64 -qmp stdio -M none -accel kvm
{execute:qmp_capabilities}
{"return": {}}
{execute: query-stats-schemas}
Segmentation fault (core dumped)

Fix it by not querying the vCPU stats if first_cpu is NULL.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-08-18 14:08:24 +02:00
Cornelia Huck
47c182fe8b kvm: don't use perror() without useful errno
perror() is designed to append the decoded errno value to a
string. This, however, only makes sense if we called something that
actually sets errno prior to that.

For the callers that check for split irqchip support that is not the
case, and we end up with confusing error messages that end in
"success". Use error_report() instead.

Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20220728142446.438177-1-cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-07-29 00:15:02 +02:00
Peter Maydell
d12dd9c7ee accel/kvm: Avoid Coverity warning in query_stats()
Coverity complains that there is a codepath in the query_stats()
function where it can leak the memory pointed to by stats_list.  This
can only happen if the caller passes something other than
STATS_TARGET_VM or STATS_TARGET_VCPU as the 'target', which no
callsite does.  Enforce this assumption using g_assert_not_reached(),
so that if we have a future bug we hit the assert rather than
silently leaking memory.

Resolves: Coverity CID 1490140
Fixes: cc01a3f4ca ("kvm: Support for querying fd-based stats")
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220719134853.327059-1-peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-07-22 19:01:44 +02:00
Peter Maydell
5288bee45f * Boolean statistics for KVM
* Fix build on Haiku
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Merge tag 'for-upstream' of https://gitlab.com/bonzini/qemu into staging

* Boolean statistics for KVM
* Fix build on Haiku

# gpg: Signature made Tue 19 Jul 2022 10:32:34 BST
# gpg:                using RSA key F13338574B662389866C7682BFFBD25F78C7AE83
# gpg:                issuer "pbonzini@redhat.com"
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [full]
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>" [full]
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4  E2F7 7E15 100C CD36 69B1
#      Subkey fingerprint: F133 3857 4B66 2389 866C  7682 BFFB D25F 78C7 AE83

* tag 'for-upstream' of https://gitlab.com/bonzini/qemu:
  util: Fix broken build on Haiku
  kvm: add support for boolean statistics
  monitor: add support for boolean statistics

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-07-21 11:13:01 +01:00
Hyman Huang(黄勇)
baa609832e softmmu/dirtylimit: Implement virtual CPU throttle
Setup a negative feedback system when vCPU thread
handling KVM_EXIT_DIRTY_RING_FULL exit by introducing
throttle_us_per_full field in struct CPUState. Sleep
throttle_us_per_full microseconds to throttle vCPU
if dirtylimit is in service.

Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Reviewed-by: Peter Xu <peterx@redhat.com>
Message-Id: <977e808e03a1cef5151cae75984658b6821be618.1656177590.git.huangy81@chinatelecom.cn>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-07-20 12:15:08 +01:00
Hyman Huang(黄勇)
4a06a7cc05 accel/kvm/kvm-all: Introduce kvm_dirty_ring_size function
Introduce kvm_dirty_ring_size util function to help calculate
dirty ring ful time.

Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Acked-by: Peter Xu <peterx@redhat.com>
Message-Id: <f9ce1f550bfc0e3a1f711e17b1dbc8f701700e56.1656177590.git.huangy81@chinatelecom.cn>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-07-20 12:15:08 +01:00
Hyman Huang(黄勇)
1667e2b97b accel/kvm/kvm-all: Refactor per-vcpu dirty ring reaping
Add a non-required argument 'CPUState' to kvm_dirty_ring_reap so
that it can cover single vcpu dirty-ring-reaping scenario.

Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Reviewed-by: Peter Xu <peterx@redhat.com>
Message-Id: <c32001242875e83b0d9f78f396fe2dcd380ba9e8.1656177590.git.huangy81@chinatelecom.cn>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-07-20 12:15:08 +01:00
Paolo Bonzini
105bb7cdbe kvm: add support for boolean statistics
The next version of Linux will introduce boolean statistics, which
can only have 0 or 1 values.  Convert them to the new QAPI fields
added in the previous commit.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-07-18 18:51:32 +02:00
Miaoqian Lin
f696b74b15 accel: kvm: Fix memory leak in find_stats_descriptors
This function doesn't release descriptors in one error path,
result in memory leak. Call g_free() to release it.

Fixes: cc01a3f4ca ("kvm: Support for querying fd-based stats")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Message-Id: <20220624063159.57411-1-linmq006@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-07-08 11:03:36 +02:00
Paolo Bonzini
cf7405bc02 qmp: add filtering of statistics by name
Allow retrieving only a subset of statistics.  This can be useful
for example in order to plot a subset of the statistics many times
a second: KVM publishes ~40 statistics for each vCPU on x86; retrieving
and serializing all of them would be useless.

Another use will be in HMP in the following patch; implementing the
filter in the backend is easy enough that it was deemed okay to make
this a public interface.

Example:

{ "execute": "query-stats",
  "arguments": {
    "target": "vcpu",
    "vcpus": [ "/machine/unattached/device[2]",
               "/machine/unattached/device[4]" ],
    "providers": [
      { "provider": "kvm",
        "names": [ "l1d_flush", "exits" ] } } }

{ "return": {
    "vcpus": [
      { "path": "/machine/unattached/device[2]"
        "providers": [
          { "provider": "kvm",
            "stats": [ { "name": "l1d_flush", "value": 41213 },
                       { "name": "exits", "value": 74291 } ] } ] },
      { "path": "/machine/unattached/device[4]"
        "providers": [
          { "provider": "kvm",
            "stats": [ { "name": "l1d_flush", "value": 16132 },
                       { "name": "exits", "value": 57922 } ] } ] } ] } }

Extracted from a patch by Mark Kanda.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-14 16:50:30 +02:00
Paolo Bonzini
068cc51d42 qmp: add filtering of statistics by provider
Allow retrieving the statistics from a specific provider only.
This can be used in the future by HMP commands such as "info
sync-profile" or "info profile".  The next patch also adds
filter-by-provider capabilities to the HMP equivalent of
query-stats, "info stats".

Example:

{ "execute": "query-stats",
  "arguments": {
    "target": "vm",
    "providers": [
      { "provider": "kvm" } ] } }

The QAPI is a bit more verbose than just a list of StatsProvider,
so that it can be subsequently extended with filtering of statistics
by name.

If a provider is specified more than once in the filter, each request
will be included separately in the output.

Extracted from a patch by Mark Kanda.

Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-14 16:50:30 +02:00
Paolo Bonzini
467ef823d8 qmp: add filtering of statistics by target vCPU
Introduce a simple filtering of statistics, that allows to retrieve
statistics for a subset of the guest vCPUs.  This will be used for
example by the HMP monitor, in order to retrieve the statistics
for the currently selected CPU.

Example:
{ "execute": "query-stats",
  "arguments": {
    "target": "vcpu",
    "vcpus": [ "/machine/unattached/device[2]",
               "/machine/unattached/device[4]" ] } }

Extracted from a patch by Mark Kanda.

Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-14 16:50:30 +02:00
Mark Kanda
cc01a3f4ca kvm: Support for querying fd-based stats
Add support for querying fd-based KVM stats - as introduced by Linux kernel
commit:

cb082bfab59a ("KVM: stats: Add fd-based API to read binary stats data")

This allows the user to analyze the behavior of the VM without access
to debugfs.

Signed-off-by: Mark Kanda <mark.kanda@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-14 16:50:30 +02:00
Peter Maydell
9323e79f10 Fix 'writeable' typos
We have about 30 instances of the typo/variant spelling 'writeable',
and over 500 of the more common 'writable'.  Standardize on the
latter.

Change produced with:

  sed -i -e 's/\([Ww][Rr][Ii][Tt]\)[Ee]\([Aa][Bb][Ll][Ee]\)/\1\2/g' $(git grep -il writeable)

and then hand-undoing the instance in linux-headers/linux/kvm.h.

Most of these changes are in comments or documentation; the
exceptions are:
 * a local variable in accel/hvf/hvf-accel-ops.c
 * a local variable in accel/kvm/kvm-all.c
 * the PMCR_WRITABLE_MASK macro in target/arm/internals.h
 * the EPT_VIOLATION_GPA_WRITABLE macro in target/i386/hvf/vmcs.h
   (which is never used anywhere)
 * the AR_TYPE_WRITABLE_MASK macro in target/i386/hvf/vmx.h
   (which is never used anywhere)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Message-id: 20220505095015.2714666-1-peter.maydell@linaro.org
2022-06-08 19:38:47 +01:00
Marc-André Lureau
8e3b0cbb72 Replace qemu_real_host_page variables with inlined functions
Replace the global variables with inlined helper functions. getpagesize() is very
likely annotated with a "const" function attribute (at least with glibc), and thus
optimization should apply even better.

This avoids the need for a constructor initialization too.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-12-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-06 10:50:38 +02:00
Marc-André Lureau
ee3eb3a7ce Replace TARGET_WORDS_BIGENDIAN
Convert the TARGET_WORDS_BIGENDIAN macro, similarly to what was done
with HOST_BIG_ENDIAN. The new TARGET_BIG_ENDIAN macro is either 0 or 1,
and thus should always be defined to prevent misuse.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Suggested-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323155743.1585078-8-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-06 10:50:37 +02:00
Marc-André Lureau
e03b56863d Replace config-time define HOST_WORDS_BIGENDIAN
Replace a config-time define with a compile time condition
define (compatible with clang and gcc) that must be declared prior to
its usage. This avoids having a global configure time define, but also
prevents from bad usage, if the config header wasn't included before.

This can help to make some code independent from qemu too.

gcc supports __BYTE_ORDER__ from about 4.6 and clang from 3.2.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
[ For the s390x parts I'm involved in ]
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323155743.1585078-7-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-06 10:50:37 +02:00
Markus Armbruster
b21e238037 Use g_new() & friends where that makes obvious sense
g_new(T, n) is neater than g_malloc(sizeof(T) * n).  It's also safer,
for two reasons.  One, it catches multiplication overflowing size_t.
Two, it returns T * rather than void *, which lets the compiler catch
more type errors.

This commit only touches allocations with size arguments of the form
sizeof(T).

Patch created mechanically with:

    $ spatch --in-place --sp-file scripts/coccinelle/use-g_new-etc.cocci \
	     --macro-file scripts/cocci-macro-file.h FILES...

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20220315144156.1595462-4-armbru@redhat.com>
Reviewed-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
2022-03-21 15:44:44 +01:00
Longpeng(Mike)
def4c5570c kvm/msi: do explicit commit when adding msi routes
We invoke the kvm_irqchip_commit_routes() for each addition to MSI route
table, which is not efficient if we are adding lots of routes in some cases.

This patch lets callers invoke the kvm_irqchip_commit_routes(), so the
callers can decide how to optimize.

[1] https://lists.gnu.org/archive/html/qemu-devel/2021-11/msg00967.html

Signed-off-by: Longpeng <longpeng2@huawei.com>
Message-Id: <20220222141116.2091-3-longpeng2@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-15 11:26:20 +01:00
Philippe Mathieu-Daudé
3919635582 accel: Introduce AccelOpsClass::cpus_are_resettable()
Add cpus_are_resettable() to AccelOps, and implement it for the
KVM accelerator.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220207075426.81934-12-f4bug@amsat.org>
2022-03-06 13:15:42 +01:00
Philippe Mathieu-Daudé
ad7d684dfd accel: Introduce AccelOpsClass::cpu_thread_is_idle()
Add cpu_thread_is_idle() to AccelOps, and implement it for the
KVM / WHPX accelerators.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220207075426.81934-11-f4bug@amsat.org>
2022-03-06 13:15:42 +01:00
Maxim Levitsky
fd2ddd1689 kvm: add support for KVM_GUESTDBG_BLOCKIRQ
Use the KVM_GUESTDBG_BLOCKIRQ debug flag if supported.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
[Extracted from Maxim's patch into a separate commit. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20211111110604.207376-6-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-10 09:47:18 +01:00
Maxim Levitsky
12bc5b4cd5 gdbstub, kvm: let KVM report supported singlestep flags
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
[Extracted from Maxim's patch into a separate commit. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20211111110604.207376-5-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-10 09:47:18 +01:00
Hyman Huang(黄勇)
7786ae40ba KVM: introduce dirty_pages and kvm_dirty_ring_enabled
dirty_pages is used to calculate dirtyrate via dirty ring, when
enabled, kvm-reaper will increase the dirty pages after gfns
being dirtied.

kvm_dirty_ring_enabled shows if kvm-reaper is working. dirtyrate
thread could use it to check if measurement can base on dirty
ring feature.

Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Message-Id: <fee5fb2ab17ec2159405fc54a3cff8e02322f816.1624040308.git.huangy81@chinatelecom.cn>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2021-11-01 22:56:43 +01:00
Philippe Mathieu-Daudé
773ab6cb16 target/i386/kvm: Restrict SEV stubs to x86 architecture
SEV is x86-specific, no need to add its stub to other
architectures. Move the stub file to target/i386/kvm/.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20211007161716.453984-5-philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-13 10:47:49 +02:00
Peter Xu
142518bda5 memory: Name all the memory listeners
Provide a name field for all the memory listeners.  It can be used to identify
which memory listener is which.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210817013553.30584-2-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30 15:30:24 +02:00
Michael Tokarev
7916b5fc8c target/i386: spelling: occured=>occurred, mininum=>minimum
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Message-Id: <20210818141352.417716-1-mjt@msgid.tls.msk.ru>
[lv: add mininum=>minimum in subject]
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2021-09-16 11:51:23 +02:00
Fabiano Rosas
380e49297c kvm: ppc: Print meaningful message on KVM_CREATE_VM failure
PowerPC has two KVM types (HV, PR) that translate into three kernel
modules:

kvm.ko - common kvm code
kvm_hv.ko - kvm running with MSR_HV=1 or MSR_HV|PR=0 in a nested guest.
kvm_pr.ko - kvm running in usermode MSR_PR=1.

Since the two KVM types can both be running at the same time, this
creates a situation in which it is possible for one or both of the
modules to fail to initialize, leaving the generic one behind. This
leads QEMU to think it can create a guest, but KVM will fail when
calling the type-specific code:

 ioctl(KVM_CREATE_VM) failed: 22 Invalid argument
 qemu-kvm: failed to initialize KVM: Invalid argument

Ideally this would be solved kernel-side, but it might be a while
until we can get rid of one of the modules. So in the meantime this
patch tries to make this less confusing for the end user by adding a
more elucidative message:

 ioctl(KVM_CREATE_VM) failed: 22 Invalid argument
 PPC KVM module is not loaded. Try 'modprobe kvm_hv'.

[dwg: Fixed error in #elif which failed compile on !ppc hosts]
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20210722141340.2367905-1-farosas@linux.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2021-07-29 10:59:49 +10:00
Peter Xu
dcafa24827 KVM: Fix dirty ring mmap incorrect size due to renaming accident
Found this when I wanted to try the per-vcpu dirty rate series out, then I
found that it's not really working and it can quickly hang death a guest.  I
found strange errors (e.g. guest crash after migration) happens even without
the per-vcpu dirty rate series.

When merging dirty ring, probably no one notice that the trivial renaming diff
[1] missed two existing references of kvm_dirty_ring_sizes; they do matter
since otherwise we'll mmap() a shorter range of memory after the renaming.

I think it didn't SIGBUS for me easily simply because some other stuff within
qemu mmap()ed right after the dirty rings (e.g. when testing 4096 slots, it
aligned with one small page on x86), so when we access the rings we've been
reading/writting to random memory elsewhere of qemu.

Fix the two sizes when map/unmap the shared dirty gfn memory.

[1] https://lore.kernel.org/qemu-devel/dac5f0c6-1bca-3daf-e5d2-6451dbbaca93@redhat.com/

Cc: Hyman Huang <huangy81@chinatelecom.cn>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210609014355.217110-1-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-25 10:54:12 +02:00
Stefano Garzarella
d0fb9657a3 docs: fix references to docs/devel/tracing.rst
Commit e50caf4a5c ("tracing: convert documentation to rST")
converted docs/devel/tracing.txt to docs/devel/tracing.rst.

We still have several references to the old file, so let's fix them
with the following command:

  sed -i s/tracing.txt/tracing.rst/ $(git grep -l docs/devel/tracing.txt)

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210517151702.109066-2-sgarzare@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2021-06-02 06:51:09 +02:00
Peter Xu
b4420f198d KVM: Dirty ring support
KVM dirty ring is a new interface to pass over dirty bits from kernel to the
userspace.  Instead of using a bitmap for each memory region, the dirty ring
contains an array of dirtied GPAs to fetch (in the form of offset in slots).
For each vcpu there will be one dirty ring that binds to it.

kvm_dirty_ring_reap() is the major function to collect dirty rings.  It can be
called either by a standalone reaper thread that runs in the background,
collecting dirty pages for the whole VM.  It can also be called directly by any
thread that has BQL taken.

Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210506160549.130416-11-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-26 14:49:46 +02:00
Peter Xu
a81a592698 KVM: Disable manual dirty log when dirty ring enabled
KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is for KVM_CLEAR_DIRTY_LOG, which is only
useful for KVM_GET_DIRTY_LOG.  Skip enabling it for kvm dirty ring.

More importantly, KVM_DIRTY_LOG_INITIALLY_SET will not wr-protect all the pages
initially, which is against how kvm dirty ring is used - there's no way for kvm
dirty ring to re-protect a page before it's notified as being written first
with a GFN entry in the ring!  So when KVM_DIRTY_LOG_INITIALLY_SET is enabled
with dirty ring, we'll see silent data loss after migration.

Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210506160549.130416-10-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-26 14:49:46 +02:00
Peter Xu
2ea5cb0a47 KVM: Add dirty-ring-size property
Add a parameter for dirty gfn count for dirty rings.  If zero, dirty ring is
disabled.  Otherwise dirty ring will be enabled with the per-vcpu gfn count as
specified.  If dirty ring cannot be enabled due to unsupported kernel or
illegal parameter, it'll fallback to dirty logging.

By default, dirty ring is not enabled (dirty-gfn-count default to 0).

Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210506160549.130416-9-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-26 14:49:45 +02:00
Peter Xu
563d32ba9b KVM: Cache kvm slot dirty bitmap size
Cache it too because we'll reference it more frequently in the future.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210506160549.130416-8-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-26 14:49:45 +02:00
Peter Xu
29b7e8be76 KVM: Simplify dirty log sync in kvm_set_phys_mem
kvm_physical_sync_dirty_bitmap() on the whole section is inaccurate, because
the section can be a superset of the memslot that we're working on.  The result
is that if the section covers multiple kvm memslots, we could be doing the
synchronization for multiple times for each kvmslot in the section.

With the two helpers that we just introduced, it's very easy to do it right now
by calling the helpers.

Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210506160549.130416-7-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-26 14:49:45 +02:00
Peter Xu
2c20b27eed KVM: Provide helper to sync dirty bitmap from slot to ramblock
kvm_physical_sync_dirty_bitmap() calculates the ramblock offset in an
awkward way from the MemoryRegionSection that passed in from the
caller.  The truth is for each KVMSlot the ramblock offset never
change for the lifecycle.  Cache the ramblock offset for each KVMSlot
into the structure when the KVMSlot is created.

With that, we can further simplify kvm_physical_sync_dirty_bitmap()
with a helper to sync KVMSlot dirty bitmap to the ramblock dirty
bitmap of a specific KVMSlot.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210506160549.130416-6-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-26 14:49:45 +02:00
Peter Xu
e65e5f50db KVM: Provide helper to get kvm dirty log
Provide a helper kvm_slot_get_dirty_log() to make the function
kvm_physical_sync_dirty_bitmap() clearer.  We can even cache the as_id
into KVMSlot when it is created, so that we don't even need to pass it
down every time.

Since at it, remove return value of kvm_physical_sync_dirty_bitmap()
because it should never fail.

Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210506160549.130416-5-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-26 14:49:45 +02:00
Peter Xu
ea776d15ad KVM: Create the KVMSlot dirty bitmap on flag changes
Previously we have two places that will create the per KVMSlot dirty
bitmap:

  1. When a newly created KVMSlot has dirty logging enabled,
  2. When the first log_sync() happens for a memory slot.

The 2nd case is lazy-init, while the 1st case is not (which is a fix
of what the 2nd case missed).

To do explicit initialization of dirty bitmaps, what we're missing is
to create the dirty bitmap when the slot changed from not-dirty-track
to dirty-track.  Do that in kvm_slot_update_flags().

With that, we can safely remove the 2nd lazy-init.

This change will be needed for kvm dirty ring because kvm dirty ring
does not use the log_sync() interface at all.

Also move all the pre-checks into kvm_slot_init_dirty_bitmap().

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210506160549.130416-4-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-26 14:49:45 +02:00
Peter Xu
a2f77862ff KVM: Use a big lock to replace per-kml slots_lock
Per-kml slots_lock will bring some trouble if we want to take all slots_lock of
all the KMLs, especially when we're in a context that we could have taken some
of the KML slots_lock, then we even need to figure out what we've taken and
what we need to take.

Make this simple by merging all KML slots_lock into a single slots lock.

Per-kml slots_lock isn't anything that helpful anyway - so far only x86 has two
address spaces (so, two slots_locks).  All the rest archs will be having one
address space always, which means there's actually one slots_lock so it will be
the same as before.

Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210506160549.130416-3-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-26 14:49:45 +02:00
Paolo Bonzini
70cbae429e KVM: do not allow setting properties at runtime
Only allow accelerator properties to be set when the
accelerator is being created.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-26 14:49:45 +02:00
Thomas Huth
ee86213aa3 Do not include exec/address-spaces.h if it's not really necessary
Stop including exec/address-spaces.h in files that don't need it.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210416171314.2074665-5-thuth@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2021-05-02 17:24:51 +02:00
Thomas Huth
4c386f8064 Do not include sysemu/sysemu.h if it's not really necessary
Stop including sysemu/sysemu.h in files that don't need it.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210416171314.2074665-2-thuth@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2021-05-02 17:24:50 +02:00
David Edmondson
56567da376 accel: kvm: clarify that extra exit data is hexadecimal
When dumping the extra exit data provided by KVM, make it clear that
the data is hexadecimal.

At the same time, zero-pad the output.

Signed-off-by: David Edmondson <david.edmondson@oracle.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210428142431.266879-1-david.edmondson@oracle.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2021-05-02 17:24:50 +02:00
Paolo Bonzini
26dbec410e Revert "accel: kvm: Add aligment assert for kvm_log_clear_one_slot"
This reverts commit 3920552846.
Thomas Huth reported a failure with CentOS 6 guests:

../../devel/qemu/accel/kvm/kvm-all.c:690: kvm_log_clear_one_slot: Assertion `QEMU_IS_ALIGNED(start | size, psize)' failed.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-03-16 14:30:30 -04:00
Andrew Jones
516fc0a081 accel: kvm: Fix kvm_type invocation
Prior to commit f2ce39b4f0 a MachineClass kvm_type method
only needed to be registered to ensure it would be executed.
With commit f2ce39b4f0 a kvm-type machine property must also
be specified. hw/arm/virt relies on the kvm_type method to pass
its selected IPA limit to KVM, but this is not exposed as a
machine property. Restore the previous functionality of invoking
kvm_type when it's present.

Fixes: f2ce39b4f0 ("vl: make qemu_get_machine_opts static")
Signed-off-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Message-id: 20210310135218.255205-2-drjones@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-03-12 12:47:11 +00:00
Keqian Zhu
3920552846 accel: kvm: Add aligment assert for kvm_log_clear_one_slot
The parameters start and size are transfered from QEMU memory
emulation layer. It can promise that they are TARGET_PAGE_SIZE
aligned. However, KVM needs they are qemu_real_page_size aligned.

Though no caller breaks this aligned requirement currently, we'd
better add an explicit assert to avoid future breaking.

Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Message-Id: <20201217014941.22872-3-zhukeqian1@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-03-06 11:41:54 +01:00
Keqian Zhu
e0a8f99355 accel: kvm: Fix memory waste under mismatch page size
When handle dirty log, we face qemu_real_host_page_size and
TARGET_PAGE_SIZE. The first one is the granule of KVM dirty
bitmap, and the second one is the granule of QEMU dirty bitmap.

As qemu_real_host_page_size >= TARGET_PAGE_SIZE (kvm_init()
enforced it), misuse TARGET_PAGE_SIZE to init kvmslot dirty_bmap
may waste memory. For example, when qemu_real_host_page_size is
64K and TARGET_PAGE_SIZE is 4K, it wastes 93.75% (15/16) memory.

Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Message-Id: <20201217014941.22872-2-zhukeqian1@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-03-06 11:41:54 +01:00