This patchset provides a file descriptor for every VM and VCPU to read
KVM statistics data in binary format.
It is meant to provide a lightweight, flexible, scalable and efficient
lock-free solution for user space telemetry applications to pull the
statistics data periodically for large scale systems. The pulling
frequency could be as high as a few times per second.
In this patchset, every statistics data are treated to have some
attributes as below:
* architecture dependent or common
* VM statistics data or VCPU statistics data
* type: cumulative, instantaneous,
* unit: none for simple counter, nanosecond, microsecond,
millisecond, second, Byte, KiByte, MiByte, GiByte. Clock Cycles
Since no lock/synchronization is used, the consistency between all
the statistics data is not guaranteed. That means not all statistics
data are read out at the exact same time, since the statistics date
are still being updated by KVM subsystems while they are read out.
---
* v3 -> v4
- Rebase to kvm/queue, commit 9f242010c3b4 ("KVM: avoid "deadlock"
between install_new_memslots and MMU notifier")
- Use C-stype comments in the whole patch
- Fix wrong count for x86 VCPU stats descriptors
- Fix KVM stats data size counting and validity check in selftest
* v2 -> v3
- Rebase to kvm/queue, commit edf408f5257b ("KVM: avoid "deadlock"
between install_new_memslots and MMU notifier")
- Resolve some nitpicks about format
* v1 -> v2
- Use ARRAY_SIZE to count the number of stats descriptors
- Fix missing `size` field initialization in macro STATS_DESC
[1] https://lore.kernel.org/kvm/20210402224359.2297157-1-jingzhangos@google.com
[2] https://lore.kernel.org/kvm/20210415151741.1607806-1-jingzhangos@google.com
[3] https://lore.kernel.org/kvm/20210423181727.596466-1-jingzhangos@google.com
---
Jing Zhang (4):
KVM: stats: Separate common stats from architecture specific ones
KVM: stats: Add fd-based API to read binary stats data
KVM: stats: Add documentation for statistics data binary interface
KVM: selftests: Add selftest for KVM statistics data binary interface
Documentation/virt/kvm/api.rst | 171 ++++++++
arch/arm64/include/asm/kvm_host.h | 9 +-
arch/arm64/kvm/guest.c | 42 +-
arch/mips/include/asm/kvm_host.h | 9 +-
arch/mips/kvm/mips.c | 67 ++-
arch/powerpc/include/asm/kvm_host.h | 9 +-
arch/powerpc/kvm/book3s.c | 68 +++-
arch/powerpc/kvm/book3s_hv.c | 12 +-
arch/powerpc/kvm/book3s_pr.c | 2 +-
arch/powerpc/kvm/book3s_pr_papr.c | 2 +-
arch/powerpc/kvm/booke.c | 63 ++-
arch/s390/include/asm/kvm_host.h | 9 +-
arch/s390/kvm/kvm-s390.c | 133 +++++-
arch/x86/include/asm/kvm_host.h | 9 +-
arch/x86/kvm/x86.c | 71 +++-
include/linux/kvm_host.h | 132 +++++-
include/linux/kvm_types.h | 12 +
include/uapi/linux/kvm.h | 50 +++
tools/testing/selftests/kvm/.gitignore | 1 +
tools/testing/selftests/kvm/Makefile | 3 +
.../testing/selftests/kvm/include/kvm_util.h | 3 +
.../selftests/kvm/kvm_bin_form_stats.c | 380 ++++++++++++++++++
tools/testing/selftests/kvm/lib/kvm_util.c | 11 +
virt/kvm/kvm_main.c | 237 ++++++++++-
24 files changed, 1415 insertions(+), 90 deletions(-)
create mode 100644 tools/testing/selftests/kvm/kvm_bin_form_stats.c
base-commit: 9f242010c3b46e63bc62f08fff42cef992d3801b
--
2.31.1.527.g47e6f16901-goog
From: Mike Rapoport <rppt(a)linux.ibm.com>
Hi,
@Andrew, this is based on v5.12-rc1, I can rebase whatever way you prefer.
This is an implementation of "secret" mappings backed by a file descriptor.
The file descriptor backing secret memory mappings is created using a
dedicated memfd_secret system call The desired protection mode for the
memory is configured using flags parameter of the system call. The mmap()
of the file descriptor created with memfd_secret() will create a "secret"
memory mapping. The pages in that mapping will be marked as not present in
the direct map and will be present only in the page table of the owning mm.
Although normally Linux userspace mappings are protected from other users,
such secret mappings are useful for environments where a hostile tenant is
trying to trick the kernel into giving them access to other tenants
mappings.
Additionally, in the future the secret mappings may be used as a mean to
protect guest memory in a virtual machine host.
For demonstration of secret memory usage we've created a userspace library
https://git.kernel.org/pub/scm/linux/kernel/git/jejb/secret-memory-preloade…
that does two things: the first is act as a preloader for openssl to
redirect all the OPENSSL_malloc calls to secret memory meaning any secret
keys get automatically protected this way and the other thing it does is
expose the API to the user who needs it. We anticipate that a lot of the
use cases would be like the openssl one: many toolkits that deal with
secret keys already have special handling for the memory to try to give
them greater protection, so this would simply be pluggable into the
toolkits without any need for user application modification.
Hiding secret memory mappings behind an anonymous file allows usage of
the page cache for tracking pages allocated for the "secret" mappings as
well as using address_space_operations for e.g. page migration callbacks.
The anonymous file may be also used implicitly, like hugetlb files, to
implement mmap(MAP_SECRET) and use the secret memory areas with "native" mm
ABIs in the future.
Removing of the pages from the direct map may cause its fragmentation on
architectures that use large pages to map the physical memory which affects
the system performance. However, the original Kconfig text for
CONFIG_DIRECT_GBPAGES said that gigabyte pages in the direct map "... can
improve the kernel's performance a tiny bit ..." (commit 00d1c5e05736
("x86: add gbpages switches")) and the recent report [1] showed that "...
although 1G mappings are a good default choice, there is no compelling
evidence that it must be the only choice". Hence, it is sufficient to have
secretmem disabled by default with the ability of a system administrator to
enable it at boot time.
In addition, there is also a long term goal to improve management of the
direct map.
[1] https://lore.kernel.org/linux-mm/213b4567-46ce-f116-9cdf-bbd0c884eb3c@linux…
v18:
* rebase on v5.12-rc1
* merge kfence fix into the original patch
* massage commit message of the patch introducing the memfd_secret syscall
v17: https://lore.kernel.org/lkml/20210208084920.2884-1-rppt@kernel.org
* Remove pool of large pages backing secretmem allocations, per Michal Hocko
* Add secretmem pages to unevictable LRU, per Michal Hocko
* Use GFP_HIGHUSER as secretmem mapping mask, per Michal Hocko
* Make secretmem an opt-in feature that is disabled by default
v16: https://lore.kernel.org/lkml/20210121122723.3446-1-rppt@kernel.org
* Fix memory leak intorduced in v15
* Clean the data left from previous page user before handing the page to
the userspace
v15: https://lore.kernel.org/lkml/20210120180612.1058-1-rppt@kernel.org
* Add riscv/Kconfig update to disable set_memory operations for nommu
builds (patch 3)
* Update the code around add_to_page_cache() per Matthew's comments
(patches 6,7)
* Add fixups for build/checkpatch errors discovered by CI systems
v14: https://lore.kernel.org/lkml/20201203062949.5484-1-rppt@kernel.org
* Finally s/mod_node_page_state/mod_lruvec_page_state/
v13: https://lore.kernel.org/lkml/20201201074559.27742-1-rppt@kernel.org
* Added Reviewed-by, thanks Catalin and David
* s/mod_node_page_state/mod_lruvec_page_state/ as Shakeel suggested
Older history:
v12: https://lore.kernel.org/lkml/20201125092208.12544-1-rppt@kernel.org
v11: https://lore.kernel.org/lkml/20201124092556.12009-1-rppt@kernel.org
v10: https://lore.kernel.org/lkml/20201123095432.5860-1-rppt@kernel.org
v9: https://lore.kernel.org/lkml/20201117162932.13649-1-rppt@kernel.org
v8: https://lore.kernel.org/lkml/20201110151444.20662-1-rppt@kernel.org
v7: https://lore.kernel.org/lkml/20201026083752.13267-1-rppt@kernel.org
v6: https://lore.kernel.org/lkml/20200924132904.1391-1-rppt@kernel.org
v5: https://lore.kernel.org/lkml/20200916073539.3552-1-rppt@kernel.org
v4: https://lore.kernel.org/lkml/20200818141554.13945-1-rppt@kernel.org
v3: https://lore.kernel.org/lkml/20200804095035.18778-1-rppt@kernel.org
v2: https://lore.kernel.org/lkml/20200727162935.31714-1-rppt@kernel.org
v1: https://lore.kernel.org/lkml/20200720092435.17469-1-rppt@kernel.org
rfc-v2: https://lore.kernel.org/lkml/20200706172051.19465-1-rppt@kernel.org/
rfc-v1: https://lore.kernel.org/lkml/20200130162340.GA14232@rapoport-lnx/
rfc-v0: https://lore.kernel.org/lkml/1572171452-7958-1-git-send-email-rppt@kernel.o…
Mike Rapoport (9):
mm: add definition of PMD_PAGE_ORDER
mmap: make mlock_future_check() global
riscv/Kconfig: make direct map manipulation options depend on MMU
set_memory: allow set_direct_map_*_noflush() for multiple pages
set_memory: allow querying whether set_direct_map_*() is actually enabled
mm: introduce memfd_secret system call to create "secret" memory areas
PM: hibernate: disable when there are active secretmem users
arch, mm: wire up memfd_secret system call where relevant
secretmem: test: add basic selftest for memfd_secret(2)
arch/arm64/include/asm/Kbuild | 1 -
arch/arm64/include/asm/cacheflush.h | 6 -
arch/arm64/include/asm/kfence.h | 2 +-
arch/arm64/include/asm/set_memory.h | 17 ++
arch/arm64/include/uapi/asm/unistd.h | 1 +
arch/arm64/kernel/machine_kexec.c | 1 +
arch/arm64/mm/mmu.c | 6 +-
arch/arm64/mm/pageattr.c | 23 +-
arch/riscv/Kconfig | 4 +-
arch/riscv/include/asm/set_memory.h | 4 +-
arch/riscv/include/asm/unistd.h | 1 +
arch/riscv/mm/pageattr.c | 8 +-
arch/x86/entry/syscalls/syscall_32.tbl | 1 +
arch/x86/entry/syscalls/syscall_64.tbl | 1 +
arch/x86/include/asm/set_memory.h | 4 +-
arch/x86/mm/pat/set_memory.c | 8 +-
fs/dax.c | 11 +-
include/linux/pgtable.h | 3 +
include/linux/secretmem.h | 30 +++
include/linux/set_memory.h | 16 +-
include/linux/syscalls.h | 1 +
include/uapi/asm-generic/unistd.h | 6 +-
include/uapi/linux/magic.h | 1 +
kernel/power/hibernate.c | 5 +-
kernel/power/snapshot.c | 4 +-
kernel/sys_ni.c | 2 +
mm/Kconfig | 3 +
mm/Makefile | 1 +
mm/gup.c | 10 +
mm/internal.h | 3 +
mm/mlock.c | 3 +-
mm/mmap.c | 5 +-
mm/secretmem.c | 261 +++++++++++++++++++
mm/vmalloc.c | 5 +-
scripts/checksyscalls.sh | 4 +
tools/testing/selftests/vm/.gitignore | 1 +
tools/testing/selftests/vm/Makefile | 3 +-
tools/testing/selftests/vm/memfd_secret.c | 296 ++++++++++++++++++++++
tools/testing/selftests/vm/run_vmtests.sh | 17 ++
39 files changed, 726 insertions(+), 53 deletions(-)
create mode 100644 arch/arm64/include/asm/set_memory.h
create mode 100644 include/linux/secretmem.h
create mode 100644 mm/secretmem.c
create mode 100644 tools/testing/selftests/vm/memfd_secret.c
--
2.28.0
Explicitly include stddef.h when building the BTI tests so that we have
a definition of NULL, with at least some toolchains this is not done
implicitly by anything else:
test.c: In function ‘start’:
test.c:214:25: error: ‘NULL’ undeclared (first use in this function)
214 | sigaction(SIGILL, &sa, NULL);
| ^~~~
test.c:20:1: note: ‘NULL’ is defined in header ‘<stddef.h>’; did you forget to ‘#include <stddef.h>’?
Signed-off-by: Mark Brown <broonie(a)kernel.org>
---
tools/testing/selftests/arm64/bti/test.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/tools/testing/selftests/arm64/bti/test.c b/tools/testing/selftests/arm64/bti/test.c
index 656b04976ccc..67b77ab83c20 100644
--- a/tools/testing/selftests/arm64/bti/test.c
+++ b/tools/testing/selftests/arm64/bti/test.c
@@ -6,6 +6,7 @@
#include "system.h"
+#include <stddef.h>
#include <linux/errno.h>
#include <linux/auxvec.h>
#include <linux/signal.h>
--
2.20.1
The result of an expression consisting of a single relational operator is
already of the bool type and does not need to be evaluated explicitly.
No functional change.
Signed-off-by: Zhen Lei <thunder.leizhen(a)huawei.com>
---
tools/testing/selftests/mount/unprivileged-remount-test.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/mount/unprivileged-remount-test.c b/tools/testing/selftests/mount/unprivileged-remount-test.c
index 584dc6bc3b06679..d2917054fe3ae56 100644
--- a/tools/testing/selftests/mount/unprivileged-remount-test.c
+++ b/tools/testing/selftests/mount/unprivileged-remount-test.c
@@ -204,7 +204,7 @@ bool test_unpriv_remount(const char *fstype, const char *mount_options,
if (!WIFEXITED(status)) {
die("child did not terminate cleanly\n");
}
- return WEXITSTATUS(status) == EXIT_SUCCESS ? true : false;
+ return WEXITSTATUS(status) == EXIT_SUCCESS;
}
create_and_enter_userns();
@@ -282,7 +282,7 @@ static bool test_priv_mount_unpriv_remount(void)
if (!WIFEXITED(status)) {
die("child did not terminate cleanly\n");
}
- return WEXITSTATUS(status) == EXIT_SUCCESS ? true : false;
+ return WEXITSTATUS(status) == EXIT_SUCCESS;
}
orig_mnt_flags = read_mnt_flags(orig_path);
--
2.26.0.106.g9fadedd
The use of typecheck() in KUNIT_EXPECT_EQ() and friends is causing more
problems than I think it's worth. Things like enums need to have their
values explicitly cast, and literals all need to be very precisely typed
for the code to compile.
While typechecking does have its uses, the additional overhead of having
lots of needless casts -- combined with the awkward error messages which
don't mention which types are involved -- makes tests less readable and
more difficult to write.
By removing the typecheck() call, the two arguments still need to be of
compatible types, but don't need to be of exactly the same time, which
seems a less confusing and more useful compromise.
Signed-off-by: David Gow <davidgow(a)google.com>
---
I appreciate that this is probably a bit controversial (and, indeed, I
was a bit hesitant about sending it out myself), but after sitting on it
for a few days, I still think this is probably an improvement overall.
The second patch does fix what I think is an actual bug, though, so even
if this isn't determined to be a good idea, it (or some equivalent)
should probably go through.
Cheers,
-- David
include/kunit/test.h | 1 -
1 file changed, 1 deletion(-)
diff --git a/include/kunit/test.h b/include/kunit/test.h
index 49601c4b98b8..4c56ffcb7403 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -775,7 +775,6 @@ void kunit_do_assertion(struct kunit *test,
do { \
typeof(left) __left = (left); \
typeof(right) __right = (right); \
- ((void)__typecheck(__left, __right)); \
\
KUNIT_ASSERTION(test, \
__left op __right, \
--
2.31.1.607.g51e8a6a459-goog
From: Mike Rapoport <rppt(a)linux.ibm.com>
Hi,
This is an updated version of page_is_secretmem() changes.
This is based on v5.12-rc7-mmots-2021-04-15-16-28.
@Andrew, please let me know if you'd like me to rebase it differently or
resend the entire set.
v3:
* add missing put_compound_head() if we are to return NULL from
gup_page_range(), thanks David.
* add unlikely() to test for page_is_secretmem.
v2:
* move the check for secretmem page in gup_pte_range after we get a
reference to the page, per Matthew.
Mike Rapoport (2):
secretmem/gup: don't check if page is secretmem without reference
secretmem: optimize page_is_secretmem()
include/linux/secretmem.h | 26 +++++++++++++++++++++++++-
mm/gup.c | 6 +++---
mm/secretmem.c | 12 +-----------
3 files changed, 29 insertions(+), 15 deletions(-)
--
2.28.0
Mike Rapoport (2):
secretmem/gup: don't check if page is secretmem without reference
secretmem: optimize page_is_secretmem()
include/linux/secretmem.h | 26 +++++++++++++++++++++++++-
mm/gup.c | 8 +++++---
mm/secretmem.c | 12 +-----------
3 files changed, 31 insertions(+), 15 deletions(-)
--
2.28.0