January 2025 - Linux-kselftest-mirror

by David Gow

As discussed in [1], the KUnit test naming scheme has changed to avoid name conflicts (and tab-completion woes) with the files being tested. These renames and moves have caused a nasty set of merge conflicts, so this series collates and rebases them all to be applied via mm-nonmm-unstable alongside any lib/ changes[2]. Thanks to everyone whose patches appear here, and everyone who reviewed on the original series. I hope I didn't break them too much during the rebase! Link: https://lore.kernel.org/lkml/20240720165441.it.320-kees@kernel.org/ [1] Link: https://lore.kernel.org/lkml/CABVgOSmbSzcGUi=E4piSojh3A4_0GjE0fAYbqKjtYGbE9… [2] --- Bruno Sobreira França (1): lib/math: Add int_log test suite Diego Vieira (1): lib/tests/kfifo_kunit.c: add tests for the kfifo structure Gabriela Bittencourt (2): unicode: kunit: refactor selftest to kunit tests unicode: kunit: change tests filename and path Kees Cook (1): lib: Move KUnit tests into tests/ subdirectory Luis Felipe Hernandez (1): lib: math: Move kunit tests into tests/ subdir MAINTAINERS | 19 +- arch/m68k/configs/amiga_defconfig | 2 +- arch/m68k/configs/apollo_defconfig | 2 +- arch/m68k/configs/atari_defconfig | 2 +- arch/m68k/configs/bvme6000_defconfig | 2 +- arch/m68k/configs/hp300_defconfig | 2 +- arch/m68k/configs/mac_defconfig | 2 +- arch/m68k/configs/multi_defconfig | 2 +- arch/m68k/configs/mvme147_defconfig | 2 +- arch/m68k/configs/mvme16x_defconfig | 2 +- arch/m68k/configs/q40_defconfig | 2 +- arch/m68k/configs/sun3_defconfig | 2 +- arch/m68k/configs/sun3x_defconfig | 2 +- arch/powerpc/configs/ppc64_defconfig | 2 +- fs/unicode/Kconfig | 5 +- fs/unicode/Makefile | 2 +- fs/unicode/tests/.kunitconfig | 3 + .../{utf8-selftest.c => tests/utf8_kunit.c} | 149 ++++++------ fs/unicode/utf8-norm.c | 2 +- lib/Kconfig.debug | 31 ++- lib/Makefile | 36 +-- lib/math/Makefile | 5 +- lib/math/tests/Makefile | 6 +- .../{test_div64.c => tests/div64_kunit.c} | 0 lib/math/tests/int_log_kunit.c | 75 ++++++ .../mul_u64_u64_div_u64_kunit.c} | 2 +- .../rational_kunit.c} | 0 lib/tests/Makefile | 39 +++ lib/{ => tests}/bitfield_kunit.c | 0 lib/{ => tests}/checksum_kunit.c | 0 lib/{ => tests}/cmdline_kunit.c | 0 lib/{ => tests}/cpumask_kunit.c | 0 lib/{ => tests}/fortify_kunit.c | 0 lib/{ => tests}/hashtable_test.c | 0 lib/{ => tests}/is_signed_type_kunit.c | 0 lib/tests/kfifo_kunit.c | 224 ++++++++++++++++++ lib/{ => tests}/kunit_iov_iter.c | 0 lib/{ => tests}/list-test.c | 0 lib/{ => tests}/memcpy_kunit.c | 0 lib/{ => tests}/overflow_kunit.c | 0 lib/{ => tests}/siphash_kunit.c | 0 lib/{ => tests}/slub_kunit.c | 0 lib/{ => tests}/stackinit_kunit.c | 0 lib/{ => tests}/string_helpers_kunit.c | 0 lib/{ => tests}/string_kunit.c | 0 lib/{ => tests}/test_bits.c | 0 lib/{ => tests}/test_fprobe.c | 0 lib/{ => tests}/test_hash.c | 0 lib/{ => tests}/test_kprobes.c | 0 lib/{ => tests}/test_linear_ranges.c | 0 lib/{ => tests}/test_list_sort.c | 0 lib/{ => tests}/test_sort.c | 0 lib/{ => tests}/usercopy_kunit.c | 0 53 files changed, 474 insertions(+), 150 deletions(-) create mode 100644 fs/unicode/tests/.kunitconfig rename fs/unicode/{utf8-selftest.c => tests/utf8_kunit.c} (64%) rename lib/math/{test_div64.c => tests/div64_kunit.c} (100%) create mode 100644 lib/math/tests/int_log_kunit.c rename lib/math/{test_mul_u64_u64_div_u64.c => tests/mul_u64_u64_div_u64_kunit.c} (98%) rename lib/math/{rational-test.c => tests/rational_kunit.c} (100%) create mode 100644 lib/tests/Makefile rename lib/{ => tests}/bitfield_kunit.c (100%) rename lib/{ => tests}/checksum_kunit.c (100%) rename lib/{ => tests}/cmdline_kunit.c (100%) rename lib/{ => tests}/cpumask_kunit.c (100%) rename lib/{ => tests}/fortify_kunit.c (100%) rename lib/{ => tests}/hashtable_test.c (100%) rename lib/{ => tests}/is_signed_type_kunit.c (100%) create mode 100644 lib/tests/kfifo_kunit.c rename lib/{ => tests}/kunit_iov_iter.c (100%) rename lib/{ => tests}/list-test.c (100%) rename lib/{ => tests}/memcpy_kunit.c (100%) rename lib/{ => tests}/overflow_kunit.c (100%) rename lib/{ => tests}/siphash_kunit.c (100%) rename lib/{ => tests}/slub_kunit.c (100%) rename lib/{ => tests}/stackinit_kunit.c (100%) rename lib/{ => tests}/string_helpers_kunit.c (100%) rename lib/{ => tests}/string_kunit.c (100%) rename lib/{ => tests}/test_bits.c (100%) rename lib/{ => tests}/test_fprobe.c (100%) rename lib/{ => tests}/test_hash.c (100%) rename lib/{ => tests}/test_kprobes.c (100%) rename lib/{ => tests}/test_linear_ranges.c (100%) rename lib/{ => tests}/test_list_sort.c (100%) rename lib/{ => tests}/test_sort.c (100%) rename lib/{ => tests}/usercopy_kunit.c (100%) -- 2.47.0.rc1.288.g06298d1525-goog

8 months

10
24
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[PATCH 00/21] bcachefs: eytzinger code

by Andreas Gruenbacher

Kent, to continue our discussion from last November, I've gone through more parts of the eytzinger code and as a result, here are some patches for you to consider. What I've not looked at are the eytzinger_to_inorder and inorder_to_eytzinger functions, as well as the implementation of sort. Those functions could use a bit more documentation, but the code iself looks reasonable. Shuah, I've also had a quick look at converting the tests into kernel selftests, but that hasn't gone very far because of the lack of support for basic functions like __fls(), __ffs(), ffz(), and rounddown_pow_of_two() in selftests. Are there any plans for making those kinds of primitives generally available to selftests? Thanks, Andreas Andreas Gruenbacher (21): bcachefs: remove dead code in is_aligned bcachefs: bch2_blacklist_entries_gc cleanup bcachefs: Run the eytzinger tests on modprobe bcachefs: EYTZINGER_DEBUG fix bcachefs: eytzinger self tests: eytzinger0_for_each loop cleanups bcachefs: eytzinger self tests: missing newline termination bcachefs: eytzinger self tests: fix cmp_u16 typo bcachefs: eytzinger[01]_test improvement bcachefs: eytzinger0_find_test improvement bcachefs: add eytzinger0_for_each_prev bcachefs: improve the eytzinger0_find_le tests bcachefs: convert eytzinger0_find to be 1-based bcachefs: convert eytzinger0_find_le to be 1-based bcachefs: simplify eytzinger0_find_le bcachefs: add eytzinger0_find_gt tests bcachefs: implement eytzinger0_find_gt directly bcachefs: add eytzinger0_find_ge tests bcachefs: implement eytzinger0_find_ge directly bcachefs: convert eytzinger sort to be 1-based (1) bcachefs: convert eytzinger sort to be 1-based (2) bcachefs: eytzinger1_{next,prev} cleanup fs/bcachefs/eytzinger.c | 89 +++++++------- fs/bcachefs/eytzinger.h | 99 +++++++-------- fs/bcachefs/journal_seq_blacklist.c | 7 +- fs/bcachefs/super.c | 5 + fs/bcachefs/util.c | 183 +++++++++++++++++++++------- fs/bcachefs/util.h | 4 + 6 files changed, 240 insertions(+), 147 deletions(-) -- 2.48.1

8 months, 1 week

3
36
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[PATCH v5 0/5] arm64: Support 2024 dpISA extensions

by Mark Brown

The 2024 architecture release includes a number of data processing extensions, mostly SVE and SME additions with a few others. These are all very straightforward extensions which add instructions but no architectural state so only need hwcaps and exposing of the ID registers to KVM guests and userspace. Signed-off-by: Mark Brown <broonie(a)kernel.org> --- Changes in v5: - Rebase onto arm64/for-next/cpufeature, which incorporates most of the sysreg updates from earlier versions. - Remove SF8MM8 and SF8MM4 register defintitions which were removed from the ISA in the 2024-12 XML release, along with their associated hwcaps. - Incorporate Marc's fix for SVE hwcaps on SME only systems and update the hwcaps for the newly added features to follow the same pattern. - Link to v4: https://lore.kernel.org/r/20241211-arm64-2024-dpisa-v4-0-0fd403876df2@kerne… Changes in v4: - Fix encodings for ID_AA64ISAR3_EL1. - Link to v3: https://lore.kernel.org/r/20241203-arm64-2024-dpisa-v3-0-a6c78b1aa297@kerne… Changes in v3: - Commit log update for the hwcap test. - Link to v2: https://lore.kernel.org/r/20241030-arm64-2024-dpisa-v2-0-b6601a15d2a5@kerne… Changes in v2: - Filter KVM guest visible bitfields in ID_AA64ISAR3_EL1 to only those we make writeable. - Link to v1: https://lore.kernel.org/r/20241028-arm64-2024-dpisa-v1-0-a38d08b008a8@kerne… --- Marc Zyngier (1): arm64: Filter out SVE hwcaps when FEAT_SVE isn't implemented Mark Brown (4): arm64/sysreg: Update ID_AA64SMFR0_EL1 to DDI0601 2024-12 arm64/hwcap: Describe 2024 dpISA extensions to userspace KVM: arm64: Allow control of dpISA extensions in ID_AA64ISAR3_EL1 kselftest/arm64: Add 2024 dpISA extensions to hwcap test Documentation/arch/arm64/elf_hwcaps.rst | 89 +++++++++-- arch/arm64/include/asm/hwcap.h | 15 ++ arch/arm64/include/uapi/asm/hwcap.h | 15 ++ arch/arm64/kernel/cpufeature.c | 71 +++++++-- arch/arm64/kernel/cpuinfo.c | 15 ++ arch/arm64/kvm/sys_regs.c | 6 +- arch/arm64/tools/sysreg | 26 +++- tools/testing/selftests/arm64/abi/hwcap.c | 235 +++++++++++++++++++++++++++++- 8 files changed, 441 insertions(+), 31 deletions(-) --- base-commit: d66e21d59ed0e043e68ef8c6541c1e9f1a962614 change-id: 20241008-arm64-2024-dpisa-8091074a7f48 Best regards, -- Mark Brown <broonie(a)kernel.org>

8 months, 1 week

4
9
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[PATCH net-next v18 00/25] Introducing OpenVPN Data Channel Offload

by Antonio Quartulli

Notable changes since v17: * fixed netdevice_tracker pointer assignment in netlink post_doit (triggered by kernel test robot on m86k) * renamed nla_get_uint() to ovpn_nla_get_uint() in ovpn-cli.c to avoid clashes with libnl-3.11.0 FTR, here are the notable changes since v16: * fixed usage of netdev tracker by removing dev_tracker member from ovpn_priv and adding it to ovpn_peer and ovpn_socket as those are the objects really holding a ref to the netdev * switched ovpn_get_dev_from_attrs() to GFP_ATOMIC to prevent sleep under rcu_read_lock * allocated netdevice_tracker in ovpn_nl_pre_doit() [stored in user_ptr[1]] to keep track of the netdev reference held during netlink handler calls * moved whole socket detaching routine to worker. This way the code is allowed to sleep and in turn it can be executed under lock_sock. This lock allows us to happily coordinate concurrent attach/detach calls. (note: lock is acquired everytime the refcnt for the socket is decremented, because this guarantees us that setting the refcnt to 0 and detaching the socket will happen atomically) * dropped kref_put_sock()/refcount handler as it's not required anymore, thanks to the point above * re-arranged ovpn_socket_new() in order to simplify error path by first allocating the new ovpn_sock and then attaching Please note that some patches were already reviewed/tested by a few people. iThese patches have retained the tags as they have hardly been touched. The latest code can also be found at: https://github.com/OpenVPN/linux-kernel-ovpn Thanks a lot! Best Regards, Antonio Quartulli OpenVPN Inc. --- Antonio Quartulli (25): net: introduce OpenVPN Data Channel Offload (ovpn) ovpn: add basic netlink support ovpn: add basic interface creation/destruction/management routines ovpn: keep carrier always on for MP interfaces ovpn: introduce the ovpn_peer object ovpn: introduce the ovpn_socket object ovpn: implement basic TX path (UDP) ovpn: implement basic RX path (UDP) ovpn: implement packet processing ovpn: store tunnel and transport statistics ipv6: export inet6_stream_ops via EXPORT_SYMBOL_GPL ovpn: implement TCP transport skb: implement skb_send_sock_locked_with_flags() ovpn: add support for MSG_NOSIGNAL in tcp_sendmsg ovpn: implement multi-peer support ovpn: implement peer lookup logic ovpn: implement keepalive mechanism ovpn: add support for updating local UDP endpoint ovpn: add support for peer floating ovpn: implement peer add/get/dump/delete via netlink ovpn: implement key add/get/del/swap via netlink ovpn: kill key and notify userspace in case of IV exhaustion ovpn: notify userspace when a peer is deleted ovpn: add basic ethtool support testing/selftests: add test tool and scripts for ovpn module Documentation/netlink/specs/ovpn.yaml | 372 +++ Documentation/netlink/specs/rt_link.yaml | 16 + MAINTAINERS | 11 + drivers/net/Kconfig | 15 + drivers/net/Makefile | 1 + drivers/net/ovpn/Makefile | 22 + drivers/net/ovpn/bind.c | 55 + drivers/net/ovpn/bind.h | 101 + drivers/net/ovpn/crypto.c | 211 ++ drivers/net/ovpn/crypto.h | 145 ++ drivers/net/ovpn/crypto_aead.c | 382 ++++ drivers/net/ovpn/crypto_aead.h | 33 + drivers/net/ovpn/io.c | 446 ++++ drivers/net/ovpn/io.h | 34 + drivers/net/ovpn/main.c | 350 +++ drivers/net/ovpn/main.h | 14 + drivers/net/ovpn/netlink-gen.c | 213 ++ drivers/net/ovpn/netlink-gen.h | 41 + drivers/net/ovpn/netlink.c | 1183 ++++++++++ drivers/net/ovpn/netlink.h | 18 + drivers/net/ovpn/ovpnstruct.h | 54 + drivers/net/ovpn/peer.c | 1269 +++++++++++ drivers/net/ovpn/peer.h | 164 ++ drivers/net/ovpn/pktid.c | 129 ++ drivers/net/ovpn/pktid.h | 87 + drivers/net/ovpn/proto.h | 118 + drivers/net/ovpn/skb.h | 60 + drivers/net/ovpn/socket.c | 204 ++ drivers/net/ovpn/socket.h | 49 + drivers/net/ovpn/stats.c | 21 + drivers/net/ovpn/stats.h | 47 + drivers/net/ovpn/tcp.c | 565 +++++ drivers/net/ovpn/tcp.h | 33 + drivers/net/ovpn/udp.c | 421 ++++ drivers/net/ovpn/udp.h | 22 + include/linux/skbuff.h | 2 + include/uapi/linux/if_link.h | 15 + include/uapi/linux/ovpn.h | 111 + include/uapi/linux/udp.h | 1 + net/core/skbuff.c | 18 +- net/ipv6/af_inet6.c | 1 + tools/testing/selftests/Makefile | 1 + tools/testing/selftests/net/ovpn/.gitignore | 2 + tools/testing/selftests/net/ovpn/Makefile | 17 + tools/testing/selftests/net/ovpn/config | 10 + tools/testing/selftests/net/ovpn/data64.key | 5 + tools/testing/selftests/net/ovpn/ovpn-cli.c | 2367 ++++++++++++++++++++ tools/testing/selftests/net/ovpn/tcp_peers.txt | 5 + .../testing/selftests/net/ovpn/test-chachapoly.sh | 9 + tools/testing/selftests/net/ovpn/test-float.sh | 9 + tools/testing/selftests/net/ovpn/test-tcp.sh | 9 + tools/testing/selftests/net/ovpn/test.sh | 185 ++ tools/testing/selftests/net/ovpn/udp_peers.txt | 5 + 53 files changed, 9673 insertions(+), 5 deletions(-) --- base-commit: 7d0da8f862340c5f42f0062b8560b8d0971a6ac4 change-id: 20241002-b4-ovpn-eeee35c694a2 Best regards, -- Antonio Quartulli <antonio(a)openvpn.net>

8 months, 1 week

3
70
0 0

[PATCH] selftests: bpf: Support dynamic linking LLVM if static not available

by Daniel Xu

Since 67ab80a01886 ("selftests/bpf: Prefer static linking for LLVM libraries"), only statically linking test_progs is supported. However, some distros only provide a dynamically linkable LLVM. This commit adds a fallback for dynamically linking LLVM if static linking is not available. If both options are available, static linking is chosen. Signed-off-by: Daniel Xu <dxu(a)dxuuu.xyz> --- tools/testing/selftests/bpf/Makefile | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 6722080b2107..da514030a153 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -184,9 +184,14 @@ ifeq ($(feature-llvm),1) LLVM_CONFIG_LIB_COMPONENTS := mcdisassembler all-targets # both llvm-config and lib.mk add -D_GNU_SOURCE, which ends up as conflict LLVM_CFLAGS += $(filter-out -D_GNU_SOURCE,$(shell $(LLVM_CONFIG) --cflags)) - LLVM_LDLIBS += $(shell $(LLVM_CONFIG) --link-static --libs $(LLVM_CONFIG_LIB_COMPONENTS)) - LLVM_LDLIBS += $(shell $(LLVM_CONFIG) --link-static --system-libs $(LLVM_CONFIG_LIB_COMPONENTS)) - LLVM_LDLIBS += -lstdc++ + # Prefer linking statically if it's available, otherwise fallback to shared + ifeq ($(shell $(LLVM_CONFIG) --link-static --libs &> /dev/null && echo static),static) + LLVM_LDLIBS += $(shell $(LLVM_CONFIG) --link-static --libs $(LLVM_CONFIG_LIB_COMPONENTS)) + LLVM_LDLIBS += $(shell $(LLVM_CONFIG) --link-static --system-libs $(LLVM_CONFIG_LIB_COMPONENTS)) + LLVM_LDLIBS += -lstdc++ + else + LLVM_LDLIBS += $(shell $(LLVM_CONFIG) --link-shared --libs $(LLVM_CONFIG_LIB_COMPONENTS)) + endif LLVM_LDFLAGS += $(shell $(LLVM_CONFIG) --ldflags) endif -- 2.47.1

8 months, 1 week

5
7
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[PATCH 0/2] tools/nolibc: support for 32-bit s390

by Thomas Weißschuh

Support for 32-bit s390 is very easy to implement and useful for testing. For example I used to test some generic compat_ptr() logic, which is only testable on 32-bit s390. The series depends on my other series "selftests/nolibc: test kernel configuration cleanups". (It's not a hard dependency, only a minor diff conflict) Signed-off-by: Thomas Weißschuh <linux(a)weissschuh.net> --- Thomas Weißschuh (2): selftests/nolibc: rename s390 to s390x tools/nolibc: add support for 32-bit s390 tools/include/nolibc/arch-s390.h | 5 +++++ tools/include/nolibc/arch.h | 2 +- tools/testing/selftests/nolibc/Makefile | 10 ++++++++-- tools/testing/selftests/nolibc/run-tests.sh | 8 +++++++- 4 files changed, 21 insertions(+), 4 deletions(-) --- base-commit: 0597614d84c8593ba906418bf3c0c0de1e02e82a change-id: 20250122-nolibc-s390-e57141682c88 Best regards, -- Thomas Weißschuh <linux(a)weissschuh.net>

8 months, 1 week

3
4
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[PATCH] bpf: Fix mix-up of 4096 and page size.

by Saket Kumar Bhaskar

For platforms on powerpc architecture with a default page size greater than 4096, there was an inconsistency in fragment size calculation. This caused the BPF selftest xdp_adjust_tail/xdp_adjust_frags_tail_grow to fail on powerpc. The issue occurred because the fragment buffer size in bpf_prog_test_run_xdp() was set to 4096, while the actual data size in the fragment within the shared skb was checked against PAGE_SIZE (65536 on powerpc) in min_t, causing it to exceed 4096 and be set accordingly. This discrepancy led to an overflow when bpf_xdp_frags_increase_tail() checked for tailroom, as skb_frag_size(frag) could be greater than rxq->frag_size (when PAGE_SIZE > 4096). This commit updates the page size references to 4096 to ensure consistency and prevent overflow issues in fragment size calculations. Fixes: 1c1949982524 ("bpf: introduce frags support to bpf_prog_test_run_xdp()") Signed-off-by: Saket Kumar Bhaskar <skb99(a)linux.ibm.com> --- net/bpf/test_run.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index 501ec4249..eb5476184 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -124,7 +124,7 @@ struct xdp_test_data { * must be updated accordingly this gets changed, otherwise BPF selftests * will fail. */ -#define TEST_XDP_FRAME_SIZE (PAGE_SIZE - sizeof(struct xdp_page_head)) +#define TEST_XDP_FRAME_SIZE (4096 - sizeof(struct xdp_page_head)) #define TEST_XDP_MAX_BATCH 256 static void xdp_test_run_init_page(netmem_ref netmem, void *arg) @@ -660,7 +660,7 @@ static void *bpf_test_init(const union bpf_attr *kattr, u32 user_size, void __user *data_in = u64_to_user_ptr(kattr->test.data_in); void *data; - if (size < ETH_HLEN || size > PAGE_SIZE - headroom - tailroom) + if (size < ETH_HLEN || size > 4096 - headroom - tailroom) return ERR_PTR(-EINVAL); if (user_size > size) @@ -1297,7 +1297,7 @@ int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr, frag = &sinfo->frags[sinfo->nr_frags++]; data_len = min_t(u32, kattr->test.data_size_in - size, - PAGE_SIZE); + 4096); skb_frag_fill_page_desc(frag, page, 0, data_len); if (copy_from_user(page_address(page), data_in + size, -- 2.43.5

8 months, 1 week

3
4
0 0

[RFC PATCH 0/4] PMU partitioning driver support

by Colton Lewis

This series introduces support in the ARM PMUv3 driver for partitioning PMU counters into two separate ranges by taking advantage of the MDCR_EL2.HPMN register field. The advantage of a partitioned PMU would be to allow KVM guests direct access to a subset of PMU functionality, greatly reducing the overhead of performance monitoring in guests. While this series could be accepted on its own merits, practically there is a lot more to be done before it will be fully useful, so I'm sending as an RFC for now. This patch is based on v6.13-rc7. It needs a small additional change after Oliver's Debug cleanups series going into 6.14, specifically this patch [1], because it changes kvm_arm_setup_mdcr_el2() to initialize HPMN from a cached value read early in the boot process instead of reading from the register. The only sensible way I can see to deal with this is returning to reading the register. [1] https://lore.kernel.org/kvmarm/20241219224116.3941496-3-oliver.upton@linux.… Colton Lewis (4): perf: arm_pmuv3: Introduce module param to partition the PMU KVM: arm64: Make guests see only counters they can access perf: arm_pmuv3: Generalize counter bitmasks perf: arm_pmuv3: Keep out of guest counter partition arch/arm/include/asm/arm_pmuv3.h | 10 ++ arch/arm64/include/asm/arm_pmuv3.h | 10 ++ arch/arm64/kvm/pmu-emul.c | 8 +- drivers/perf/arm_pmuv3.c | 113 ++++++++++++++++-- include/linux/perf/arm_pmu.h | 2 + include/linux/perf/arm_pmuv3.h | 34 +++++- .../kvm/aarch64/vpmu_counter_access.c | 2 +- 7 files changed, 160 insertions(+), 19 deletions(-) base-commit: 5bc55a333a2f7316b58edc7573e8e893f7acb532 -- 2.48.1.262.g85cc9f2d1e-goog

8 months, 1 week

4
14
0 0

Re: [PATCH 2/3] KVM: x86: Add support for VMware guest specific hypercalls

by Doug Covelli

On Wed, Nov 13, 2024 at 2:31 AM Paolo Bonzini <pbonzini(a)redhat.com> wrote: > > > > Il mar 12 nov 2024, 21:44 Doug Covelli <doug.covelli(a)broadcom.com> ha scritto: >> >> > Split irqchip should be the best tradeoff. Without it, moves from cr8 >> > stay in the kernel, but moves to cr8 always go to userspace with a >> > KVM_EXIT_SET_TPR exit. You also won't be able to use Intel >> > flexpriority (in-processor accelerated TPR) because KVM does not know >> > which bits are set in IRR. So it will be *really* every move to cr8 >> > that goes to userspace. >> >> Sorry to hijack this thread but is there a technical reason not to allow CR8 >> based accesses to the TPR (not MMIO accesses) when the in-kernel local APIC is >> not in use? > > > No worries, you're not hijacking :) The only reason is that it would be more code for a seldom used feature and anyway with worse performance. (To be clear, CR8 based accesses are allowed, but stores cause an exit in order to check the new TPR against IRR. That's because KVM's API does not have an equivalent of the TPR threshold as you point out below). I have not really looked at the code but it seems like it could also simplify things as CR8 would be handled more uniformly regardless of who is virtualizing the local APIC. >> Also I could not find these documented anywhere but with MSFT's APIC our monitor >> relies on extensions for trapping certain events such as INIT/SIPI plus LINT0 >> and SVR writes: >> >> UINT64 X64ApicInitSipiExitTrap : 1; // WHvRunVpExitReasonX64ApicInitSipiTrap >> UINT64 X64ApicWriteLint0ExitTrap : 1; // WHvRunVpExitReasonX64ApicWriteTrap >> UINT64 X64ApicWriteLint1ExitTrap : 1; // WHvRunVpExitReasonX64ApicWriteTrap >> UINT64 X64ApicWriteSvrExitTrap : 1; // WHvRunVpExitReasonX64ApicWriteTrap > > > There's no need for this in KVM's in-kernel APIC model. INIT and SIPI are handled in the hypervisor and you can get the current state of APs via KVM_GET_MPSTATE. LINT0 and LINT1 are injected with KVM_INTERRUPT and KVM_NMI respectively, and they obey IF/PPR and NMI blocking respectively, plus the interrupt shadow; so there's no need for userspace to know when LINT0/LINT1 themselves change. The spurious interrupt vector register is also handled completely in kernel. I realize that KVM can handle LINT0/SVR updates themselves but our interrupt subsystem relies on knowing the current values of these registers even when not virtualizing the local APIC. I suppose we could use KVM_GET_LAPIC to sync things up on demand but that seems like it might nor be great from a performance point of view. >> I did not see any similar functionality for KVM. Does anything like that exist? >> In any case we would be happy to add support for handling CR8 accesses w/o >> exiting w/o the in-kernel APIC along with some sort of a way to configure the >> TPR threshold if folks are not opposed to that. > > > As far I know everybody who's using KVM (whether proprietary or open source) has had no need for that, so I don't think it's a good idea to make the API more complex. Performance of Windows guests is going to be bad anyway with userspace APIC. From what I have seen the exit cost with KVM is significantly lower than with WHP/Hyper-V. I don't think performance of Windows guests with userspace APIC emulation would be bad if CR8 exits could be avoided (Linux guests perf isn't bad from what I have observed and the main difference is the astronomical number of CR8 exits). It seems like it would be pretty decent although I agree if you want the absolute best performance then you would want to use the in kernel APIC to speed up handling of ICR/EOI writes but those are relatively infrequent compared to CR8 accesses . Anyway I just saw Sean's response while writing this and it seems he is not in favor of avoiding CR8 exits w/o the in kernel APIC either so I suppose we will have to look into making use of the in kernel APIC. Doug > Paolo > >> Doug >> >> > > For now I think it makes sense to handle BDOOR_CMD_GET_VCPU_INFO at userlevel >> > > like we do on Windows and macOS. >> > > >> > > BDOOR_CMD_GETTIME/BDOOR_CMD_GETTIMEFULL are similar with the former being >> > > deprecated in favor of the latter. Both do essentially the same thing which is >> > > to return the host OS's time - on Linux this is obtained via gettimeofday. I >> > > believe this is mainly used by tools to fix up the VM's time when resuming from >> > > suspend. I think it is fine to continue handling these at userlevel. >> > >> > As long as the TSC is not involved it should be okay. >> > >> > Paolo >> > >> > > > >> Anyway, one question apart from this: is the API the same for the I/O >> > > > >> port and hypercall backdoors? >> > > > > >> > > > > Yeah the calls and arguments are the same. The hypercall based >> > > > > interface is an attempt to modernize the backdoor since as you pointed >> > > > > out the I/O based interface is kind of hacky as it bypasses the normal >> > > > > checks for an I/O port access at CPL3. It would be nice to get rid of >> > > > > it but unfortunately I don't think that will happen in the foreseeable >> > > > > future as there are a lot of existing VMs out there with older SW that >> > > > > still uses this interface. >> > > > >> > > > Yeah, but I think it still justifies that the KVM_ENABLE_CAP API can >> > > > enable the hypercall but not the I/O port. >> > > > >> > > > Paolo >> > >> >> -- >> This electronic communication and the information and any files transmitted >> with it, or attached to it, are confidential and are intended solely for >> the use of the individual or entity to whom it is addressed and may contain >> information that is confidential, legally privileged, protected by privacy >> laws, or otherwise restricted from disclosure to anyone else. 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8 months, 1 week

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[PATCH 0/6] selftests/nolibc: wire up riscv32

by Thomas Weißschuh

Nolibc has support for riscv32. But the testsuite did not allow to test it so far. Add a test configuration. Signed-off-by: Thomas Weißschuh <linux(a)weissschuh.net> --- Thomas Weißschuh (6): tools/nolibc: add support for waitid() selftests/nolibc: use waitid() over waitpid() selftests/nolibc: use a pipe to in vfprintf tests selftests/nolibc: skip tests for unimplemented syscalls selftests/nolibc: rename riscv to riscv64 selftests/nolibc: add configurations for riscv32 tools/include/nolibc/sys.h | 18 ++++++++++++ tools/testing/selftests/nolibc/Makefile | 11 +++++++ tools/testing/selftests/nolibc/nolibc-test.c | 44 ++++++++++++++++------------ tools/testing/selftests/nolibc/run-tests.sh | 2 +- 4 files changed, 56 insertions(+), 19 deletions(-) --- base-commit: 499551201b5f4fd3c0618a3e95e3d0d15ea18f31 change-id: 20241219-nolibc-rv32-cff8a3e22394 Best regards, -- Thomas Weißschuh <linux(a)weissschuh.net>

8 months, 1 week

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