On Wed, Nov 13, 2024, Paolo Bonzini 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).
>
> > 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 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.
+1
> Performance of Windows guests is going to be bad anyway with userspace APIC.
Heh, on modern hardware, performance of any guest is going to suck with a userspace
APIC, compared to what is possible with an in-kernel APIC.
More importantly, I really, really don't want to encourage non-trivial usage of
a local APIC in userspace. KVM's support for a userspace local APIC is very
poorly tested these days. I have zero desire to spend any amount of time reviewing
and fixing issues that are unique to emulating the local APIC in userspace. And
long term, I would love to force an in-kernel local APIC, though I don't know if
that's entirely feasible.
This patchset fixes a bug where bnxt driver was failing to report that
an ntuple rule is redirecting to an RSS context. First commit is the
fix, then second commit extends selftests to detect if other/new drivers
are compliant with ntuple/rss_ctx API.
Daniel Xu (2):
bnxt_en: ethtool: Supply ntuple rss context action
selftests: drv-net: rss_ctx: Add test for ntuple rule
drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c | 8 ++++++--
tools/testing/selftests/drivers/net/hw/rss_ctx.py | 13 ++++++++++++-
2 files changed, 18 insertions(+), 3 deletions(-)
--
2.46.0
To be able to switch VMware products running on Linux to KVM some minor
changes are required to let KVM run/resume unmodified VMware guests.
First allow enabling of the VMware backdoor via an api. Currently the
setting of the VMware backdoor is limited to kernel boot parameters,
which forces all VM's running on a host to either run with or without
the VMware backdoor. Add a simple cap to allow enabling of the VMware
backdoor on a per VM basis. The default for that setting remains the
kvm.enable_vmware_backdoor boot parameter (which is false by default)
and can be changed on a per-vm basis via the KVM_CAP_X86_VMWARE_BACKDOOR
cap.
Second add a cap to forward hypercalls to userspace. I know that in
general that's frowned upon but VMwre guests send quite a few hypercalls
from userspace and it would be both impractical and largelly impossible
to handle all in the kernel. The change is trivial and I'd be maintaining
this code so I hope it's not a big deal.
The third commit just adds a self-test for the "forward VMware hypercalls
to userspace" functionality.
Cc: Doug Covelli <doug.covelli(a)broadcom.com>
Cc: Paolo Bonzini <pbonzini(a)redhat.com>
Cc: Jonathan Corbet <corbet(a)lwn.net>
Cc: Sean Christopherson <seanjc(a)google.com>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: Borislav Petkov <bp(a)alien8.de>
Cc: Dave Hansen <dave.hansen(a)linux.intel.com>
Cc: x86(a)kernel.org
Cc: "H. Peter Anvin" <hpa(a)zytor.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Namhyung Kim <namhyung(a)kernel.org>
Cc: Arnaldo Carvalho de Melo <acme(a)redhat.com>
Cc: Isaku Yamahata <isaku.yamahata(a)intel.com>
Cc: Joel Stanley <joel(a)jms.id.au>
Cc: Zack Rusin <zack.rusin(a)broadcom.com>
Cc: kvm(a)vger.kernel.org
Cc: linux-doc(a)vger.kernel.org
Cc: linux-kernel(a)vger.kernel.org
Cc: linux-kselftest(a)vger.kernel.org
Zack Rusin (3):
KVM: x86: Allow enabling of the vmware backdoor via a cap
KVM: x86: Add support for VMware guest specific hypercalls
KVM: selftests: x86: Add a test for KVM_CAP_X86_VMWARE_HYPERCALL
Documentation/virt/kvm/api.rst | 56 ++++++++-
arch/x86/include/asm/kvm_host.h | 2 +
arch/x86/kvm/emulate.c | 5 +-
arch/x86/kvm/svm/svm.c | 6 +-
arch/x86/kvm/vmx/vmx.c | 4 +-
arch/x86/kvm/x86.c | 47 ++++++++
arch/x86/kvm/x86.h | 7 +-
include/uapi/linux/kvm.h | 2 +
tools/include/uapi/linux/kvm.h | 2 +
tools/testing/selftests/kvm/Makefile | 1 +
.../kvm/x86_64/vmware_hypercall_test.c | 108 ++++++++++++++++++
11 files changed, 227 insertions(+), 13 deletions(-)
create mode 100644 tools/testing/selftests/kvm/x86_64/vmware_hypercall_test.c
--
2.43.0
This patch series represents the final release of KTAP version 2.
There have been having open discussions on version 2 for just over 2
years. This patch series marks the end of KTAP version 2 development
and beginning of the KTAP version 3 development.
The largest component of KTAP version 2 release is the addition of test
metadata to the specification. KTAP metadata could include any test
information that is pertinent for user interaction before or after the
running of the test. For example, the test file path or the test speed.
Example of KTAP Metadata:
KTAP version 2
#:ktap_test: main
#:ktap_arch: uml
1..1
KTAP version 2
#:ktap_test: suite_1
#:ktap_subsystem: example
#:ktap_test_file: lib/test.c
1..2
ok 1 test_1
#:ktap_test: test_2
#:ktap_speed: very_slow
# test_2 has begun
#:custom_is_flaky: true
ok 2 test_2
# suite_1 has passed
ok 1 suite_1
The release also includes some formatting fixes and changes to update
the specification to version 2.
Frank Rowand (2):
ktap_v2: change version to 2-rc in KTAP specification
ktap_v2: change "version 1" to "version 2" in examples
Rae Moar (3):
ktap_v2: add test metadata
ktap_v2: formatting fixes to ktap spec
ktap_v2: change version to 2 in KTAP specification
Documentation/dev-tools/ktap.rst | 276 +++++++++++++++++++++++++++++--
1 file changed, 260 insertions(+), 16 deletions(-)
base-commit: 2d5404caa8c7bb5c4e0435f94b28834ae5456623
--
2.47.0.277.g8800431eea-goog
Since commit 49f59573e9e0 ("selftests/mm: Enable pkey_sighandler_tests
on arm64"), pkey_sighandler_tests.c (which includes pkey-arm64.h via
pkey-helpers.h) ends up compiled for arm64. Since it doesn't use
aarch64_write_signal_pkey(), the compiler warns:
In file included from pkey-helpers.h:106,
from pkey_sighandler_tests.c:31:
pkey-arm64.h:130:13: warning: ‘aarch64_write_signal_pkey’ defined but not used [-Wunused-function]
130 | static void aarch64_write_signal_pkey(ucontext_t *uctxt, u64 pkey)
| ^~~~~~~~~~~~~~~~~~~~~~~~~
Make the aarch64_write_signal_pkey() a 'static inline void' function to
avoid the compiler warning.
Fixes: f5b5ea51f78f ("selftests: mm: make protection_keys test work on arm64")
Cc: Shuah Khan <skhan(a)linuxfoundation.org>
Cc: Joey Gouly <joey.gouly(a)arm.com>
Cc: Kevin Brodsky <kevin.brodsky(a)arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas(a)arm.com>
---
I'll add this on top of the arm64 for-next/pkey-signal branch together with
Kevin's other patches.
tools/testing/selftests/mm/pkey-arm64.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/mm/pkey-arm64.h b/tools/testing/selftests/mm/pkey-arm64.h
index d57fbeace38f..d9d2100eafc0 100644
--- a/tools/testing/selftests/mm/pkey-arm64.h
+++ b/tools/testing/selftests/mm/pkey-arm64.h
@@ -127,7 +127,7 @@ static inline u64 get_pkey_bits(u64 reg, int pkey)
return 0;
}
-static void aarch64_write_signal_pkey(ucontext_t *uctxt, u64 pkey)
+static inline void aarch64_write_signal_pkey(ucontext_t *uctxt, u64 pkey)
{
struct _aarch64_ctx *ctx = GET_UC_RESV_HEAD(uctxt);
struct poe_context *poe_ctx =
It looks like people started ignoring the compiler warnings (or even
errors) when building the arm64-specific kselftests. The first three
patches are printf() arguments adjustment. The last one adds
".arch_extension sme", otherwise they fail to build (with my toolchain
versions at least).
Note for future kselftest contributors - try to keep them warning-free.
Catalin Marinas (4):
kselftest/arm64: Fix printf() compiler warnings in the arm64 fp tests
kselftest/arm64: Fix printf() warning in the arm64 MTE prctl() test
kselftest/arm64: Fix printf() compiler warnings in the arm64
syscall-abi.c tests
kselftest/arm64: Fix compilation of SME instructions in the arm64 fp
tests
tools/testing/selftests/arm64/abi/syscall-abi.c | 8 ++++----
tools/testing/selftests/arm64/fp/sve-ptrace.c | 16 +++++++++-------
tools/testing/selftests/arm64/fp/za-ptrace.c | 8 +++++---
tools/testing/selftests/arm64/fp/za-test.S | 1 +
tools/testing/selftests/arm64/fp/zt-ptrace.c | 8 +++++---
tools/testing/selftests/arm64/fp/zt-test.S | 1 +
tools/testing/selftests/arm64/mte/check_prctl.c | 2 +-
7 files changed, 26 insertions(+), 18 deletions(-)
Currently we test signal delivery to the programs run by fp-stress but
our signal handlers simply count the number of signals seen and don't do
anything with the floating point state. The original fpsimd-test and
sve-test programs had signal handlers called irritators which modify the
live register state, verifying that we restore the signal context on
return, but a combination of misleading comments and code resulted in
them never being used and the equivalent handlers in the other tests
being stubbed or omitted.
Clarify the code, implement effective irritator handlers for the test
programs that can have them and then switch the signals generated by the
fp-stress program over to use the irritators, ensuring that we validate
that we restore the saved signal context properly.
Signed-off-by: Mark Brown <broonie(a)kernel.org>
---
Changes in v2:
- Change instruction and commit log for corruption of predicat
registers.
- Link to v1: https://lore.kernel.org/r/20241023-arm64-fp-stress-irritator-v1-0-a51af298d…
---
Mark Brown (6):
kselftest/arm64: Correct misleading comments on fp-stress irritators
kselftest/arm64: Remove unused ADRs from irritator handlers
kselftest/arm64: Corrupt P0 in the irritator when testing SSVE
kselftest/arm64: Implement irritators for ZA and ZT
kselftest/arm64: Provide a SIGUSR1 handler in the kernel mode FP stress test
kselftest/arm64: Test signal handler state modification in fp-stress
tools/testing/selftests/arm64/fp/fp-stress.c | 2 +-
tools/testing/selftests/arm64/fp/fpsimd-test.S | 4 +---
tools/testing/selftests/arm64/fp/kernel-test.c | 4 ++++
tools/testing/selftests/arm64/fp/sve-test.S | 8 +++-----
tools/testing/selftests/arm64/fp/za-test.S | 13 ++++---------
tools/testing/selftests/arm64/fp/zt-test.S | 13 ++++---------
6 files changed, 17 insertions(+), 27 deletions(-)
---
base-commit: 8e929cb546ee42c9a61d24fae60605e9e3192354
change-id: 20241023-arm64-fp-stress-irritator-5415fe92adef
Best regards,
--
Mark Brown <broonie(a)kernel.org>
This series contains a bit of a grab bag of improvements to the floating
point tests, mainly fp-ptrace. Globally over all the tests we start
using defines from the generated sysregs (following the example of the
KVM selftests) for SVCR, stop being quite so wasteful with registers
when calling into the assembler code then expand the coverage of both ZA
writes and FPMR (which was not there since fp-ptrace and the 2023 dpISA
extensions were on the list at the same time).
Signed-off-by: Mark Brown <broonie(a)kernel.org>
---
Changes in v2:
- Drop attempt to reference sysreg-defs.h due to build issues, just
import the defines directly into fp-ptrace. We can revisit later.
- Link to v1: https://lore.kernel.org/r/20241107-arm64-fp-ptrace-fpmr-v1-0-3e5e0b6e3be9@k…
---
Mark Brown (3):
kselftets/arm64: Use flag bits for features in fp-ptrace assembler code
kselftest/arm64: Expand the set of ZA writes fp-ptrace does
kselftest/arm64: Add FPMR coverage to fp-ptrace
tools/testing/selftests/arm64/fp/fp-ptrace-asm.S | 41 ++++--
tools/testing/selftests/arm64/fp/fp-ptrace.c | 161 +++++++++++++++++++++--
tools/testing/selftests/arm64/fp/fp-ptrace.h | 12 ++
tools/testing/selftests/arm64/fp/sme-inst.h | 2 +
4 files changed, 188 insertions(+), 28 deletions(-)
---
base-commit: 8e929cb546ee42c9a61d24fae60605e9e3192354
change-id: 20241105-arm64-fp-ptrace-fpmr-ff061facd3da
Best regards,
--
Mark Brown <broonie(a)kernel.org>