* Re: [PATCH v8 38/46] KVM: selftests: Add helpers to pin pages with CONFIG_GUP_TEST
From: Fuad Tabba @ 2026-06-25 7:40 UTC (permalink / raw)
To: ackerleytng
Cc: aik, andrew.jones, binbin.wu, brauner, chao.p.peng, david,
jmattson, jthoughton, michael.roth, oupton, pankaj.gupta, qperret,
rick.p.edgecombe, rientjes, shivankg, steven.price, willy, wyihan,
yan.y.zhao, forkloop, pratyush, suzuki.poulose, aneesh.kumar,
liam, Paolo Bonzini, Sean Christopherson, Thomas Gleixner,
Ingo Molnar, Borislav Petkov, Dave Hansen, x86, H. Peter Anvin,
Steven Rostedt, Masami Hiramatsu, Mathieu Desnoyers,
Jonathan Corbet, Shuah Khan, Shuah Khan, Vishal Annapurve,
Andrew Morton, Chris Li, Kairui Song, Kemeng Shi, Nhat Pham,
Barry Song, Axel Rasmussen, Yuanchu Xie, Wei Xu, Youngjun Park,
Qi Zheng, Shakeel Butt, Kiryl Shutsemau, Baoquan He,
Jason Gunthorpe, Vlastimil Babka, kvm, linux-kernel,
linux-trace-kernel, linux-doc, linux-kselftest, linux-mm,
linux-coco
In-Reply-To: <20260618-gmem-inplace-conversion-v8-38-9d2959357853@google.com>
On Fri, 19 Jun 2026 at 01:32, Ackerley Tng via B4 Relay
<devnull+ackerleytng.google.com@kernel.org> wrote:
>
> From: Ackerley Tng <ackerleytng@google.com>
>
> Add helper functions to allow KVM selftests to pin memory using
> CONFIG_GUP_TEST. This is useful for testing scenarios where some page has
> an increased refcount. such as in guest_memfd in-place conversion tests.
>
> The helpers open /sys/kernel/debug/gup_test and invoke the
> PIN_LONGTERM_TEST_START and PIN_LONGTERM_TEST_STOP ioctls. Since this
> functionality depends on the kernel being built with CONFIG_GUP_TEST,
> provide stub implementations that trigger a test failure if the
> configuration is missing.
>
> Signed-off-by: Ackerley Tng <ackerleytng@google.com>
nit below, otherwise:
Reviewed-by: Fuad Tabba <tabba@google.com>
Cheers,
/fuad
> ---
> tools/testing/selftests/kvm/include/kvm_util.h | 3 +++
> tools/testing/selftests/kvm/lib/kvm_util.c | 23 +++++++++++++++++++++++
> 2 files changed, 26 insertions(+)
>
> diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
> index 323d06b5699ec..79ab64ac8b869 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util.h
> @@ -1195,6 +1195,9 @@ static inline int pin_self_to_any_cpu(void)
> return pin_task_to_any_cpu(pthread_self());
> }
>
> +void pin_pages(void *vaddr, uint64_t size);
> +void unpin_pages(void);
> +
> void kvm_print_vcpu_pinning_help(void);
> void kvm_parse_vcpu_pinning(const char *pcpus_string, u32 vcpu_to_pcpu[],
> int nr_vcpus);
> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> index b73817f7bc803..524ef97d634bf 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -18,6 +18,8 @@
> #include <unistd.h>
> #include <linux/kernel.h>
>
> +#include "../../../../mm/gup_test.h"
> +
> #define KVM_UTIL_MIN_PFN 2
>
> u32 guest_random_seed;
> @@ -639,6 +641,27 @@ int __pin_task_to_cpu(pthread_t task, int cpu)
> return pthread_setaffinity_np(task, sizeof(cpuset), &cpuset);
> }
>
> +static int gup_test_fd = -1;
> +
> +void pin_pages(void *vaddr, uint64_t size)
> +{
> + const struct pin_longterm_test args = {
> + .addr = (uint64_t)vaddr,
> + .size = size,
> + .flags = PIN_LONGTERM_TEST_FLAG_USE_WRITE,
> + };
> +
> + gup_test_fd = __open_path_or_exit("/sys/kernel/debug/gup_test", O_RDWR,
> + "Is CONFIG_GUP_TEST enabled?");
nit: should you close this/reset it to -1 after the tests?
> +
> + TEST_ASSERT_EQ(ioctl(gup_test_fd, PIN_LONGTERM_TEST_START, &args), 0);
> +}
> +
> +void unpin_pages(void)
> +{
> + TEST_ASSERT_EQ(ioctl(gup_test_fd, PIN_LONGTERM_TEST_STOP), 0);
> +}
> +
> static u32 parse_pcpu(const char *cpu_str, const cpu_set_t *allowed_mask)
> {
> u32 pcpu = atoi_non_negative("CPU number", cpu_str);
>
> --
> 2.55.0.rc0.738.g0c8ab3ebcc-goog
>
>
^ permalink raw reply
* Re: [PATCH v3 0/2] tracing: Remove trace_printk.h from kernel.h
From: Sebastian Andrzej Siewior @ 2026-06-25 7:56 UTC (permalink / raw)
To: Steven Rostedt
Cc: linux-kernel, linux-trace-kernel, Masami Hiramatsu, Mark Rutland,
Mathieu Desnoyers, Andrew Morton, Linus Torvalds, John Ogness,
Thomas Gleixner, Peter Zijlstra, Julia Lawall, Yury Norov
In-Reply-To: <20260624081806.120105649@kernel.org>
On 2026-06-24 04:18:06 [-0400], Steven Rostedt wrote:
> Remove trace_printk.h by creating a trace_controls.h for those places that
> need access to tracing prototypes like tracing_off() and for the places that
> need trace_printk() directly, to have it included directly.
That sounds reasonable. Thank you for doing it.
Sebastian
^ permalink raw reply
* Re: [PATCH v8 39/46] KVM: selftests: Test conversion with elevated page refcount
From: Fuad Tabba @ 2026-06-25 8:04 UTC (permalink / raw)
To: ackerleytng
Cc: aik, andrew.jones, binbin.wu, brauner, chao.p.peng, david,
jmattson, jthoughton, michael.roth, oupton, pankaj.gupta, qperret,
rick.p.edgecombe, rientjes, shivankg, steven.price, willy, wyihan,
yan.y.zhao, forkloop, pratyush, suzuki.poulose, aneesh.kumar,
liam, Paolo Bonzini, Sean Christopherson, Thomas Gleixner,
Ingo Molnar, Borislav Petkov, Dave Hansen, x86, H. Peter Anvin,
Steven Rostedt, Masami Hiramatsu, Mathieu Desnoyers,
Jonathan Corbet, Shuah Khan, Shuah Khan, Vishal Annapurve,
Andrew Morton, Chris Li, Kairui Song, Kemeng Shi, Nhat Pham,
Barry Song, Axel Rasmussen, Yuanchu Xie, Wei Xu, Youngjun Park,
Qi Zheng, Shakeel Butt, Kiryl Shutsemau, Baoquan He,
Jason Gunthorpe, Vlastimil Babka, kvm, linux-kernel,
linux-trace-kernel, linux-doc, linux-kselftest, linux-mm,
linux-coco
In-Reply-To: <20260618-gmem-inplace-conversion-v8-39-9d2959357853@google.com>
On Fri, 19 Jun 2026 at 01:32, Ackerley Tng via B4 Relay
<devnull+ackerleytng.google.com@kernel.org> wrote:
>
> From: Ackerley Tng <ackerleytng@google.com>
>
> Add a selftest to verify that converting a shared guest_memfd page to a
> private page fails if the page has an elevated reference count.
>
> When KVM converts a shared page to a private one, it expects the page to
> have a reference count equal to the reference counts taken by the
> filemap. If another kernel subsystem holds a reference to the page, the
> conversion must be aborted.
>
> The test asserts that both bulk and single-page conversion attempts
> correctly fail with EAGAIN for the pinned page. After the page is unpinned,
> the test verifies that subsequent conversions succeed.
>
> Signed-off-by: Ackerley Tng <ackerleytng@google.com>
> Co-developed-by: Sean Christopherson <seanjc@google.com>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
Not sure Sashiko's concern is worth it.
Reviewed-by: Fuad Tabba <tabba@google.com>
Cheers,
/fuad
> ---
> .../kvm/x86/guest_memfd_conversions_test.c | 56 ++++++++++++++++++++++
> 1 file changed, 56 insertions(+)
>
> diff --git a/tools/testing/selftests/kvm/x86/guest_memfd_conversions_test.c b/tools/testing/selftests/kvm/x86/guest_memfd_conversions_test.c
> index 99b0023609670..4ebbd29029526 100644
> --- a/tools/testing/selftests/kvm/x86/guest_memfd_conversions_test.c
> +++ b/tools/testing/selftests/kvm/x86/guest_memfd_conversions_test.c
> @@ -441,6 +441,62 @@ GMEM_CONVERSION_TEST_INIT_SHARED(forked_accesses)
> #undef TEST_STATE_AWAIT
> }
>
> +static void test_convert_to_private_fails(test_data_t *t, u64 pgoff,
> + size_t nr_pages,
> + u64 expected_error_offset)
> +{
> + /* +1 to make it anything but expected_error_offset. */
> + u64 error_offset = expected_error_offset + 1;
> + u64 offset = pgoff * page_size;
> + int ret;
> +
> + do {
> + ret = __gmem_set_private(t->gmem_fd, offset,
> + nr_pages * page_size, &error_offset);
> + } while (ret == -1 && errno == EINTR);
> + TEST_ASSERT(ret == -1 && errno == EAGAIN,
> + "Wanted EAGAIN on page %lu, got %d (ret = %d)", pgoff,
> + errno, ret);
> + TEST_ASSERT_EQ(error_offset, expected_error_offset);
> +}
> +
> +GMEM_CONVERSION_MULTIPAGE_TEST_INIT_SHARED(elevated_refcount, 4)
> +{
> + int i;
> +
> + pin_pages(t->mem + test_page * page_size, page_size);
> +
> + for (i = 0; i < nr_pages; i++)
> + test_shared(t, i, 0, 'A', 'B');
> +
> + /*
> + * Converting in bulk should fail as long any page in the range has
> + * unexpected refcounts.
> + */
> + test_convert_to_private_fails(t, 0, nr_pages, test_page * page_size);
> +
> + for (i = 0; i < nr_pages; i++) {
> + /*
> + * Converting page-wise should also fail as long any page in the
> + * range has unexpected refcounts.
> + */
> + if (i == test_page)
> + test_convert_to_private_fails(t, i, 1, test_page * page_size);
> + else
> + test_convert_to_private(t, i, 'B', 'C');
> + }
> +
> + unpin_pages();
> +
> + gmem_set_private(t->gmem_fd, 0, nr_pages * page_size);
> +
> + for (i = 0; i < nr_pages; i++) {
> + char expected = i == test_page ? 'B' : 'C';
> +
> + test_private(t, i, expected, 'D');
> + }
> +}
> +
> int main(int argc, char *argv[])
> {
> TEST_REQUIRE(kvm_check_cap(KVM_CAP_VM_TYPES) & BIT(KVM_X86_SW_PROTECTED_VM));
>
> --
> 2.55.0.rc0.738.g0c8ab3ebcc-goog
>
>
^ permalink raw reply
* Re: [PATCH v4 09/13] verification/rvgen: Delete __parse_constraint()
From: Gabriele Monaco @ 2026-06-25 8:21 UTC (permalink / raw)
To: Nam Cao
Cc: Steven Rostedt, Wander Lairson Costa, linux-trace-kernel,
linux-kernel
In-Reply-To: <b22a5a3822fe53afb8e2cf1df623a0e4c9ed5f49.1781847583.git.namcao@linutronix.de>
On Fri, 2026-06-19 at 07:52 +0200, Nam Cao wrote:
> All previous users of self.invariants and self.guards have been
> converted
> to the Lark parser, delete __parse_constraints() and its associates.
>
> Signed-off-by: Nam Cao <namcao@linutronix.de>
This one was missing the
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
The series looks ready for inclusion to me, thanks!
Gabriele
> ---
> tools/verification/rvgen/rvgen/dot2k.py | 67 ++---------------------
> --
> 1 file changed, 4 insertions(+), 63 deletions(-)
>
> diff --git a/tools/verification/rvgen/rvgen/dot2k.py
> b/tools/verification/rvgen/rvgen/dot2k.py
> index 4ea1ecc55c80..f1f5fa297adb 100644
> --- a/tools/verification/rvgen/rvgen/dot2k.py
> +++ b/tools/verification/rvgen/rvgen/dot2k.py
> @@ -177,7 +177,6 @@ class ha2k(dot2k):
> if not self.is_hybrid_automata():
> raise AutomataError("Detected deterministic automaton,
> use the 'da' class")
> self.trace_h = self._read_template_file("trace_hybrid.h")
> - self.__parse_constraints()
> self.has_invariant = False
> self.has_guard = False
> for state in self._states:
> @@ -308,64 +307,6 @@ class ha2k(dot2k):
> separator = "\n\t\t " if sum(len(r) for r in rules) >
> 80 else " "
> return ["res = " + separator.join(rules) + ";"]
>
> - def __validate_constraint(self, key: tuple[int, int] | int,
> constr: str,
> - rule, reset) -> None:
> - # event constrains are tuples and allow both rules and reset
> - # state constraints are only used for expirations (e.g.
> clk<N)
> - if self.is_event_constraint(key):
> - if not rule and not reset:
> - raise AutomataError("Unrecognised event constraint "
> -
> f"({self.states[key[0]]}/{self.events[key[1]]}: {constr})")
> - if rule and (rule["env"] in self.env_types and
> - rule["env"] not in self.env_stored):
> - raise AutomataError("Clocks in hybrid automata
> always require a storage"
> - f" ({rule["env"]})")
> - else:
> - if not rule:
> - raise AutomataError("Unrecognised state constraint "
> - f"({self.states[key]}:
> {constr})")
> - if rule["env"] not in self.env_stored:
> - raise AutomataError("State constraints always
> require a storage "
> - f"({rule["env"]})")
> - if rule["op"] not in ["<", "<="]:
> - raise AutomataError("State constraints must be clock
> expirations like"
> - f" clk<N ({rule.string})")
> -
> - def __parse_constraints(self) -> None:
> - self.guards: dict[_EventConstraintKey, str] = {}
> - self.invariants: dict[_StateConstraintKey, str] = {}
> - for key, constraint in self.constraints.items():
> - rules = []
> - resets = []
> - for c, sep in self._split_constraint_expr(constraint):
> - rule = self.constraint_rule.search(c)
> - reset = self.constraint_reset.search(c)
> - self.__validate_constraint(key, c, rule, reset)
> - if rule:
> - value = rule["val"]
> - value_len = len(rule["val"])
> - unit = None
> - if rule.groupdict().get("unit"):
> - value_len += len(rule["unit"])
> - unit = rule["unit"]
> - c = c[:-(value_len)]
> - value = self.__adjust_value(value, unit)
> - if self.is_event_constraint(key):
> - c = self.__parse_single_constraint(rule,
> value)
> - if sep:
> - c += f" {sep}"
> - else:
> - c = self.__parse_timer_constraint(rule,
> value)
> - rules.append(c)
> - if reset:
> - c = f"ha_reset_env(ha_mon,
> {reset["env"]}{self.enum_suffix}, time_ns)"
> - resets.append(c)
> - if self.is_event_constraint(key):
> - res = self.__format_guard_rules(rules) + resets
> - self.guards[key] = ";".join(res)
> - else:
> - self.invariants[key] = rules[0]
> -
> def __fill_verify_invariants_func(self) -> list[str]:
> if not self.has_invariant:
> return []
> @@ -490,15 +431,15 @@ f"""static bool ha_verify_constraint(struct
> ha_monitor *ha_mon,
> \t\t\t\t enum {self.enum_states_def} next_state, u64 time_ns)
> {{""")
>
> - if self.invariants:
> + if self.has_invariant:
> buff.append("\tif (!ha_verify_invariants(ha_mon,
> curr_state, "
> "event, next_state, time_ns))\n\t\treturn
> false;\n")
>
> - if self.guards:
> + if self.has_guard:
> buff.append("\tif (!ha_verify_guards(ha_mon, curr_state,
> event, "
> "next_state, time_ns))\n\t\treturn
> false;\n")
>
> - if self.invariants:
> + if self.has_invariant:
> buff.append("\tha_setup_invariants(ha_mon, curr_state,
> event, next_state, time_ns);\n")
>
> buff.append("\treturn true;\n}\n")
> @@ -575,7 +516,7 @@ f"""static bool ha_verify_constraint(struct
> ha_monitor *ha_mon,
> return self.__fill_hybrid_get_reset_functions() +
> self.__fill_constr_func()
>
> def _fill_timer_type(self) -> list:
> - if self.invariants:
> + if self.has_invariant:
> return [
> "/* XXX: If the monitor has several instances,
> consider HA_TIMER_WHEEL */",
> "#define HA_TIMER_TYPE HA_TIMER_HRTIMER"
^ permalink raw reply
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