From: Sean Christopherson <seanjc@google.com>
To: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Russell King <linux@armlinux.org.uk>,
Marc Zyngier <maz@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Guo Ren <guoren@kernel.org>, Nick Hu <nickhu@andestech.com>,
Greentime Hu <green.hu@gmail.com>,
Vincent Chen <deanbo422@gmail.com>,
Paul Walmsley <paul.walmsley@sifive.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Albert Ou <aou@eecs.berkeley.edu>,
Thomas Gleixner <tglx@linutronix.de>,
Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, Paolo Bonzini <pbonzini@redhat.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Juergen Gross <jgross@suse.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
James Morse <james.morse@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
Stefano Stabellini <sstabellini@kernel.org>,
linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-csky@vger.kernel.org,
linux-riscv@lists.infradead.org, kvm@vger.kernel.org,
xen-devel@lists.xenproject.org,
Artem Kashkanov <artem.kashkanov@intel.com>,
Like Xu <like.xu.linux@gmail.com>,
Like Xu <like.xu@linux.intel.com>,
Zhu Lingshan <lingshan.zhu@intel.com>
Subject: [PATCH v4 07/17] perf: Add wrappers for invoking guest callbacks
Date: Thu, 11 Nov 2021 02:07:28 +0000 [thread overview]
Message-ID: <20211111020738.2512932-8-seanjc@google.com> (raw)
In-Reply-To: <20211111020738.2512932-1-seanjc@google.com>
Add helpers for the guest callbacks to prepare for burying the callbacks
behind a Kconfig (it's a lot easier to provide a few stubs than to #ifdef
piles of code), and also to prepare for converting the callbacks to
static_call(). perf_instruction_pointer() in particular will have subtle
semantics with static_call(), as the "no callbacks" case will return 0 if
the callbacks are unregistered between querying guest state and getting
the IP. Implement the change now to avoid a functional change when adding
static_call() support, and because the new helper needs to return
_something_ in this case.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/arm64/kernel/perf_callchain.c | 16 +++++-----------
arch/x86/events/core.c | 15 +++++----------
arch/x86/events/intel/core.c | 5 +----
include/linux/perf_event.h | 24 ++++++++++++++++++++++++
4 files changed, 35 insertions(+), 25 deletions(-)
diff --git a/arch/arm64/kernel/perf_callchain.c b/arch/arm64/kernel/perf_callchain.c
index 274dc3e11b6d..db04a55cee7e 100644
--- a/arch/arm64/kernel/perf_callchain.c
+++ b/arch/arm64/kernel/perf_callchain.c
@@ -102,9 +102,7 @@ compat_user_backtrace(struct compat_frame_tail __user *tail,
void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
- struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs();
-
- if (guest_cbs && guest_cbs->state()) {
+ if (perf_guest_state()) {
/* We don't support guest os callchain now */
return;
}
@@ -149,10 +147,9 @@ static bool callchain_trace(void *data, unsigned long pc)
void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
- struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs();
struct stackframe frame;
- if (guest_cbs && guest_cbs->state()) {
+ if (perf_guest_state()) {
/* We don't support guest os callchain now */
return;
}
@@ -163,18 +160,15 @@ void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
unsigned long perf_instruction_pointer(struct pt_regs *regs)
{
- struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs();
-
- if (guest_cbs && guest_cbs->state())
- return guest_cbs->get_ip();
+ if (perf_guest_state())
+ return perf_guest_get_ip();
return instruction_pointer(regs);
}
unsigned long perf_misc_flags(struct pt_regs *regs)
{
- struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs();
- unsigned int guest_state = guest_cbs ? guest_cbs->state() : 0;
+ unsigned int guest_state = perf_guest_state();
int misc = 0;
if (guest_state) {
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index e29312a1003a..620347398027 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2768,11 +2768,10 @@ static bool perf_hw_regs(struct pt_regs *regs)
void
perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
{
- struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs();
struct unwind_state state;
unsigned long addr;
- if (guest_cbs && guest_cbs->state()) {
+ if (perf_guest_state()) {
/* TODO: We don't support guest os callchain now */
return;
}
@@ -2872,11 +2871,10 @@ perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry_ctx *ent
void
perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
{
- struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs();
struct stack_frame frame;
const struct stack_frame __user *fp;
- if (guest_cbs && guest_cbs->state()) {
+ if (perf_guest_state()) {
/* TODO: We don't support guest os callchain now */
return;
}
@@ -2953,18 +2951,15 @@ static unsigned long code_segment_base(struct pt_regs *regs)
unsigned long perf_instruction_pointer(struct pt_regs *regs)
{
- struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs();
-
- if (guest_cbs && guest_cbs->state())
- return guest_cbs->get_ip();
+ if (perf_guest_state())
+ return perf_guest_get_ip();
return regs->ip + code_segment_base(regs);
}
unsigned long perf_misc_flags(struct pt_regs *regs)
{
- struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs();
- unsigned int guest_state = guest_cbs ? guest_cbs->state() : 0;
+ unsigned int guest_state = perf_guest_state();
int misc = 0;
if (guest_state) {
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 24adbd6282d4..a5fb247a6a27 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -2837,7 +2837,6 @@ static int handle_pmi_common(struct pt_regs *regs, u64 status)
{
struct perf_sample_data data;
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
- struct perf_guest_info_callbacks *guest_cbs;
int bit;
int handled = 0;
u64 intel_ctrl = hybrid(cpuc->pmu, intel_ctrl);
@@ -2904,9 +2903,7 @@ static int handle_pmi_common(struct pt_regs *regs, u64 status)
*/
if (__test_and_clear_bit(GLOBAL_STATUS_TRACE_TOPAPMI_BIT, (unsigned long *)&status)) {
handled++;
-
- guest_cbs = perf_get_guest_cbs();
- if (likely(!guest_cbs || !guest_cbs->handle_intel_pt_intr()))
+ if (!perf_guest_handle_intel_pt_intr())
intel_pt_interrupt();
}
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 5e6b346d62a7..346d5aff5804 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -1254,6 +1254,30 @@ static inline struct perf_guest_info_callbacks *perf_get_guest_cbs(void)
*/
return rcu_dereference(perf_guest_cbs);
}
+static inline unsigned int perf_guest_state(void)
+{
+ struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs();
+
+ return guest_cbs ? guest_cbs->state() : 0;
+}
+static inline unsigned long perf_guest_get_ip(void)
+{
+ struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs();
+
+ /*
+ * Arbitrarily return '0' in the unlikely scenario that the callbacks
+ * are unregistered between checking guest state and getting the IP.
+ */
+ return guest_cbs ? guest_cbs->get_ip() : 0;
+}
+static inline unsigned int perf_guest_handle_intel_pt_intr(void)
+{
+ struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs();
+
+ if (guest_cbs && guest_cbs->handle_intel_pt_intr)
+ return guest_cbs->handle_intel_pt_intr();
+ return 0;
+}
extern void perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs);
extern void perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs);
--
2.34.0.rc0.344.g81b53c2807-goog
next prev parent reply other threads:[~2021-11-11 2:08 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-11 2:07 [PATCH v4 00/17] perf: KVM: Fix, optimize, and clean up callbacks Sean Christopherson
2021-11-11 2:07 ` [PATCH v4 01/17] perf: Protect perf_guest_cbs with RCU Sean Christopherson
2021-11-11 7:26 ` Paolo Bonzini
2021-11-11 10:47 ` Peter Zijlstra
2021-11-12 7:55 ` Paolo Bonzini
2021-11-11 2:07 ` [PATCH v4 02/17] KVM: x86: Register perf callbacks after calling vendor's hardware_setup() Sean Christopherson
2021-11-11 2:07 ` [PATCH v4 03/17] KVM: x86: Register Processor Trace interrupt hook iff PT enabled in guest Sean Christopherson
2021-11-11 2:07 ` [PATCH v4 04/17] perf: Stop pretending that perf can handle multiple guest callbacks Sean Christopherson
2021-11-11 2:07 ` [PATCH v4 05/17] perf: Drop dead and useless guest "support" from arm, csky, nds32 and riscv Sean Christopherson
2021-11-11 2:07 ` [PATCH v4 06/17] perf/core: Rework guest callbacks to prepare for static_call support Sean Christopherson
2021-11-11 2:07 ` Sean Christopherson [this message]
2021-11-11 2:07 ` [PATCH v4 08/17] perf: Force architectures to opt-in to guest callbacks Sean Christopherson
2021-11-11 2:07 ` [PATCH v4 09/17] perf/core: Use static_call to optimize perf_guest_info_callbacks Sean Christopherson
2021-11-11 2:07 ` [PATCH v4 10/17] KVM: x86: Drop current_vcpu for kvm_running_vcpu + kvm_arch_vcpu variable Sean Christopherson
2021-11-11 2:07 ` [PATCH v4 11/17] KVM: x86: More precisely identify NMI from guest when handling PMI Sean Christopherson
2021-11-11 2:07 ` [PATCH v4 12/17] KVM: Move x86's perf guest info callbacks to generic KVM Sean Christopherson
2021-11-11 2:07 ` [PATCH v4 13/17] KVM: x86: Move Intel Processor Trace interrupt handler to vmx.c Sean Christopherson
2021-11-11 2:07 ` [PATCH v4 14/17] KVM: arm64: Convert to the generic perf callbacks Sean Christopherson
2021-11-11 2:07 ` [PATCH v4 15/17] KVM: arm64: Hide kvm_arm_pmu_available behind CONFIG_HW_PERF_EVENTS=y Sean Christopherson
2021-11-11 21:49 ` Marc Zyngier
2021-11-11 2:07 ` [PATCH v4 16/17] KVM: arm64: Drop perf.c and fold its tiny bits of code into arm.c Sean Christopherson
2021-11-11 21:49 ` Marc Zyngier
2021-11-11 2:07 ` [PATCH v4 17/17] perf: Drop guest callback (un)register stubs Sean Christopherson
2021-11-11 11:19 ` [PATCH v4 00/17] perf: KVM: Fix, optimize, and clean up callbacks Peter Zijlstra
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