From: Giacomo Mazzola <gmazz@amazon.de>
To: <kvm@vger.kernel.org>
Cc: Giacomo Mazzola <gmazz@amazon.de>
Subject: [kvm-unit-tests PATCH 3/8] x86: skip PMU init when no PMU is advertised
Date: Tue, 9 Jun 2026 14:08:55 +0000 [thread overview]
Message-ID: <20260609140901.95727-4-gmazz@amazon.de> (raw)
In-Reply-To: <20260609140901.95727-1-gmazz@amazon.de>
Guard pmu_init() behind CPUID checks: Intel's architectural PMU
version (CPUID 0xA EAX[7:0]) and AMD's PERFCTR_CORE feature bit.
Without a PMU, accessing performance counter MSRs triggers #GP.
Signed-off-by: Giacomo Mazzola <gmazz@amazon.de>
---
lib/x86/setup.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/lib/x86/setup.c b/lib/x86/setup.c
index 09241b33..8c8b6e63 100644
--- a/lib/x86/setup.c
+++ b/lib/x86/setup.c
@@ -416,5 +416,7 @@ void bsp_rest_init(void)
bringup_aps();
enable_x2apic();
smp_init();
- pmu_init();
+ if (this_cpu_property(X86_PROPERTY_PMU_VERSION) ||
+ this_cpu_has(X86_FEATURE_PERFCTR_CORE))
+ pmu_init();
}
--
2.47.3
Amazon Web Services Development Center Germany GmbH
Tamara-Danz-Str. 13
10243 Berlin
Geschaeftsfuehrung: Christof Hellmis, Andreas Stieger
Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B
Sitz: Berlin
Ust-ID: DE 365 538 597
next prev parent reply other threads:[~2026-06-09 14:11 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-09 14:08 [kvm-unit-tests PATCH 0/8] x86: fixes for running KUT as EFI on non-QEMU KVM hosts Giacomo Mazzola
2026-06-09 14:08 ` [kvm-unit-tests PATCH 1/8] x86: efi: use PER_CPU_SIZE for per-CPU stack allocation Giacomo Mazzola
2026-06-09 14:08 ` [kvm-unit-tests PATCH 2/8] x86: fix EFI memory allocator to clamp regions to 4 GiB Giacomo Mazzola
2026-06-09 14:08 ` Giacomo Mazzola [this message]
2026-06-09 14:08 ` [kvm-unit-tests PATCH 4/8] x86: fix ISR thunk to use absolute indirect jump Giacomo Mazzola
2026-06-09 14:08 ` [kvm-unit-tests PATCH 5/8] x86: replace per-AP bringup prints with a single summary line Giacomo Mazzola
2026-06-09 14:08 ` [kvm-unit-tests PATCH 6/8] x86: add timeout-based SMP bringup when fw_cfg is unavailable Giacomo Mazzola
2026-06-09 14:08 ` [kvm-unit-tests PATCH 7/8] efi: fix load_options_size conversion to character count Giacomo Mazzola
2026-06-10 16:09 ` Andrew Jones
2026-06-09 14:09 ` [kvm-unit-tests PATCH 8/8] efi: parse KUT_ENV= from load options into environ Giacomo Mazzola
2026-06-10 18:18 ` Andrew Jones
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