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[Qemu-devel] [PATCH 1/1] target/arm: clear PMUVER field of AA64DFR0 when
From: |
Wei Huang |
Subject: |
[Qemu-devel] [PATCH 1/1] target/arm: clear PMUVER field of AA64DFR0 when vPMU=off |
Date: |
Thu, 18 May 2017 11:11:29 -0500 |
The PMUv3 driver of linux kernel (in arch/arm64/kernel/perf_event.c)
relies on the PMUVER field of id_aa64dfr0_el1 to decide if PMU support
is present or not. This patch clears the PMUVER field under TCG mode
when vPMU=off. Without it, PMUv3 will init insider guest VMs even
with vPMU=off. This patch also removes a redundant line inside the
if-statement.
Signed-off-by: Wei Huang <address@hidden>
---
target/arm/cpu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index c185eb1..4e8fe1c 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -750,8 +750,8 @@ static void arm_cpu_realizefn(DeviceState *dev, Error
**errp)
}
if (!cpu->has_pmu) {
- cpu->has_pmu = false;
unset_feature(env, ARM_FEATURE_PMU);
+ cpu->id_aa64dfr0 &= ~0xf00;
}
if (!arm_feature(env, ARM_FEATURE_EL2)) {
--
1.8.3.1
- [Qemu-devel] [PATCH 1/1] target/arm: clear PMUVER field of AA64DFR0 when vPMU=off,
Wei Huang <=