target/arm: clear PMUVER field of AA64DFR0 when vPMU=off
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 <wei@redhat.com>
Message-id: 1495123889-32301-1-git-send-email-wei@redhat.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
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 @@
}
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)) {
