diff mbox series

[PULL,06/27] target/arm: clear PMUVER field of AA64DFR0 when vPMU=off

Message ID 1496337035-30213-7-git-send-email-peter.maydell@linaro.org
State Accepted
Commit 2b3ffa929249b15a75d8bde3e8e57a744f52aff0
Headers show
Series target-arm queue | expand

Commit Message

Peter Maydell June 1, 2017, 5:10 p.m. UTC 
From: Wei Huang <wei@redhat.com>


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>

---
 target/arm/cpu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

-- 
2.7.4
diff mbox series

Patch

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)) {