[Qemu-devel] [PATCH V3 4/4] target-arm: Enable vPMU support under TCG mode

[Wei Huang <wei@redhat.com>]

This patch contains several fixes to enable vPMU under TCG mode. It
first removes the checking of kvm_enabled() while unsetting
ARM_FEATURE_PMU. With it, the .pmu option can be used to turn on/off vPMU
under TCG mode. Secondly the PMU node of DT table is now created under TCG.
The last fix is to disable the masking of PMUver field of ID_AA64DFR0_EL1.

Signed-off-by: Wei Huang <wei@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/arm/virt.c       | 2 +-
 target/arm/cpu.c    | 2 +-
 target/arm/helper.c | 7 +------
 3 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 1f216cf..8eef143 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -471,7 +471,7 @@ static void fdt_add_pmu_nodes(const VirtMachineState *vms)
     CPU_FOREACH(cpu) {
         armcpu = ARM_CPU(cpu);
         if (!arm_feature(&armcpu->env, ARM_FEATURE_PMU) ||
-            !kvm_arm_pmu_create(cpu, PPI(VIRTUAL_PMU_IRQ))) {
+            (kvm_enabled() && !kvm_arm_pmu_create(cpu, PPI(VIRTUAL_PMU_IRQ)))) {
             return;
         }
     }
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index e9f10f7..9a2bc8a 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -745,7 +745,7 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
         unset_feature(env, ARM_FEATURE_EL2);
     }
 
-    if (!cpu->has_pmu || !kvm_enabled()) {
+    if (!cpu->has_pmu) {
         cpu->has_pmu = false;
         unset_feature(env, ARM_FEATURE_PMU);
     }
diff --git a/target/arm/helper.c b/target/arm/helper.c
index c4daa6e..d363d02 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -4633,12 +4633,7 @@ void register_cp_regs_for_features(ARMCPU *cpu)
             { .name = "ID_AA64DFR0_EL1", .state = ARM_CP_STATE_AA64,
               .opc0 = 3, .opc1 = 0, .crn = 0, .crm = 5, .opc2 = 0,
               .access = PL1_R, .type = ARM_CP_CONST,
-              /* We mask out the PMUVer field, because we don't currently
-               * implement the PMU. Not advertising it prevents the guest
-               * from trying to use it and getting UNDEFs on registers we
-               * don't implement.
-               */
-              .resetvalue = cpu->id_aa64dfr0 & ~0xf00 },
+              .resetvalue = cpu->id_aa64dfr0 },
             { .name = "ID_AA64DFR1_EL1", .state = ARM_CP_STATE_AA64,
               .opc0 = 3, .opc1 = 0, .crn = 0, .crm = 5, .opc2 = 1,
               .access = PL1_R, .type = ARM_CP_CONST,
-- 
1.8.3.1