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Re: [Qemu-devel] [PATCH RFC 1/1] arm64: add an option to turn on/off vpm
From: |
Shannon Zhao |
Subject: |
Re: [Qemu-devel] [PATCH RFC 1/1] arm64: add an option to turn on/off vpmu support |
Date: |
Fri, 29 Jul 2016 08:59:58 +0800 |
User-agent: |
Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 |
On 2016/7/29 0:38, Wei Huang wrote:
> This patch adds a pmu=[on/off] option to enable/disable vpmu support
> in guest vm. There are several reasons to justify this option. First
> vpmu can be problematic for cross-migration between different SoC as
> perf counters is architecture-dependent. It is more flexible to
> have an option to turn it on/off. Secondly it matches the -cpu pmu
> option in libivrt. This patch has been tested on both DT/ACPI modes.
>
> Signed-off-by: Wei Huang <address@hidden>
Reviewed-by:Shannon Zhao <address@hidden>
> ---
> hw/arm/virt-acpi-build.c | 2 +-
> hw/arm/virt.c | 2 +-
> target-arm/cpu.c | 1 +
> target-arm/cpu.h | 5 +++--
> target-arm/kvm64.c | 10 +++++-----
> 5 files changed, 11 insertions(+), 9 deletions(-)
>
> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> index 28fc59c..dc5f66d 100644
> --- a/hw/arm/virt-acpi-build.c
> +++ b/hw/arm/virt-acpi-build.c
> @@ -540,7 +540,7 @@ build_madt(GArray *table_data, BIOSLinker *linker,
> VirtGuestInfo *guest_info)
> gicc->uid = i;
> gicc->flags = cpu_to_le32(ACPI_GICC_ENABLED);
>
> - if (armcpu->has_pmu) {
> + if (armcpu->enable_pmu) {
> gicc->performance_interrupt = cpu_to_le32(PPI(VIRTUAL_PMU_IRQ));
> }
> }
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index a193b5a..6aea901 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -477,7 +477,7 @@ static void fdt_add_pmu_nodes(const VirtBoardInfo *vbi,
> int gictype)
>
> CPU_FOREACH(cpu) {
> armcpu = ARM_CPU(cpu);
> - if (!armcpu->has_pmu ||
> + if (!armcpu->enable_pmu ||
> !kvm_arm_pmu_create(cpu, PPI(VIRTUAL_PMU_IRQ))) {
> return;
> }
> diff --git a/target-arm/cpu.c b/target-arm/cpu.c
> index ce8b8f4..f7daf81 100644
> --- a/target-arm/cpu.c
> +++ b/target-arm/cpu.c
> @@ -1412,6 +1412,7 @@ static const ARMCPUInfo arm_cpus[] = {
> };
>
> static Property arm_cpu_properties[] = {
> + DEFINE_PROP_BOOL("pmu", ARMCPU, enable_pmu, true),
> DEFINE_PROP_BOOL("start-powered-off", ARMCPU, start_powered_off, false),
> DEFINE_PROP_UINT32("psci-conduit", ARMCPU, psci_conduit, 0),
> DEFINE_PROP_UINT32("midr", ARMCPU, midr, 0),
> diff --git a/target-arm/cpu.h b/target-arm/cpu.h
> index 76d824d..f2341c0 100644
> --- a/target-arm/cpu.h
> +++ b/target-arm/cpu.h
> @@ -579,8 +579,9 @@ struct ARMCPU {
> bool powered_off;
> /* CPU has security extension */
> bool has_el3;
> - /* CPU has PMU (Performance Monitor Unit) */
> - bool has_pmu;
> +
> + /* CPU has vPMU (Performance Monitor Unit) support */
> + bool enable_pmu;
>
> /* CPU has memory protection unit */
> bool has_mpu;
> diff --git a/target-arm/kvm64.c b/target-arm/kvm64.c
> index 5faa76c..ca21670 100644
> --- a/target-arm/kvm64.c
> +++ b/target-arm/kvm64.c
> @@ -501,11 +501,11 @@ int kvm_arch_init_vcpu(CPUState *cs)
> if (!arm_feature(&cpu->env, ARM_FEATURE_AARCH64)) {
> cpu->kvm_init_features[0] |= 1 << KVM_ARM_VCPU_EL1_32BIT;
> }
> - if (kvm_irqchip_in_kernel() &&
> - kvm_check_extension(cs->kvm_state, KVM_CAP_ARM_PMU_V3)) {
> - cpu->has_pmu = true;
> - cpu->kvm_init_features[0] |= 1 << KVM_ARM_VCPU_PMU_V3;
> - }
> +
> + /* enable vPMU based on KVM mode and hardware capability */
> + cpu->enable_pmu &= (kvm_irqchip_in_kernel() &&
> + kvm_check_extension(cs->kvm_state, KVM_CAP_ARM_PMU_V3));
> + cpu->kvm_init_features[0] |= cpu->enable_pmu << KVM_ARM_VCPU_PMU_V3;
>
> /* Do KVM_ARM_VCPU_INIT ioctl */
> ret = kvm_arm_vcpu_init(cs);
>
--
Shannon