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[PATCH 2/2] target/arm: Initlaize PMU feature for scratch vcpu
From: |
Gavin Shan |
Subject: |
[PATCH 2/2] target/arm: Initlaize PMU feature for scratch vcpu |
Date: |
Wed, 7 Apr 2021 12:01:00 +0800 |
If the scratch vCPU is initialized without PMU feature, we receive
error on reading PMCR_EL0 as it's invisible in this case. It leads
to host probing failure.
This fixes the issue by initializing the scratch vcpu with the PMU
feature enabled and reading PMCR_EL0 from host. Otherwise, its value
is set according to the detected target.
Fixes: f7fb73b8cdd3 ("target/arm: Make number of counters in PMCR follow the
CPU")
Signed-off-by: Gavin Shan <gshan@redhat.com>
---
target/arm/kvm64.c | 32 +++++++++++++++++++++++++++-----
1 file changed, 27 insertions(+), 5 deletions(-)
diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c
index 79800f00a7..7311e86d1d 100644
--- a/target/arm/kvm64.c
+++ b/target/arm/kvm64.c
@@ -516,11 +516,14 @@ bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures
*ahcf)
QEMU_KVM_ARM_TARGET_NONE
};
struct kvm_vcpu_init init = {
- .features[0] = 0;
+ .features[0] = (1 << KVM_ARM_VCPU_PMU_V3),
};
- if (!kvm_arm_create_scratch_host_vcpu(cpus_to_try, fdarray, &init)) {
- return false;
+ if (!kvm_arm_create_scratch_host_vcpu(NULL, fdarray, &init)) {
+ init.features[0] = 0;
+ if (!kvm_arm_create_scratch_host_vcpu(cpus_to_try, fdarray, &init)) {
+ return false;
+ }
}
ahcf->target = init.target;
@@ -564,8 +567,27 @@ bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures
*ahcf)
ARM64_SYS_REG(3, 0, 0, 7, 1));
err |= read_sys_reg64(fdarray[2], &ahcf->isar.id_aa64mmfr2,
ARM64_SYS_REG(3, 0, 0, 7, 2));
- err |= read_sys_reg64(fdarray[2], &ahcf->isar.reset_pmcr_el0,
- ARM64_SYS_REG(3, 3, 9, 12, 0));
+
+ /*
+ * Read PMCR_EL0 from host if PMU feature has been enabled
+ * successfully. Otherwise, the value is set according to
+ * the detected target.
+ */
+ if (init.features[0] & (1 << KVM_ARM_VCPU_PMU_V3)) {
+ err |= read_sys_reg64(fdarray[2], &ahcf->isar.reset_pmcr_el0,
+ ARM64_SYS_REG(3, 3, 9, 12, 0));
+ } else {
+ switch (init.target) {
+ case KVM_ARM_TARGET_CORTEX_A53:
+ ahcf->isar.reset_pmcr_el0 = 0x41033000;
+ break;
+ case KVM_ARM_TARGET_CORTEX_A57:
+ ahcf->isar.reset_pmcr_el0 = 0x41013000;
+ break;
+ default:
+ ahcf->isar.reset_pmcr_el0 = 0x41023000;
+ }
+ }
/*
* Note that if AArch32 support is not present in the host,
--
2.23.0