[PATCH v11 4/6] target-arm: kvm64: detect guest RAS EXTENSION feature
From: Peter Maydell <hidden>
Date: 2017-09-05 17:27:06
Also in:
kvm, kvmarm, linux-acpi, lkml, qemu-arm, qemu-devel
On 18 August 2017 at 15:23, Dongjiu Geng [off-list ref] wrote:
quoted hunk ↗ jump to hunk
check if kvm supports guest RAS EXTENSION. if so, set corresponding feature bit for vcpu. Signed-off-by: Dongjiu Geng <redacted> --- linux-headers/linux/kvm.h | 1 + target/arm/cpu.h | 3 +++ target/arm/kvm64.c | 8 ++++++++ 3 files changed, 12 insertions(+)diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h index 7971a4f..2aa176e 100644 --- a/linux-headers/linux/kvm.h +++ b/linux-headers/linux/kvm.h@@ -929,6 +929,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_PPC_SMT_POSSIBLE 147 #define KVM_CAP_HYPERV_SYNIC2 148 #define KVM_CAP_HYPERV_VP_INDEX 149 +#define KVM_CAP_ARM_RAS_EXTENSION 150 #ifdef KVM_CAP_IRQ_ROUTING
Hi. Changes to linux-headers need to be done as a patch of their own created using scripts/update-linux-headers.sh run against a mainline kernel tree (and with a commit message that quotes the kernel commit hash used). This ensures that we have a consistent set of headers that don't diverge from the kernel copy.
quoted hunk ↗ jump to hunk
diff --git a/target/arm/cpu.h b/target/arm/cpu.h index b39d64a..6b0961b 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h@@ -611,6 +611,8 @@ struct ARMCPU { /* CPU has memory protection unit */ bool has_mpu; + /* CPU has ras extension unit */ + bool has_ras_extension; /* PMSAv7 MPU number of supported regions */ uint32_t pmsav7_dregion;@@ -1229,6 +1231,7 @@ enum arm_features { ARM_FEATURE_THUMB_DSP, /* DSP insns supported in the Thumb encodings */ ARM_FEATURE_PMU, /* has PMU support */ ARM_FEATURE_VBAR, /* has cp15 VBAR */ + ARM_FEATURE_RAS_EXTENSION, /*has RAS extension support */
Missing space after '/*' ?
quoted hunk ↗ jump to hunk
}; static inline int arm_feature(CPUARMState *env, int feature)diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c index a16abc8..0781367 100644 --- a/target/arm/kvm64.c +++ b/target/arm/kvm64.c@@ -518,6 +518,14 @@ int kvm_arch_init_vcpu(CPUState *cs) unset_feature(&env->features, ARM_FEATURE_PMU); } + if (kvm_check_extension(cs->kvm_state, KVM_CAP_ARM_RAS_EXTENSION)) { + cpu->has_ras_extension = true; + set_feature(&env->features, ARM_FEATURE_RAS_EXTENSION); + } else { + cpu->has_ras_extension = false; + unset_feature(&env->features, ARM_FEATURE_RAS_EXTENSION); + } +
Shouldn't we need to also tell the kernel that we actually want it to expose RAS to the guest? Compare the PMU code in this function, where we set a kvm_init_features bit to do this. (This suggests that your ABI for the kernel part of this feature may not be correct?) You should also not be calling set_feature() here -- if the CPU features bit doesn't say "this CPU should have the RAS extensions" we shouldn't create a CPU with them. Instead you should set it in kvm_arm_get_host_cpu_features() (again, compare the PMU code). thanks -- PMM