If KVM supports user provided MPIDRs for the vcpus, then provide
them. This simplifies management of vcpus as we can be sure of
the identity of a vcpu even before it's been instantiated.
Cc: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Andrew Jones <drjones@redhat.com>
---
target/arm/cpu.c | 3 +--
target/arm/kvm32.c | 22 ++++++++++++++--------
target/arm/kvm64.c | 22 ++++++++++++++--------
3 files changed, 29 insertions(+), 18 deletions(-)
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index f7157dc0e59d..83cd5eefbef8 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -741,8 +741,7 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
return;
}
- /* This cpu-id-to-MPIDR affinity is used only for TCG; KVM will override it.
- * We don't support setting cluster ID ([16..23]) (known as Aff2
+ /* We don't currently support setting cluster ID ([16..23]) (known as Aff2
* in later ARM ARM versions), or any of the higher affinity level fields,
* so these bits always RAZ.
*/
diff --git a/target/arm/kvm32.c b/target/arm/kvm32.c
index 069da0c5fd10..5ad732498e5c 100644
--- a/target/arm/kvm32.c
+++ b/target/arm/kvm32.c
@@ -186,7 +186,6 @@ int kvm_arch_init_vcpu(CPUState *cs)
{
int ret;
uint64_t v;
- uint32_t mpidr;
struct kvm_one_reg r;
ARMCPU *cpu = ARM_CPU(cs);
@@ -223,16 +222,23 @@ int kvm_arch_init_vcpu(CPUState *cs)
return -EINVAL;
}
- /*
- * When KVM is in use, PSCI is emulated in-kernel and not by qemu.
- * Currently KVM has its own idea about MPIDR assignment, so we
- * override our defaults with what we get from KVM.
- */
- ret = kvm_get_one_reg(cs, ARM_CP15_REG32(ARM_CPU_ID_MPIDR), &mpidr);
+ if (kvm_check_extension(cs->kvm_state, KVM_CAP_ARM_USER_MPIDR)) {
+ ret = kvm_set_one_reg(cs, ARM_CP15_REG32(ARM_CPU_ID_MPIDR),
+ &cpu->mp_affinity);
+ } else {
+ /* If we can't set the MPIDR, then KVM will generate one. We must
+ * update our copy to that one in order to stay synchronized.
+ */
+ uint32_t mpidr;
+
+ ret = kvm_get_one_reg(cs, ARM_CP15_REG32(ARM_CPU_ID_MPIDR), &mpidr);
+ if (!ret) {
+ cpu->mp_affinity = mpidr & ARM32_AFFINITY_MASK;
+ }
+ }
if (ret) {
return ret;
}
- cpu->mp_affinity = mpidr & ARM32_AFFINITY_MASK;
return kvm_arm_init_cpreg_list(cpu);
}
diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c
index 61111091ad3b..a7d3f876c43b 100644
--- a/target/arm/kvm64.c
+++ b/target/arm/kvm64.c
@@ -486,7 +486,6 @@ bool kvm_arm_get_host_cpu_features(ARMHostCPUClass *ahcc)
int kvm_arch_init_vcpu(CPUState *cs)
{
int ret;
- uint64_t mpidr;
ARMCPU *cpu = ARM_CPU(cs);
CPUARMState *env = &cpu->env;
@@ -524,16 +523,23 @@ int kvm_arch_init_vcpu(CPUState *cs)
return ret;
}
- /*
- * When KVM is in use, PSCI is emulated in-kernel and not by qemu.
- * Currently KVM has its own idea about MPIDR assignment, so we
- * override our defaults with what we get from KVM.
- */
- ret = kvm_get_one_reg(cs, ARM64_SYS_REG(ARM_CPU_ID_MPIDR), &mpidr);
+ if (kvm_check_extension(cs->kvm_state, KVM_CAP_ARM_USER_MPIDR)) {
+ ret = kvm_set_one_reg(cs, ARM64_SYS_REG(ARM_CPU_ID_MPIDR),
+ &cpu->mp_affinity);
+ } else {
+ /* If we can't set the MPIDR, then KVM will generate one. We must
+ * update our copy to that one in order to stay synchronized.
+ */
+ uint64_t mpidr;
+
+ ret = kvm_get_one_reg(cs, ARM64_SYS_REG(ARM_CPU_ID_MPIDR), &mpidr);
+ if (!ret) {
+ cpu->mp_affinity = mpidr & ARM64_AFFINITY_MASK;
+ }
+ }
if (ret) {
return ret;
}
- cpu->mp_affinity = mpidr & ARM64_AFFINITY_MASK;
kvm_arm_init_debug(cs);
--
2.9.3
On 27 February 2017 at 17:37, Andrew Jones <drjones@redhat.com> wrote:
> If KVM supports user provided MPIDRs for the vcpus, then provide
> them. This simplifies management of vcpus as we can be sure of
> the identity of a vcpu even before it's been instantiated.
>
> Cc: Igor Mammedov <imammedo@redhat.com>
> Signed-off-by: Andrew Jones <drjones@redhat.com>
> ---
> target/arm/cpu.c | 3 +--
> target/arm/kvm32.c | 22 ++++++++++++++--------
> target/arm/kvm64.c | 22 ++++++++++++++--------
> 3 files changed, 29 insertions(+), 18 deletions(-)
>
> diff --git a/target/arm/cpu.c b/target/arm/cpu.c
> index f7157dc0e59d..83cd5eefbef8 100644
> --- a/target/arm/cpu.c
> +++ b/target/arm/cpu.c
> @@ -741,8 +741,7 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
> return;
> }
>
> - /* This cpu-id-to-MPIDR affinity is used only for TCG; KVM will override it.
> - * We don't support setting cluster ID ([16..23]) (known as Aff2
> + /* We don't currently support setting cluster ID ([16..23]) (known as Aff2
> * in later ARM ARM versions), or any of the higher affinity level fields,
> * so these bits always RAZ.
> */
> diff --git a/target/arm/kvm32.c b/target/arm/kvm32.c
> index 069da0c5fd10..5ad732498e5c 100644
> --- a/target/arm/kvm32.c
> +++ b/target/arm/kvm32.c
> @@ -186,7 +186,6 @@ int kvm_arch_init_vcpu(CPUState *cs)
> {
> int ret;
> uint64_t v;
> - uint32_t mpidr;
> struct kvm_one_reg r;
> ARMCPU *cpu = ARM_CPU(cs);
>
> @@ -223,16 +222,23 @@ int kvm_arch_init_vcpu(CPUState *cs)
> return -EINVAL;
> }
>
> - /*
> - * When KVM is in use, PSCI is emulated in-kernel and not by qemu.
> - * Currently KVM has its own idea about MPIDR assignment, so we
> - * override our defaults with what we get from KVM.
> - */
> - ret = kvm_get_one_reg(cs, ARM_CP15_REG32(ARM_CPU_ID_MPIDR), &mpidr);
> + if (kvm_check_extension(cs->kvm_state, KVM_CAP_ARM_USER_MPIDR)) {
> + ret = kvm_set_one_reg(cs, ARM_CP15_REG32(ARM_CPU_ID_MPIDR),
> + &cpu->mp_affinity);
mp_affinity is only the affinity bits of the MPIDR. I would expect
the kernel set_one_reg interface for the MPIDR to want a complete
MPIDR value with M, U and MT bits.
(compare the way that when we set mp_affinity from the kernel
reg. value we mask out the bits we don't care about).
Similarly with the 64-bit version of this code.
> + } else {
> + /* If we can't set the MPIDR, then KVM will generate one. We must
> + * update our copy to that one in order to stay synchronized.
> + */
> + uint32_t mpidr;
> +
> + ret = kvm_get_one_reg(cs, ARM_CP15_REG32(ARM_CPU_ID_MPIDR), &mpidr);
> + if (!ret) {
> + cpu->mp_affinity = mpidr & ARM32_AFFINITY_MASK;
> + }
> + }
> if (ret) {
> return ret;
> }
> - cpu->mp_affinity = mpidr & ARM32_AFFINITY_MASK;
>
> return kvm_arm_init_cpreg_list(cpu);
Otherwise this looks fine to me.
PS: I assume we are targeting 2.10 (or whatever we call it) with this.
thanks
-- PMM
On Thu, Mar 02, 2017 at 04:13:40PM +0000, Peter Maydell wrote:
> On 27 February 2017 at 17:37, Andrew Jones <drjones@redhat.com> wrote:
> > If KVM supports user provided MPIDRs for the vcpus, then provide
> > them. This simplifies management of vcpus as we can be sure of
> > the identity of a vcpu even before it's been instantiated.
> >
> > Cc: Igor Mammedov <imammedo@redhat.com>
> > Signed-off-by: Andrew Jones <drjones@redhat.com>
> > ---
> > target/arm/cpu.c | 3 +--
> > target/arm/kvm32.c | 22 ++++++++++++++--------
> > target/arm/kvm64.c | 22 ++++++++++++++--------
> > 3 files changed, 29 insertions(+), 18 deletions(-)
> >
> > diff --git a/target/arm/cpu.c b/target/arm/cpu.c
> > index f7157dc0e59d..83cd5eefbef8 100644
> > --- a/target/arm/cpu.c
> > +++ b/target/arm/cpu.c
> > @@ -741,8 +741,7 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
> > return;
> > }
> >
> > - /* This cpu-id-to-MPIDR affinity is used only for TCG; KVM will override it.
> > - * We don't support setting cluster ID ([16..23]) (known as Aff2
> > + /* We don't currently support setting cluster ID ([16..23]) (known as Aff2
> > * in later ARM ARM versions), or any of the higher affinity level fields,
> > * so these bits always RAZ.
> > */
> > diff --git a/target/arm/kvm32.c b/target/arm/kvm32.c
> > index 069da0c5fd10..5ad732498e5c 100644
> > --- a/target/arm/kvm32.c
> > +++ b/target/arm/kvm32.c
> > @@ -186,7 +186,6 @@ int kvm_arch_init_vcpu(CPUState *cs)
> > {
> > int ret;
> > uint64_t v;
> > - uint32_t mpidr;
> > struct kvm_one_reg r;
> > ARMCPU *cpu = ARM_CPU(cs);
> >
> > @@ -223,16 +222,23 @@ int kvm_arch_init_vcpu(CPUState *cs)
> > return -EINVAL;
> > }
> >
> > - /*
> > - * When KVM is in use, PSCI is emulated in-kernel and not by qemu.
> > - * Currently KVM has its own idea about MPIDR assignment, so we
> > - * override our defaults with what we get from KVM.
> > - */
> > - ret = kvm_get_one_reg(cs, ARM_CP15_REG32(ARM_CPU_ID_MPIDR), &mpidr);
> > + if (kvm_check_extension(cs->kvm_state, KVM_CAP_ARM_USER_MPIDR)) {
> > + ret = kvm_set_one_reg(cs, ARM_CP15_REG32(ARM_CPU_ID_MPIDR),
> > + &cpu->mp_affinity);
>
> mp_affinity is only the affinity bits of the MPIDR. I would expect
> the kernel set_one_reg interface for the MPIDR to want a complete
> MPIDR value with M, U and MT bits.
Thanks, I'll fix this.
>
> (compare the way that when we set mp_affinity from the kernel
> reg. value we mask out the bits we don't care about).
>
> Similarly with the 64-bit version of this code.
>
> > + } else {
> > + /* If we can't set the MPIDR, then KVM will generate one. We must
> > + * update our copy to that one in order to stay synchronized.
> > + */
> > + uint32_t mpidr;
> > +
> > + ret = kvm_get_one_reg(cs, ARM_CP15_REG32(ARM_CPU_ID_MPIDR), &mpidr);
> > + if (!ret) {
> > + cpu->mp_affinity = mpidr & ARM32_AFFINITY_MASK;
> > + }
> > + }
> > if (ret) {
> > return ret;
> > }
> > - cpu->mp_affinity = mpidr & ARM32_AFFINITY_MASK;
> >
> > return kvm_arm_init_cpreg_list(cpu);
>
> Otherwise this looks fine to me.
>
> PS: I assume we are targeting 2.10 (or whatever we call it) with this.
Yeah, this is 2.10 material.
Thanks,
drew
© 2016 - 2025 Red Hat, Inc.