| Message ID | 1396353232-3835-4-git-send-email-pranavkumar@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 1 April 2014 12:53, Pranavkumar Sawargaonkar <pranavkumar@linaro.org> wrote: > Latest linux kernel supports in-kernel emulation of PSCI v0.2 but > to enable it we need to select KVM_ARM_VCPU_PSCI_0_2 feature using > KVM_ARM_VCPU_INIT ioctl. > > Also, we can use KVM_ARM_VCPU_PSCI_0_2 feature for VCPU only when > linux kernel has KVM_CAP_ARM_PSCI_0_2 capability. > > This patch updates kvm_arch_init_vcpu() to enable KVM_ARM_VCPU_PSCI_0_2 > feature for VCPU when KVM ARM/ARM64 has KVM_CAP_ARM_PSCI_0_2 capability. > > Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org> > Signed-off-by: Anup Patel <anup.patel@linaro.org> > --- > target-arm/kvm32.c | 5 ++++- > target-arm/kvm64.c | 5 ++++- > 2 files changed, 8 insertions(+), 2 deletions(-) > > diff --git a/target-arm/kvm32.c b/target-arm/kvm32.c > index a4fde07..afeff01 100644 > --- a/target-arm/kvm32.c > +++ b/target-arm/kvm32.c > @@ -181,7 +181,10 @@ int kvm_arch_init_vcpu(CPUState *cs) > init.target = cpu->kvm_target; > memset(init.features, 0, sizeof(init.features)); > if (cpu->start_powered_off) { > - init.features[0] = 1 << KVM_ARM_VCPU_POWER_OFF; > + init.features[0] |= 1 << KVM_ARM_VCPU_POWER_OFF; > + } > + if (kvm_check_extension(cs->kvm_state, KVM_CAP_ARM_PSCI_0_2)) { > + init.features[0] |= 1 << KVM_ARM_VCPU_PSCI_0_2; > } I vaguely remember mentioning migration incompatibilities last time round. You can't do this because this means that a QEMU running on a non-0.2-aware kernel won't be able to migrate its VM to a QEMU running on a 0.2-aware kernel. PSCI version is probably going to need to be a CPU property; needs more thought. thanks -- PMM
Hi Peter, On 1 April 2014 17:46, Peter Maydell <peter.maydell@linaro.org> wrote: > On 1 April 2014 12:53, Pranavkumar Sawargaonkar <pranavkumar@linaro.org> wrote: >> Latest linux kernel supports in-kernel emulation of PSCI v0.2 but >> to enable it we need to select KVM_ARM_VCPU_PSCI_0_2 feature using >> KVM_ARM_VCPU_INIT ioctl. >> >> Also, we can use KVM_ARM_VCPU_PSCI_0_2 feature for VCPU only when >> linux kernel has KVM_CAP_ARM_PSCI_0_2 capability. >> >> This patch updates kvm_arch_init_vcpu() to enable KVM_ARM_VCPU_PSCI_0_2 >> feature for VCPU when KVM ARM/ARM64 has KVM_CAP_ARM_PSCI_0_2 capability. >> >> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org> >> Signed-off-by: Anup Patel <anup.patel@linaro.org> >> --- >> target-arm/kvm32.c | 5 ++++- >> target-arm/kvm64.c | 5 ++++- >> 2 files changed, 8 insertions(+), 2 deletions(-) >> >> diff --git a/target-arm/kvm32.c b/target-arm/kvm32.c >> index a4fde07..afeff01 100644 >> --- a/target-arm/kvm32.c >> +++ b/target-arm/kvm32.c >> @@ -181,7 +181,10 @@ int kvm_arch_init_vcpu(CPUState *cs) >> init.target = cpu->kvm_target; >> memset(init.features, 0, sizeof(init.features)); >> if (cpu->start_powered_off) { >> - init.features[0] = 1 << KVM_ARM_VCPU_POWER_OFF; >> + init.features[0] |= 1 << KVM_ARM_VCPU_POWER_OFF; >> + } >> + if (kvm_check_extension(cs->kvm_state, KVM_CAP_ARM_PSCI_0_2)) { >> + init.features[0] |= 1 << KVM_ARM_VCPU_PSCI_0_2; >> } > > I vaguely remember mentioning migration incompatibilities > last time round. You can't do this because this means that > a QEMU running on a non-0.2-aware kernel won't be able to > migrate its VM to a QEMU running on a 0.2-aware kernel. > PSCI version is probably going to need to be a CPU property; > needs more thought. > Yes you had mentioned about this issue in v1. During V1 of this patch-set Christoffer mentioned that he will address this issue in migration for ARMv8. But till that time can we go with this current approach ? (May be I can add a comment about this) > thanks > -- PMM Thanks, Pranav
diff --git a/target-arm/kvm32.c b/target-arm/kvm32.c index a4fde07..afeff01 100644 --- a/target-arm/kvm32.c +++ b/target-arm/kvm32.c @@ -181,7 +181,10 @@ int kvm_arch_init_vcpu(CPUState *cs) init.target = cpu->kvm_target; memset(init.features, 0, sizeof(init.features)); if (cpu->start_powered_off) { - init.features[0] = 1 << KVM_ARM_VCPU_POWER_OFF; + init.features[0] |= 1 << KVM_ARM_VCPU_POWER_OFF; + } + if (kvm_check_extension(cs->kvm_state, KVM_CAP_ARM_PSCI_0_2)) { + init.features[0] |= 1 << KVM_ARM_VCPU_PSCI_0_2; } ret = kvm_vcpu_ioctl(cs, KVM_ARM_VCPU_INIT, &init); if (ret) { diff --git a/target-arm/kvm64.c b/target-arm/kvm64.c index 1b7ca90..02bba45 100644 --- a/target-arm/kvm64.c +++ b/target-arm/kvm64.c @@ -90,7 +90,10 @@ int kvm_arch_init_vcpu(CPUState *cs) init.target = cpu->kvm_target; memset(init.features, 0, sizeof(init.features)); if (cpu->start_powered_off) { - init.features[0] = 1 << KVM_ARM_VCPU_POWER_OFF; + init.features[0] |= 1 << KVM_ARM_VCPU_POWER_OFF; + } + if (kvm_check_extension(cs->kvm_state, KVM_CAP_ARM_PSCI_0_2)) { + init.features[0] |= 1 << KVM_ARM_VCPU_PSCI_0_2; } ret = kvm_vcpu_ioctl(cs, KVM_ARM_VCPU_INIT, &init);