diff options
| author | Andrew Jones <drjones@redhat.com> | 2019-10-24 14:18:08 +0200 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2019-10-24 17:16:29 +0100 |
| commit | a54ce80d408295b24ac1f15da8dc67ff6ed01206 (patch) | |
| tree | 88129f1abf15a3be007fafcf60fe161642192487 /target/arm/kvm64.c | |
| parent | 8c780cf85275a763e489058ab701c69b298dd634 (diff) | |
target/arm/kvm: host cpu: Add support for sve<N> properties
Allow cpu 'host' to enable SVE when it's available, unless the
user chooses to disable it with the added 'sve=off' cpu property.
Also give the user the ability to select vector lengths with the
sve<N> properties. We don't adopt 'max' cpu's other sve property,
sve-max-vq, because that property is difficult to use with KVM.
That property assumes all vector lengths in the range from 1 up
to and including the specified maximum length are supported, but
there may be optional lengths not supported by the host in that
range. With KVM one must be more specific when enabling vector
lengths.
Signed-off-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Message-id: 20191024121808.9612-10-drjones@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'target/arm/kvm64.c')
| -rw-r--r-- | target/arm/kvm64.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c index c93bbee425..876184b8fe 100644 --- a/target/arm/kvm64.c +++ b/target/arm/kvm64.c @@ -488,7 +488,9 @@ bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf) * and then query that CPU for the relevant ID registers. */ int fdarray[3]; + bool sve_supported; uint64_t features = 0; + uint64_t t; int err; /* Old kernels may not know about the PREFERRED_TARGET ioctl: however @@ -578,13 +580,23 @@ bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf) ARM64_SYS_REG(3, 0, 0, 3, 2)); } + sve_supported = ioctl(fdarray[0], KVM_CHECK_EXTENSION, KVM_CAP_ARM_SVE) > 0; + kvm_arm_destroy_scratch_host_vcpu(fdarray); if (err < 0) { return false; } - /* We can assume any KVM supporting CPU is at least a v8 + /* Add feature bits that can't appear until after VCPU init. */ + if (sve_supported) { + t = ahcf->isar.id_aa64pfr0; + t = FIELD_DP64(t, ID_AA64PFR0, SVE, 1); + ahcf->isar.id_aa64pfr0 = t; + } + + /* + * We can assume any KVM supporting CPU is at least a v8 * with VFPv4+Neon; this in turn implies most of the other * feature bits. */ |