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| author | Eric Auger <eric.auger@redhat.com> | 2019-10-03 17:46:40 +0200 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2019-10-15 18:09:02 +0100 |
| commit | fff9f5558d0e0813d4f80bfe1602acf225eca4fd (patch) | |
| tree | cee5237ae0bc5bbfada5bd53667ae2d96b8514e0 | |
| parent | f6530926e2310147a7844a3e663230d47b3d7333 (diff) | |
| download | focaccia-qemu-fff9f5558d0e0813d4f80bfe1602acf225eca4fd.tar.gz focaccia-qemu-fff9f5558d0e0813d4f80bfe1602acf225eca4fd.zip | |
ARM: KVM: Check KVM_CAP_ARM_IRQ_LINE_LAYOUT_2 for smp_cpus > 256
Host kernel within [4.18, 5.3] report an erroneous KVM_MAX_VCPUS=512 for ARM. The actual capability to instantiate more than 256 vcpus was fixed in 5.4 with the upgrade of the KVM_IRQ_LINE ABI to support vcpu id encoded on 12 bits instead of 8 and a redistributor consuming a single KVM IO device instead of 2. So let's check this capability when attempting to use more than 256 vcpus within any ARM kvm accelerated machine. Signed-off-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Andrew Jones <drjones@redhat.com> Acked-by: Marc Zyngier <maz@kernel.org> Message-id: 20191003154640.22451-4-eric.auger@redhat.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
| -rw-r--r-- | target/arm/kvm.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/target/arm/kvm.c b/target/arm/kvm.c index b10581fa06..b473c63edb 100644 --- a/target/arm/kvm.c +++ b/target/arm/kvm.c @@ -182,6 +182,7 @@ int kvm_arm_get_max_vm_ipa_size(MachineState *ms) int kvm_arch_init(MachineState *ms, KVMState *s) { + int ret = 0; /* For ARM interrupt delivery is always asynchronous, * whether we are using an in-kernel VGIC or not. */ @@ -195,7 +196,14 @@ int kvm_arch_init(MachineState *ms, KVMState *s) cap_has_mp_state = kvm_check_extension(s, KVM_CAP_MP_STATE); - return 0; + if (ms->smp.cpus > 256 && + !kvm_check_extension(s, KVM_CAP_ARM_IRQ_LINE_LAYOUT_2)) { + error_report("Using more than 256 vcpus requires a host kernel " + "with KVM_CAP_ARM_IRQ_LINE_LAYOUT_2"); + ret = -EINVAL; + } + + return ret; } unsigned long kvm_arch_vcpu_id(CPUState *cpu) |