Currently the ARM GIC checks the number of VCPUs against a fixed
limit, which is GICv2 specific. Don't pretend we know better than the
kernel and let's get rid of that explicit check.
Instead be more relaxed about KVM_CREATE_VCPU failing with EINVAL,
which is the way the kernel communicates having reached a VCPU limit.
If we see this and have at least brought up one VCPU already
successfully, then don't panic, but limit the number of VCPUs instead.
Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
---
arm/gic.c | 6 ------
arm/kvm-cpu.c | 7 ++++++-
kvm-cpu.c | 7 +++++++
3 files changed, 13 insertions(+), 7 deletions(-)
diff --git a/arm/gic.c b/arm/gic.c
index 99f0d2b..05f85a2 100644
--- a/arm/gic.c
+++ b/arm/gic.c
@@ -84,12 +84,6 @@ int gic__create(struct kvm *kvm)
{
int err;
- if (kvm->nrcpus > GIC_MAX_CPUS) {
- pr_warning("%d CPUS greater than maximum of %d -- truncating\n",
- kvm->nrcpus, GIC_MAX_CPUS);
- kvm->nrcpus = GIC_MAX_CPUS;
- }
-
/* Try the new way first, and fallback on legacy method otherwise */
err = gic__create_device(kvm);
if (err)
diff --git a/arm/kvm-cpu.c b/arm/kvm-cpu.c
index 7780251..b2fd6ed 100644
--- a/arm/kvm-cpu.c
+++ b/arm/kvm-cpu.c
@@ -51,8 +51,13 @@ struct kvm_cpu *kvm_cpu__arch_init(struct kvm *kvm, unsigned long cpu_id)
return NULL;
vcpu->vcpu_fd = ioctl(kvm->vm_fd, KVM_CREATE_VCPU, cpu_id);
- if (vcpu->vcpu_fd < 0)
+ if (vcpu->vcpu_fd < 0) {
+ if (errno == EINVAL) {
+ free(vcpu);
+ return NULL;
+ }
die_perror("KVM_CREATE_VCPU ioctl");
+ }
mmap_size = ioctl(kvm->sys_fd, KVM_GET_VCPU_MMAP_SIZE, 0);
if (mmap_size < 0)
diff --git a/kvm-cpu.c b/kvm-cpu.c
index 5d90664..7a9d689 100644
--- a/kvm-cpu.c
+++ b/kvm-cpu.c
@@ -222,11 +222,18 @@ int kvm_cpu__init(struct kvm *kvm)
for (i = 0; i < kvm->nrcpus; i++) {
kvm->cpus[i] = kvm_cpu__arch_init(kvm, i);
if (!kvm->cpus[i]) {
+ if (i > 0 && errno == EINVAL)
+ break;
pr_warning("unable to initialize KVM VCPU");
goto fail_alloc;
}
}
+ if (i < kvm->nrcpus) {
+ kvm->nrcpus = i;
+ printf(" # The kernel limits the number of CPUs to %d\n", i);
+ }
+
return 0;
fail_alloc:
--
2.3.5
--
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