On Tue, 27 Sept 2022 at 18:07, Eric Auger <eric.au...@redhat.com> wrote: > > Hi Peter, > > On 9/27/22 18:49, Peter Maydell wrote: > > Occasionally the KVM_CREATE_VM ioctl can return EINTR, even though > > there is no pending signal to be taken. In commit 94ccff13382055 > > we added a retry-on-EINTR loop to the KVM_CREATE_VM call in the > > generic KVM code. Adopt the same approach for the use of the > > ioctl in the Arm-specific KVM code (where we use it to create a > > scratch VM for probing for various things). > > > > For more information, see the mailing list thread: > > https://lore.kernel.org/qemu-devel/8735e0s1zw.wl-...@kernel.org/ > > > > Reported-by: Vitaly Chikunov <v...@altlinux.org> > > Signed-off-by: Peter Maydell <peter.mayd...@linaro.org> > > --- > > The view in the thread seems to be that this is a kernel bug (because > > in QEMU's case there shouldn't be a signal to be delivered at this > > point because of our signal handling strategy); so I've adopted the > > same "just retry-on-EINTR for this specific ioctl" approach that > > commit 94ccff13 did, rather than, for instance, something wider like > > "make kvm_ioctl() and friends always retry on EINTR". > > > > v2: correctly check for -1 and errno is EINTR... > > --- > > target/arm/kvm.c | 4 +++- > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > diff --git a/target/arm/kvm.c b/target/arm/kvm.c > > index e5c1bd50d29..356199c9e25 100644 > > --- a/target/arm/kvm.c > > +++ b/target/arm/kvm.c > > @@ -79,7 +79,9 @@ bool kvm_arm_create_scratch_host_vcpu(const uint32_t > > *cpus_to_try, > > if (max_vm_pa_size < 0) { > > max_vm_pa_size = 0; > > } > > - vmfd = ioctl(kvmfd, KVM_CREATE_VM, max_vm_pa_size); > > + do { > > + vmfd = ioctl(kvmfd, KVM_CREATE_VM, max_vm_pa_size); > > + } while (vmfd == -1 && errno == -EINTR); > shouldn't it be errno == EINTR?
Augh. Yes. -- PMM
