From 380e49297c302fdcf8e5d56abdbe07868d3af8d8 Mon Sep 17 00:00:00 2001 From: Fabiano Rosas Date: Thu, 22 Jul 2021 11:13:40 -0300 Subject: [PATCH] kvm: ppc: Print meaningful message on KVM_CREATE_VM failure PowerPC has two KVM types (HV, PR) that translate into three kernel modules: kvm.ko - common kvm code kvm_hv.ko - kvm running with MSR_HV=1 or MSR_HV|PR=0 in a nested guest. kvm_pr.ko - kvm running in usermode MSR_PR=1. Since the two KVM types can both be running at the same time, this creates a situation in which it is possible for one or both of the modules to fail to initialize, leaving the generic one behind. This leads QEMU to think it can create a guest, but KVM will fail when calling the type-specific code: ioctl(KVM_CREATE_VM) failed: 22 Invalid argument qemu-kvm: failed to initialize KVM: Invalid argument Ideally this would be solved kernel-side, but it might be a while until we can get rid of one of the modules. So in the meantime this patch tries to make this less confusing for the end user by adding a more elucidative message: ioctl(KVM_CREATE_VM) failed: 22 Invalid argument PPC KVM module is not loaded. Try 'modprobe kvm_hv'. [dwg: Fixed error in #elif which failed compile on !ppc hosts] Signed-off-by: Fabiano Rosas Message-Id: <20210722141340.2367905-1-farosas@linux.ibm.com> Signed-off-by: David Gibson --- accel/kvm/kvm-all.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index e5b10dd129..0125c17edb 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -2397,6 +2397,12 @@ static int kvm_init(MachineState *ms) "- for kernels supporting the vm.allocate_pgste sysctl, " "whether it is enabled\n"); } +#elif defined(TARGET_PPC) + if (ret == -EINVAL) { + fprintf(stderr, + "PPC KVM module is not loaded. Try modprobe kvm_%s.\n", + (type == 2) ? "pr" : "hv"); + } #endif goto err; }