From: David Gibson <david@gibson.dropbear.id.au>
To: Fabiano Rosas <farosas@linux.ibm.com>
Cc: pbonzini@redhat.com, qemu-ppc@nongnu.org, qemu-devel@nongnu.org,
groug@kaod.org
Subject: Re: [PATCH] kvm: ppc: Print meaningful message on KVM_CREATE_VM failure
Date: Mon, 26 Jul 2021 12:25:20 +1000 [thread overview]
Message-ID: <YP4dEI+nJkMgbHmu@yekko> (raw)
In-Reply-To: <20210722141340.2367905-1-farosas@linux.ibm.com>
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On Thu, Jul 22, 2021 at 11:13:40AM -0300, Fabiano Rosas wrote:
> 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'.
>
> Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Applied to ppc-for-6.1, thanks.
> ---
> 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 3bd17135ce..4d9a7c7bfc 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 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;
> }
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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prev parent reply other threads:[~2021-07-26 2:44 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-22 14:13 [PATCH] kvm: ppc: Print meaningful message on KVM_CREATE_VM failure Fabiano Rosas
2021-07-26 2:25 ` David Gibson [this message]
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