Hi,
CC'ing the kvmtool maintainers and other people that might be interested in this
thread. Sorry for hijacking your patch!
On Wed, Jan 18, 2023 at 05:20:07PM +0000, Rajnesh Kanwal wrote:
> Adding force-pci option to allow forcing virtio
> devices to use pci as the default transport.
arm is in the same situation, MMIO is the default virtio transport. I was bitten
by that in the past. It also cought other people unaware, and I remember maz
complaining about it on the list.
So I was thinking about adding a new command line parameter, --virtio-transport,
with the possible values mmio-legacy, mmio, pci-legacy and pci. Then each
architecture can define the default value for the transport. For arm, that would
be pci.
What do you guys think?
Thanks,
Alex
>
> Signed-off-by: Rajnesh Kanwal <rkanwal@xxxxxxxxxxxx>
> ---
> riscv/include/kvm/kvm-arch.h | 6 ++++--
> riscv/include/kvm/kvm-config-arch.h | 7 ++++++-
> 2 files changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/riscv/include/kvm/kvm-arch.h b/riscv/include/kvm/kvm-arch.h
> index 1e130f5..2cf41c5 100644
> --- a/riscv/include/kvm/kvm-arch.h
> +++ b/riscv/include/kvm/kvm-arch.h
> @@ -46,8 +46,10 @@
>
> #define KVM_VM_TYPE 0
>
> -#define VIRTIO_DEFAULT_TRANS(kvm) \
> - ((kvm)->cfg.virtio_legacy ? VIRTIO_MMIO_LEGACY : VIRTIO_MMIO)
> +#define VIRTIO_DEFAULT_TRANS(kvm) \
> + ((kvm)->cfg.arch.virtio_trans_pci ? \
> + ((kvm)->cfg.virtio_legacy ? VIRTIO_PCI_LEGACY : VIRTIO_PCI) : \
> + ((kvm)->cfg.virtio_legacy ? VIRTIO_MMIO_LEGACY : VIRTIO_MMIO))
>
> #define VIRTIO_RING_ENDIAN VIRTIO_ENDIAN_LE
>
> diff --git a/riscv/include/kvm/kvm-config-arch.h b/riscv/include/kvm/kvm-config-arch.h
> index 188125c..901a5e0 100644
> --- a/riscv/include/kvm/kvm-config-arch.h
> +++ b/riscv/include/kvm/kvm-config-arch.h
> @@ -6,6 +6,7 @@
> struct kvm_config_arch {
> const char *dump_dtb_filename;
> bool ext_disabled[KVM_RISCV_ISA_EXT_MAX];
> + bool virtio_trans_pci;
> };
>
> #define OPT_ARCH_RUN(pfx, cfg) \
> @@ -26,6 +27,10 @@ struct kvm_config_arch {
> "Disable Zicbom Extension"), \
> OPT_BOOLEAN('\0', "disable-zihintpause", \
> &(cfg)->ext_disabled[KVM_RISCV_ISA_EXT_ZIHINTPAUSE],\
> - "Disable Zihintpause Extension"),
> + "Disable Zihintpause Extension"), \
> + OPT_BOOLEAN('\0', "force-pci", \
> + &(cfg)->virtio_trans_pci, \
> + "Force virtio devices to use PCI as their " \
> + "default transport"),
>
> #endif /* KVM__KVM_CONFIG_ARCH_H */
> --
> 2.25.1
>
