On 12.05.2025 17:55, Oleksii Kurochko wrote:
> --- a/xen/arch/riscv/Makefile
> +++ b/xen/arch/riscv/Makefile
> @@ -1,5 +1,6 @@
> obj-y += aplic.o
> obj-y += cpufeature.o
> +obj-y += dom0less-build.o
Arm uses
obj-$(CONFIG_DOM0LESS_BOOT) += dom0less-build.init.o
Why the two differences?
> --- /dev/null
> +++ b/xen/arch/riscv/dom0less-build.c
> @@ -0,0 +1,30 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +
> +#include <xen/bug.h>
> +#include <xen/device_tree.h>
> +#include <xen/errno.h>
> +#include <xen/fdt-kernel.h>
> +#include <xen/init.h>
> +#include <xen/sched.h>
> +
> +#include <asm/vsbi-uart.h>
> +
> +int __init init_vuart(struct domain *d, struct kernel_info *kinfo,
> + const struct dt_device_node *node)
> +{
> + int rc = -EINVAL;
> +
> + kinfo->arch.vsbi_uart = dt_property_read_bool(node, "vsbi_uart");
> +
> + if ( kinfo->arch.vsbi_uart )
> + {
> + rc = domain_vsbi_uart_init(d, NULL);
> + if ( rc < 0 )
> + return rc;
> + }
> +
> + if ( rc )
> + panic("%s: what a domain should use as an UART?\n", __func__);
Is this a reason to panic()? Isn't it possible for domains to be fine
without any UART?
> --- /dev/null
> +++ b/xen/arch/riscv/vsbi-uart.c
> @@ -0,0 +1,62 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +
> +#include <xen/errno.h>
> +#include <xen/lib.h>
> +#include <xen/mm.h>
> +#include <xen/sched.h>
> +#include <xen/xmalloc.h>
> +
> +#include <asm/vsbi-uart.h>
> +
> +int domain_vsbi_uart_init(struct domain *d, struct vsbi_uart_init_info *info)
> +{
> + int rc;
> + struct vsbi_uart *vsbi_uart = &d->arch.vsbi_uart;
> +
> + if ( vsbi_uart->backend.dom.ring_buf )
> + {
> + printk("%s: ring_buf != 0\n", __func__);
> + return -EINVAL;
> + }
> +
> + /*
> + * info is NULL when the backend is in Xen.
> + * info is != NULL when the backend is in a domain.
> + */
> + if ( info != NULL )
> + {
> + printk("%s: vsbi_uart backend in a domain isn't supported\n",
> __func__);
> + rc = -EOPNOTSUPP;
> + goto out;
> + }
> + else
Pointless "else" after "goto".
> + {
> + vsbi_uart->backend_in_domain = false;
> +
> + vsbi_uart->backend.xen = xzalloc(struct vsbi_uart_xen_backend);
> + if ( vsbi_uart->backend.xen == NULL )
> + {
> + rc = -ENOMEM;
> + goto out;
> + }
> + }
> +
> + spin_lock_init(&vsbi_uart->lock);
> +
> + return 0;
> +
> +out:
Nit (you know what, I suppose).
> + domain_vsbi_uart_deinit(d);
> +
> + return rc;
> +}
> +
> +void domain_vsbi_uart_deinit(struct domain *d)
> +{
> + struct vsbi_uart *vsbi_uart = &d->arch.vsbi_uart;
> +
> + if ( vsbi_uart->backend_in_domain )
> + printk("%s: backed in a domain isn't supported\n", __func__);
Is this relevant in a de-init function?
Jan
