Re: [PATCH 04/35] s390/protvirt: add ultravisor initialization

[David Hildenbrand <david@redhat.com>]

[...]

>  #if defined(CONFIG_PROTECTED_VIRTUALIZATION_GUEST) ||                          \
> diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
> index f2ab2528859f..5f178d557cc8 100644
> --- a/arch/s390/kernel/setup.c
> +++ b/arch/s390/kernel/setup.c
> @@ -560,6 +560,8 @@ static void __init setup_memory_end(void)
>  			vmax = _REGION1_SIZE; /* 4-level kernel page table */
>  	}
>  
> +	adjust_to_uv_max(&vmax);

I'd somewhat prefer

if (prot_virt_host)
	adjust_to_uv_max(&vmax);

> +
>  	/* module area is at the end of the kernel address space. */
>  	MODULES_END = vmax;
>  	MODULES_VADDR = MODULES_END - MODULES_LEN;
> @@ -1140,6 +1142,7 @@ void __init setup_arch(char **cmdline_p)
>  	 */
>  	memblock_trim_memory(1UL << (MAX_ORDER - 1 + PAGE_SHIFT));
>  
> +	setup_uv();

and

if (prot_virt_host)
	setup_uv();

Moving the checks out of the functions. Makes it clearer that this is
optional.

>  	setup_memory_end();
>  	setup_memory();
>  	dma_contiguous_reserve(memory_end);
> diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
> index fbf2a98de642..a06a628a88da 100644
> --- a/arch/s390/kernel/uv.c
> +++ b/arch/s390/kernel/uv.c
> @@ -46,4 +46,57 @@ static int __init prot_virt_setup(char *val)
>  	return rc;
>  }
>  early_param("prot_virt", prot_virt_setup);
> +
> +static int __init uv_init(unsigned long stor_base, unsigned long stor_len)
> +{
> +	struct uv_cb_init uvcb = {
> +		.header.cmd = UVC_CMD_INIT_UV,
> +		.header.len = sizeof(uvcb),
> +		.stor_origin = stor_base,
> +		.stor_len = stor_len,
> +	};
> +	int cc;
> +
> +	cc = uv_call(0, (uint64_t)&uvcb);

Could do

int cc = uv_call(0, (uint64_t)&uvcb);

> +	if (cc || uvcb.header.rc != UVC_RC_EXECUTED) {
> +		pr_err("Ultravisor init failed with cc: %d rc: 0x%hx\n", cc,
> +		       uvcb.header.rc);
> +		return -1;
> +	}
> +	return 0;
> +}
> +
> +void __init setup_uv(void)
> +{
> +	unsigned long uv_stor_base;
> +
> +	if (!prot_virt_host)
> +		return;
> +
> +	uv_stor_base = (unsigned long)memblock_alloc_try_nid(
> +		uv_info.uv_base_stor_len, SZ_1M, SZ_2G,
> +		MEMBLOCK_ALLOC_ACCESSIBLE, NUMA_NO_NODE);
> +	if (!uv_stor_base) {
> +		pr_info("Failed to reserve %lu bytes for ultravisor base storage\n",
> +			uv_info.uv_base_stor_len);

pr_err() ? pr_warn()?

> +		goto fail;
> +	}
> +
> +	if (uv_init(uv_stor_base, uv_info.uv_base_stor_len)) {
> +		memblock_free(uv_stor_base, uv_info.uv_base_stor_len);
> +		goto fail;
> +	}
> +
> +	pr_info("Reserving %luMB as ultravisor base storage\n",
> +		uv_info.uv_base_stor_len >> 20);
> +	return;
> +fail:

I'd add here:

pr_info("Disabling support for protected virtualization");

> +	prot_virt_host = 0;> +}
> +
> +void adjust_to_uv_max(unsigned long *vmax)
> +{
> +	if (prot_virt_host && *vmax > uv_info.max_sec_stor_addr)
> +		*vmax = uv_info.max_sec_stor_addr;

Once you move the prot virt check out of this function

	*vmax = max_t(unsigned long, *vmax, uv_info.max_sec_stor_addr);

> +}
>  #endif
> 


-- 
Thanks,

David / dhildenb