linux/arch/s390/kernel/uv.c
Vasily Gorbik ecdc5d842b s390/protvirt: introduce host side setup
Add "prot_virt" command line option which controls if the kernel
protected VMs support is enabled at early boot time. This has to be
done early, because it needs large amounts of memory and will disable
some features like STP time sync for the lpar.

Extend ultravisor info definitions and expose it via uv_info struct
filled in during startup.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
[borntraeger@de.ibm.com: patch merging, splitting, fixing]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-27 19:44:40 +01:00

53 lines
1.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Common Ultravisor functions and initialization
*
* Copyright IBM Corp. 2019, 2020
*/
#define KMSG_COMPONENT "prot_virt"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/sizes.h>
#include <linux/bitmap.h>
#include <linux/memblock.h>
#include <asm/facility.h>
#include <asm/sections.h>
#include <asm/uv.h>
/* the bootdata_preserved fields come from ones in arch/s390/boot/uv.c */
#ifdef CONFIG_PROTECTED_VIRTUALIZATION_GUEST
int __bootdata_preserved(prot_virt_guest);
#endif
#if IS_ENABLED(CONFIG_KVM)
int prot_virt_host;
EXPORT_SYMBOL(prot_virt_host);
struct uv_info __bootdata_preserved(uv_info);
EXPORT_SYMBOL(uv_info);
static int __init prot_virt_setup(char *val)
{
bool enabled;
int rc;
rc = kstrtobool(val, &enabled);
if (!rc && enabled)
prot_virt_host = 1;
if (is_prot_virt_guest() && prot_virt_host) {
prot_virt_host = 0;
pr_warn("Protected virtualization not available in protected guests.");
}
if (prot_virt_host && !test_facility(158)) {
prot_virt_host = 0;
pr_warn("Protected virtualization not supported by the hardware.");
}
return rc;
}
early_param("prot_virt", prot_virt_setup);
#endif