linux_dsm_epyc7002/arch/s390/include/asm/uv.h
Christian Borntraeger 157309a970 s390/uv: use EOPNOTSUPP instead of ENOTSUPP
ENOTSUP is just an internal kernel error and should never reach
userspace. The return value of the share function is not exported to
userspace, but to avoid giving bad examples let us use EOPNOTSUPP:

Suggested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-12-11 19:53:24 +01:00

133 lines
2.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Ultravisor Interfaces
*
* Copyright IBM Corp. 2019
*
* Author(s):
* Vasily Gorbik <gor@linux.ibm.com>
* Janosch Frank <frankja@linux.ibm.com>
*/
#ifndef _ASM_S390_UV_H
#define _ASM_S390_UV_H
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/bug.h>
#include <asm/page.h>
#define UVC_RC_EXECUTED 0x0001
#define UVC_RC_INV_CMD 0x0002
#define UVC_RC_INV_STATE 0x0003
#define UVC_RC_INV_LEN 0x0005
#define UVC_RC_NO_RESUME 0x0007
#define UVC_CMD_QUI 0x0001
#define UVC_CMD_SET_SHARED_ACCESS 0x1000
#define UVC_CMD_REMOVE_SHARED_ACCESS 0x1001
/* Bits in installed uv calls */
enum uv_cmds_inst {
BIT_UVC_CMD_QUI = 0,
BIT_UVC_CMD_SET_SHARED_ACCESS = 8,
BIT_UVC_CMD_REMOVE_SHARED_ACCESS = 9,
};
struct uv_cb_header {
u16 len;
u16 cmd; /* Command Code */
u16 rc; /* Response Code */
u16 rrc; /* Return Reason Code */
} __packed __aligned(8);
struct uv_cb_qui {
struct uv_cb_header header;
u64 reserved08;
u64 inst_calls_list[4];
u64 reserved30[15];
} __packed __aligned(8);
struct uv_cb_share {
struct uv_cb_header header;
u64 reserved08[3];
u64 paddr;
u64 reserved28;
} __packed __aligned(8);
static inline int uv_call(unsigned long r1, unsigned long r2)
{
int cc;
asm volatile(
"0: .insn rrf,0xB9A40000,%[r1],%[r2],0,0\n"
" brc 3,0b\n"
" ipm %[cc]\n"
" srl %[cc],28\n"
: [cc] "=d" (cc)
: [r1] "a" (r1), [r2] "a" (r2)
: "memory", "cc");
return cc;
}
#ifdef CONFIG_PROTECTED_VIRTUALIZATION_GUEST
extern int prot_virt_guest;
static inline int is_prot_virt_guest(void)
{
return prot_virt_guest;
}
static inline int share(unsigned long addr, u16 cmd)
{
struct uv_cb_share uvcb = {
.header.cmd = cmd,
.header.len = sizeof(uvcb),
.paddr = addr
};
if (!is_prot_virt_guest())
return -EOPNOTSUPP;
/*
* Sharing is page wise, if we encounter addresses that are
* not page aligned, we assume something went wrong. If
* malloced structs are passed to this function, we could leak
* data to the hypervisor.
*/
BUG_ON(addr & ~PAGE_MASK);
if (!uv_call(0, (u64)&uvcb))
return 0;
return -EINVAL;
}
/*
* Guest 2 request to the Ultravisor to make a page shared with the
* hypervisor for IO.
*
* @addr: Real or absolute address of the page to be shared
*/
static inline int uv_set_shared(unsigned long addr)
{
return share(addr, UVC_CMD_SET_SHARED_ACCESS);
}
/*
* Guest 2 request to the Ultravisor to make a page unshared.
*
* @addr: Real or absolute address of the page to be unshared
*/
static inline int uv_remove_shared(unsigned long addr)
{
return share(addr, UVC_CMD_REMOVE_SHARED_ACCESS);
}
void uv_query_info(void);
#else
#define is_prot_virt_guest() 0
static inline int uv_set_shared(unsigned long addr) { return 0; }
static inline int uv_remove_shared(unsigned long addr) { return 0; }
static inline void uv_query_info(void) {}
#endif
#endif /* _ASM_S390_UV_H */