arch/s390/include/asm/uv.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Ultravisor Interfaces
   4  *
   5  * Copyright IBM Corp. 2019
   6  *
   7  * Author(s):
   8  *      Vasily Gorbik <gor@linux.ibm.com>
   9  *      Janosch Frank <frankja@linux.ibm.com>
  10  */
  11 #ifndef _ASM_S390_UV_H
  12 #define _ASM_S390_UV_H
  13
  14 #include <linux/types.h>
  15 #include <linux/errno.h>
  16 #include <linux/bug.h>
  17 #include <asm/page.h>
  18
  19 #define UVC_RC_EXECUTED         0x0001
  20 #define UVC_RC_INV_CMD          0x0002
  21 #define UVC_RC_INV_STATE        0x0003
  22 #define UVC_RC_INV_LEN          0x0005
  23 #define UVC_RC_NO_RESUME        0x0007
  24
  25 #define UVC_CMD_QUI                     0x0001
  26 #define UVC_CMD_SET_SHARED_ACCESS       0x1000
  27 #define UVC_CMD_REMOVE_SHARED_ACCESS    0x1001
  28
  29 /* Bits in installed uv calls */
  30 enum uv_cmds_inst {
  31         BIT_UVC_CMD_QUI = 0,
  32         BIT_UVC_CMD_SET_SHARED_ACCESS = 8,
  33         BIT_UVC_CMD_REMOVE_SHARED_ACCESS = 9,
  34 };
  35
  36 struct uv_cb_header {
  37         u16 len;
  38         u16 cmd;        /* Command Code */
  39         u16 rc;         /* Response Code */
  40         u16 rrc;        /* Return Reason Code */
  41 } __packed __aligned(8);
  42
  43 struct uv_cb_qui {
  44         struct uv_cb_header header;
  45         u64 reserved08;
  46         u64 inst_calls_list[4];
  47         u64 reserved30[15];
  48 } __packed __aligned(8);
  49
  50 struct uv_cb_share {
  51         struct uv_cb_header header;
  52         u64 reserved08[3];
  53         u64 paddr;
  54         u64 reserved28;
  55 } __packed __aligned(8);
  56
  57 static inline int uv_call(unsigned long r1, unsigned long r2)
  58 {
  59         int cc;
  60
  61         asm volatile(
  62                 "0:     .insn rrf,0xB9A40000,%[r1],%[r2],0,0\n"
  63                 "               brc     3,0b\n"
  64                 "               ipm     %[cc]\n"
  65                 "               srl     %[cc],28\n"
  66                 : [cc] "=d" (cc)
  67                 : [r1] "a" (r1), [r2] "a" (r2)
  68                 : "memory", "cc");
  69         return cc;
  70 }
  71
  72 #ifdef CONFIG_PROTECTED_VIRTUALIZATION_GUEST
  73 extern int prot_virt_guest;
  74
  75 static inline int is_prot_virt_guest(void)
  76 {
  77         return prot_virt_guest;
  78 }
  79
  80 static inline int share(unsigned long addr, u16 cmd)
  81 {
  82         struct uv_cb_share uvcb = {
  83                 .header.cmd = cmd,
  84                 .header.len = sizeof(uvcb),
  85                 .paddr = addr
  86         };
  87
  88         if (!is_prot_virt_guest())
  89                 return -EOPNOTSUPP;
  90         /*
  91          * Sharing is page wise, if we encounter addresses that are
  92          * not page aligned, we assume something went wrong. If
  93          * malloced structs are passed to this function, we could leak
  94          * data to the hypervisor.
  95          */
  96         BUG_ON(addr & ~PAGE_MASK);
  97
  98         if (!uv_call(0, (u64)&uvcb))
  99                 return 0;
 100         return -EINVAL;
 101 }
 102
 103 /*
 104  * Guest 2 request to the Ultravisor to make a page shared with the
 105  * hypervisor for IO.
 106  *
 107  * @addr: Real or absolute address of the page to be shared
 108  */
 109 static inline int uv_set_shared(unsigned long addr)
 110 {
 111         return share(addr, UVC_CMD_SET_SHARED_ACCESS);
 112 }
 113
 114 /*
 115  * Guest 2 request to the Ultravisor to make a page unshared.
 116  *
 117  * @addr: Real or absolute address of the page to be unshared
 118  */
 119 static inline int uv_remove_shared(unsigned long addr)
 120 {
 121         return share(addr, UVC_CMD_REMOVE_SHARED_ACCESS);
 122 }
 123
 124 void uv_query_info(void);
 125 #else
 126 #define is_prot_virt_guest() 0
 127 static inline int uv_set_shared(unsigned long addr) { return 0; }
 128 static inline int uv_remove_shared(unsigned long addr) { return 0; }
 129 static inline void uv_query_info(void) {}
 130 #endif
 131
 132 #endif /* _ASM_S390_UV_H */