Pileus Git - ~andy/linux/blob - arch/powerpc/kernel/kvm_emul.S

   1 /*
   2  * This program is free software; you can redistribute it and/or modify
   3  * it under the terms of the GNU General Public License, version 2, as
   4  * published by the Free Software Foundation.
   5  *
   6  * This program is distributed in the hope that it will be useful,
   7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9  * GNU General Public License for more details.
  10  *
  11  * You should have received a copy of the GNU General Public License
  12  * along with this program; if not, write to the Free Software
  13  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  14  *
  15  * Copyright SUSE Linux Products GmbH 2010
  16  *
  17  * Authors: Alexander Graf <agraf@suse.de>
  18  */
  19
  20 #include <asm/ppc_asm.h>
  21 #include <asm/kvm_asm.h>
  22 #include <asm/reg.h>
  23 #include <asm/page.h>
  24 #include <asm/asm-offsets.h>
  25
  26 /* Hypercall entry point. Will be patched with device tree instructions. */
  27
  28 .global kvm_hypercall_start
  29 kvm_hypercall_start:
  30         li      r3, -1
  31         nop
  32         nop
  33         nop
  34         blr
  35
  36 #define KVM_MAGIC_PAGE          (-4096)
  37
  38 #ifdef CONFIG_64BIT
  39 #define LL64(reg, offs, reg2)   ld      reg, (offs)(reg2)
  40 #define STL64(reg, offs, reg2)  std     reg, (offs)(reg2)
  41 #else
  42 #define LL64(reg, offs, reg2)   lwz     reg, (offs + 4)(reg2)
  43 #define STL64(reg, offs, reg2)  stw     reg, (offs + 4)(reg2)
  44 #endif
  45
  46 #define SCRATCH_SAVE                                                    \
  47         /* Enable critical section. We are critical if                  \
  48            shared->critical == r1 */                                    \
  49         STL64(r1, KVM_MAGIC_PAGE + KVM_MAGIC_CRITICAL, 0);              \
  50                                                                         \
  51         /* Save state */                                                \
  52         PPC_STL r31, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH1)(0);          \
  53         PPC_STL r30, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH2)(0);          \
  54         mfcr    r31;                                                    \
  55         stw     r31, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH3)(0);
  56
  57 #define SCRATCH_RESTORE                                                 \
  58         /* Restore state */                                             \
  59         PPC_LL  r31, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH1)(0);          \
  60         lwz     r30, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH3)(0);          \
  61         mtcr    r30;                                                    \
  62         PPC_LL  r30, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH2)(0);          \
  63                                                                         \
  64         /* Disable critical section. We are critical if                 \
  65            shared->critical == r1 and r2 is always != r1 */             \
  66         STL64(r2, KVM_MAGIC_PAGE + KVM_MAGIC_CRITICAL, 0);
  67
  68 .global kvm_emulate_mtmsrd
  69 kvm_emulate_mtmsrd:
  70
  71         SCRATCH_SAVE
  72
  73         /* Put MSR & ~(MSR_EE|MSR_RI) in r31 */
  74         LL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
  75         lis     r30, (~(MSR_EE | MSR_RI))@h
  76         ori     r30, r30, (~(MSR_EE | MSR_RI))@l
  77         and     r31, r31, r30
  78
  79         /* OR the register's (MSR_EE|MSR_RI) on MSR */
  80 kvm_emulate_mtmsrd_reg:
  81         andi.   r30, r0, (MSR_EE|MSR_RI)
  82         or      r31, r31, r30
  83
  84         /* Put MSR back into magic page */
  85         STL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
  86
  87         /* Check if we have to fetch an interrupt */
  88         lwz     r31, (KVM_MAGIC_PAGE + KVM_MAGIC_INT)(0)
  89         cmpwi   r31, 0
  90         beq+    no_check
  91
  92         /* Check if we may trigger an interrupt */
  93         andi.   r30, r30, MSR_EE
  94         beq     no_check
  95
  96         SCRATCH_RESTORE
  97
  98         /* Nag hypervisor */
  99         tlbsync
 100
 101         b       kvm_emulate_mtmsrd_branch
 102
 103 no_check:
 104
 105         SCRATCH_RESTORE
 106
 107         /* Go back to caller */
 108 kvm_emulate_mtmsrd_branch:
 109         b       .
 110 kvm_emulate_mtmsrd_end:
 111
 112 .global kvm_emulate_mtmsrd_branch_offs
 113 kvm_emulate_mtmsrd_branch_offs:
 114         .long (kvm_emulate_mtmsrd_branch - kvm_emulate_mtmsrd) / 4
 115
 116 .global kvm_emulate_mtmsrd_reg_offs
 117 kvm_emulate_mtmsrd_reg_offs:
 118         .long (kvm_emulate_mtmsrd_reg - kvm_emulate_mtmsrd) / 4
 119
 120 .global kvm_emulate_mtmsrd_len
 121 kvm_emulate_mtmsrd_len:
 122         .long (kvm_emulate_mtmsrd_end - kvm_emulate_mtmsrd) / 4