linux/arch/powerpc/kvm/book3s_interrupts.S
Alexander Graf e1f8acf838 KVM: PPC: Save/Restore CR over vcpu_run
On PPC, CR2-CR4 are nonvolatile, thus have to be saved across function calls.
We didn't respect that for any architecture until Paul spotted it in his
patch for Book3S-HV. This patch saves/restores CR for all KVM capable PPC hosts.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2012-04-03 16:42:34 +10:00

202 lines
5.0 KiB
ArmAsm

/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Copyright SUSE Linux Products GmbH 2009
*
* Authors: Alexander Graf <agraf@suse.de>
*/
#include <asm/ppc_asm.h>
#include <asm/kvm_asm.h>
#include <asm/reg.h>
#include <asm/page.h>
#include <asm/asm-offsets.h>
#include <asm/exception-64s.h>
#if defined(CONFIG_PPC_BOOK3S_64)
#define ULONG_SIZE 8
#define FUNC(name) GLUE(.,name)
#elif defined(CONFIG_PPC_BOOK3S_32)
#define ULONG_SIZE 4
#define FUNC(name) name
#endif /* CONFIG_PPC_BOOK3S_XX */
#define VCPU_GPR(n) (VCPU_GPRS + (n * ULONG_SIZE))
#define VCPU_LOAD_NVGPRS(vcpu) \
PPC_LL r14, VCPU_GPR(r14)(vcpu); \
PPC_LL r15, VCPU_GPR(r15)(vcpu); \
PPC_LL r16, VCPU_GPR(r16)(vcpu); \
PPC_LL r17, VCPU_GPR(r17)(vcpu); \
PPC_LL r18, VCPU_GPR(r18)(vcpu); \
PPC_LL r19, VCPU_GPR(r19)(vcpu); \
PPC_LL r20, VCPU_GPR(r20)(vcpu); \
PPC_LL r21, VCPU_GPR(r21)(vcpu); \
PPC_LL r22, VCPU_GPR(r22)(vcpu); \
PPC_LL r23, VCPU_GPR(r23)(vcpu); \
PPC_LL r24, VCPU_GPR(r24)(vcpu); \
PPC_LL r25, VCPU_GPR(r25)(vcpu); \
PPC_LL r26, VCPU_GPR(r26)(vcpu); \
PPC_LL r27, VCPU_GPR(r27)(vcpu); \
PPC_LL r28, VCPU_GPR(r28)(vcpu); \
PPC_LL r29, VCPU_GPR(r29)(vcpu); \
PPC_LL r30, VCPU_GPR(r30)(vcpu); \
PPC_LL r31, VCPU_GPR(r31)(vcpu); \
/*****************************************************************************
* *
* Guest entry / exit code that is in kernel module memory (highmem) *
* *
****************************************************************************/
/* Registers:
* r3: kvm_run pointer
* r4: vcpu pointer
*/
_GLOBAL(__kvmppc_vcpu_run)
kvm_start_entry:
/* Write correct stack frame */
mflr r0
PPC_STL r0,PPC_LR_STKOFF(r1)
/* Save host state to the stack */
PPC_STLU r1, -SWITCH_FRAME_SIZE(r1)
/* Save r3 (kvm_run) and r4 (vcpu) */
SAVE_2GPRS(3, r1)
/* Save non-volatile registers (r14 - r31) */
SAVE_NVGPRS(r1)
/* Save CR */
mfcr r14
stw r14, _CCR(r1)
/* Save LR */
PPC_STL r0, _LINK(r1)
/* Load non-volatile guest state from the vcpu */
VCPU_LOAD_NVGPRS(r4)
kvm_start_lightweight:
#ifdef CONFIG_PPC_BOOK3S_64
PPC_LL r3, VCPU_HFLAGS(r4)
rldicl r3, r3, 0, 63 /* r3 &= 1 */
stb r3, HSTATE_RESTORE_HID5(r13)
#endif /* CONFIG_PPC_BOOK3S_64 */
PPC_LL r4, VCPU_SHADOW_MSR(r4) /* get shadow_msr */
/* Jump to segment patching handler and into our guest */
bl FUNC(kvmppc_entry_trampoline)
nop
/*
* This is the handler in module memory. It gets jumped at from the
* lowmem trampoline code, so it's basically the guest exit code.
*
*/
.global kvmppc_handler_highmem
kvmppc_handler_highmem:
/*
* Register usage at this point:
*
* R1 = host R1
* R2 = host R2
* R12 = exit handler id
* R13 = PACA
* SVCPU.* = guest *
*
*/
/* R7 = vcpu */
PPC_LL r7, GPR4(r1)
PPC_STL r14, VCPU_GPR(r14)(r7)
PPC_STL r15, VCPU_GPR(r15)(r7)
PPC_STL r16, VCPU_GPR(r16)(r7)
PPC_STL r17, VCPU_GPR(r17)(r7)
PPC_STL r18, VCPU_GPR(r18)(r7)
PPC_STL r19, VCPU_GPR(r19)(r7)
PPC_STL r20, VCPU_GPR(r20)(r7)
PPC_STL r21, VCPU_GPR(r21)(r7)
PPC_STL r22, VCPU_GPR(r22)(r7)
PPC_STL r23, VCPU_GPR(r23)(r7)
PPC_STL r24, VCPU_GPR(r24)(r7)
PPC_STL r25, VCPU_GPR(r25)(r7)
PPC_STL r26, VCPU_GPR(r26)(r7)
PPC_STL r27, VCPU_GPR(r27)(r7)
PPC_STL r28, VCPU_GPR(r28)(r7)
PPC_STL r29, VCPU_GPR(r29)(r7)
PPC_STL r30, VCPU_GPR(r30)(r7)
PPC_STL r31, VCPU_GPR(r31)(r7)
/* Pass the exit number as 3rd argument to kvmppc_handle_exit */
mr r5, r12
/* Restore r3 (kvm_run) and r4 (vcpu) */
REST_2GPRS(3, r1)
bl FUNC(kvmppc_handle_exit)
/* If RESUME_GUEST, get back in the loop */
cmpwi r3, RESUME_GUEST
beq kvm_loop_lightweight
cmpwi r3, RESUME_GUEST_NV
beq kvm_loop_heavyweight
kvm_exit_loop:
PPC_LL r4, _LINK(r1)
mtlr r4
lwz r14, _CCR(r1)
mtcr r14
/* Restore non-volatile host registers (r14 - r31) */
REST_NVGPRS(r1)
addi r1, r1, SWITCH_FRAME_SIZE
blr
kvm_loop_heavyweight:
PPC_LL r4, _LINK(r1)
PPC_STL r4, (PPC_LR_STKOFF + SWITCH_FRAME_SIZE)(r1)
/* Load vcpu and cpu_run */
REST_2GPRS(3, r1)
/* Load non-volatile guest state from the vcpu */
VCPU_LOAD_NVGPRS(r4)
/* Jump back into the beginning of this function */
b kvm_start_lightweight
kvm_loop_lightweight:
/* We'll need the vcpu pointer */
REST_GPR(4, r1)
/* Jump back into the beginning of this function */
b kvm_start_lightweight