mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2025-01-03 20:34:58 +08:00
7e57cba060
We're being horribly racy right now. All the entry and exit code hijacks random fields from the PACA that could easily be used by different code in case we get interrupted, for example by a #MC or even page fault. After discussing this with Ben, we figured it's best to reserve some more space in the PACA and just shove off some vcpu state to there. That way we can drastically improve the readability of the code, make it less racy and less complex. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
293 lines
6.7 KiB
ArmAsm
293 lines
6.7 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>
|
|
*/
|
|
|
|
#define SHADOW_SLB_ESID(num) (SLBSHADOW_SAVEAREA + (num * 0x10))
|
|
#define SHADOW_SLB_VSID(num) (SLBSHADOW_SAVEAREA + (num * 0x10) + 0x8)
|
|
#define UNBOLT_SLB_ENTRY(num) \
|
|
ld r9, SHADOW_SLB_ESID(num)(r12); \
|
|
/* Invalid? Skip. */; \
|
|
rldicl. r0, r9, 37, 63; \
|
|
beq slb_entry_skip_ ## num; \
|
|
xoris r9, r9, SLB_ESID_V@h; \
|
|
std r9, SHADOW_SLB_ESID(num)(r12); \
|
|
slb_entry_skip_ ## num:
|
|
|
|
#define REBOLT_SLB_ENTRY(num) \
|
|
ld r10, SHADOW_SLB_ESID(num)(r11); \
|
|
cmpdi r10, 0; \
|
|
beq slb_exit_skip_ ## num; \
|
|
oris r10, r10, SLB_ESID_V@h; \
|
|
ld r9, SHADOW_SLB_VSID(num)(r11); \
|
|
slbmte r9, r10; \
|
|
std r10, SHADOW_SLB_ESID(num)(r11); \
|
|
slb_exit_skip_ ## num:
|
|
|
|
/******************************************************************************
|
|
* *
|
|
* Entry code *
|
|
* *
|
|
*****************************************************************************/
|
|
|
|
.global kvmppc_handler_trampoline_enter
|
|
kvmppc_handler_trampoline_enter:
|
|
|
|
/* Required state:
|
|
*
|
|
* MSR = ~IR|DR
|
|
* R13 = PACA
|
|
* R1 = host R1
|
|
* R2 = host R2
|
|
* R9 = guest IP
|
|
* R10 = guest MSR
|
|
* all other GPRS = free
|
|
* PACA[KVM_CR] = guest CR
|
|
* PACA[KVM_XER] = guest XER
|
|
*/
|
|
|
|
mtsrr0 r9
|
|
mtsrr1 r10
|
|
|
|
/* Remove LPAR shadow entries */
|
|
|
|
#if SLB_NUM_BOLTED == 3
|
|
|
|
ld r12, PACA_SLBSHADOWPTR(r13)
|
|
|
|
/* Save off the first entry so we can slbie it later */
|
|
ld r10, SHADOW_SLB_ESID(0)(r12)
|
|
ld r11, SHADOW_SLB_VSID(0)(r12)
|
|
|
|
/* Remove bolted entries */
|
|
UNBOLT_SLB_ENTRY(0)
|
|
UNBOLT_SLB_ENTRY(1)
|
|
UNBOLT_SLB_ENTRY(2)
|
|
|
|
#else
|
|
#error unknown number of bolted entries
|
|
#endif
|
|
|
|
/* Flush SLB */
|
|
|
|
slbia
|
|
|
|
/* r0 = esid & ESID_MASK */
|
|
rldicr r10, r10, 0, 35
|
|
/* r0 |= CLASS_BIT(VSID) */
|
|
rldic r12, r11, 56 - 36, 36
|
|
or r10, r10, r12
|
|
slbie r10
|
|
|
|
isync
|
|
|
|
/* Fill SLB with our shadow */
|
|
|
|
lbz r12, PACA_KVM_SLB_MAX(r13)
|
|
mulli r12, r12, 16
|
|
addi r12, r12, PACA_KVM_SLB
|
|
add r12, r12, r13
|
|
|
|
/* for (r11 = kvm_slb; r11 < kvm_slb + kvm_slb_size; r11+=slb_entry) */
|
|
li r11, PACA_KVM_SLB
|
|
add r11, r11, r13
|
|
|
|
slb_loop_enter:
|
|
|
|
ld r10, 0(r11)
|
|
|
|
rldicl. r0, r10, 37, 63
|
|
beq slb_loop_enter_skip
|
|
|
|
ld r9, 8(r11)
|
|
slbmte r9, r10
|
|
|
|
slb_loop_enter_skip:
|
|
addi r11, r11, 16
|
|
cmpd cr0, r11, r12
|
|
blt slb_loop_enter
|
|
|
|
slb_do_enter:
|
|
|
|
/* Enter guest */
|
|
|
|
ld r0, (PACA_KVM_R0)(r13)
|
|
ld r1, (PACA_KVM_R1)(r13)
|
|
ld r2, (PACA_KVM_R2)(r13)
|
|
ld r3, (PACA_KVM_R3)(r13)
|
|
ld r4, (PACA_KVM_R4)(r13)
|
|
ld r5, (PACA_KVM_R5)(r13)
|
|
ld r6, (PACA_KVM_R6)(r13)
|
|
ld r7, (PACA_KVM_R7)(r13)
|
|
ld r8, (PACA_KVM_R8)(r13)
|
|
ld r9, (PACA_KVM_R9)(r13)
|
|
ld r10, (PACA_KVM_R10)(r13)
|
|
ld r12, (PACA_KVM_R12)(r13)
|
|
|
|
lwz r11, (PACA_KVM_CR)(r13)
|
|
mtcr r11
|
|
|
|
ld r11, (PACA_KVM_XER)(r13)
|
|
mtxer r11
|
|
|
|
ld r11, (PACA_KVM_R11)(r13)
|
|
ld r13, (PACA_KVM_R13)(r13)
|
|
|
|
RFI
|
|
kvmppc_handler_trampoline_enter_end:
|
|
|
|
|
|
|
|
/******************************************************************************
|
|
* *
|
|
* Exit code *
|
|
* *
|
|
*****************************************************************************/
|
|
|
|
.global kvmppc_handler_trampoline_exit
|
|
kvmppc_handler_trampoline_exit:
|
|
|
|
/* Register usage at this point:
|
|
*
|
|
* SPRG_SCRATCH0 = guest R13
|
|
* R12 = exit handler id
|
|
* R13 = PACA
|
|
* PACA.KVM.SCRATCH0 = guest R12
|
|
* PACA.KVM.SCRATCH1 = guest CR
|
|
*
|
|
*/
|
|
|
|
/* Save registers */
|
|
|
|
std r0, PACA_KVM_R0(r13)
|
|
std r1, PACA_KVM_R1(r13)
|
|
std r2, PACA_KVM_R2(r13)
|
|
std r3, PACA_KVM_R3(r13)
|
|
std r4, PACA_KVM_R4(r13)
|
|
std r5, PACA_KVM_R5(r13)
|
|
std r6, PACA_KVM_R6(r13)
|
|
std r7, PACA_KVM_R7(r13)
|
|
std r8, PACA_KVM_R8(r13)
|
|
std r9, PACA_KVM_R9(r13)
|
|
std r10, PACA_KVM_R10(r13)
|
|
std r11, PACA_KVM_R11(r13)
|
|
|
|
/* Restore R1/R2 so we can handle faults */
|
|
ld r1, PACA_KVM_HOST_R1(r13)
|
|
ld r2, PACA_KVM_HOST_R2(r13)
|
|
|
|
/* Save guest PC and MSR in GPRs */
|
|
mfsrr0 r3
|
|
mfsrr1 r4
|
|
|
|
/* Get scratch'ed off registers */
|
|
mfspr r9, SPRN_SPRG_SCRATCH0
|
|
std r9, PACA_KVM_R13(r13)
|
|
|
|
ld r8, PACA_KVM_SCRATCH0(r13)
|
|
std r8, PACA_KVM_R12(r13)
|
|
|
|
lwz r7, PACA_KVM_SCRATCH1(r13)
|
|
stw r7, PACA_KVM_CR(r13)
|
|
|
|
/* Save more register state */
|
|
|
|
mfxer r6
|
|
stw r6, PACA_KVM_XER(r13)
|
|
|
|
mfdar r5
|
|
mfdsisr r6
|
|
|
|
/* Unset guest state */
|
|
li r9, 0
|
|
stb r9, PACA_KVM_IN_GUEST(r13)
|
|
|
|
/*
|
|
* In order for us to easily get the last instruction,
|
|
* we got the #vmexit at, we exploit the fact that the
|
|
* virtual layout is still the same here, so we can just
|
|
* ld from the guest's PC address
|
|
*/
|
|
|
|
/* We only load the last instruction when it's safe */
|
|
cmpwi r12, BOOK3S_INTERRUPT_DATA_STORAGE
|
|
beq ld_last_inst
|
|
cmpwi r12, BOOK3S_INTERRUPT_PROGRAM
|
|
beq ld_last_inst
|
|
|
|
b no_ld_last_inst
|
|
|
|
ld_last_inst:
|
|
/* Save off the guest instruction we're at */
|
|
/* 1) enable paging for data */
|
|
mfmsr r9
|
|
ori r11, r9, MSR_DR /* Enable paging for data */
|
|
mtmsr r11
|
|
/* 2) fetch the instruction */
|
|
/* XXX implement PACA_KVM_IN_GUEST=2 path to safely jump over this */
|
|
lwz r0, 0(r3)
|
|
/* 3) disable paging again */
|
|
mtmsr r9
|
|
|
|
no_ld_last_inst:
|
|
|
|
/* Restore bolted entries from the shadow and fix it along the way */
|
|
|
|
/* We don't store anything in entry 0, so we don't need to take care of it */
|
|
slbia
|
|
isync
|
|
|
|
#if SLB_NUM_BOLTED == 3
|
|
|
|
ld r11, PACA_SLBSHADOWPTR(r13)
|
|
|
|
REBOLT_SLB_ENTRY(0)
|
|
REBOLT_SLB_ENTRY(1)
|
|
REBOLT_SLB_ENTRY(2)
|
|
|
|
#else
|
|
#error unknown number of bolted entries
|
|
#endif
|
|
|
|
slb_do_exit:
|
|
|
|
/* Register usage at this point:
|
|
*
|
|
* R0 = guest last inst
|
|
* R1 = host R1
|
|
* R2 = host R2
|
|
* R3 = guest PC
|
|
* R4 = guest MSR
|
|
* R5 = guest DAR
|
|
* R6 = guest DSISR
|
|
* R12 = exit handler id
|
|
* R13 = PACA
|
|
* PACA.KVM.* = guest *
|
|
*
|
|
*/
|
|
|
|
/* RFI into the highmem handler */
|
|
mfmsr r7
|
|
ori r7, r7, MSR_IR|MSR_DR|MSR_RI /* Enable paging */
|
|
mtsrr1 r7
|
|
ld r8, PACA_KVM_VMHANDLER(r13) /* Highmem handler address */
|
|
mtsrr0 r8
|
|
|
|
RFI
|
|
kvmppc_handler_trampoline_exit_end:
|
|
|