linux/arch/powerpc/kvm/book3s_64_slb.S
Alexander Graf af415087d2 KVM: PPC: Book3S: PR: No isync in slbie path
While messing around with the SLBs we're running in real mode. The
entry to guest space goes through rfid, which is context synchronizing,
so there's no need to manually synchronize anything through isync.

With this patch and a simple priviledged SPR access loop guest, I get
a speed bump from 2035607 to 2181301 exits per second.

Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-06 16:19:09 +02:00

165 lines
4.1 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 *
* *
*****************************************************************************/
.macro LOAD_GUEST_SEGMENTS
/* Required state:
*
* MSR = ~IR|DR
* R13 = PACA
* R1 = host R1
* R2 = host R2
* R3 = shadow vcpu
* all other volatile GPRS = free except R4, R6
* SVCPU[CR] = guest CR
* SVCPU[XER] = guest XER
* SVCPU[CTR] = guest CTR
* SVCPU[LR] = guest LR
*/
/* 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
/* Fill SLB with our shadow */
lbz r12, SVCPU_SLB_MAX(r3)
mulli r12, r12, 16
addi r12, r12, SVCPU_SLB
add r12, r12, r3
/* for (r11 = kvm_slb; r11 < kvm_slb + kvm_slb_size; r11+=slb_entry) */
li r11, SVCPU_SLB
add r11, r11, r3
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:
.endm
/******************************************************************************
* *
* Exit code *
* *
*****************************************************************************/
.macro LOAD_HOST_SEGMENTS
/* Register usage at this point:
*
* R1 = host R1
* R2 = host R2
* R12 = exit handler id
* R13 = shadow vcpu - SHADOW_VCPU_OFF [=PACA on PPC64]
* SVCPU.* = guest *
* SVCPU[CR] = guest CR
* SVCPU[XER] = guest XER
* SVCPU[CTR] = guest CTR
* SVCPU[LR] = guest LR
*
*/
/* 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:
.endm