linux_dsm_epyc7002/arch/powerpc/kvm/book3s_32_sr.S
Paul Mackerras 0214394760 KVM: PPC: book3s_pr: Simplify transitions between virtual and real mode
This simplifies the way that the book3s_pr makes the transition to
real mode when entering the guest.  We now call kvmppc_entry_trampoline
(renamed from kvmppc_rmcall) in the base kernel using a normal function
call instead of doing an indirect call through a pointer in the vcpu.
If kvm is a module, the module loader takes care of generating a
trampoline as it does for other calls to functions outside the module.

kvmppc_entry_trampoline then disables interrupts and jumps to
kvmppc_handler_trampoline_enter in real mode using an rfi[d].
That then uses the link register as the address to return to
(potentially in module space) when the guest exits.

This also simplifies the way that we call the Linux interrupt handler
when we exit the guest due to an external, decrementer or performance
monitor interrupt.  Instead of turning on the MMU, then deciding that
we need to call the Linux handler and turning the MMU back off again,
we now go straight to the handler at the point where we would turn the
MMU on.  The handler will then return to the virtual-mode code
(potentially in the module).

Along the way, this moves the setting and clearing of the HID5 DCBZ32
bit into real-mode interrupts-off code, and also makes sure that
we clear the MSR[RI] bit before loading values into SRR0/1.

The net result is that we no longer need any code addresses to be
stored in vcpu->arch.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2011-09-25 19:52:29 +03:00

144 lines
3.7 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>
*/
/******************************************************************************
* *
* Entry code *
* *
*****************************************************************************/
.macro LOAD_GUEST_SEGMENTS
/* Required state:
*
* MSR = ~IR|DR
* 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
*/
#define XCHG_SR(n) lwz r9, (SVCPU_SR+(n*4))(r3); \
mtsr n, r9
XCHG_SR(0)
XCHG_SR(1)
XCHG_SR(2)
XCHG_SR(3)
XCHG_SR(4)
XCHG_SR(5)
XCHG_SR(6)
XCHG_SR(7)
XCHG_SR(8)
XCHG_SR(9)
XCHG_SR(10)
XCHG_SR(11)
XCHG_SR(12)
XCHG_SR(13)
XCHG_SR(14)
XCHG_SR(15)
/* Clear BATs. */
#define KVM_KILL_BAT(n, reg) \
mtspr SPRN_IBAT##n##U,reg; \
mtspr SPRN_IBAT##n##L,reg; \
mtspr SPRN_DBAT##n##U,reg; \
mtspr SPRN_DBAT##n##L,reg; \
li r9, 0
KVM_KILL_BAT(0, r9)
KVM_KILL_BAT(1, r9)
KVM_KILL_BAT(2, r9)
KVM_KILL_BAT(3, r9)
.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
* SVCPU.* = guest *
* SVCPU[CR] = guest CR
* SVCPU[XER] = guest XER
* SVCPU[CTR] = guest CTR
* SVCPU[LR] = guest LR
*
*/
/* Restore BATs */
/* We only overwrite the upper part, so we only restoree
the upper part. */
#define KVM_LOAD_BAT(n, reg, RA, RB) \
lwz RA,(n*16)+0(reg); \
lwz RB,(n*16)+4(reg); \
mtspr SPRN_IBAT##n##U,RA; \
mtspr SPRN_IBAT##n##L,RB; \
lwz RA,(n*16)+8(reg); \
lwz RB,(n*16)+12(reg); \
mtspr SPRN_DBAT##n##U,RA; \
mtspr SPRN_DBAT##n##L,RB; \
lis r9, BATS@ha
addi r9, r9, BATS@l
tophys(r9, r9)
KVM_LOAD_BAT(0, r9, r10, r11)
KVM_LOAD_BAT(1, r9, r10, r11)
KVM_LOAD_BAT(2, r9, r10, r11)
KVM_LOAD_BAT(3, r9, r10, r11)
/* Restore Segment Registers */
/* 0xc - 0xf */
li r0, 4
mtctr r0
LOAD_REG_IMMEDIATE(r3, 0x20000000 | (0x111 * 0xc))
lis r4, 0xc000
3: mtsrin r3, r4
addi r3, r3, 0x111 /* increment VSID */
addis r4, r4, 0x1000 /* address of next segment */
bdnz 3b
/* 0x0 - 0xb */
/* 'current->mm' needs to be in r4 */
tophys(r4, r2)
lwz r4, MM(r4)
tophys(r4, r4)
/* This only clobbers r0, r3, r4 and r5 */
bl switch_mmu_context
.endm