021ec9c69f
Currently we're racy when doing the transition from IR=1 to IR=0, from the module memory entry code to the real mode SLB switching code. To work around that I took a look at the RTAS entry code which is faced with a similar problem and did the same thing: A small helper in linear mapped memory that does mtmsr with IR=0 and then RFIs info the actual handler. Thanks to that trick we can safely take page faults in the entry code and only need to be really wary of what to do as of the SLB switching part. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
170 lines
4.5 KiB
ArmAsm
170 lines
4.5 KiB
ArmAsm
/*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License, version 2, as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*
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* Copyright SUSE Linux Products GmbH 2009
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*
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* Authors: Alexander Graf <agraf@suse.de>
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*/
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#include <asm/ppc_asm.h>
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#include <asm/kvm_asm.h>
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#include <asm/reg.h>
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#include <asm/page.h>
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#include <asm/asm-offsets.h>
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#include <asm/exception-64s.h>
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/*****************************************************************************
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* *
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* Real Mode handlers that need to be in low physical memory *
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* *
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****************************************************************************/
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.macro INTERRUPT_TRAMPOLINE intno
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.global kvmppc_trampoline_\intno
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kvmppc_trampoline_\intno:
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mtspr SPRN_SPRG_SCRATCH0, r13 /* Save r13 */
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/*
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* First thing to do is to find out if we're coming
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* from a KVM guest or a Linux process.
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*
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* To distinguish, we check a magic byte in the PACA
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*/
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mfspr r13, SPRN_SPRG_PACA /* r13 = PACA */
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std r12, PACA_KVM_SCRATCH0(r13)
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mfcr r12
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stw r12, PACA_KVM_SCRATCH1(r13)
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lbz r12, PACA_KVM_IN_GUEST(r13)
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cmpwi r12, KVM_GUEST_MODE_NONE
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bne ..kvmppc_handler_hasmagic_\intno
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/* No KVM guest? Then jump back to the Linux handler! */
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lwz r12, PACA_KVM_SCRATCH1(r13)
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mtcr r12
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ld r12, PACA_KVM_SCRATCH0(r13)
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mfspr r13, SPRN_SPRG_SCRATCH0 /* r13 = original r13 */
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b kvmppc_resume_\intno /* Get back original handler */
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/* Now we know we're handling a KVM guest */
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..kvmppc_handler_hasmagic_\intno:
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/* Should we just skip the faulting instruction? */
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cmpwi r12, KVM_GUEST_MODE_SKIP
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beq kvmppc_handler_skip_ins
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/* Let's store which interrupt we're handling */
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li r12, \intno
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/* Jump into the SLB exit code that goes to the highmem handler */
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b kvmppc_handler_trampoline_exit
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.endm
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_SYSTEM_RESET
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_MACHINE_CHECK
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_DATA_STORAGE
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_DATA_SEGMENT
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_INST_STORAGE
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_INST_SEGMENT
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_EXTERNAL
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_ALIGNMENT
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_PROGRAM
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_FP_UNAVAIL
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_DECREMENTER
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_SYSCALL
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_TRACE
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_PERFMON
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_ALTIVEC
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INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_VSX
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/*
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* Bring us back to the faulting code, but skip the
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* faulting instruction.
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*
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* This is a generic exit path from the interrupt
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* trampolines above.
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*
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* Input Registers:
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*
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* R12 = free
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* R13 = PACA
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* PACA.KVM.SCRATCH0 = guest R12
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* PACA.KVM.SCRATCH1 = guest CR
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* SPRG_SCRATCH0 = guest R13
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*
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*/
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kvmppc_handler_skip_ins:
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/* Patch the IP to the next instruction */
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mfsrr0 r12
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addi r12, r12, 4
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mtsrr0 r12
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/* Clean up all state */
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lwz r12, PACA_KVM_SCRATCH1(r13)
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mtcr r12
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ld r12, PACA_KVM_SCRATCH0(r13)
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mfspr r13, SPRN_SPRG_SCRATCH0
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/* And get back into the code */
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RFI
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/*
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* This trampoline brings us back to a real mode handler
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*
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* Input Registers:
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*
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* R5 = SRR0
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* R6 = SRR1
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* LR = real-mode IP
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*
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*/
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.global kvmppc_handler_lowmem_trampoline
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kvmppc_handler_lowmem_trampoline:
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mtsrr0 r5
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mtsrr1 r6
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blr
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kvmppc_handler_lowmem_trampoline_end:
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/*
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* Call a function in real mode
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*
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* Input Registers:
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*
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* R3 = function
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* R4 = MSR
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* R5 = CTR
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*
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*/
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_GLOBAL(kvmppc_rmcall)
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mtmsr r4 /* Disable relocation, so mtsrr
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doesn't get interrupted */
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mtctr r5
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mtsrr0 r3
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mtsrr1 r4
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RFI
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.global kvmppc_trampoline_lowmem
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kvmppc_trampoline_lowmem:
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.long kvmppc_handler_lowmem_trampoline - _stext
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.global kvmppc_trampoline_enter
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kvmppc_trampoline_enter:
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.long kvmppc_handler_trampoline_enter - _stext
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#include "book3s_64_slb.S"
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