linux/arch/powerpc/kvm/book3s_segment.S

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/*
* 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 2010
*
* Authors: Alexander Graf <agraf@suse.de>
*/
/* Real mode helpers */
#if defined(CONFIG_PPC_BOOK3S_64)
#define GET_SHADOW_VCPU(reg) \
mr reg, r13
#elif defined(CONFIG_PPC_BOOK3S_32)
#define GET_SHADOW_VCPU(reg) \
tophys(reg, r2); \
lwz reg, (THREAD + THREAD_KVM_SVCPU)(reg); \
tophys(reg, reg)
#endif
/* Disable for nested KVM */
#define USE_QUICK_LAST_INST
/* Get helper functions for subarch specific functionality */
#if defined(CONFIG_PPC_BOOK3S_64)
#include "book3s_64_slb.S"
#elif defined(CONFIG_PPC_BOOK3S_32)
#include "book3s_32_sr.S"
#endif
/******************************************************************************
* *
* Entry code *
* *
*****************************************************************************/
.global kvmppc_handler_trampoline_enter
kvmppc_handler_trampoline_enter:
/* Required state:
*
* MSR = ~IR|DR
* R1 = host R1
* R2 = host R2
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>
2011-07-23 07:41:44 +00:00
* R4 = guest shadow MSR
* R5 = normal host MSR
* R6 = current host MSR (EE, IR, DR off)
* LR = highmem guest exit code
* all other volatile GPRS = free
* SVCPU[CR] = guest CR
* SVCPU[XER] = guest XER
* SVCPU[CTR] = guest CTR
* SVCPU[LR] = guest LR
*/
/* r3 = shadow vcpu */
GET_SHADOW_VCPU(r3)
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>
2011-07-23 07:41:44 +00:00
/* Save guest exit handler address and MSR */
mflr r0
PPC_STL r0, HSTATE_VMHANDLER(r3)
PPC_STL r5, HSTATE_HOST_MSR(r3)
/* Save R1/R2 in the PACA (64-bit) or shadow_vcpu (32-bit) */
PPC_STL r1, HSTATE_HOST_R1(r3)
PPC_STL r2, HSTATE_HOST_R2(r3)
/* Activate guest mode, so faults get handled by KVM */
li r11, KVM_GUEST_MODE_GUEST
stb r11, HSTATE_IN_GUEST(r3)
/* Switch to guest segment. This is subarch specific. */
LOAD_GUEST_SEGMENTS
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>
2011-07-23 07:41:44 +00:00
#ifdef CONFIG_PPC_BOOK3S_64
BEGIN_FTR_SECTION
/* Save host FSCR */
mfspr r8, SPRN_FSCR
std r8, HSTATE_HOST_FSCR(r13)
/* Set FSCR during guest execution */
ld r9, SVCPU_SHADOW_FSCR(r13)
mtspr SPRN_FSCR, r9
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
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>
2011-07-23 07:41:44 +00:00
/* Some guests may need to have dcbz set to 32 byte length.
*
* Usually we ensure that by patching the guest's instructions
* to trap on dcbz and emulate it in the hypervisor.
*
* If we can, we should tell the CPU to use 32 byte dcbz though,
* because that's a lot faster.
*/
lbz r0, HSTATE_RESTORE_HID5(r3)
cmpwi r0, 0
beq no_dcbz32_on
mfspr r0,SPRN_HID5
ori r0, r0, 0x80 /* XXX HID5_dcbz32 = 0x80 */
mtspr SPRN_HID5,r0
no_dcbz32_on:
#endif /* CONFIG_PPC_BOOK3S_64 */
/* Enter guest */
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>
2011-07-23 07:41:44 +00:00
PPC_LL r8, SVCPU_CTR(r3)
PPC_LL r9, SVCPU_LR(r3)
lwz r10, SVCPU_CR(r3)
lwz r11, SVCPU_XER(r3)
mtctr r8
mtlr r9
mtcr r10
mtxer r11
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>
2011-07-23 07:41:44 +00:00
/* Move SRR0 and SRR1 into the respective regs */
PPC_LL r9, SVCPU_PC(r3)
/* First clear RI in our current MSR value */
li r0, MSR_RI
andc r6, r6, r0
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 00:21:34 +00:00
PPC_LL r0, SVCPU_R0(r3)
PPC_LL r1, SVCPU_R1(r3)
PPC_LL r2, SVCPU_R2(r3)
PPC_LL r5, SVCPU_R5(r3)
PPC_LL r7, SVCPU_R7(r3)
PPC_LL r8, SVCPU_R8(r3)
PPC_LL r10, SVCPU_R10(r3)
PPC_LL r11, SVCPU_R11(r3)
PPC_LL r12, SVCPU_R12(r3)
PPC_LL r13, SVCPU_R13(r3)
MTMSR_EERI(r6)
mtsrr0 r9
mtsrr1 r4
PPC_LL r4, SVCPU_R4(r3)
PPC_LL r6, SVCPU_R6(r3)
PPC_LL r9, SVCPU_R9(r3)
PPC_LL r3, (SVCPU_R3)(r3)
RFI
kvmppc_handler_trampoline_enter_end:
/******************************************************************************
* *
* Exit code *
* *
*****************************************************************************/
.global kvmppc_handler_trampoline_exit
kvmppc_handler_trampoline_exit:
.global kvmppc_interrupt_pr
kvmppc_interrupt_pr:
/* Register usage at this point:
*
* SPRG_SCRATCH0 = guest R13
* R12 = exit handler id
* R13 = shadow vcpu (32-bit) or PACA (64-bit)
* HSTATE.SCRATCH0 = guest R12
* HSTATE.SCRATCH1 = guest CR
*
*/
/* Save registers */
PPC_STL r0, SVCPU_R0(r13)
PPC_STL r1, SVCPU_R1(r13)
PPC_STL r2, SVCPU_R2(r13)
PPC_STL r3, SVCPU_R3(r13)
PPC_STL r4, SVCPU_R4(r13)
PPC_STL r5, SVCPU_R5(r13)
PPC_STL r6, SVCPU_R6(r13)
PPC_STL r7, SVCPU_R7(r13)
PPC_STL r8, SVCPU_R8(r13)
PPC_STL r9, SVCPU_R9(r13)
PPC_STL r10, SVCPU_R10(r13)
PPC_STL r11, SVCPU_R11(r13)
/* Restore R1/R2 so we can handle faults */
PPC_LL r1, HSTATE_HOST_R1(r13)
PPC_LL r2, HSTATE_HOST_R2(r13)
/* Save guest PC and MSR */
#ifdef CONFIG_PPC64
BEGIN_FTR_SECTION
andi. r0, r12, 0x2
cmpwi cr1, r0, 0
beq 1f
mfspr r3,SPRN_HSRR0
mfspr r4,SPRN_HSRR1
andi. r12,r12,0x3ffd
b 2f
END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
#endif
1: mfsrr0 r3
mfsrr1 r4
2:
PPC_STL r3, SVCPU_PC(r13)
PPC_STL r4, SVCPU_SHADOW_SRR1(r13)
/* Get scratch'ed off registers */
GET_SCRATCH0(r9)
PPC_LL r8, HSTATE_SCRATCH0(r13)
lwz r7, HSTATE_SCRATCH1(r13)
PPC_STL r9, SVCPU_R13(r13)
PPC_STL r8, SVCPU_R12(r13)
stw r7, SVCPU_CR(r13)
/* Save more register state */
mfxer r5
mfdar r6
mfdsisr r7
mfctr r8
mflr r9
stw r5, SVCPU_XER(r13)
PPC_STL r6, SVCPU_FAULT_DAR(r13)
stw r7, SVCPU_FAULT_DSISR(r13)
PPC_STL r8, SVCPU_CTR(r13)
PPC_STL r9, SVCPU_LR(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
cmpwi r12, BOOK3S_INTERRUPT_SYSCALL
beq ld_last_prev_inst
cmpwi r12, BOOK3S_INTERRUPT_ALIGNMENT
beq- ld_last_inst
#ifdef CONFIG_PPC64
BEGIN_FTR_SECTION
cmpwi r12, BOOK3S_INTERRUPT_H_EMUL_ASSIST
beq- ld_last_inst
END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
BEGIN_FTR_SECTION
cmpwi r12, BOOK3S_INTERRUPT_FAC_UNAVAIL
beq- ld_last_inst
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
#endif
b no_ld_last_inst
ld_last_prev_inst:
addi r3, r3, -4
ld_last_inst:
/* Save off the guest instruction we're at */
/* In case lwz faults */
li r0, KVM_INST_FETCH_FAILED
#ifdef USE_QUICK_LAST_INST
/* Set guest mode to 'jump over instruction' so if lwz faults
* we'll just continue at the next IP. */
li r9, KVM_GUEST_MODE_SKIP
stb r9, HSTATE_IN_GUEST(r13)
/* 1) enable paging for data */
mfmsr r9
ori r11, r9, MSR_DR /* Enable paging for data */
mtmsr r11
sync
/* 2) fetch the instruction */
lwz r0, 0(r3)
/* 3) disable paging again */
mtmsr r9
sync
#endif
stw r0, SVCPU_LAST_INST(r13)
no_ld_last_inst:
/* Unset guest mode */
li r9, KVM_GUEST_MODE_NONE
stb r9, HSTATE_IN_GUEST(r13)
/* Switch back to host MMU */
LOAD_HOST_SEGMENTS
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>
2011-07-23 07:41:44 +00:00
#ifdef CONFIG_PPC_BOOK3S_64
lbz r5, HSTATE_RESTORE_HID5(r13)
cmpwi r5, 0
beq no_dcbz32_off
li r4, 0
mfspr r5,SPRN_HID5
rldimi r5,r4,6,56
mtspr SPRN_HID5,r5
no_dcbz32_off:
BEGIN_FTR_SECTION
/* Save guest FSCR on a FAC_UNAVAIL interrupt */
cmpwi r12, BOOK3S_INTERRUPT_FAC_UNAVAIL
bne+ no_fscr_save
mfspr r7, SPRN_FSCR
std r7, SVCPU_SHADOW_FSCR(r13)
no_fscr_save:
/* Restore host FSCR */
ld r8, HSTATE_HOST_FSCR(r13)
mtspr SPRN_FSCR, r8
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
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>
2011-07-23 07:41:44 +00:00
#endif /* CONFIG_PPC_BOOK3S_64 */
/*
* For some interrupts, we need to call the real Linux
* handler, so it can do work for us. This has to happen
* as if the interrupt arrived from the kernel though,
* so let's fake it here where most state is restored.
*
* Having set up SRR0/1 with the address where we want
* to continue with relocation on (potentially in module
* space), we either just go straight there with rfi[d],
* or we jump to an interrupt handler if there is an
* interrupt to be handled first. In the latter case,
* the rfi[d] at the end of the interrupt handler will
* get us back to where we want to continue.
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>
2011-07-23 07:41:44 +00:00
*/
/* Register usage at this point:
*
* R1 = host R1
* R2 = host R2
* R10 = raw exit handler id
* R12 = exit handler id
* R13 = shadow vcpu (32-bit) or PACA (64-bit)
* SVCPU.* = guest *
*
*/
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>
2011-07-23 07:41:44 +00:00
PPC_LL r6, HSTATE_HOST_MSR(r13)
PPC_LL r8, HSTATE_VMHANDLER(r13)
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>
2011-07-23 07:41:44 +00:00
#ifdef CONFIG_PPC64
BEGIN_FTR_SECTION
beq cr1, 1f
mtspr SPRN_HSRR1, r6
mtspr SPRN_HSRR0, r8
END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
#endif
1: /* Restore host msr -> SRR1 */
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>
2011-07-23 07:41:44 +00:00
mtsrr1 r6
/* Load highmem handler address */
mtsrr0 r8
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>
2011-07-23 07:41:44 +00:00
/* RFI into the highmem handler, or jump to interrupt handler */
cmpwi r12, BOOK3S_INTERRUPT_EXTERNAL
beqa BOOK3S_INTERRUPT_EXTERNAL
cmpwi r12, BOOK3S_INTERRUPT_DECREMENTER
beqa BOOK3S_INTERRUPT_DECREMENTER
cmpwi r12, BOOK3S_INTERRUPT_PERFMON
beqa BOOK3S_INTERRUPT_PERFMON
KVM: PPC: Book3S PR: Cope with doorbell interrupts When the PR host is running on a POWER8 machine in POWER8 mode, it will use doorbell interrupts for IPIs. If one of them arrives while we are in the guest, we pop out of the guest with trap number 0xA00, which isn't handled by kvmppc_handle_exit_pr, leading to the following BUG_ON: [ 331.436215] exit_nr=0xa00 | pc=0x1d2c | msr=0x800000000000d032 [ 331.437522] ------------[ cut here ]------------ [ 331.438296] kernel BUG at arch/powerpc/kvm/book3s_pr.c:982! [ 331.439063] Oops: Exception in kernel mode, sig: 5 [#2] [ 331.439819] SMP NR_CPUS=1024 NUMA pSeries [ 331.440552] Modules linked in: tun nf_conntrack_netbios_ns nf_conntrack_broadcast ipt_MASQUERADE ip6t_REJECT xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw virtio_net kvm binfmt_misc ibmvscsi scsi_transport_srp scsi_tgt virtio_blk [ 331.447614] CPU: 11 PID: 1296 Comm: qemu-system-ppc Tainted: G D 3.11.7-200.2.fc19.ppc64p7 #1 [ 331.448920] task: c0000003bdc8c000 ti: c0000003bd32c000 task.ti: c0000003bd32c000 [ 331.450088] NIP: d0000000025d6b9c LR: d0000000025d6b98 CTR: c0000000004cfdd0 [ 331.451042] REGS: c0000003bd32f420 TRAP: 0700 Tainted: G D (3.11.7-200.2.fc19.ppc64p7) [ 331.452331] MSR: 800000000282b032 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI> CR: 28004824 XER: 20000000 [ 331.454616] SOFTE: 1 [ 331.455106] CFAR: c000000000848bb8 [ 331.455726] GPR00: d0000000025d6b98 c0000003bd32f6a0 d0000000026017b8 0000000000000032 GPR04: c0000000018627f8 c000000001873208 320d0a3030303030 3030303030643033 GPR08: c000000000c490a8 0000000000000000 0000000000000000 0000000000000002 GPR12: 0000000028004822 c00000000fdc6300 0000000000000000 00000100076ec310 GPR16: 000000002ae343b8 00003ffffd397398 0000000000000000 0000000000000000 GPR20: 00000100076f16f4 00000100076ebe60 0000000000000008 ffffffffffffffff GPR24: 0000000000000000 0000008001041e60 0000000000000000 0000008001040ce8 GPR28: c0000003a2d80000 0000000000000a00 0000000000000001 c0000003a2681810 [ 331.466504] NIP [d0000000025d6b9c] .kvmppc_handle_exit_pr+0x75c/0xa80 [kvm] [ 331.466999] LR [d0000000025d6b98] .kvmppc_handle_exit_pr+0x758/0xa80 [kvm] [ 331.467517] Call Trace: [ 331.467909] [c0000003bd32f6a0] [d0000000025d6b98] .kvmppc_handle_exit_pr+0x758/0xa80 [kvm] (unreliable) [ 331.468553] [c0000003bd32f750] [d0000000025d98f0] kvm_start_lightweight+0xb4/0xc4 [kvm] [ 331.469189] [c0000003bd32f920] [d0000000025d7648] .kvmppc_vcpu_run_pr+0xd8/0x270 [kvm] [ 331.469838] [c0000003bd32f9c0] [d0000000025cf748] .kvmppc_vcpu_run+0xc8/0xf0 [kvm] [ 331.470790] [c0000003bd32fa50] [d0000000025cc19c] .kvm_arch_vcpu_ioctl_run+0x5c/0x1b0 [kvm] [ 331.471401] [c0000003bd32fae0] [d0000000025c4888] .kvm_vcpu_ioctl+0x478/0x730 [kvm] [ 331.472026] [c0000003bd32fc90] [c00000000026192c] .do_vfs_ioctl+0x4dc/0x7a0 [ 331.472561] [c0000003bd32fd80] [c000000000261cc4] .SyS_ioctl+0xd4/0xf0 [ 331.473095] [c0000003bd32fe30] [c000000000009ed8] syscall_exit+0x0/0x98 [ 331.473633] Instruction dump: [ 331.473766] 4bfff9b4 2b9d0800 419efc18 60000000 60420000 3d220000 e8bf11a0 e8df12a8 [ 331.474733] 7fa4eb78 e8698660 48015165 e8410028 <0fe00000> 813f00e4 3ba00000 39290001 [ 331.475386] ---[ end trace 49fc47d994c1f8f2 ]--- [ 331.479817] This fixes the problem by making kvmppc_handle_exit_pr() recognize the interrupt. We also need to jump to the doorbell interrupt handler in book3s_segment.S to handle the interrupt on the way out of the guest. Having done that, there's nothing further to be done in kvmppc_handle_exit_pr(). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-01-08 10:25:36 +00:00
cmpwi r12, BOOK3S_INTERRUPT_DOORBELL
beqa BOOK3S_INTERRUPT_DOORBELL
RFI
kvmppc_handler_trampoline_exit_end: