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KVM: PPC: Book3S HV: Restructure kvmppc_hv_entry to be a subroutine 

We have two paths into and out of the low-level guest entry and exit
code: from a vcpu task via kvmppc_hv_entry_trampoline, and from the
system reset vector for an offline secondary thread on POWER7 via
kvm_start_guest.  Currently both just branch to kvmppc_hv_entry to
enter the guest, and on guest exit, we test the vcpu physical thread
ID to detect which way we came in and thus whether we should return
to the vcpu task or go back to nap mode.

In order to make the code flow clearer, and to keep the code relating
to each flow together, this turns kvmppc_hv_entry into a subroutine
that follows the normal conventions for call and return.  This means
that kvmppc_hv_entry_trampoline() and kvmppc_hv_entry() now establish
normal stack frames, and we use the normal stack slots for saving
return addresses rather than local_paca->kvm_hstate.vmhandler.  Apart
from that this is mostly moving code around unchanged.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
This commit is contained in:
Paul Mackerras 2013-09-06 13:23:44 +10:00 committed by Alexander Graf
parent 42d7604d0c
commit 218309b75b
1 changed files with 178 additions and 166 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

344
arch/powerpc/kvm/book3s_hv_rmhandlers.S
View File

@ -66,8 +66,11 @@ kvmppc_skip_Hinterrupt:
* LR = return address to continue at after eventually re-enabling MMU
*/
_GLOBAL(kvmppc_hv_entry_trampoline)
mflr r0
std r0, PPC_LR_STKOFF(r1)
stdu r1, -112(r1)
mfmsr r10
LOAD_REG_ADDR(r5, kvmppc_hv_entry)
LOAD_REG_ADDR(r5, kvmppc_call_hv_entry)
li r0,MSR_RI
andc r0,r10,r0
li r6,MSR_IR | MSR_DR
@ -77,11 +80,103 @@ _GLOBAL(kvmppc_hv_entry_trampoline)
mtsrr1 r6
RFI
/******************************************************************************
* *
* Entry code *
* *
*****************************************************************************/
kvmppc_call_hv_entry:
bl kvmppc_hv_entry
/* Back from guest - restore host state and return to caller */
/* Restore host DABR and DABRX */
ld r5,HSTATE_DABR(r13)
li r6,7
mtspr SPRN_DABR,r5
mtspr SPRN_DABRX,r6
/* Restore SPRG3 */
ld r3,PACA_SPRG3(r13)
mtspr SPRN_SPRG3,r3
/*
* Reload DEC. HDEC interrupts were disabled when
* we reloaded the host's LPCR value.
*/
ld r3, HSTATE_DECEXP(r13)
mftb r4
subf r4, r4, r3
mtspr SPRN_DEC, r4
/* Reload the host's PMU registers */
ld r3, PACALPPACAPTR(r13) /* is the host using the PMU? */
lbz r4, LPPACA_PMCINUSE(r3)
cmpwi r4, 0
beq 23f /* skip if not */
lwz r3, HSTATE_PMC(r13)
lwz r4, HSTATE_PMC + 4(r13)
lwz r5, HSTATE_PMC + 8(r13)
lwz r6, HSTATE_PMC + 12(r13)
lwz r8, HSTATE_PMC + 16(r13)
lwz r9, HSTATE_PMC + 20(r13)
BEGIN_FTR_SECTION
lwz r10, HSTATE_PMC + 24(r13)
lwz r11, HSTATE_PMC + 28(r13)
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
mtspr SPRN_PMC1, r3
mtspr SPRN_PMC2, r4
mtspr SPRN_PMC3, r5
mtspr SPRN_PMC4, r6
mtspr SPRN_PMC5, r8
mtspr SPRN_PMC6, r9
BEGIN_FTR_SECTION
mtspr SPRN_PMC7, r10
mtspr SPRN_PMC8, r11
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
ld r3, HSTATE_MMCR(r13)
ld r4, HSTATE_MMCR + 8(r13)
ld r5, HSTATE_MMCR + 16(r13)
mtspr SPRN_MMCR1, r4
mtspr SPRN_MMCRA, r5
mtspr SPRN_MMCR0, r3
isync
23:
/*
* For external and machine check interrupts, we need
* to call the Linux handler to process the interrupt.
* We do that by jumping to absolute address 0x500 for
* external interrupts, or the machine_check_fwnmi label
* for machine checks (since firmware might have patched
* the vector area at 0x200). The [h]rfid at the end of the
* handler will return to the book3s_hv_interrupts.S code.
* For other interrupts we do the rfid to get back
* to the book3s_hv_interrupts.S code here.
*/
ld r8, 112+PPC_LR_STKOFF(r1)
addi r1, r1, 112
ld r7, HSTATE_HOST_MSR(r13)
cmpwi cr1, r12, BOOK3S_INTERRUPT_MACHINE_CHECK
cmpwi r12, BOOK3S_INTERRUPT_EXTERNAL
BEGIN_FTR_SECTION
beq 11f
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
/* RFI into the highmem handler, or branch to interrupt handler */
mfmsr r6
li r0, MSR_RI
andc r6, r6, r0
mtmsrd r6, 1 /* Clear RI in MSR */
mtsrr0 r8
mtsrr1 r7
beqa 0x500 /* external interrupt (PPC970) */
beq cr1, 13f /* machine check */
RFI
/* On POWER7, we have external interrupts set to use HSRR0/1 */
11: mtspr SPRN_HSRR0, r8
mtspr SPRN_HSRR1, r7
ba 0x500
13: b machine_check_fwnmi
/*
* We come in here when wakened from nap mode on a secondary hw thread.
@ -137,7 +232,7 @@ kvm_start_guest:
cmpdi r4,0
/* if we have no vcpu to run, go back to sleep */
beq kvm_no_guest
b kvmppc_hv_entry
b 30f
27: /* XXX should handle hypervisor maintenance interrupts etc. here */
b kvm_no_guest
@ -147,6 +242,57 @@ kvm_start_guest:
stw r8,HSTATE_SAVED_XIRR(r13)
b kvm_no_guest
30: bl kvmppc_hv_entry
/* Back from the guest, go back to nap */
/* Clear our vcpu pointer so we don't come back in early */
li r0, 0
std r0, HSTATE_KVM_VCPU(r13)
lwsync
/* Clear any pending IPI - we're an offline thread */
ld r5, HSTATE_XICS_PHYS(r13)
li r7, XICS_XIRR
lwzcix r3, r5, r7 /* ack any pending interrupt */
rlwinm. r0, r3, 0, 0xffffff /* any pending? */
beq 37f
sync
li r0, 0xff
li r6, XICS_MFRR
stbcix r0, r5, r6 /* clear the IPI */
stwcix r3, r5, r7 /* EOI it */
37: sync
/* increment the nap count and then go to nap mode */
ld r4, HSTATE_KVM_VCORE(r13)
addi r4, r4, VCORE_NAP_COUNT
lwsync /* make previous updates visible */
51: lwarx r3, 0, r4
addi r3, r3, 1
stwcx. r3, 0, r4
bne 51b
kvm_no_guest:
li r0, KVM_HWTHREAD_IN_NAP
stb r0, HSTATE_HWTHREAD_STATE(r13)
li r3, LPCR_PECE0
mfspr r4, SPRN_LPCR
rlwimi r4, r3, 0, LPCR_PECE0 | LPCR_PECE1
mtspr SPRN_LPCR, r4
isync
std r0, HSTATE_SCRATCH0(r13)
ptesync
ld r0, HSTATE_SCRATCH0(r13)
1: cmpd r0, r0
bne 1b
nap
b .
/******************************************************************************
* *
* Entry code *
* *
*****************************************************************************/
.global kvmppc_hv_entry
kvmppc_hv_entry:
@ -159,7 +305,8 @@ kvmppc_hv_entry:
* all other volatile GPRS = free
*/
mflr r0
std r0, HSTATE_VMHANDLER(r13)
std r0, PPC_LR_STKOFF(r1)
stdu r1, -112(r1)
/* Set partition DABR */
/* Do this before re-enabling PMU to avoid P7 DABR corruption bug */
@ -1198,103 +1345,30 @@ BEGIN_FTR_SECTION
stw r11, VCPU_PMC + 28(r9)
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
22:
ld r0, 112+PPC_LR_STKOFF(r1)
addi r1, r1, 112
mtlr r0
blr
secondary_too_late:
ld r5,HSTATE_KVM_VCORE(r13)
HMT_LOW
13: lbz r3,VCORE_IN_GUEST(r5)
cmpwi r3,0
bne 13b
HMT_MEDIUM
li r0, KVM_GUEST_MODE_NONE
stb r0, HSTATE_IN_GUEST(r13)
ld r11,PACA_SLBSHADOWPTR(r13)
/* Secondary threads go off to take a nap on POWER7 */
BEGIN_FTR_SECTION
lwz r0,VCPU_PTID(r9)
cmpwi r0,0
bne secondary_nap
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
/* Restore host DABR and DABRX */
ld r5,HSTATE_DABR(r13)
li r6,7
mtspr SPRN_DABR,r5
mtspr SPRN_DABRX,r6
/* Restore SPRG3 */
ld r3,PACA_SPRG3(r13)
mtspr SPRN_SPRG3,r3
/*
* Reload DEC. HDEC interrupts were disabled when
* we reloaded the host's LPCR value.
*/
ld r3, HSTATE_DECEXP(r13)
mftb r4
subf r4, r4, r3
mtspr SPRN_DEC, r4
/* Reload the host's PMU registers */
ld r3, PACALPPACAPTR(r13) /* is the host using the PMU? */
lbz r4, LPPACA_PMCINUSE(r3)
cmpwi r4, 0
beq 23f /* skip if not */
lwz r3, HSTATE_PMC(r13)
lwz r4, HSTATE_PMC + 4(r13)
lwz r5, HSTATE_PMC + 8(r13)
lwz r6, HSTATE_PMC + 12(r13)
lwz r8, HSTATE_PMC + 16(r13)
lwz r9, HSTATE_PMC + 20(r13)
BEGIN_FTR_SECTION
lwz r10, HSTATE_PMC + 24(r13)
lwz r11, HSTATE_PMC + 28(r13)
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
mtspr SPRN_PMC1, r3
mtspr SPRN_PMC2, r4
mtspr SPRN_PMC3, r5
mtspr SPRN_PMC4, r6
mtspr SPRN_PMC5, r8
mtspr SPRN_PMC6, r9
BEGIN_FTR_SECTION
mtspr SPRN_PMC7, r10
mtspr SPRN_PMC8, r11
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
ld r3, HSTATE_MMCR(r13)
ld r4, HSTATE_MMCR + 8(r13)
ld r5, HSTATE_MMCR + 16(r13)
mtspr SPRN_MMCR1, r4
mtspr SPRN_MMCRA, r5
mtspr SPRN_MMCR0, r3
isync
23:
/*
* For external and machine check interrupts, we need
* to call the Linux handler to process the interrupt.
* We do that by jumping to absolute address 0x500 for
* external interrupts, or the machine_check_fwnmi label
* for machine checks (since firmware might have patched
* the vector area at 0x200). The [h]rfid at the end of the
* handler will return to the book3s_hv_interrupts.S code.
* For other interrupts we do the rfid to get back
* to the book3s_hv_interrupts.S code here.
*/
ld r8, HSTATE_VMHANDLER(r13)
ld r7, HSTATE_HOST_MSR(r13)
cmpwi cr1, r12, BOOK3S_INTERRUPT_MACHINE_CHECK
cmpwi r12, BOOK3S_INTERRUPT_EXTERNAL
BEGIN_FTR_SECTION
beq 11f
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
/* RFI into the highmem handler, or branch to interrupt handler */
mfmsr r6
li r0, MSR_RI
andc r6, r6, r0
mtmsrd r6, 1 /* Clear RI in MSR */
mtsrr0 r8
mtsrr1 r7
beqa 0x500 /* external interrupt (PPC970) */
beq cr1, 13f /* machine check */
RFI
/* On POWER7, we have external interrupts set to use HSRR0/1 */
11: mtspr SPRN_HSRR0, r8
mtspr SPRN_HSRR1, r7
ba 0x500
13: b machine_check_fwnmi
.rept SLB_NUM_BOLTED
ld r5,SLBSHADOW_SAVEAREA(r11)
ld r6,SLBSHADOW_SAVEAREA+8(r11)
andis. r7,r5,SLB_ESID_V@h
beq 1f
slbmte r6,r5
1: addi r11,r11,16
.endr
b 22b
/*
* Check whether an HDSI is an HPTE not found fault or something else.
@ -1741,68 +1815,6 @@ machine_check_realmode:
rotldi r11, r11, 63
b fast_interrupt_c_return
secondary_too_late:
ld r5,HSTATE_KVM_VCORE(r13)
HMT_LOW
13: lbz r3,VCORE_IN_GUEST(r5)
cmpwi r3,0
bne 13b
HMT_MEDIUM
ld r11,PACA_SLBSHADOWPTR(r13)
.rept SLB_NUM_BOLTED
ld r5,SLBSHADOW_SAVEAREA(r11)
ld r6,SLBSHADOW_SAVEAREA+8(r11)
andis. r7,r5,SLB_ESID_V@h
beq 1f
slbmte r6,r5
1: addi r11,r11,16
.endr
secondary_nap:
/* Clear our vcpu pointer so we don't come back in early */
li r0, 0
std r0, HSTATE_KVM_VCPU(r13)
lwsync
/* Clear any pending IPI - assume we're a secondary thread */
ld r5, HSTATE_XICS_PHYS(r13)
li r7, XICS_XIRR
lwzcix r3, r5, r7 /* ack any pending interrupt */
rlwinm. r0, r3, 0, 0xffffff /* any pending? */
beq 37f
sync
li r0, 0xff
li r6, XICS_MFRR
stbcix r0, r5, r6 /* clear the IPI */
stwcix r3, r5, r7 /* EOI it */
37: sync
/* increment the nap count and then go to nap mode */
ld r4, HSTATE_KVM_VCORE(r13)
addi r4, r4, VCORE_NAP_COUNT
lwsync /* make previous updates visible */
51: lwarx r3, 0, r4
addi r3, r3, 1
stwcx. r3, 0, r4
bne 51b
kvm_no_guest:
li r0, KVM_HWTHREAD_IN_NAP
stb r0, HSTATE_HWTHREAD_STATE(r13)
li r3, LPCR_PECE0
mfspr r4, SPRN_LPCR
rlwimi r4, r3, 0, LPCR_PECE0 | LPCR_PECE1
mtspr SPRN_LPCR, r4
isync
std r0, HSTATE_SCRATCH0(r13)
ptesync
ld r0, HSTATE_SCRATCH0(r13)
1: cmpd r0, r0
bne 1b
nap
b .
/*
* Save away FP, VMX and VSX registers.
* r3 = vcpu pointer