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authorPaul Mackerras <paulus@ozlabs.org>2018-03-21 21:32:01 +1100
committerMichael Ellerman <mpe@ellerman.id.au>2018-03-24 00:39:13 +1100
commit4bb3c7a0208fc13ca70598efd109901a7cd45ae7 (patch)
tree603753d07e9d0d0b9900a4c4ecb0c9d55a645d18 /arch/powerpc/kvm
parent7672691a08c886e53ccbf8cdca406f8c92ec7a20 (diff)
KVM: PPC: Book3S HV: Work around transactional memory bugs in POWER9
POWER9 has hardware bugs relating to transactional memory and thread reconfiguration (changes to hardware SMT mode). Specifically, the core does not have enough storage to store a complete checkpoint of all the architected state for all four threads. The DD2.2 version of POWER9 includes hardware modifications designed to allow hypervisor software to implement workarounds for these problems. This patch implements those workarounds in KVM code so that KVM guests see a full, working transactional memory implementation. The problems center around the use of TM suspended state, where the CPU has a checkpointed state but execution is not transactional. The workaround is to implement a "fake suspend" state, which looks to the guest like suspended state but the CPU does not store a checkpoint. In this state, any instruction that would cause a transition to transactional state (rfid, rfebb, mtmsrd, tresume) or would use the checkpointed state (treclaim) causes a "soft patch" interrupt (vector 0x1500) to the hypervisor so that it can be emulated. The trechkpt instruction also causes a soft patch interrupt. On POWER9 DD2.2, we avoid returning to the guest in any state which would require a checkpoint to be present. The trechkpt in the guest entry path which would normally create that checkpoint is replaced by either a transition to fake suspend state, if the guest is in suspend state, or a rollback to the pre-transactional state if the guest is in transactional state. Fake suspend state is indicated by a flag in the PACA plus a new bit in the PSSCR. The new PSSCR bit is write-only and reads back as 0. On exit from the guest, if the guest is in fake suspend state, we still do the treclaim instruction as we would in real suspend state, in order to get into non-transactional state, but we do not save the resulting register state since there was no checkpoint. Emulation of the instructions that cause a softpatch interrupt is handled in two paths. If the guest is in real suspend mode, we call kvmhv_p9_tm_emulation_early() to handle the cases where the guest is transitioning to transactional state. This is called before we do the treclaim in the guest exit path; because we haven't done treclaim, we can get back to the guest with the transaction still active. If the instruction is a case that kvmhv_p9_tm_emulation_early() doesn't handle, or if the guest is in fake suspend state, then we proceed to do the complete guest exit path and subsequently call kvmhv_p9_tm_emulation() in host context with the MMU on. This handles all the cases including the cases that generate program interrupts (illegal instruction or TM Bad Thing) and facility unavailable interrupts. The emulation is reasonably straightforward and is mostly concerned with checking for exception conditions and updating the state of registers such as MSR and CR0. The treclaim emulation takes care to ensure that the TEXASR register gets updated as if it were the guest treclaim instruction that had done failure recording, not the treclaim done in hypervisor state in the guest exit path. With this, the KVM_CAP_PPC_HTM capability returns true (1) even if transactional memory is not available to host userspace. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kvm')
-rw-r--r--arch/powerpc/kvm/Makefile7
-rw-r--r--arch/powerpc/kvm/book3s_hv.c18
-rw-r--r--arch/powerpc/kvm/book3s_hv_rmhandlers.S143
-rw-r--r--arch/powerpc/kvm/book3s_hv_tm.c216
-rw-r--r--arch/powerpc/kvm/book3s_hv_tm_builtin.c109
-rw-r--r--arch/powerpc/kvm/powerpc.c5
6 files changed, 491 insertions, 7 deletions
diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
index 85ba80de7133..4b19da8c87ae 100644
--- a/arch/powerpc/kvm/Makefile
+++ b/arch/powerpc/kvm/Makefile
@@ -74,9 +74,15 @@ kvm-hv-y += \
book3s_64_mmu_hv.o \
book3s_64_mmu_radix.o
+kvm-hv-$(CONFIG_PPC_TRANSACTIONAL_MEM) += \
+ book3s_hv_tm.o
+
kvm-book3s_64-builtin-xics-objs-$(CONFIG_KVM_XICS) := \
book3s_hv_rm_xics.o book3s_hv_rm_xive.o
+kvm-book3s_64-builtin-tm-objs-$(CONFIG_PPC_TRANSACTIONAL_MEM) += \
+ book3s_hv_tm_builtin.o
+
ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HANDLER) += \
book3s_hv_hmi.o \
@@ -84,6 +90,7 @@ kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HANDLER) += \
book3s_hv_rm_mmu.o \
book3s_hv_ras.o \
book3s_hv_builtin.o \
+ $(kvm-book3s_64-builtin-tm-objs-y) \
$(kvm-book3s_64-builtin-xics-objs-y)
endif
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 89707354c2ef..a043bde4952c 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1206,6 +1206,19 @@ static int kvmppc_handle_exit_hv(struct kvm_run *run, struct kvm_vcpu *vcpu,
r = RESUME_GUEST;
}
break;
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+ case BOOK3S_INTERRUPT_HV_SOFTPATCH:
+ /*
+ * This occurs for various TM-related instructions that
+ * we need to emulate on POWER9 DD2.2. We have already
+ * handled the cases where the guest was in real-suspend
+ * mode and was transitioning to transactional state.
+ */
+ r = kvmhv_p9_tm_emulation(vcpu);
+ break;
+#endif
+
case BOOK3S_INTERRUPT_HV_RM_HARD:
r = RESUME_PASSTHROUGH;
break;
@@ -1978,7 +1991,9 @@ static struct kvm_vcpu *kvmppc_core_vcpu_create_hv(struct kvm *kvm,
* turn off the HFSCR bit, which causes those instructions to trap.
*/
vcpu->arch.hfscr = mfspr(SPRN_HFSCR);
- if (!cpu_has_feature(CPU_FTR_TM))
+ if (cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
+ vcpu->arch.hfscr |= HFSCR_TM;
+ else if (!cpu_has_feature(CPU_FTR_TM_COMP))
vcpu->arch.hfscr &= ~HFSCR_TM;
if (cpu_has_feature(CPU_FTR_ARCH_300))
vcpu->arch.hfscr &= ~HFSCR_MSGP;
@@ -2242,6 +2257,7 @@ static void kvmppc_start_thread(struct kvm_vcpu *vcpu, struct kvmppc_vcore *vc)
tpaca = &paca[cpu];
tpaca->kvm_hstate.kvm_vcpu = vcpu;
tpaca->kvm_hstate.ptid = cpu - vc->pcpu;
+ tpaca->kvm_hstate.fake_suspend = 0;
/* Order stores to hstate.kvm_vcpu etc. before store to kvm_vcore */
smp_wmb();
tpaca->kvm_hstate.kvm_vcore = vc;
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index f31f357b8c5a..5af617459244 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -787,12 +787,18 @@ BEGIN_FTR_SECTION
END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+/*
+ * Branch around the call if both CPU_FTR_TM and
+ * CPU_FTR_P9_TM_HV_ASSIST are off.
+ */
BEGIN_FTR_SECTION
+ b 91f
+END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0)
/*
* NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS INCLUDING CR
*/
bl kvmppc_restore_tm
-END_FTR_SECTION_IFSET(CPU_FTR_TM)
+91:
#endif
/* Load guest PMU registers */
@@ -915,11 +921,14 @@ BEGIN_FTR_SECTION
mtspr SPRN_ACOP, r6
mtspr SPRN_CSIGR, r7
mtspr SPRN_TACR, r8
+ nop
FTR_SECTION_ELSE
/* POWER9-only registers */
ld r5, VCPU_TID(r4)
ld r6, VCPU_PSSCR(r4)
+ lbz r8, HSTATE_FAKE_SUSPEND(r13)
oris r6, r6, PSSCR_EC@h /* This makes stop trap to HV */
+ rldimi r6, r8, PSSCR_FAKE_SUSPEND_LG, 63 - PSSCR_FAKE_SUSPEND_LG
ld r7, VCPU_HFSCR(r4)
mtspr SPRN_TIDR, r5
mtspr SPRN_PSSCR, r6
@@ -1370,6 +1379,12 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
std r3, VCPU_CTR(r9)
std r4, VCPU_XER(r9)
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+ /* For softpatch interrupt, go off and do TM instruction emulation */
+ cmpwi r12, BOOK3S_INTERRUPT_HV_SOFTPATCH
+ beq kvmppc_tm_emul
+#endif
+
/* If this is a page table miss then see if it's theirs or ours */
cmpwi r12, BOOK3S_INTERRUPT_H_DATA_STORAGE
beq kvmppc_hdsi
@@ -1729,12 +1744,18 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
bl kvmppc_save_fp
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+/*
+ * Branch around the call if both CPU_FTR_TM and
+ * CPU_FTR_P9_TM_HV_ASSIST are off.
+ */
BEGIN_FTR_SECTION
+ b 91f
+END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0)
/*
* NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS INCLUDING CR
*/
bl kvmppc_save_tm
-END_FTR_SECTION_IFSET(CPU_FTR_TM)
+91:
#endif
/* Increment yield count if they have a VPA */
@@ -2054,6 +2075,42 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX)
mtlr r0
blr
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+/*
+ * Softpatch interrupt for transactional memory emulation cases
+ * on POWER9 DD2.2. This is early in the guest exit path - we
+ * haven't saved registers or done a treclaim yet.
+ */
+kvmppc_tm_emul:
+ /* Save instruction image in HEIR */
+ mfspr r3, SPRN_HEIR
+ stw r3, VCPU_HEIR(r9)
+
+ /*
+ * The cases we want to handle here are those where the guest
+ * is in real suspend mode and is trying to transition to
+ * transactional mode.
+ */
+ lbz r0, HSTATE_FAKE_SUSPEND(r13)
+ cmpwi r0, 0 /* keep exiting guest if in fake suspend */
+ bne guest_exit_cont
+ rldicl r3, r11, 64 - MSR_TS_S_LG, 62
+ cmpwi r3, 1 /* or if not in suspend state */
+ bne guest_exit_cont
+
+ /* Call C code to do the emulation */
+ mr r3, r9
+ bl kvmhv_p9_tm_emulation_early
+ nop
+ ld r9, HSTATE_KVM_VCPU(r13)
+ li r12, BOOK3S_INTERRUPT_HV_SOFTPATCH
+ cmpwi r3, 0
+ beq guest_exit_cont /* continue exiting if not handled */
+ ld r10, VCPU_PC(r9)
+ ld r11, VCPU_MSR(r9)
+ b fast_interrupt_c_return /* go back to guest if handled */
+#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
+
/*
* Check whether an HDSI is an HPTE not found fault or something else.
* If it is an HPTE not found fault that is due to the guest accessing
@@ -2587,13 +2644,19 @@ _GLOBAL(kvmppc_h_cede) /* r3 = vcpu pointer, r11 = msr, r13 = paca */
bl kvmppc_save_fp
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+/*
+ * Branch around the call if both CPU_FTR_TM and
+ * CPU_FTR_P9_TM_HV_ASSIST are off.
+ */
BEGIN_FTR_SECTION
+ b 91f
+END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0)
/*
* NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS INCLUDING CR
*/
ld r9, HSTATE_KVM_VCPU(r13)
bl kvmppc_save_tm
-END_FTR_SECTION_IFSET(CPU_FTR_TM)
+91:
#endif
/*
@@ -2700,12 +2763,18 @@ kvm_end_cede:
#endif
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+/*
+ * Branch around the call if both CPU_FTR_TM and
+ * CPU_FTR_P9_TM_HV_ASSIST are off.
+ */
BEGIN_FTR_SECTION
+ b 91f
+END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0)
/*
* NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS INCLUDING CR
*/
bl kvmppc_restore_tm
-END_FTR_SECTION_IFSET(CPU_FTR_TM)
+91:
#endif
/* load up FP state */
@@ -3046,6 +3115,15 @@ kvmppc_save_tm:
std r1, HSTATE_HOST_R1(r13)
li r3, TM_CAUSE_KVM_RESCHED
+BEGIN_FTR_SECTION
+ /* Emulation of the treclaim instruction needs TEXASR before treclaim */
+ mfspr r6, SPRN_TEXASR
+ std r6, VCPU_ORIG_TEXASR(r9)
+
+ rldicl. r8, r8, 64 - MSR_TS_S_LG, 62
+ beq 3f
+END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_HV_ASSIST)
+
/* Clear the MSR RI since r1, r13 are all going to be foobar. */
li r5, 0
mtmsrd r5, 1
@@ -3057,6 +3135,38 @@ kvmppc_save_tm:
SET_SCRATCH0(r13)
GET_PACA(r13)
std r9, PACATMSCRATCH(r13)
+
+ /* If doing TM emulation on POWER9 DD2.2, check for fake suspend mode */
+BEGIN_FTR_SECTION
+3:
+ lbz r9, HSTATE_FAKE_SUSPEND(r13)
+ cmpwi r9, 0
+ beq 2f
+ /*
+ * We were in fake suspend, so we are not going to save the
+ * register state as the guest checkpointed state (since
+ * we already have it), therefore we can now use any volatile GPR.
+ */
+ /* Reload stack pointer and TOC. */
+ ld r1, HSTATE_HOST_R1(r13)
+ ld r2, PACATOC(r13)
+ li r5, MSR_RI
+ mtmsrd r5, 1
+ HMT_MEDIUM
+ ld r6, HSTATE_DSCR(r13)
+ mtspr SPRN_DSCR, r6
+ li r0, 0
+ stb r0, HSTATE_FAKE_SUSPEND(r13)
+ mfspr r3, SPRN_PSSCR
+ /* PSSCR_FAKE_SUSPEND is a write-only bit, but clear it anyway */
+ li r0, PSSCR_FAKE_SUSPEND
+ andc r3, r3, r0
+ mtspr SPRN_PSSCR, r3
+ ld r9, HSTATE_KVM_VCPU(r13)
+ b 1f
+2:
+END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_HV_ASSIST)
+
ld r9, HSTATE_KVM_VCPU(r13)
/* Get a few more GPRs free. */
@@ -3182,6 +3292,15 @@ kvmppc_restore_tm:
mtspr SPRN_TEXASR, r7
/*
+ * If we are doing TM emulation for the guest on a POWER9 DD2,
+ * then we don't actually do a trechkpt -- we either set up
+ * fake-suspend mode, or emulate a TM rollback.
+ */
+BEGIN_FTR_SECTION
+ b .Ldo_tm_fake_load
+END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_HV_ASSIST)
+
+ /*
* We need to load up the checkpointed state for the guest.
* We need to do this early as it will blow away any GPRs, VSRs and
* some SPRs.
@@ -3253,10 +3372,24 @@ kvmppc_restore_tm:
/* Set the MSR RI since we have our registers back. */
li r5, MSR_RI
mtmsrd r5, 1
-
+9:
ld r0, PPC_LR_STKOFF(r1)
mtlr r0
blr
+
+.Ldo_tm_fake_load:
+ cmpwi r5, 1 /* check for suspended state */
+ bgt 10f
+ stb r5, HSTATE_FAKE_SUSPEND(r13)
+ b 9b /* and return */
+10: stdu r1, -PPC_MIN_STKFRM(r1)
+ /* guest is in transactional state, so simulate rollback */
+ mr r3, r4
+ bl kvmhv_emulate_tm_rollback
+ nop
+ ld r4, HSTATE_KVM_VCPU(r13) /* our vcpu pointer has been trashed */
+ addi r1, r1, PPC_MIN_STKFRM
+ b 9b
#endif
/*
diff --git a/arch/powerpc/kvm/book3s_hv_tm.c b/arch/powerpc/kvm/book3s_hv_tm.c
new file mode 100644
index 000000000000..bf710ad3a6d7
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_hv_tm.c
@@ -0,0 +1,216 @@
+/*
+ * Copyright 2017 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
+ *
+ * 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.
+ */
+
+#include <linux/kvm_host.h>
+
+#include <asm/kvm_ppc.h>
+#include <asm/kvm_book3s.h>
+#include <asm/kvm_book3s_64.h>
+#include <asm/reg.h>
+#include <asm/ppc-opcode.h>
+
+static void emulate_tx_failure(struct kvm_vcpu *vcpu, u64 failure_cause)
+{
+ u64 texasr, tfiar;
+ u64 msr = vcpu->arch.shregs.msr;
+
+ tfiar = vcpu->arch.pc & ~0x3ull;
+ texasr = (failure_cause << 56) | TEXASR_ABORT | TEXASR_FS | TEXASR_EXACT;
+ if (MSR_TM_SUSPENDED(vcpu->arch.shregs.msr))
+ texasr |= TEXASR_SUSP;
+ if (msr & MSR_PR) {
+ texasr |= TEXASR_PR;
+ tfiar |= 1;
+ }
+ vcpu->arch.tfiar = tfiar;
+ /* Preserve ROT and TL fields of existing TEXASR */
+ vcpu->arch.texasr = (vcpu->arch.texasr & 0x3ffffff) | texasr;
+}
+
+/*
+ * This gets called on a softpatch interrupt on POWER9 DD2.2 processors.
+ * We expect to find a TM-related instruction to be emulated. The
+ * instruction image is in vcpu->arch.emul_inst. If the guest was in
+ * TM suspended or transactional state, the checkpointed state has been
+ * reclaimed and is in the vcpu struct. The CPU is in virtual mode in
+ * host context.
+ */
+int kvmhv_p9_tm_emulation(struct kvm_vcpu *vcpu)
+{
+ u32 instr = vcpu->arch.emul_inst;
+ u64 msr = vcpu->arch.shregs.msr;
+ u64 newmsr, bescr;
+ int ra, rs;
+
+ switch (instr & 0xfc0007ff) {
+ case PPC_INST_RFID:
+ /* XXX do we need to check for PR=0 here? */
+ newmsr = vcpu->arch.shregs.srr1;
+ /* should only get here for Sx -> T1 transition */
+ WARN_ON_ONCE(!(MSR_TM_SUSPENDED(msr) &&
+ MSR_TM_TRANSACTIONAL(newmsr) &&
+ (newmsr & MSR_TM)));
+ newmsr = sanitize_msr(newmsr);
+ vcpu->arch.shregs.msr = newmsr;
+ vcpu->arch.cfar = vcpu->arch.pc - 4;
+ vcpu->arch.pc = vcpu->arch.shregs.srr0;
+ return RESUME_GUEST;
+
+ case PPC_INST_RFEBB:
+ if ((msr & MSR_PR) && (vcpu->arch.vcore->pcr & PCR_ARCH_206)) {
+ /* generate an illegal instruction interrupt */
+ kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
+ return RESUME_GUEST;
+ }
+ /* check EBB facility is available */
+ if (!(vcpu->arch.hfscr & HFSCR_EBB)) {
+ /* generate an illegal instruction interrupt */
+ kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
+ return RESUME_GUEST;
+ }
+ if ((msr & MSR_PR) && !(vcpu->arch.fscr & FSCR_EBB)) {
+ /* generate a facility unavailable interrupt */
+ vcpu->arch.fscr = (vcpu->arch.fscr & ~(0xffull << 56)) |
+ ((u64)FSCR_EBB_LG << 56);
+ kvmppc_book3s_queue_irqprio(vcpu, BOOK3S_INTERRUPT_FAC_UNAVAIL);
+ return RESUME_GUEST;
+ }
+ bescr = vcpu->arch.bescr;
+ /* expect to see a S->T transition requested */
+ WARN_ON_ONCE(!(MSR_TM_SUSPENDED(msr) &&
+ ((bescr >> 30) & 3) == 2));
+ bescr &= ~BESCR_GE;
+ if (instr & (1 << 11))
+ bescr |= BESCR_GE;
+ vcpu->arch.bescr = bescr;
+ msr = (msr & ~MSR_TS_MASK) | MSR_TS_T;
+ vcpu->arch.shregs.msr = msr;
+ vcpu->arch.cfar = vcpu->arch.pc - 4;
+ vcpu->arch.pc = vcpu->arch.ebbrr;
+ return RESUME_GUEST;
+
+ case PPC_INST_MTMSRD:
+ /* XXX do we need to check for PR=0 here? */
+ rs = (instr >> 21) & 0x1f;
+ newmsr = kvmppc_get_gpr(vcpu, rs);
+ /* check this is a Sx -> T1 transition */
+ WARN_ON_ONCE(!(MSR_TM_SUSPENDED(msr) &&
+ MSR_TM_TRANSACTIONAL(newmsr) &&
+ (newmsr & MSR_TM)));
+ /* mtmsrd doesn't change LE */
+ newmsr = (newmsr & ~MSR_LE) | (msr & MSR_LE);
+ newmsr = sanitize_msr(newmsr);
+ vcpu->arch.shregs.msr = newmsr;
+ return RESUME_GUEST;
+
+ case PPC_INST_TSR:
+ /* check for PR=1 and arch 2.06 bit set in PCR */
+ if ((msr & MSR_PR) && (vcpu->arch.vcore->pcr & PCR_ARCH_206)) {
+ /* generate an illegal instruction interrupt */
+ kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
+ return RESUME_GUEST;
+ }
+ /* check for TM disabled in the HFSCR or MSR */
+ if (!(vcpu->arch.hfscr & HFSCR_TM)) {
+ /* generate an illegal instruction interrupt */
+ kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
+ return RESUME_GUEST;
+ }
+ if (!(msr & MSR_TM)) {
+ /* generate a facility unavailable interrupt */
+ vcpu->arch.fscr = (vcpu->arch.fscr & ~(0xffull << 56)) |
+ ((u64)FSCR_TM_LG << 56);
+ kvmppc_book3s_queue_irqprio(vcpu,
+ BOOK3S_INTERRUPT_FAC_UNAVAIL);
+ return RESUME_GUEST;
+ }
+ /* Set CR0 to indicate previous transactional state */
+ vcpu->arch.cr = (vcpu->arch.cr & 0x0fffffff) |
+ (((msr & MSR_TS_MASK) >> MSR_TS_S_LG) << 28);
+ /* L=1 => tresume, L=0 => tsuspend */
+ if (instr & (1 << 21)) {
+ if (MSR_TM_SUSPENDED(msr))
+ msr = (msr & ~MSR_TS_MASK) | MSR_TS_T;
+ } else {
+ if (MSR_TM_TRANSACTIONAL(msr))
+ msr = (msr & ~MSR_TS_MASK) | MSR_TS_S;
+ }
+ vcpu->arch.shregs.msr = msr;
+ return RESUME_GUEST;
+
+ case PPC_INST_TRECLAIM:
+ /* check for TM disabled in the HFSCR or MSR */
+ if (!(vcpu->arch.hfscr & HFSCR_TM)) {
+ /* generate an illegal instruction interrupt */
+ kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
+ return RESUME_GUEST;
+ }
+ if (!(msr & MSR_TM)) {
+ /* generate a facility unavailable interrupt */
+ vcpu->arch.fscr = (vcpu->arch.fscr & ~(0xffull << 56)) |
+ ((u64)FSCR_TM_LG << 56);
+ kvmppc_book3s_queue_irqprio(vcpu,
+ BOOK3S_INTERRUPT_FAC_UNAVAIL);
+ return RESUME_GUEST;
+ }
+ /* If no transaction active, generate TM bad thing */
+ if (!MSR_TM_ACTIVE(msr)) {
+ kvmppc_core_queue_program(vcpu, SRR1_PROGTM);
+ return RESUME_GUEST;
+ }
+ /* If failure was not previously recorded, recompute TEXASR */
+ if (!(vcpu->arch.orig_texasr & TEXASR_FS)) {
+ ra = (instr >> 16) & 0x1f;
+ if (ra)
+ ra = kvmppc_get_gpr(vcpu, ra) & 0xff;
+ emulate_tx_failure(vcpu, ra);
+ }
+
+ copy_from_checkpoint(vcpu);
+
+ /* Set CR0 to indicate previous transactional state */
+ vcpu->arch.cr = (vcpu->arch.cr & 0x0fffffff) |
+ (((msr & MSR_TS_MASK) >> MSR_TS_S_LG) << 28);
+ vcpu->arch.shregs.msr &= ~MSR_TS_MASK;
+ return RESUME_GUEST;
+
+ case PPC_INST_TRECHKPT:
+ /* XXX do we need to check for PR=0 here? */
+ /* check for TM disabled in the HFSCR or MSR */
+ if (!(vcpu->arch.hfscr & HFSCR_TM)) {
+ /* generate an illegal instruction interrupt */
+ kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
+ return RESUME_GUEST;
+ }
+ if (!(msr & MSR_TM)) {
+ /* generate a facility unavailable interrupt */
+ vcpu->arch.fscr = (vcpu->arch.fscr & ~(0xffull << 56)) |
+ ((u64)FSCR_TM_LG << 56);
+ kvmppc_book3s_queue_irqprio(vcpu,
+ BOOK3S_INTERRUPT_FAC_UNAVAIL);
+ return RESUME_GUEST;
+ }
+ /* If transaction active or TEXASR[FS] = 0, bad thing */
+ if (MSR_TM_ACTIVE(msr) || !(vcpu->arch.texasr & TEXASR_FS)) {
+ kvmppc_core_queue_program(vcpu, SRR1_PROGTM);
+ return RESUME_GUEST;
+ }
+
+ copy_to_checkpoint(vcpu);
+
+ /* Set CR0 to indicate previous transactional state */
+ vcpu->arch.cr = (vcpu->arch.cr & 0x0fffffff) |
+ (((msr & MSR_TS_MASK) >> MSR_TS_S_LG) << 28);
+ vcpu->arch.shregs.msr = msr | MSR_TS_S;
+ return RESUME_GUEST;
+ }
+
+ /* What should we do here? We didn't recognize the instruction */
+ WARN_ON_ONCE(1);
+ return RESUME_GUEST;
+}
diff --git a/arch/powerpc/kvm/book3s_hv_tm_builtin.c b/arch/powerpc/kvm/book3s_hv_tm_builtin.c
new file mode 100644
index 000000000000..d98ccfd2b88c
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_hv_tm_builtin.c
@@ -0,0 +1,109 @@
+/*
+ * Copyright 2017 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
+ *
+ * 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.
+ */
+
+#include <linux/kvm_host.h>
+
+#include <asm/kvm_ppc.h>
+#include <asm/kvm_book3s.h>
+#include <asm/kvm_book3s_64.h>
+#include <asm/reg.h>
+#include <asm/ppc-opcode.h>
+
+/*
+ * This handles the cases where the guest is in real suspend mode
+ * and we want to get back to the guest without dooming the transaction.
+ * The caller has checked that the guest is in real-suspend mode
+ * (MSR[TS] = S and the fake-suspend flag is not set).
+ */
+int kvmhv_p9_tm_emulation_early(struct kvm_vcpu *vcpu)
+{
+ u32 instr = vcpu->arch.emul_inst;
+ u64 newmsr, msr, bescr;
+ int rs;
+
+ switch (instr & 0xfc0007ff) {
+ case PPC_INST_RFID:
+ /* XXX do we need to check for PR=0 here? */
+ newmsr = vcpu->arch.shregs.srr1;
+ /* should only get here for Sx -> T1 transition */
+ if (!(MSR_TM_TRANSACTIONAL(newmsr) && (newmsr & MSR_TM)))
+ return 0;
+ newmsr = sanitize_msr(newmsr);
+ vcpu->arch.shregs.msr = newmsr;
+ vcpu->arch.cfar = vcpu->arch.pc - 4;
+ vcpu->arch.pc = vcpu->arch.shregs.srr0;
+ return 1;
+
+ case PPC_INST_RFEBB:
+ /* check for PR=1 and arch 2.06 bit set in PCR */
+ msr = vcpu->arch.shregs.msr;
+ if ((msr & MSR_PR) && (vcpu->arch.vcore->pcr & PCR_ARCH_206))
+ return 0;
+ /* check EBB facility is available */
+ if (!(vcpu->arch.hfscr & HFSCR_EBB) ||
+ ((msr & MSR_PR) && !(mfspr(SPRN_FSCR) & FSCR_EBB)))
+ return 0;
+ bescr = mfspr(SPRN_BESCR);
+ /* expect to see a S->T transition requested */
+ if (((bescr >> 30) & 3) != 2)
+ return 0;
+ bescr &= ~BESCR_GE;
+ if (instr & (1 << 11))
+ bescr |= BESCR_GE;
+ mtspr(SPRN_BESCR, bescr);
+ msr = (msr & ~MSR_TS_MASK) | MSR_TS_T;
+ vcpu->arch.shregs.msr = msr;
+ vcpu->arch.cfar = vcpu->arch.pc - 4;
+ vcpu->arch.pc = mfspr(SPRN_EBBRR);
+ return 1;
+
+ case PPC_INST_MTMSRD:
+ /* XXX do we need to check for PR=0 here? */
+ rs = (instr >> 21) & 0x1f;
+ newmsr = kvmppc_get_gpr(vcpu, rs);
+ msr = vcpu->arch.shregs.msr;
+ /* check this is a Sx -> T1 transition */
+ if (!(MSR_TM_TRANSACTIONAL(newmsr) && (newmsr & MSR_TM)))
+ return 0;
+ /* mtmsrd doesn't change LE */
+ newmsr = (newmsr & ~MSR_LE) | (msr & MSR_LE);
+ newmsr = sanitize_msr(newmsr);
+ vcpu->arch.shregs.msr = newmsr;
+ return 1;
+
+ case PPC_INST_TSR:
+ /* we know the MSR has the TS field = S (0b01) here */
+ msr = vcpu->arch.shregs.msr;
+ /* check for PR=1 and arch 2.06 bit set in PCR */
+ if ((msr & MSR_PR) && (vcpu->arch.vcore->pcr & PCR_ARCH_206))
+ return 0;
+ /* check for TM disabled in the HFSCR or MSR */
+ if (!(vcpu->arch.hfscr & HFSCR_TM) || !(msr & MSR_TM))
+ return 0;
+ /* L=1 => tresume => set TS to T (0b10) */
+ if (instr & (1 << 21))
+ vcpu->arch.shregs.msr = (msr & ~MSR_TS_MASK) | MSR_TS_T;
+ /* Set CR0 to 0b0010 */
+ vcpu->arch.cr = (vcpu->arch.cr & 0x0fffffff) | 0x20000000;
+ return 1;
+ }
+
+ return 0;
+}
+
+/*
+ * This is called when we are returning to a guest in TM transactional
+ * state. We roll the guest state back to the checkpointed state.
+ */
+void kvmhv_emulate_tm_rollback(struct kvm_vcpu *vcpu)
+{
+ vcpu->arch.shregs.msr &= ~MSR_TS_MASK; /* go to N state */
+ vcpu->arch.pc = vcpu->arch.tfhar;
+ copy_from_checkpoint(vcpu);
+ vcpu->arch.cr = (vcpu->arch.cr & 0x0fffffff) | 0xa0000000;
+}
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 403e642c78f5..677b98e6650f 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -646,10 +646,13 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
r = hv_enabled;
break;
#endif
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
case KVM_CAP_PPC_HTM:
r = hv_enabled &&
- (cur_cpu_spec->cpu_user_features2 & PPC_FEATURE2_HTM_COMP);
+ (!!(cur_cpu_spec->cpu_user_features2 & PPC_FEATURE2_HTM) ||
+ cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST));
break;
+#endif
default:
r = 0;
break;