From 7284ca8a5eaee311d2e4aec73b2df9bd57e0cdcb Mon Sep 17 00:00:00 2001 From: Simon Guo Date: Wed, 23 May 2018 15:02:07 +0800 Subject: [PATCH] KVM: PPC: Book3S PR: Support TAR handling for PR KVM HTM Currently guest kernel doesn't handle TAR facility unavailable and it always runs with TAR bit on. PR KVM will lazily enable TAR. TAR is not a frequent-use register and it is not included in SVCPU struct. Due to the above, the checkpointed TAR val might be a bogus TAR val. To solve this issue, we will make vcpu->arch.fscr tar bit consistent with shadow_fscr when TM is enabled. At the end of emulating treclaim., the correct TAR val need to be loaded into the register if FSCR_TAR bit is on. At the beginning of emulating trechkpt., TAR needs to be flushed so that the right tar val can be copied into tar_tm. Tested with: tools/testing/selftests/powerpc/tm/tm-tar tools/testing/selftests/powerpc/ptrace/ptrace-tm-tar (remove DSCR/PPR related testing). Signed-off-by: Simon Guo Signed-off-by: Paul Mackerras --- arch/powerpc/include/asm/kvm_book3s.h | 2 ++ arch/powerpc/kvm/book3s_emulate.c | 4 ++++ arch/powerpc/kvm/book3s_pr.c | 23 ++++++++++++++++++----- arch/powerpc/kvm/tm.S | 16 ++++++++++++++-- 4 files changed, 38 insertions(+), 7 deletions(-) diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h index 2940de7bac08..1f345a0b6ba2 100644 --- a/arch/powerpc/include/asm/kvm_book3s.h +++ b/arch/powerpc/include/asm/kvm_book3s.h @@ -271,6 +271,8 @@ static inline void kvmppc_save_tm_sprs(struct kvm_vcpu *vcpu) {} static inline void kvmppc_restore_tm_sprs(struct kvm_vcpu *vcpu) {} #endif +void kvmppc_giveup_fac(struct kvm_vcpu *vcpu, ulong fac); + extern int kvm_irq_bypass; static inline struct kvmppc_vcpu_book3s *to_book3s(struct kvm_vcpu *vcpu) diff --git a/arch/powerpc/kvm/book3s_emulate.c b/arch/powerpc/kvm/book3s_emulate.c index 67d0fb40e8b2..fdbc695038dc 100644 --- a/arch/powerpc/kvm/book3s_emulate.c +++ b/arch/powerpc/kvm/book3s_emulate.c @@ -173,6 +173,9 @@ static void kvmppc_emulate_treclaim(struct kvm_vcpu *vcpu, int ra_val) guest_msr &= ~(MSR_TS_MASK); kvmppc_set_msr(vcpu, guest_msr); preempt_enable(); + + if (vcpu->arch.shadow_fscr & FSCR_TAR) + mtspr(SPRN_TAR, vcpu->arch.tar); } static void kvmppc_emulate_trchkpt(struct kvm_vcpu *vcpu) @@ -185,6 +188,7 @@ static void kvmppc_emulate_trchkpt(struct kvm_vcpu *vcpu) * copy. */ kvmppc_giveup_ext(vcpu, MSR_VSX); + kvmppc_giveup_fac(vcpu, FSCR_TAR_LG); kvmppc_copyto_vcpu_tm(vcpu); kvmppc_save_tm_sprs(vcpu); diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index ad0a2ee8d8b1..eaf0c4f03c47 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -55,7 +55,9 @@ static int kvmppc_handle_ext(struct kvm_vcpu *vcpu, unsigned int exit_nr, ulong msr); -static void kvmppc_giveup_fac(struct kvm_vcpu *vcpu, ulong fac); +#ifdef CONFIG_PPC_BOOK3S_64 +static int kvmppc_handle_fac(struct kvm_vcpu *vcpu, ulong fac); +#endif /* Some compatibility defines */ #ifdef CONFIG_PPC_BOOK3S_32 @@ -346,6 +348,7 @@ void kvmppc_save_tm_pr(struct kvm_vcpu *vcpu) return; } + kvmppc_giveup_fac(vcpu, FSCR_TAR_LG); kvmppc_giveup_ext(vcpu, MSR_VSX); preempt_disable(); @@ -357,8 +360,11 @@ void kvmppc_restore_tm_pr(struct kvm_vcpu *vcpu) { if (!MSR_TM_ACTIVE(kvmppc_get_msr(vcpu))) { kvmppc_restore_tm_sprs(vcpu); - if (kvmppc_get_msr(vcpu) & MSR_TM) + if (kvmppc_get_msr(vcpu) & MSR_TM) { kvmppc_handle_lost_math_exts(vcpu); + if (vcpu->arch.fscr & FSCR_TAR) + kvmppc_handle_fac(vcpu, FSCR_TAR_LG); + } return; } @@ -366,9 +372,11 @@ void kvmppc_restore_tm_pr(struct kvm_vcpu *vcpu) _kvmppc_restore_tm_pr(vcpu, kvmppc_get_msr(vcpu)); preempt_enable(); - if (kvmppc_get_msr(vcpu) & MSR_TM) + if (kvmppc_get_msr(vcpu) & MSR_TM) { kvmppc_handle_lost_math_exts(vcpu); - + if (vcpu->arch.fscr & FSCR_TAR) + kvmppc_handle_fac(vcpu, FSCR_TAR_LG); + } } #endif @@ -819,7 +827,7 @@ void kvmppc_giveup_ext(struct kvm_vcpu *vcpu, ulong msr) } /* Give up facility (TAR / EBB / DSCR) */ -static void kvmppc_giveup_fac(struct kvm_vcpu *vcpu, ulong fac) +void kvmppc_giveup_fac(struct kvm_vcpu *vcpu, ulong fac) { #ifdef CONFIG_PPC_BOOK3S_64 if (!(vcpu->arch.shadow_fscr & (1ULL << fac))) { @@ -1020,7 +1028,12 @@ void kvmppc_set_fscr(struct kvm_vcpu *vcpu, u64 fscr) if ((vcpu->arch.fscr & FSCR_TAR) && !(fscr & FSCR_TAR)) { /* TAR got dropped, drop it in shadow too */ kvmppc_giveup_fac(vcpu, FSCR_TAR_LG); + } else if (!(vcpu->arch.fscr & FSCR_TAR) && (fscr & FSCR_TAR)) { + vcpu->arch.fscr = fscr; + kvmppc_handle_fac(vcpu, FSCR_TAR_LG); + return; } + vcpu->arch.fscr = fscr; } #endif diff --git a/arch/powerpc/kvm/tm.S b/arch/powerpc/kvm/tm.S index 4a68dd4050a4..90e330f21356 100644 --- a/arch/powerpc/kvm/tm.S +++ b/arch/powerpc/kvm/tm.S @@ -172,15 +172,21 @@ _GLOBAL(_kvmppc_save_tm_pr) mfmsr r5 SAVE_GPR(5, r1) - /* also save DSCR/CR so that it can be recovered later */ + /* also save DSCR/CR/TAR so that it can be recovered later */ mfspr r6, SPRN_DSCR SAVE_GPR(6, r1) mfcr r7 stw r7, _CCR(r1) + mfspr r8, SPRN_TAR + SAVE_GPR(8, r1) + bl __kvmppc_save_tm + REST_GPR(8, r1) + mtspr SPRN_TAR, r8 + ld r7, _CCR(r1) mtcr r7 @@ -340,15 +346,21 @@ _GLOBAL(_kvmppc_restore_tm_pr) mfmsr r5 SAVE_GPR(5, r1) - /* also save DSCR/CR so that it can be recovered later */ + /* also save DSCR/CR/TAR so that it can be recovered later */ mfspr r6, SPRN_DSCR SAVE_GPR(6, r1) mfcr r7 stw r7, _CCR(r1) + mfspr r8, SPRN_TAR + SAVE_GPR(8, r1) + bl __kvmppc_restore_tm + REST_GPR(8, r1) + mtspr SPRN_TAR, r8 + ld r7, _CCR(r1) mtcr r7 -- 2.11.0