| Message ID | 1526875786-10372-25-git-send-email-wei.guo.simon@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | KVM: PPC: Book3S PR: Transaction memory support on PR KVM | expand |
On Mon, May 21, 2018 at 12:09:41PM +0800, wei.guo.simon@gmail.com wrote: > From: Simon Guo <wei.guo.simon@gmail.com> > > Currently guest kernel doesn't handle TAR fac unavailable and it always > runs with TAR bit on. PR KVM will lazily enable TAR. TAR is not a > frequent-use reg 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 enabled. > > At the end of emulating treclaim., the correct TAR val need to be loaded > into reg 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 copy 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). With this patch, a 32-bit powermac compile with PR KVM enabled gives this error: arch/powerpc/kvm/book3s_pr.c:58:12: error: ‘kvmppc_handle_fac’ declared ‘static’ but never defined [-Werror=unused-function] static int kvmppc_handle_fac(struct kvm_vcpu *vcpu, ulong fac); ^ cc1: all warnings being treated as errors scripts/Makefile.build:312: recipe for target 'arch/powerpc/kvm/book3s_pr.o' failed The easy fix is a #ifdef CONFIG_PPC_BOOK3S_64 around the forward static definition. Paul.
Hi Paul, On Tue, May 22, 2018 at 09:44:47PM +1000, Paul Mackerras wrote: > On Mon, May 21, 2018 at 12:09:41PM +0800, wei.guo.simon@gmail.com wrote: > > From: Simon Guo <wei.guo.simon@gmail.com> > > > > Currently guest kernel doesn't handle TAR fac unavailable and it always > > runs with TAR bit on. PR KVM will lazily enable TAR. TAR is not a > > frequent-use reg 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 enabled. > > > > At the end of emulating treclaim., the correct TAR val need to be loaded > > into reg 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 copy 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). > > With this patch, a 32-bit powermac compile with PR KVM enabled gives > this error: > > arch/powerpc/kvm/book3s_pr.c:58:12: error: ‘kvmppc_handle_fac’ declared ‘static’ but never defined [-Werror=unused-function] > static int kvmppc_handle_fac(struct kvm_vcpu *vcpu, ulong fac); > ^ > cc1: all warnings being treated as errors > scripts/Makefile.build:312: recipe for target 'arch/powerpc/kvm/book3s_pr.o' failed > > The easy fix is a #ifdef CONFIG_PPC_BOOK3S_64 around the forward > static definition. Thx for find that. I will fix that and send V4 includes that simple fix. BR, - Simon
diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h index 2940de7..1f345a0 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 67d0fb40..fdbc695 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 526c928..8efc87b 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -55,7 +55,7 @@ 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); +static int kvmppc_handle_fac(struct kvm_vcpu *vcpu, ulong fac); /* Some compatibility defines */ #ifdef CONFIG_PPC_BOOK3S_32 @@ -346,6 +346,7 @@ 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 +358,11 @@ 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 +370,11 @@ 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 +825,7 @@ 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 +1026,12 @@ 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 42a7cd8..e6ce4c7 100644 --- a/arch/powerpc/kvm/tm.S +++ b/arch/powerpc/kvm/tm.S @@ -225,15 +225,21 @@ _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 @@ -423,15 +429,21 @@ _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