From: Simon Guo <wei.guo.simon@xxxxxxxxx> HV KVM and PR KVM need different MSR source to indicate whether treclaim. or trecheckpoint. is necessary. This patch add new parameter (guest MSR) for these kvmppc_save_tm/ kvmppc_restore_tm() APIs: - For HV KVM, it is VCPU_MSR - For PR KVM, it is current host MSR or VCPU_SHADOW_SRR1 This enhancement enables these 2 APIs to be reused by PR KVM later. And the patch keeps HV KVM logic unchanged. This patch also reworks kvmppc_save_tm()/kvmppc_restore_tm() to have a clean ABI: r3 for vcpu and r4 for guest_msr. During kvmppc_save_tm/kvmppc_restore_tm(), the R1 need to be saved or restored. Currently the R1 is saved into HSTATE_HOST_R1. In PR KVM, we are going to add a C function wrapper for kvmppc_save_tm/kvmppc_restore_tm() where the R1 will be incremented with added stackframe and save into HSTATE_HOST_R1. There are several places in HV KVM to load HSTATE_HOST_R1 as R1, and we don't want to bring risk or confusion by TM code. This patch will use HSTATE_SCRATCH2 to save/restore R1 in kvmppc_save_tm/kvmppc_restore_tm() to avoid future confusion, since the r1 is actually a temporary/scratch value to be saved/stored. Signed-off-by: Simon Guo <wei.guo.simon@xxxxxxxxx> --- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 12 ++++++- arch/powerpc/kvm/tm.S | 61 ++++++++++++++++++--------------- 2 files changed, 45 insertions(+), 28 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index a7460d5..df13cea 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -788,7 +788,10 @@ BEGIN_FTR_SECTION /* * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS INCLUDING CR */ + mr r3, r4 + ld r4, VCPU_MSR(r3) bl kvmppc_restore_tm + ld r4, HSTATE_KVM_VCPU(r13) END_FTR_SECTION_IFSET(CPU_FTR_TM) #endif @@ -1730,7 +1733,10 @@ BEGIN_FTR_SECTION /* * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS INCLUDING CR */ + mr r3, r9 + ld r4, VCPU_MSR(r3) bl kvmppc_save_tm + ld r9, HSTATE_KVM_VCPU(r13) END_FTR_SECTION_IFSET(CPU_FTR_TM) #endif @@ -2588,7 +2594,8 @@ BEGIN_FTR_SECTION /* * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS INCLUDING CR */ - ld r9, HSTATE_KVM_VCPU(r13) + ld r3, HSTATE_KVM_VCPU(r13) + ld r4, VCPU_MSR(r3) bl kvmppc_save_tm END_FTR_SECTION_IFSET(CPU_FTR_TM) #endif @@ -2701,7 +2708,10 @@ BEGIN_FTR_SECTION /* * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS INCLUDING CR */ + mr r3, r4 + ld r4, VCPU_MSR(r3) bl kvmppc_restore_tm + ld r4, HSTATE_KVM_VCPU(r13) END_FTR_SECTION_IFSET(CPU_FTR_TM) #endif diff --git a/arch/powerpc/kvm/tm.S b/arch/powerpc/kvm/tm.S index 072d35e..e779b15 100644 --- a/arch/powerpc/kvm/tm.S +++ b/arch/powerpc/kvm/tm.S @@ -28,9 +28,12 @@ #ifdef CONFIG_PPC_TRANSACTIONAL_MEM /* * Save transactional state and TM-related registers. - * Called with r9 pointing to the vcpu struct. + * Called with: + * - r3 pointing to the vcpu struct + * - r4 points to the MSR with current TS bits: + * (For HV KVM, it is VCPU_MSR ; For PR KVM, it is host MSR). * This can modify all checkpointed registers, but - * restores r1, r2 and r9 (vcpu pointer) before exit. + * restores r1, r2 before exit. */ _GLOBAL(kvmppc_save_tm) mflr r0 @@ -42,11 +45,11 @@ _GLOBAL(kvmppc_save_tm) rldimi r8, r0, MSR_TM_LG, 63-MSR_TM_LG mtmsrd r8 - ld r5, VCPU_MSR(r9) - rldicl. r5, r5, 64 - MSR_TS_S_LG, 62 + rldicl. r4, r4, 64 - MSR_TS_S_LG, 62 beq 1f /* TM not active in guest. */ - std r1, HSTATE_HOST_R1(r13) + std r1, HSTATE_SCRATCH2(r13) + std r3, HSTATE_SCRATCH1(r13) li r3, TM_CAUSE_KVM_RESCHED /* Clear the MSR RI since r1, r13 are all going to be foobar. */ @@ -60,7 +63,7 @@ _GLOBAL(kvmppc_save_tm) SET_SCRATCH0(r13) GET_PACA(r13) std r9, PACATMSCRATCH(r13) - ld r9, HSTATE_KVM_VCPU(r13) + ld r9, HSTATE_SCRATCH1(r13) /* Get a few more GPRs free. */ std r29, VCPU_GPRS_TM(29)(r9) @@ -92,7 +95,7 @@ _GLOBAL(kvmppc_save_tm) std r4, VCPU_GPRS_TM(9)(r9) /* Reload stack pointer and TOC. */ - ld r1, HSTATE_HOST_R1(r13) + ld r1, HSTATE_SCRATCH2(r13) ld r2, PACATOC(r13) /* Set MSR RI now we have r1 and r13 back. */ @@ -145,9 +148,13 @@ _GLOBAL(kvmppc_save_tm) /* * Restore transactional state and TM-related registers. - * Called with r4 pointing to the vcpu struct. + * Called with: + * - r3 pointing to the vcpu struct. + * - r4 is the guest MSR with desired TS bits: + * For HV KVM, it is VCPU_MSR + * For PR KVM, it is provided by caller * This potentially modifies all checkpointed registers. - * It restores r1, r2, r4 from the PACA. + * It restores r1, r2 from the PACA. */ _GLOBAL(kvmppc_restore_tm) mflr r0 @@ -166,17 +173,17 @@ _GLOBAL(kvmppc_restore_tm) * The user may change these outside of a transaction, so they must * always be context switched. */ - ld r5, VCPU_TFHAR(r4) - ld r6, VCPU_TFIAR(r4) - ld r7, VCPU_TEXASR(r4) + ld r5, VCPU_TFHAR(r3) + ld r6, VCPU_TFIAR(r3) + ld r7, VCPU_TEXASR(r3) mtspr SPRN_TFHAR, r5 mtspr SPRN_TFIAR, r6 mtspr SPRN_TEXASR, r7 - ld r5, VCPU_MSR(r4) + mr r5, r4 rldicl. r5, r5, 64 - MSR_TS_S_LG, 62 beqlr /* TM not active in guest */ - std r1, HSTATE_HOST_R1(r13) + std r1, HSTATE_SCRATCH2(r13) /* Make sure the failure summary is set, otherwise we'll program check * when we trechkpt. It's possible that this might have been not set @@ -192,21 +199,21 @@ _GLOBAL(kvmppc_restore_tm) * some SPRs. */ - mr r31, r4 + mr r31, r3 addi r3, r31, VCPU_FPRS_TM bl load_fp_state addi r3, r31, VCPU_VRS_TM bl load_vr_state - mr r4, r31 - lwz r7, VCPU_VRSAVE_TM(r4) + mr r3, r31 + lwz r7, VCPU_VRSAVE_TM(r3) mtspr SPRN_VRSAVE, r7 - ld r5, VCPU_LR_TM(r4) - lwz r6, VCPU_CR_TM(r4) - ld r7, VCPU_CTR_TM(r4) - ld r8, VCPU_AMR_TM(r4) - ld r9, VCPU_TAR_TM(r4) - ld r10, VCPU_XER_TM(r4) + ld r5, VCPU_LR_TM(r3) + lwz r6, VCPU_CR_TM(r3) + ld r7, VCPU_CTR_TM(r3) + ld r8, VCPU_AMR_TM(r3) + ld r9, VCPU_TAR_TM(r3) + ld r10, VCPU_XER_TM(r3) mtlr r5 mtcr r6 mtctr r7 @@ -219,8 +226,8 @@ _GLOBAL(kvmppc_restore_tm) * till the last moment to avoid running with userspace PPR and DSCR for * too long. */ - ld r29, VCPU_DSCR_TM(r4) - ld r30, VCPU_PPR_TM(r4) + ld r29, VCPU_DSCR_TM(r3) + ld r30, VCPU_PPR_TM(r3) std r2, PACATMSCRATCH(r13) /* Save TOC */ @@ -253,8 +260,7 @@ _GLOBAL(kvmppc_restore_tm) ld r29, HSTATE_DSCR(r13) mtspr SPRN_DSCR, r29 #endif - ld r4, HSTATE_KVM_VCPU(r13) - ld r1, HSTATE_HOST_R1(r13) + ld r1, HSTATE_SCRATCH2(r13) ld r2, PACATMSCRATCH(r13) /* Set the MSR RI since we have our registers back. */ @@ -264,4 +270,5 @@ _GLOBAL(kvmppc_restore_tm) ld r0, PPC_LR_STKOFF(r1) mtlr r0 blr + #endif -- 1.8.3.1
