4 files changed, 47 insertions, 45 deletions

diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index 4c02a7378d06..e7377b73cfec 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -96,6 +96,7 @@ struct kvmppc_vcore {
         struct kvm_vcpu *runner;
         struct kvm *kvm;
         u64 tb_offset;          /* guest timebase - host timebase */
+        u64 tb_offset_applied;  /* timebase offset currently in force */
         ulong lpcr;
         u32 arch_compat;
         ulong pcr;
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 6bee65f3cfd3..373dc1d6ef44 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -562,6 +562,7 @@ int main(void)
         OFFSET(VCORE_NAPPING_THREADS, kvmppc_vcore, napping_threads);
         OFFSET(VCORE_KVM, kvmppc_vcore, kvm);
         OFFSET(VCORE_TB_OFFSET, kvmppc_vcore, tb_offset);
+        OFFSET(VCORE_TB_OFFSET_APPL, kvmppc_vcore, tb_offset_applied);
         OFFSET(VCORE_LPCR, kvmppc_vcore, lpcr);
         OFFSET(VCORE_PCR, kvmppc_vcore, pcr);
         OFFSET(VCORE_DPDES, kvmppc_vcore, dpdes);
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 4d07fca5121c..9963f65c212b 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -2441,6 +2441,7 @@ static void init_vcore_to_run(struct kvmppc_vcore *vc)
         vc->in_guest = 0;
         vc->napping_threads = 0;
         vc->conferring_threads = 0;
+        vc->tb_offset_applied = 0;
 }
 
 static bool can_dynamic_split(struct kvmppc_vcore *vc, struct core_info *cip)
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index bd63fa8a08b5..25c32e421b57 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -692,6 +692,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 22:     ld      r8,VCORE_TB_OFFSET(r5)
         cmpdi   r8,0
         beq     37f
+        std     r8, VCORE_TB_OFFSET_APPL(r5)
         mftb    r6              /* current host timebase */
         add     r8,r8,r6
         mtspr   SPRN_TBU40,r8   /* update upper 40 bits */
@@ -940,18 +941,6 @@ FTR_SECTION_ELSE
 ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
 8:
 
-        /*
-         * Set the decrementer to the guest decrementer.
-         */
-        ld      r8,VCPU_DEC_EXPIRES(r4)
-        /* r8 is a host timebase value here, convert to guest TB */
-        ld      r5,HSTATE_KVM_VCORE(r13)
-        ld      r6,VCORE_TB_OFFSET(r5)
-        add     r8,r8,r6
-        mftb    r7
-        subf    r3,r7,r8
-        mtspr   SPRN_DEC,r3
-
         ld      r5, VCPU_SPRG0(r4)
         ld      r6, VCPU_SPRG1(r4)
         ld      r7, VCPU_SPRG2(r4)
@@ -1005,6 +994,18 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
         mtspr   SPRN_LPCR,r8
         isync
 
+        /*
+         * Set the decrementer to the guest decrementer.
+         */
+        ld      r8,VCPU_DEC_EXPIRES(r4)
+        /* r8 is a host timebase value here, convert to guest TB */
+        ld      r5,HSTATE_KVM_VCORE(r13)
+        ld      r6,VCORE_TB_OFFSET_APPL(r5)
+        add     r8,r8,r6
+        mftb    r7
+        subf    r3,r7,r8
+        mtspr   SPRN_DEC,r3
+
         /* Check if HDEC expires soon */
         mfspr   r3, SPRN_HDEC
         EXTEND_HDEC(r3)
@@ -1597,8 +1598,27 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX)
 
 guest_bypass:
         stw     r12, STACK_SLOT_TRAP(r1)
-        mr      r3, r12
+
+        /* Save DEC */
+        /* Do this before kvmhv_commence_exit so we know TB is guest TB */
+        ld      r3, HSTATE_KVM_VCORE(r13)
+        mfspr   r5,SPRN_DEC
+        mftb    r6
+        /* On P9, if the guest has large decr enabled, don't sign extend */
+BEGIN_FTR_SECTION
+        ld      r4, VCORE_LPCR(r3)
+        andis.  r4, r4, LPCR_LD@h
+        bne     16f
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
+        extsw   r5,r5
+16:     add     r5,r5,r6
+        /* r5 is a guest timebase value here, convert to host TB */
+        ld      r4,VCORE_TB_OFFSET_APPL(r3)
+        subf    r5,r4,r5
+        std     r5,VCPU_DEC_EXPIRES(r9)
+
         /* Increment exit count, poke other threads to exit */
+        mr      r3, r12
         bl      kvmhv_commence_exit
         nop
         ld      r9, HSTATE_KVM_VCPU(r13)
@@ -1639,23 +1659,6 @@ guest_bypass:
         mtspr   SPRN_PURR,r3
         mtspr   SPRN_SPURR,r4
 
-        /* Save DEC */
-        ld      r3, HSTATE_KVM_VCORE(r13)
-        mfspr   r5,SPRN_DEC
-        mftb    r6
-        /* On P9, if the guest has large decr enabled, don't sign extend */
-BEGIN_FTR_SECTION
-        ld      r4, VCORE_LPCR(r3)
-        andis.  r4, r4, LPCR_LD@h
-        bne     16f
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
-        extsw   r5,r5
-16:     add     r5,r5,r6
-        /* r5 is a guest timebase value here, convert to host TB */
-        ld      r4,VCORE_TB_OFFSET(r3)
-        subf    r5,r4,r5
-        std     r5,VCPU_DEC_EXPIRES(r9)
-
 BEGIN_FTR_SECTION
         b       8f
 END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
@@ -2017,9 +2020,11 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 
 27:
         /* Subtract timebase offset from timebase */
-        ld      r8,VCORE_TB_OFFSET(r5)
+        ld      r8, VCORE_TB_OFFSET_APPL(r5)
         cmpdi   r8,0
         beq     17f
+        li      r0, 0
+        std     r0, VCORE_TB_OFFSET_APPL(r5)
         mftb    r6                      /* current guest timebase */
         subf    r8,r8,r6
         mtspr   SPRN_TBU40,r8           /* update upper 40 bits */
@@ -2700,7 +2705,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
         add     r3, r3, r5
         ld      r4, HSTATE_KVM_VCPU(r13)
         ld      r5, HSTATE_KVM_VCORE(r13)
-        ld      r6, VCORE_TB_OFFSET(r5)
+        ld      r6, VCORE_TB_OFFSET_APPL(r5)
         subf    r3, r6, r3      /* convert to host TB value */
         std     r3, VCPU_DEC_EXPIRES(r4)
 
@@ -2799,7 +2804,7 @@ END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0)
         /* Restore guest decrementer */
         ld      r3, VCPU_DEC_EXPIRES(r4)
         ld      r5, HSTATE_KVM_VCORE(r13)
-        ld      r6, VCORE_TB_OFFSET(r5)
+        ld      r6, VCORE_TB_OFFSET_APPL(r5)
         add     r3, r3, r6      /* convert host TB to guest TB value */
         mftb    r7
         subf    r3, r7, r3
@@ -3606,12 +3611,9 @@ kvmppc_fix_pmao:
  */
 kvmhv_start_timing:
         ld      r5, HSTATE_KVM_VCORE(r13)
-        lbz     r6, VCORE_IN_GUEST(r5)
-        cmpwi   r6, 0
-        beq     5f                              /* if in guest, need to */
-        ld      r6, VCORE_TB_OFFSET(r5)         /* subtract timebase offset */
-5:      mftb    r5
-        subf    r5, r6, r5
+        ld      r6, VCORE_TB_OFFSET_APPL(r5)
+        mftb    r5
+        subf    r5, r6, r5      /* subtract current timebase offset */
         std     r3, VCPU_CUR_ACTIVITY(r4)
         std     r5, VCPU_ACTIVITY_START(r4)
         blr
@@ -3622,15 +3624,12 @@ kvmhv_start_timing:
  */
 kvmhv_accumulate_time:
         ld      r5, HSTATE_KVM_VCORE(r13)
-        lbz     r8, VCORE_IN_GUEST(r5)
-        cmpwi   r8, 0
-        beq     4f                              /* if in guest, need to */
-        ld      r8, VCORE_TB_OFFSET(r5)         /* subtract timebase offset */
-4:      ld      r5, VCPU_CUR_ACTIVITY(r4)
+        ld      r8, VCORE_TB_OFFSET_APPL(r5)
+        ld      r5, VCPU_CUR_ACTIVITY(r4)
         ld      r6, VCPU_ACTIVITY_START(r4)
         std     r3, VCPU_CUR_ACTIVITY(r4)
         mftb    r7
-        subf    r7, r8, r7
+        subf    r7, r8, r7      /* subtract current timebase offset */
         std     r7, VCPU_ACTIVITY_START(r4)
         cmpdi   r5, 0
         beqlr