KVM: PPC: Split host-state fields out of kvmppc_book3s_shadow_vcpu

There are several fields in struct kvmppc_book3s_shadow_vcpu that
temporarily store bits of host state while a guest is running,
rather than anything relating to the particular guest or vcpu.
This splits them out into a new kvmppc_host_state structure and
modifies the definitions in asm-offsets.c to suit.

On 32-bit, we have a kvmppc_host_state structure inside the
kvmppc_book3s_shadow_vcpu since the assembly code needs to be able
to get to them both with one pointer.  On 64-bit they are separate
fields in the PACA.  This means that on 64-bit we don't need to
copy the kvmppc_host_state in and out on vcpu load/unload, and
in future will mean that the book3s_hv code doesn't need a
shadow_vcpu struct in the PACA at all.  That does mean that we
have to be careful not to rely on any values persisting in the
hstate field of the paca across any point where we could block
or get preempted.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>

3 files changed, 54 insertions, 59 deletions

diff --git a/arch/powerpc/kvm/book3s_interrupts.S b/arch/powerpc/kvm/book3s_interrupts.S
index 8c5e0e160107..c54b0e30cf3f 100644
--- a/arch/powerpc/kvm/book3s_interrupts.S
+++ b/arch/powerpc/kvm/book3s_interrupts.S
@@ -29,8 +29,7 @@
 #define ULONG_SIZE              8
 #define FUNC(name)              GLUE(.,name)
 
-#define GET_SHADOW_VCPU(reg)    \
-        addi    reg, r13, PACA_KVM_SVCPU
+#define GET_SHADOW_VCPU_R13
 
 #define DISABLE_INTERRUPTS      \
         mfmsr   r0;             \
@@ -43,8 +42,8 @@
 #define ULONG_SIZE              4
 #define FUNC(name)              name
 
-#define GET_SHADOW_VCPU(reg)    \
-        lwz     reg, (THREAD + THREAD_KVM_SVCPU)(r2)
+#define GET_SHADOW_VCPU_R13     \
+        lwz     r13, (THREAD + THREAD_KVM_SVCPU)(r2)
 
 #define DISABLE_INTERRUPTS      \
         mfmsr   r0;             \
@@ -107,17 +106,11 @@ kvm_start_entry:
         /* Load non-volatile guest state from the vcpu */
         VCPU_LOAD_NVGPRS(r4)
 
-        GET_SHADOW_VCPU(r5)
-
-        /* Save R1/R2 in the PACA */
-        PPC_STL r1, SVCPU_HOST_R1(r5)
-        PPC_STL r2, SVCPU_HOST_R2(r5)
+kvm_start_lightweight:
 
-        /* XXX swap in/out on load? */
+        GET_SHADOW_VCPU_R13
         PPC_LL  r3, VCPU_HIGHMEM_HANDLER(r4)
-        PPC_STL r3, SVCPU_VMHANDLER(r5)
-
-kvm_start_lightweight:
+        PPC_STL r3, HSTATE_VMHANDLER(r13)
 
         PPC_LL  r10, VCPU_SHADOW_MSR(r4)        /* r10 = vcpu->arch.shadow_msr */
 
diff --git a/arch/powerpc/kvm/book3s_rmhandlers.S b/arch/powerpc/kvm/book3s_rmhandlers.S
index dd03689fc609..c1f877c4a884 100644
--- a/arch/powerpc/kvm/book3s_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_rmhandlers.S
@@ -36,7 +36,6 @@
 #if defined(CONFIG_PPC_BOOK3S_64)
 
 #define LOAD_SHADOW_VCPU(reg)   GET_PACA(reg)                                   
-#define SHADOW_VCPU_OFF         PACA_KVM_SVCPU
 #define MSR_NOIRQ               MSR_KERNEL & ~(MSR_IR | MSR_DR)
 #define FUNC(name)              GLUE(.,name)
 
@@ -66,7 +65,6 @@ kvmppc_skip_Hinterrupt:
 
 #elif defined(CONFIG_PPC_BOOK3S_32)
 
-#define SHADOW_VCPU_OFF         0
 #define MSR_NOIRQ               MSR_KERNEL
 #define FUNC(name)              name
 
@@ -96,14 +94,14 @@ kvmppc_trampoline_\intno:
         b       kvmppc_resume_\intno            /* Get back original handler */
 
 1:      tophys(r13, r13)
-        stw     r12, (SHADOW_VCPU_OFF + SVCPU_SCRATCH1)(r13)
+        stw     r12, HSTATE_SCRATCH1(r13)
         mfspr   r12, SPRN_SPRG_SCRATCH1
-        stw     r12, (SHADOW_VCPU_OFF + SVCPU_SCRATCH0)(r13)
-        lbz     r12, (SHADOW_VCPU_OFF + SVCPU_IN_GUEST)(r13)
+        stw     r12, HSTATE_SCRATCH0(r13)
+        lbz     r12, HSTATE_IN_GUEST(r13)
         cmpwi   r12, KVM_GUEST_MODE_NONE
         bne     ..kvmppc_handler_hasmagic_\intno
         /* No KVM guest? Then jump back to the Linux handler! */
-        lwz     r12, (SHADOW_VCPU_OFF + SVCPU_SCRATCH1)(r13)
+        lwz     r12, HSTATE_SCRATCH1(r13)
         b       2b
 
         /* Now we know we're handling a KVM guest */
@@ -146,8 +144,8 @@ INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_ALTIVEC
  *
  * R12            = free
  * R13            = Shadow VCPU (PACA)
- * SVCPU.SCRATCH0 = guest R12
- * SVCPU.SCRATCH1 = guest CR
+ * HSTATE.SCRATCH0 = guest R12
+ * HSTATE.SCRATCH1 = guest CR
  * SPRG_SCRATCH0  = guest R13
  *
  */
@@ -159,9 +157,9 @@ kvmppc_handler_skip_ins:
         mtsrr0  r12
 
         /* Clean up all state */
-        lwz     r12, (SHADOW_VCPU_OFF + SVCPU_SCRATCH1)(r13)
+        lwz     r12, HSTATE_SCRATCH1(r13)
         mtcr    r12
-        PPC_LL  r12, (SHADOW_VCPU_OFF + SVCPU_SCRATCH0)(r13)
+        PPC_LL  r12, HSTATE_SCRATCH0(r13)
         GET_SCRATCH0(r13)
 
         /* And get back into the code */
diff --git a/arch/powerpc/kvm/book3s_segment.S b/arch/powerpc/kvm/book3s_segment.S
index 4a623eb28a53..1cc25e8c0cf1 100644
--- a/arch/powerpc/kvm/book3s_segment.S
+++ b/arch/powerpc/kvm/book3s_segment.S
@@ -22,7 +22,7 @@
 #if defined(CONFIG_PPC_BOOK3S_64)
 
 #define GET_SHADOW_VCPU(reg)    \
-        addi    reg, r13, PACA_KVM_SVCPU
+        mr      reg, r13
 
 #elif defined(CONFIG_PPC_BOOK3S_32)
 
@@ -71,6 +71,10 @@ kvmppc_handler_trampoline_enter:
         /* r3 = shadow vcpu */
         GET_SHADOW_VCPU(r3)
 
+        /* Save R1/R2 in the PACA (64-bit) or shadow_vcpu (32-bit) */
+        PPC_STL r1, HSTATE_HOST_R1(r3)
+        PPC_STL r2, HSTATE_HOST_R2(r3)
+
         /* Move SRR0 and SRR1 into the respective regs */
         PPC_LL  r9, SVCPU_PC(r3)
         mtsrr0  r9
@@ -78,7 +82,7 @@ kvmppc_handler_trampoline_enter:
 
         /* Activate guest mode, so faults get handled by KVM */
         li      r11, KVM_GUEST_MODE_GUEST
-        stb     r11, SVCPU_IN_GUEST(r3)
+        stb     r11, HSTATE_IN_GUEST(r3)
 
         /* Switch to guest segment. This is subarch specific. */
         LOAD_GUEST_SEGMENTS
@@ -132,30 +136,30 @@ kvmppc_interrupt:
          *
          * SPRG_SCRATCH0  = guest R13
          * R12            = exit handler id
-         * R13            = shadow vcpu - SHADOW_VCPU_OFF [=PACA on PPC64]
-         * SVCPU.SCRATCH0 = guest R12
-         * SVCPU.SCRATCH1 = guest CR
+         * R13            = shadow vcpu (32-bit) or PACA (64-bit)
+         * HSTATE.SCRATCH0 = guest R12
+         * HSTATE.SCRATCH1 = guest CR
          *
          */
 
         /* Save registers */
 
-        PPC_STL r0, (SHADOW_VCPU_OFF + SVCPU_R0)(r13)
-        PPC_STL r1, (SHADOW_VCPU_OFF + SVCPU_R1)(r13)
-        PPC_STL r2, (SHADOW_VCPU_OFF + SVCPU_R2)(r13)
-        PPC_STL r3, (SHADOW_VCPU_OFF + SVCPU_R3)(r13)
-        PPC_STL r4, (SHADOW_VCPU_OFF + SVCPU_R4)(r13)
-        PPC_STL r5, (SHADOW_VCPU_OFF + SVCPU_R5)(r13)
-        PPC_STL r6, (SHADOW_VCPU_OFF + SVCPU_R6)(r13)
-        PPC_STL r7, (SHADOW_VCPU_OFF + SVCPU_R7)(r13)
-        PPC_STL r8, (SHADOW_VCPU_OFF + SVCPU_R8)(r13)
-        PPC_STL r9, (SHADOW_VCPU_OFF + SVCPU_R9)(r13)
-        PPC_STL r10, (SHADOW_VCPU_OFF + SVCPU_R10)(r13)
-        PPC_STL r11, (SHADOW_VCPU_OFF + SVCPU_R11)(r13)
+        PPC_STL r0, SVCPU_R0(r13)
+        PPC_STL r1, SVCPU_R1(r13)
+        PPC_STL r2, SVCPU_R2(r13)
+        PPC_STL r3, SVCPU_R3(r13)
+        PPC_STL r4, SVCPU_R4(r13)
+        PPC_STL r5, SVCPU_R5(r13)
+        PPC_STL r6, SVCPU_R6(r13)
+        PPC_STL r7, SVCPU_R7(r13)
+        PPC_STL r8, SVCPU_R8(r13)
+        PPC_STL r9, SVCPU_R9(r13)
+        PPC_STL r10, SVCPU_R10(r13)
+        PPC_STL r11, SVCPU_R11(r13)
 
         /* Restore R1/R2 so we can handle faults */
-        PPC_LL  r1, (SHADOW_VCPU_OFF + SVCPU_HOST_R1)(r13)
-        PPC_LL  r2, (SHADOW_VCPU_OFF + SVCPU_HOST_R2)(r13)
+        PPC_LL  r1, HSTATE_HOST_R1(r13)
+        PPC_LL  r2, HSTATE_HOST_R2(r13)
 
         /* Save guest PC and MSR */
 #ifdef CONFIG_PPC64
@@ -171,17 +175,17 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE_206)
 1:      mfsrr0  r3
         mfsrr1  r4
 2:
-        PPC_STL r3, (SHADOW_VCPU_OFF + SVCPU_PC)(r13)
-        PPC_STL r4, (SHADOW_VCPU_OFF + SVCPU_SHADOW_SRR1)(r13)
+        PPC_STL r3, SVCPU_PC(r13)
+        PPC_STL r4, SVCPU_SHADOW_SRR1(r13)
 
         /* Get scratch'ed off registers */
         GET_SCRATCH0(r9)
-        PPC_LL  r8, (SHADOW_VCPU_OFF + SVCPU_SCRATCH0)(r13)
-        lwz     r7, (SHADOW_VCPU_OFF + SVCPU_SCRATCH1)(r13)
+        PPC_LL  r8, HSTATE_SCRATCH0(r13)
+        lwz     r7, HSTATE_SCRATCH1(r13)
 
-        PPC_STL r9, (SHADOW_VCPU_OFF + SVCPU_R13)(r13)
-        PPC_STL r8, (SHADOW_VCPU_OFF + SVCPU_R12)(r13)
-        stw     r7, (SHADOW_VCPU_OFF + SVCPU_CR)(r13)
+        PPC_STL r9, SVCPU_R13(r13)
+        PPC_STL r8, SVCPU_R12(r13)
+        stw     r7, SVCPU_CR(r13)
 
         /* Save more register state  */
 
@@ -191,11 +195,11 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE_206)
         mfctr   r8
         mflr    r9
 
-        stw     r5, (SHADOW_VCPU_OFF + SVCPU_XER)(r13)
-        PPC_STL r6, (SHADOW_VCPU_OFF + SVCPU_FAULT_DAR)(r13)
-        stw     r7, (SHADOW_VCPU_OFF + SVCPU_FAULT_DSISR)(r13)
-        PPC_STL r8, (SHADOW_VCPU_OFF + SVCPU_CTR)(r13)
-        PPC_STL r9, (SHADOW_VCPU_OFF + SVCPU_LR)(r13)
+        stw     r5, SVCPU_XER(r13)
+        PPC_STL r6, SVCPU_FAULT_DAR(r13)
+        stw     r7, SVCPU_FAULT_DSISR(r13)
+        PPC_STL r8, SVCPU_CTR(r13)
+        PPC_STL r9, SVCPU_LR(r13)
 
         /*
          * In order for us to easily get the last instruction,
@@ -225,7 +229,7 @@ ld_last_inst:
         /* Set guest mode to 'jump over instruction' so if lwz faults
          * we'll just continue at the next IP. */
         li      r9, KVM_GUEST_MODE_SKIP
-        stb     r9, (SHADOW_VCPU_OFF + SVCPU_IN_GUEST)(r13)
+        stb     r9, HSTATE_IN_GUEST(r13)
 
         /*    1) enable paging for data */
         mfmsr   r9
@@ -239,13 +243,13 @@ ld_last_inst:
         sync
 
 #endif
-        stw     r0, (SHADOW_VCPU_OFF + SVCPU_LAST_INST)(r13)
+        stw     r0, SVCPU_LAST_INST(r13)
 
 no_ld_last_inst:
 
         /* Unset guest mode */
         li      r9, KVM_GUEST_MODE_NONE
-        stb     r9, (SHADOW_VCPU_OFF + SVCPU_IN_GUEST)(r13)
+        stb     r9, HSTATE_IN_GUEST(r13)
 
         /* Switch back to host MMU */
         LOAD_HOST_SEGMENTS
@@ -255,7 +259,7 @@ no_ld_last_inst:
          * R1       = host R1
          * R2       = host R2
          * R12      = exit handler id
-         * R13      = shadow vcpu - SHADOW_VCPU_OFF [=PACA on PPC64]
+         * R13      = shadow vcpu (32-bit) or PACA (64-bit)
          * SVCPU.*  = guest *
          *
          */
@@ -265,7 +269,7 @@ no_ld_last_inst:
         ori     r7, r7, MSR_IR|MSR_DR|MSR_RI|MSR_ME     /* Enable paging */
         mtsrr1  r7
         /* Load highmem handler address */
-        PPC_LL  r8, (SHADOW_VCPU_OFF + SVCPU_VMHANDLER)(r13)
+        PPC_LL  r8, HSTATE_VMHANDLER(r13)
         mtsrr0  r8
 
         RFI