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>

1 files changed, 40 insertions, 36 deletions

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