[PATCH v1 1/2] s390/entry: Pass the asce as parameter to sie64a()

[Claudio Imbrenda <imbrenda@linux.ibm.com>]

Pass the guest ASCE explicitly as parameter, instead of having sie64a()
take it from lowcore.

This removes hidden state from lowcore, and makes things look cleaner.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
 arch/s390/include/asm/kvm_host.h   | 7 ++++---
 arch/s390/include/asm/stacktrace.h | 1 +
 arch/s390/kernel/asm-offsets.c     | 1 +
 arch/s390/kernel/entry.S           | 8 +++-----
 arch/s390/kvm/kvm-s390.c           | 3 ++-
 arch/s390/kvm/vsie.c               | 2 +-
 6 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 95990461888f..2d4e3f50a823 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -1029,11 +1029,12 @@ void kvm_arch_crypto_clear_masks(struct kvm *kvm);
 void kvm_arch_crypto_set_masks(struct kvm *kvm, unsigned long *apm,
 			       unsigned long *aqm, unsigned long *adm);
 
-int __sie64a(phys_addr_t sie_block_phys, struct kvm_s390_sie_block *sie_block, u64 *rsa);
+int __sie64a(phys_addr_t sie_block_phys, struct kvm_s390_sie_block *sie_block, u64 *rsa,
+	     unsigned long gasce);
 
-static inline int sie64a(struct kvm_s390_sie_block *sie_block, u64 *rsa)
+static inline int sie64a(struct kvm_s390_sie_block *sie_block, u64 *rsa, unsigned long gasce)
 {
-	return __sie64a(virt_to_phys(sie_block), sie_block, rsa);
+	return __sie64a(virt_to_phys(sie_block), sie_block, rsa, gasce);
 }
 
 extern char sie_exit;
diff --git a/arch/s390/include/asm/stacktrace.h b/arch/s390/include/asm/stacktrace.h
index 85b6738b826a..1d5ca13dc90f 100644
--- a/arch/s390/include/asm/stacktrace.h
+++ b/arch/s390/include/asm/stacktrace.h
@@ -65,6 +65,7 @@ struct stack_frame {
 			unsigned long sie_reason;
 			unsigned long sie_flags;
 			unsigned long sie_control_block_phys;
+			unsigned long sie_guest_asce;
 		};
 	};
 	unsigned long gprs[10];
diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c
index f55979f64d49..26bb45d0e6f1 100644
--- a/arch/s390/kernel/asm-offsets.c
+++ b/arch/s390/kernel/asm-offsets.c
@@ -63,6 +63,7 @@ int main(void)
 	OFFSET(__SF_SIE_REASON, stack_frame, sie_reason);
 	OFFSET(__SF_SIE_FLAGS, stack_frame, sie_flags);
 	OFFSET(__SF_SIE_CONTROL_PHYS, stack_frame, sie_control_block_phys);
+	OFFSET(__SF_SIE_GUEST_ASCE, stack_frame, sie_guest_asce);
 	DEFINE(STACK_FRAME_OVERHEAD, sizeof(struct stack_frame));
 	BLANK();
 	OFFSET(__SFUSER_BACKCHAIN, stack_frame_user, back_chain);
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 60cf917a7122..454b6b92c7f8 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -179,6 +179,7 @@ SYM_FUNC_END(__switch_to_asm)
  * %r2 pointer to sie control block phys
  * %r3 pointer to sie control block virt
  * %r4 guest register save area
+ * %r5 guest asce
  */
 SYM_FUNC_START(__sie64a)
 	stmg	%r6,%r14,__SF_GPRS(%r15)	# save kernel registers
@@ -186,15 +187,12 @@ SYM_FUNC_START(__sie64a)
 	stg	%r2,__SF_SIE_CONTROL_PHYS(%r15)	# save sie block physical..
 	stg	%r3,__SF_SIE_CONTROL(%r15)	# ...and virtual addresses
 	stg	%r4,__SF_SIE_SAVEAREA(%r15)	# save guest register save area
+	stg	%r5,__SF_SIE_GUEST_ASCE(%r15)	# save guest asce
 	xc	__SF_SIE_REASON(8,%r15),__SF_SIE_REASON(%r15) # reason code = 0
 	mvc	__SF_SIE_FLAGS(8,%r15),__TI_flags(%r12) # copy thread flags
 	lmg	%r0,%r13,0(%r4)			# load guest gprs 0-13
-	lg	%r14,__LC_GMAP			# get gmap pointer
-	ltgr	%r14,%r14
-	jz	.Lsie_gmap
 	oi	__LC_CPU_FLAGS+7,_CIF_SIE
-	lctlg	%c1,%c1,__GMAP_ASCE(%r14)	# load primary asce
-.Lsie_gmap:
+	lctlg	%c1,%c1,__SF_SIE_GUEST_ASCE(%r15) # load primary asce
 	lg	%r14,__SF_SIE_CONTROL(%r15)	# get control block pointer
 	oi	__SIE_PROG0C+3(%r14),1		# we are going into SIE now
 	tm	__SIE_PROG20+3(%r14),3		# last exit...
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 82e9631cd9ef..148dff562386 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -4829,7 +4829,8 @@ static int __vcpu_run(struct kvm_vcpu *vcpu)
 			       sizeof(sie_page->pv_grregs));
 		}
 		exit_reason = sie64a(vcpu->arch.sie_block,
-				     vcpu->run->s.regs.gprs);
+				     vcpu->run->s.regs.gprs,
+				     gmap_get_enabled()->asce);
 		if (kvm_s390_pv_cpu_is_protected(vcpu)) {
 			memcpy(vcpu->run->s.regs.gprs,
 			       sie_page->pv_grregs,
diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c
index c9ecae830634..97a70c2b83ee 100644
--- a/arch/s390/kvm/vsie.c
+++ b/arch/s390/kvm/vsie.c
@@ -1150,7 +1150,7 @@ static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 	vcpu->arch.sie_block->prog0c |= PROG_IN_SIE;
 	barrier();
 	if (!kvm_s390_vcpu_sie_inhibited(vcpu))
-		rc = sie64a(scb_s, vcpu->run->s.regs.gprs);
+		rc = sie64a(scb_s, vcpu->run->s.regs.gprs, gmap_get_enabled()->asce);
 	barrier();
 	vcpu->arch.sie_block->prog0c &= ~PROG_IN_SIE;
 
-- 
2.45.2