---

yaml --- r: 96144 b: refs/heads/master c: 0eaeafa h: refs/heads/master v: v3
git-mirror · May 7, 2008 · d67e371 · d67e371
1 parent 67ddf56
commit d67e371
Show file tree

Hide file tree

Showing 6 changed files with 35 additions and 7 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 2688905e6a9b3647bf7b452cb0ff2bdb166bd8fe
+refs/heads/master: 0eaeafa10f3b2bd027e95859a6785d4c7fcc174c
diff --git a/trunk/arch/s390/kernel/entry64.S b/trunk/arch/s390/kernel/entry64.S
@@ -607,14 +607,37 @@ io_restore_trace_psw:
 #endif
 
 #
-# switch to kernel stack, then check TIF bits
+# There is work todo, we need to check if we return to userspace, then
+# check, if we are in SIE, if yes leave it
 #
 io_work:
 	tm	SP_PSW+1(%r15),0x01	# returning to user ?
 #ifndef CONFIG_PREEMPT
+#if defined(CONFIG_KVM) || defined(CONFIG_KVM_MODULE)
+	jnz	io_work_user		# yes -> no need to check for SIE
+	la	%r1, BASED(sie_opcode)	# we return to kernel here
+	lg	%r2, SP_PSW+8(%r15)
+	clc	0(2,%r1), 0(%r2)	# is current instruction = SIE?
+	jne	io_restore		# no-> return to kernel
+	lg	%r1, SP_PSW+8(%r15)	# yes-> add 4 bytes to leave SIE
+	aghi	%r1, 4
+	stg	%r1, SP_PSW+8(%r15)
+	j	io_restore		# return to kernel
+#else
 	jno	io_restore		# no-> skip resched & signal
+#endif
 #else
 	jnz	io_work_user		# yes -> do resched & signal
+#if defined(CONFIG_KVM) || defined(CONFIG_KVM_MODULE)
+	la	%r1, BASED(sie_opcode)
+	lg	%r2, SP_PSW+8(%r15)
+	clc	0(2,%r1), 0(%r2)	# is current instruction = SIE?
+	jne	0f			# no -> leave PSW alone
+	lg	%r1, SP_PSW+8(%r15)	# yes-> add 4 bytes to leave SIE
+	aghi	%r1, 4
+	stg	%r1, SP_PSW+8(%r15)
+0:
+#endif
 	# check for preemptive scheduling
 	icm	%r0,15,__TI_precount(%r9)
 	jnz	io_restore		# preemption is disabled
@@ -652,6 +675,11 @@ io_work_loop:
 	j	io_restore
 io_work_done:
 
+#if defined(CONFIG_KVM) || defined(CONFIG_KVM_MODULE)
+sie_opcode:
+	.long 0xb2140000
+#endif
+
 #
 # _TIF_MCCK_PENDING is set, call handler
 #

diff --git a/trunk/arch/s390/kvm/Kconfig b/trunk/arch/s390/kvm/Kconfig
@@ -22,7 +22,6 @@ config KVM
 	select PREEMPT_NOTIFIERS
 	select ANON_INODES
 	select S390_SWITCH_AMODE
-	select PREEMPT
 	---help---
 	  Support hosting paravirtualized guest machines using the SIE
 	  virtualization capability on the mainframe. This should work

diff --git a/trunk/arch/s390/kvm/intercept.c b/trunk/arch/s390/kvm/intercept.c
@@ -105,6 +105,9 @@ static intercept_handler_t instruction_handlers[256] = {
 static int handle_noop(struct kvm_vcpu *vcpu)
 {
 	switch (vcpu->arch.sie_block->icptcode) {
+	case 0x0:
+		vcpu->stat.exit_null++;
+		break;
 	case 0x10:
 		vcpu->stat.exit_external_request++;
 		break;

diff --git a/trunk/arch/s390/kvm/kvm-s390.c b/trunk/arch/s390/kvm/kvm-s390.c
@@ -31,6 +31,7 @@
 
 struct kvm_stats_debugfs_item debugfs_entries[] = {
 	{ "userspace_handled", VCPU_STAT(exit_userspace) },
+	{ "exit_null", VCPU_STAT(exit_null) },
 	{ "exit_validity", VCPU_STAT(exit_validity) },
 	{ "exit_stop_request", VCPU_STAT(exit_stop_request) },
 	{ "exit_external_request", VCPU_STAT(exit_external_request) },
@@ -221,10 +222,6 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 	vcpu->arch.guest_fpregs.fpc &= FPC_VALID_MASK;
 	restore_fp_regs(&vcpu->arch.guest_fpregs);
 	restore_access_regs(vcpu->arch.guest_acrs);
-
-	if (signal_pending(current))
-		atomic_set_mask(CPUSTAT_STOP_INT,
-			&vcpu->arch.sie_block->cpuflags);
 }
 
 void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)

diff --git a/trunk/include/asm-s390/kvm_host.h b/trunk/include/asm-s390/kvm_host.h
@@ -104,6 +104,7 @@ struct sie_block {
 
 struct kvm_vcpu_stat {
 	u32 exit_userspace;
+	u32 exit_null;
 	u32 exit_external_request;
 	u32 exit_external_interrupt;
 	u32 exit_stop_request;