From 70455a36a073cbb83ca17f92d135a6128c73cb3c Mon Sep 17 00:00:00 2001
From: Christian Borntraeger <borntraeger@de.ibm.com>
Date: Thu, 22 Jan 2009 10:28:29 +0100
Subject: KVM: s390: Fix problem state check for b2 intercepts
The kernel handles some priviledged instruction exits. While I was
unable to trigger such an exit from guest userspace, the code should
check for supervisor state before emulating a priviledged instruction.
I also renamed kvm_s390_handle_priv to kvm_s390_handle_b2. After all
there are non priviledged b2 instructions like stck (store clock).
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
---
arch/s390/kvm/priv.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)
(limited to 'arch/s390/kvm/priv.c')
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index 3605df45dd41..4b88834b8dd8 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -304,12 +304,24 @@ static intercept_handler_t priv_handlers[256] = {
[0xb1] = handle_stfl,
};
-int kvm_s390_handle_priv(struct kvm_vcpu *vcpu)
+int kvm_s390_handle_b2(struct kvm_vcpu *vcpu)
{
intercept_handler_t handler;
+ /*
+ * a lot of B2 instructions are priviledged. We first check for
+ * the priviledges ones, that we can handle in the kernel. If the
+ * kernel can handle this instruction, we check for the problem
+ * state bit and (a) handle the instruction or (b) send a code 2
+ * program check.
+ * Anything else goes to userspace.*/
handler = priv_handlers[vcpu->arch.sie_block->ipa & 0x00ff];
- if (handler)
- return handler(vcpu);
+ if (handler) {
+ if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
+ return kvm_s390_inject_program_int(vcpu,
+ PGM_PRIVILEGED_OPERATION);
+ else
+ return handler(vcpu);
+ }
return -ENOTSUPP;
}
--
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