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authorJan Kiszka <jan.kiszka@siemens.com>2010-02-23 17:47:53 +0100
committerMarcelo Tosatti <mtosatti@redhat.com>2010-03-01 12:36:14 -0300
commitc573cd22939e54fc1b8e672054a505048987a7cb (patch)
treefdfb036f42f93c97cc06b1c505ad02963dfb7b82 /arch
parente54cfa97a9ca9a544a7257b89b530b505ae1b892 (diff)
downloadblackbird-obmc-linux-c573cd22939e54fc1b8e672054a505048987a7cb.tar.gz
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KVM: VMX: Update instruction length on intercepted BP
We intercept #BP while in guest debugging mode. As VM exits due to intercepted exceptions do not necessarily come with valid idt_vectoring, we have to update event_exit_inst_len explicitly in such cases. At least in the absence of migration, this ensures that re-injections of #BP will find and use the correct instruction length. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: stable@kernel.org (2.6.32, 2.6.33) Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/vmx.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index f82b0723afa5..14873b9f8430 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2775,6 +2775,12 @@ static int handle_rmode_exception(struct kvm_vcpu *vcpu,
kvm_queue_exception(vcpu, vec);
return 1;
case BP_VECTOR:
+ /*
+ * Update instruction length as we may reinject the exception
+ * from user space while in guest debugging mode.
+ */
+ to_vmx(vcpu)->vcpu.arch.event_exit_inst_len =
+ vmcs_read32(VM_EXIT_INSTRUCTION_LEN);
if (vcpu->guest_debug & KVM_GUESTDBG_USE_SW_BP)
return 0;
/* fall through */
@@ -2897,6 +2903,13 @@ static int handle_exception(struct kvm_vcpu *vcpu)
kvm_run->debug.arch.dr7 = vmcs_readl(GUEST_DR7);
/* fall through */
case BP_VECTOR:
+ /*
+ * Update instruction length as we may reinject #BP from
+ * user space while in guest debugging mode. Reading it for
+ * #DB as well causes no harm, it is not used in that case.
+ */
+ vmx->vcpu.arch.event_exit_inst_len =
+ vmcs_read32(VM_EXIT_INSTRUCTION_LEN);
kvm_run->exit_reason = KVM_EXIT_DEBUG;
kvm_run->debug.arch.pc = vmcs_readl(GUEST_CS_BASE) + rip;
kvm_run->debug.arch.exception = ex_no;
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