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| author | Jan Kiszka <jan.kiszka@siemens.com> | 2010-02-23 17:47:53 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-04-26 07:48:04 -0700 |
| commit | 68f35500d733ed5cc3153c09f685e0abcfce4956 (patch) | |
| tree | 18e722dd63f911ce8071281a97a4a5b719f4b8da | |
| parent | e6b2d9c9a2e5689aa03d3d38b6c19dc86738a536 (diff) | |
| download | lwn-68f35500d733ed5cc3153c09f685e0abcfce4956.tar.gz lwn-68f35500d733ed5cc3153c09f685e0abcfce4956.zip | |
KVM: VMX: Update instruction length on intercepted BP
(Cherry-picked from commit c573cd22939e54fc1b8e672054a505048987a7cb)
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>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | arch/x86/kvm/vmx.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 8a8e13965076..85904fa41f03 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2719,6 +2719,12 @@ 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 */ @@ -2841,6 +2847,13 @@ 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; |