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KVM: prevent spurious exit to userspace during task switch emulation. 

If kvm_task_switch() fails code exits to userspace without specifying
exit reason, so the previous exit reason is reused by userspace. Fix
this by specifying exit reason correctly.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
hifive-unleashed-5.1
Gleb Natapov 2010-04-15 21:03:50 +03:00 committed by Avi Kivity
parent 6b18493d60
commit acb5451789
2 changed files with 14 additions and 4 deletions
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10
arch/x86/kvm/svm.c
View File

@ -2266,8 +2266,14 @@ static int task_switch_interception(struct vcpu_svm *svm)
(int_vec == OF_VECTOR || int_vec == BP_VECTOR)))
skip_emulated_instruction(&svm->vcpu);
return kvm_task_switch(&svm->vcpu, tss_selector, reason,
has_error_code, error_code);
if (kvm_task_switch(&svm->vcpu, tss_selector, reason,
has_error_code, error_code) == EMULATE_FAIL) {
svm->vcpu.run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
svm->vcpu.run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION;
svm->vcpu.run->internal.ndata = 0;
return 0;
}
return 1;
}
static int cpuid_interception(struct vcpu_svm *svm)

8
arch/x86/kvm/vmx.c
View File

@ -3316,9 +3316,13 @@ static int handle_task_switch(struct kvm_vcpu *vcpu)
type != INTR_TYPE_NMI_INTR))
skip_emulated_instruction(vcpu);
if (!kvm_task_switch(vcpu, tss_selector, reason, has_error_code,
error_code))
if (kvm_task_switch(vcpu, tss_selector, reason,
has_error_code, error_code) == EMULATE_FAIL) {
vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION;
vcpu->run->internal.ndata = 0;
return 0;
}
/* clear all local breakpoint enable flags */
vmcs_writel(GUEST_DR7, vmcs_readl(GUEST_DR7) & ~55);