[PATCH 19/29] KVM: X86: Propagate fetch faults

From: Joerg Roedel
Date: Fri Sep 10 2010 - 11:36:24 EST


KVM currently ignores fetch faults in the instruction
emulator. With nested-npt we could have such faults. This
patch adds the code to handle these.

Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
---
arch/x86/kvm/emulate.c | 3 +++
arch/x86/kvm/x86.c | 4 ++++
2 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 2b08b78..aead72e 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1198,6 +1198,9 @@ static int emulate_popf(struct x86_emulate_ctxt *ctxt,
*(unsigned long *)dest =
(ctxt->eflags & ~change_mask) | (val & change_mask);

+ if (rc == X86EMUL_PROPAGATE_FAULT)
+ emulate_pf(ctxt);
+
return rc;
}

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2816e5a..16c044b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4233,6 +4233,9 @@ int emulate_instruction(struct kvm_vcpu *vcpu,
vcpu->arch.emulate_ctxt.perm_ok = false;

r = x86_decode_insn(&vcpu->arch.emulate_ctxt);
+ if (r == X86EMUL_PROPAGATE_FAULT)
+ goto done;
+
trace_kvm_emulate_insn_start(vcpu);

/* Only allow emulation of specific instructions on #UD
@@ -4291,6 +4294,7 @@ restart:
return handle_emulation_failure(vcpu);
}

+done:
if (vcpu->arch.emulate_ctxt.exception >= 0) {
inject_emulated_exception(vcpu);
r = EMULATE_DONE;
--
1.7.0.4


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