diff options
| author | Nadav Amit <[email protected]> | 2014-09-30 20:49:19 +0300 |
|---|---|---|
| committer | Paolo Bonzini <[email protected]> | 2014-11-03 12:07:24 +0100 |
| commit | 518547b32ab41b12c1303d12e6e15fb1621dca4c (patch) | |
| tree | a73ab7b46108c449f8a288ed1f3a2034047a47c3 | |
| parent | 6bdf06625d240361e92254143a123ab432e337f8 (diff) | |
KVM: x86: Emulator does not calculate address correctly
In long-mode, when the address size is 4 bytes, the linear address is not
truncated as the emulator mistakenly does. Instead, the offset within the
segment (the ea field) should be truncated according to the address size.
As Intel SDM says: "In 64-bit mode, the effective address components are added
and the effective address is truncated ... before adding the full 64-bit
segment base."
Signed-off-by: Nadav Amit <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
| -rw-r--r-- | arch/x86/kvm/emulate.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 058aff86cfba..bdd4197e31fa 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -655,7 +655,8 @@ static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt, u16 sel; unsigned cpl; - la = seg_base(ctxt, addr.seg) + addr.ea; + la = seg_base(ctxt, addr.seg) + + (fetch || ctxt->ad_bytes == 8 ? addr.ea : (u32)addr.ea); *max_size = 0; switch (ctxt->mode) { case X86EMUL_MODE_PROT64: @@ -717,7 +718,7 @@ static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt, } break; } - if (fetch ? ctxt->mode != X86EMUL_MODE_PROT64 : ctxt->ad_bytes != 8) + if (ctxt->mode != X86EMUL_MODE_PROT64) la &= (u32)-1; if (insn_aligned(ctxt, size) && ((la & (size - 1)) != 0)) return emulate_gp(ctxt, 0); |